Updates to model-data comparisons

(Note, that I’m not quite sure how this comparison should be baselined. The models are simply the difference from the control, while the observations are ‘as is’ from NOAA). I have linearly extended the ensemble mean model values for the post 2003 period (using a regression from 1993-2002) to get a rough sense of where those runs could have gone.

And finally, let’s revisit the oldest GCM projection of all, Hansen et al (1988). The Scenario B in that paper is running a little high compared with the actual forcings growth (by about 10%), and the old GISS model had a climate sensitivity that was a little higher (4.2ºC for a doubling of CO2) than the current best estimate (~3ºC).

The trends are probably most useful to think about, and for the period 1984 to 2009 (the 1984 date chosen because that is when these projections started), scenario B has a trend of 0.26+/-0.05 ºC/dec (95% uncertainties, no correction for auto-correlation). For the GISTEMP and HadCRUT3 data (assuming that the 2009 estimate is ok), the trends are 0.19+/-0.05 ºC/dec (note that the GISTEMP met-station index has 0.21+/-0.06 ºC/dec). Corrections for auto-correlation would make the uncertainties larger, but as it stands, the difference between the trends is just about significant.

Thus, it seems that the Hansen et al ‘B’ projection is likely running a little warm compared to the real world, but assuming (a little recklessly) that the 26 yr trend scales linearly with the sensitivity and the forcing, we could use this mismatch to estimate a sensitivity for the real world. That would give us 4.2/(0.26*0.9) * 0.19=~ 3.4 ºC. Of course, the error bars are quite large (I estimate about +/-1ºC due to uncertainty in the true underlying trends and the true forcings), but it’s interesting to note that the best estimate sensitivity deduced from this projection, is very close to what we think in any case. For reference, the trends in the AR4 models for the same period have a range 0.21+/-0.16 ºC/dec (95%). Note too, that the Hansen et al projection had very clear skill compared to a null hypothesis of no further warming.

The sharp-eyed among you might notice a couple of differences between the variance in the AR4 models in the first graph, and the Hansen et al model in the last. This is a real feature. The model used in the mid-1980s had a very simple representation of the ocean – it simply allowed the temperatures in the mixed layer to change based on the changing the fluxes at the surface. It did not contain any dynamic ocean variability – no El Niño events, no Atlantic multidecadal variability etc. and thus the variance from year to year was less than one would expect. Models today have dynamic ocean components and more ocean variability of various sorts, and I think that is clearly closer to reality than the 1980s vintage models, but the large variation in simulated variability still implies that there is some way to go.

So to conclude, despite the fact these are relatively crude metrics against which to judge the models, and there is a substantial degree of unforced variability, the matches to observations are still pretty good, and we are getting to the point where a better winnowing of models dependent on their skill may soon be possible. But more on that in the New Year.

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906 comments on this post.
  1. David B. Benson:

    Good summary. Quite clear.

  2. Lance Olsen:

    Many thanks. Given the recent report that Earth may be more sensitive than previously estimated, I was very interested in your overview on sensitivity. And just as interested in your observations on the progress of models. My bias is that we can expect too much of models, and that the (important! worthy!) effort to improve them will one day face a point of diminishing returns, so I’m looking forward to next year’s look at skill and winnowing. Mexico City inches closer every day.

  3. Norbert:

    By how much does the solar forcing, which is currently remaining unusually long at a low value, affect this picture?

  4. Molnar:

    Yay! Science is back! :)

  5. andre:

    Do you intuitively think the dynamic ocean components will ever be predictable over more than a cycle or so or should they be considered ocean “weather” which will always cause a variance between measured and predicted climate?

    [Response: It's possible that different parts of the ocean 'weather' will be predictable over different timescales. ENSO might only be for six months, but the AMO might give useful info a decade or so out. However, the amount of variance that you might be able to explain could still be small. It's an active research area. - gavin]

  6. tamino:

    Because you’ve used annual averages rather than monthly, the impact of autocorrelation on the trend analysis is small. Just a rough guess: the corrected error ranges will be about 20% larger than the stated values.

    [Response: Thanks. I used annual averages in the data because that's what I have from the models. Like with like etc... - gavin]

  7. Douglas:

    Is the occasional Pinatubo-type eruption also included in the models? Do we have an idea from vulcanolagists how often these (and stronger) eruptions might be expected to occur? Thanks.

    [Response: Sometimes. There was a volcano in 1995 in the Hansen runs for instance. However, there weren't any in the AR4 runs. We've done other experiments including volcanoes and it doesn't make that much difference in the long term (at least for the occasional eruption). - gavin]

  8. robert:

    Have you considered inviting George Will up for a personal tour of GISS ?

    [Response: I've not invited him personally, but we have standing invites to the Wall Street Journal editorial board (no response), I tried to get Alexander Cockburn to come (no response), and of course Michael Crichton did come (to very little effect it appears). - gavin]

  9. Graham:

    As someone who has taught simulation studies at university level I find the discussion somewhat amusing.
    It is possible to remove the CO2 component of all models and replace it with any submartingale and arrive at the same upward sloping graph.
    There are many such statistics in the real world – the number of Mars bars consumed, for example.
    The link between CO2, or Mars bars, and climate change is not proven by the models.

    [edit]

    [Response: Perhaps you can point me to a subroutine that uses Mars bar concentrations in a calculation of the radiative transfer in the atmosphere? And then show me the lab results that calibrate it's effects? The radiative code involving CO2 is available here for comparison. - gavin]

  10. David B. Benson:

    Norbert (3) — See papers by Tung and co-authors for the newest estimates of global temperature variation over the course of an average solar cycle. I don’t know how well accepted this work is yet.

    Douglas (7) — Big volcanoes erupt randomly so other than putting in some in model runs following the power law distribution on VIX magnitude there is not much to do. But as Gavin states, occasion eruptions won’t matter much and big ones are certainly only occasional.

  11. RiHo08:

    If atmospheric CO2 is linked to surface temperatures in a dose relationship, why aren’t we seeing that? Especially when observing graph 3 “How well did Hanson do?” On the otherhand if atmospheric C02 is only a quasi reflection for the generation of particulates, and atmospheric particulates are more determanent of surface temperatures as we have seen when volcanos erupt, then the variable distribution of particulates would be better to track than atmospheric CO2. Instead of trying to improve existing climate models tracking CO2 and temperature, maybe models should be developed to track atmospheric particulates and surface temperatures. I come at this from the point: when the model fails, discard the model.

    [Response: Not sure what you are really asking. The latest generation of models include interactive particulates and atmospheric chemistry and have those changing through time as well as the greenhouse gases (and solar and volcanoes etc.). The models are not 'fitted' to the temperature record and so what you are seeing are temperature changes associated with plausible trends in all of the components. The models, while imperfect, have not 'failed'. - gavin]

  12. Jari:

    Is it possible to add error bars to the surface temperature records?

    [Response: About 0.1 deg C for every annual value, and about 0.05 deg C/dec in the trends. - gavin]

  13. David B. Benson:

    Graham (9) — Do explain how Mars bars cause stratospheric cooling, please.

  14. Fred Magyar:

    Graham @ 9,

    You know, you may actually have a point.
    http://www.venganza.org/about/open-letter/

    You may be interested to know that global warming, earthquakes, hurricanes, and other natural disasters are a direct effect of the shrinking numbers of Pirates since the 1800s. For your interest, I have included a graph of the approximate number of pirates versus the average global temperature over the last 200 years. As you can see, there is a statistically significant inverse relationship between pirates and global temperature.

    Then again perhaps you are just a troll :-)

  15. Doug Bostrom:

    Regarding post #9, citing one’s own credentials as a university lecturer, physicist, software engineer, airline pilot, janitor, or any of myriad of other “qualifications” is rather silly when that pose is struck in support of a jocular sophomoric prank or confidently expressed but naive statement borne of ignorance.

    Influence in this discussion stems purely from serious intellectual content, not window-dressing. There are numerous excellent examples of posters here on RC able to support serious discussion, including a vanishingly tiny handful of genuine skeptics, persons worth emulating whatever one’s inclination may be.

    In the case of #9, we see conversation on Gavin’s interesting topic essentially being vandalized by irrelevantly self-described lecturer “Graham”. To what end? We can only guess, but the intention of making a contribution to improvement of the human condition can be ruled out. One thing we can conclude is that it took a very short time indeed for somebody to begin emptying garbage on this thread.

    Surely you can do better, “Graham”.

  16. MarkusR:

    Fred @14 has a point. The “cooling” we have seen since 1998, or was it 2001, has been the result of increased pirate activity around the horn of Africa. Once the pirate activity goes down we can expect the global warming to return.

  17. Nick:

    Graph 1
    =======

    The IPCC AR4 came out in 2007. Now the prediction would have been made a short time before that. Why does the comparison graph start way before 2007?

    This to mean comes across as betting on a horse race after it has started, already knowing who has fallen and who hasn’t.

    ie. The test has to be a test on future temperatures, not on whether or not the model fits the past. Otherwise you’re cherry picking.

    Graph 2
    =======

    Same applies. When was the prediction made, and how well has it performed after the prediction? I don’t know of many forecasts made in 1953.

    Also here, no confidence intervals, so given the inclusion of known data to say how good a prediction something is, its not good statistics.

    Graph 3
    =======

    Again, it looks like you are starting the graph in 1985 (from the lines) for a prediction starting 1988 (could be a delay in publication, perhaps you can explain)

    Similarly, why don’t the scenarios all start at the same point when the prediction is made?

    Conclusion
    ==========

    ie. From the graphs, the strong conclusion is that the prediction is both a forecast and a hind cast, and so doesn’t demonstrate predictive ability.

    If we take the first graph, a simple polynomial curve fit would also show a hindcast that matches and a good forecast, but in reality be a useless predictor of the future.

    Since some of these models have been fitted to the temperature record, and the temperature record has been shown to be suspect, isn’t it a case of garbage in, garbage out?

    Nick

    [Response: Err.. no. Since none of these models were fit to any of these measures, this is perhaps more likely a case of you not wanting to pay attention to anything that might threaten your presupposition that models can't possibly work? For graph 1, I used all the models with no picking to see which ones did better in the hindcast. For graph 2, the ocean heat content numbers are new and were not used in any model training, and for graph 3, the true projections started in 1984 as stated. That gives 26 years for evaluation, something clearly not available for the AR4 models (projections starting from 2003 or 2000 depending on the modeling group). If you just look at the changes since 2000 say, the spread is wider but there is no obvious discrepancy either (you can draw in the 2009 values if you like). - gavin]

  18. Jim:

    A troll, but a very amusing troll.

  19. Ray Ladbury:

    RiHo08@11, we seem to have something in common: Neither of us has a frigging clue what the hell you are talking about. Particulates? What particulates? Aerosols? Soot?

    We would all love to hear about your miraculous “particulate warming mechanism”. However, whatever you come up with, the greenhouse nature of CO2 is KNOWN physics–that’s why it is in the models, and why your imaginary mechanism is not.

  20. chris:

    re Norbert 28 December 2009 at 6:12 PM

    The solar max – solar min is calculated to give a surface temperature contribution of 0.11K according to Lean and Rind [*]. The contribution of Tung (0.2 oC max to min; and back again of course!) is considered to be on the high side (Lean and Rind suggest that Tung’s value is a bit too high due to neglecting to account for volcanic cooling which was in phase with 2 of the last 5 solar cycles).

    So all else being equal, the solar cycle contribution should completely negate a CO2-induced temperature rise of 0.2 oC per decade, during the descending period of the solar cycle (2003-2009 for the current cycle). Since the current solar minimum has been somewhat contracted, the solar cycle contribution to current temperature variation might be a little bit more negative….

    On top of this there has seemingly been a very small overall reduction in the secular solar trend since the mid 1980′s…[**]

    [*] Lean JL, Rind DH (2008) How natural and anthropogenic influences alter global and regional surface temperatures: 1889 to 2006 Geophys. Res. Lett. 35, L18701

    [**] Lockwood M, Frohlich C (2007) Recent oppositely directed trends in solar climate forcings and the global mean surface air temperature Proc. Roy. Soc. A 463,2447-2460

  21. Hank Roberts:

    Fred, while the year isn’t over yet, both the temperature number and the number of pirate attacks increased (the pirate attacks more than doubled) since 2008. Obviously more study is going to be needed. It’s complicated by the use of high-power water cannon to repel pirates, which probably increases low-level cloud nuclei over the oceans.

  22. Bill K:

    It’s a bit disingenuous to use an entire degree as your error range.

    [Response: Would you rather I made up certainty that doesn't exist? - gavin]

  23. jl:

    it really doesn’t match which
    did you mean matter??

    [Response: yes. thanks. - gavin]

  24. Peter Backes:

    How about a map of Arctic temperature anomolies?

  25. David Stern:

    Graham’s point is somewhat valid (correlation alone doesn’t equal causation) but then he spoils it with the Mars Bar example (where there is no possible causation anyway)… So I think he didn’t understand what is being done here. If I regressed observed temperatures on a Mars Bar time series then I’d get a positive relationship between them (though other diagnostics could tell me that there is a problem). But that’s not what is being done here. Rather forecasts are being compared to the observations. And these show that the climate models could be correct. But they don’t rule out an alternative explanation. But you’d have to be able to show a causal mechanism for that other explanation and then show that the predictions from that other explanation could also produce decent forecasts. So Mars Bars are ruled out.

  26. Andrew:

    @Graham: “As someone who has taught simulation studies at university level I find the discussion somewhat amusing. It is possible to remove the CO2 component of all models and replace it with any submartingale and arrive at the same upward sloping graph.”

    What a coincidence. I’ve taught simulation at the graduate level myself. I can give you a submartingale which does not reproduce the upward slope. You can too, if you think about it for a second.

  27. Norbert:

    David, thanks! Forcing by the solar cycle was apparently estimated to possibly add about 0.18 deg C (from the current min), although there have been doubts and it is perhaps not established yet. However if correct, and if the solar cycle had come back as usual, then it seems that the temperature would now already be visibly higher, and noticeably closer to the IPCC ensemble prediction. (?)

  28. wildlifer:

    Where McIntyre has stick and stirs:
    http://climateaudit.org/2007/12/01/tuning-gcms/

    about Kiehl’s paper on models.

  29. Chad:

    Gavin,

    I’ve looked at the AR4 TOA downward solar flux data and found that GISS ER/EH were the only models with realistic post-20C3M variability. The other modeling groups just used a flat solar constant, not even a solar constant + cycle. I was surprised to find that some used a flat solar constant for the entire 20C3M period.

    How do you think this unrealistic solar irradiance (pre/post 20C3M) affects the quality of the simulations? I had done some tests looking for changes in variance in the pre/post-20C3M periods but didn’t find anything conclusive. I suspect that without that solar-induced variability, it would allow CO2 to have an unrealistically large influence.

    [Response: We've always striven to include as much of what is happening in the real world as possible. Our next set of runs will have significantly more (chemistry feedbacks, other land surface changes etc), and clearly this does impact variability to some extent. However, the existence of the 11 yr cycle in this class of models is only a minor contribution - each model's internal variability is a much bigger factor in the decadal-scale changes (and the attribution problem). Note that some of the modelling groups in AR4 were doing this for the first time, and so did not have as sophisticated a set up as some of the more established groups. Whether this matters or not depends a little on the analysis - for these graphs, it isn't very relevant, but if you think it does, suggest some variations and I'll look into it. - gavin]

  30. Fred Magyar:

    Hank @ 21,

    While you are correct in saying that the issue of low-level cloud nuclei formation over the oceans possibly caused by use of high-power water cannon to repel the pirates requires further study and better modeling techniques, the fact remains that this in and of itself doesn’t in any way undermine the trend in warming and the clear linkage with the decreasing number of pirates.

    You see, we haven’t established any direct correlation or causation of any warming due to increase in pirate attacks. The data is still showing a clear reduction in the number of actual pirates, despite the fact that attacks by this reduced number of pirates has increased.

    I realize this may at first glance seem to be somewhat counter intuitive to the layman who has not delved deeper into modeling of this particular phenomenon. I will however be more than happy to post both my data and the actual source code which underlies the models.

    Happy New Year to all and may “REAL” science prosper :-)

  31. Eli Rabett:

    Hansen as much as said that would happen IN the 1988 paper: The sharp eyed Auditoriums have seen that the NOAA forcings are higher than the GISS ones. These are all calculated from concentrations, but using slightly different formulas. So, what does this say about the model. In Hansen’s 1988 words

    The climate model we employ has a global mean surface air equilibrium sensitivity of 4.2 C for doubled CO2. Other recent GCMs yield equilibrium sensitivities of 2.5-5.5 C…..

    Forecast temperature trends for time scales of a few decades or less are not very sensitive to the model’s equilibrium climate sensitivity (reference provided). Therefore climate sensitivity would have to be much smaller than 4.2 C, say 1.5 to 2 C, in order for us to modify our conclusions significantly.

    Well, 20 years down the road you can finally see the difference. Of course you could re run the 1988 model with the more likely sensitivity to CO2 forcing.

  32. RiHo08:

    Global cooling after volcanic eruptions has been recorded in ice core data and thermometers,:1809, 1815, 1883, 1980 etc. and others. If coal burning produces particulates, especially those sources with unregulated emissions, particulates, sulfer dioxide, etc. may impact climate changes. Since the last decade of divergence of atmospheric CO2 and surface temperatures suggests that any linkage between the two is much more complex than current modeling would imply, other ideas regarding climate change and what is influencing it should occur to all of us. I am mearly suggesting another idea that has caused global cooling in the past. In this case, atmospheric CO2 is only a surrogate marker for the particulates/SO2 etc. A plausible and testable hypothesis.

  33. Richard Ordway:

    Thanks,

    Time to publish it!

  34. Gort:

    I would like to test my understanding by responding to Graham’s comment. After looking it up in Wikipedia, it seems to me that a submartingale has the property that its expected value will grow over time.

    Ok, so then I think the point of the comment is that one cannot infer a causal relationship between CO2 and warming from the data.

    But then the comment misses a crucial point, because (if I understand) the purpose of the simulation is NOT to prove a causal relationship. The causal relationship stems from the physics. The main point of the simulation is to estimate parameters and project more detailed effects than the global mean temperature.

    Of course, if the projection had been grossly inconsistent with the data, one would have to search for overlooked physical considerations.

    So, it may be that the same relationship holds between Mars bars and global temperature, but, of all the things that have been trending upwards over the interval in question, CO2 is of interest because there are strong a priori reasons to suspect that CO2 would result in increasing temperature (and no such reason for Mars bars, etc.)

  35. Lamont:

    re: gavin’s response to #9…

    when are scientists going to stop writing code in fortran?

    as crimes go, using fortran is far worse than anything revealed in “climategate”…

    [Response: You might think that, but it's just not true. Fortran is simple, it works well for these kinds of problems, it complies efficiently on everything from a laptop to massively parallel supercomputer, plus we have 100,000s of lines of code already. If we had to rewrite everything each time there was some new fad in computer science (you know, like 'C' or something ;) ), we'd never get anywhere. - gavin]

  36. Nicolas Nierenberg:

    There is something about these climate models that I would like to understand. Perhaps you could point what is wrong with my logic.

    These are model runs that were published in time for AR4 which was published in 2007. Assuming that they had to be completed a bit before that these runs would have been done around 2006. Looking at the graph that you produced the average tracks the HadCRUT3 average almost perfectly up until that time. Given that the HadCRUT3 average is a kind of standard of correctness in this field isn’t that what we would expect?

    I know that people talk about the models being independent in some way of the actual values, but this seems unrealistic to me as any significant deviation would probably indicate an error to the modelers, or to the people selecting models for inclusion in a consensus document.

    [Response: The AR4 runs were done in 2004, using observed concentration data that went up to 2000 (or 2002/3 for a couple of groups). None of them were tuned to the HadCRUT3 temperature data and no model simulations were rejected because they didn't fit. - gavin]

    Therefore I would tend to judge your graph by looking at the period prior to 2007 as being the “known” period for the models, and the period after 2007 being the forecast period. Based on this principle all one could say is that the actual results have diverged downward from the forecast. Certainly any economic model would have been judged in this way.

    So the summary of what you have shown is that in the long term the model produced by Hansen in 1988 is significantly too high with current temperatures actually being below his scenario “C”. A comparison of actual temperatures with those forecast/projected by AR4 shows that AR4 in the very short term is also running too high.

  37. STG:

    What did Hansen do right in scenario C? Are we able to figure out where and why his model succeeds?

    [Response: 'C' had constant concentrations after 2000 - which obviously did not happen, but it's useful to compare the two simulations for a sense of how important the forcings are over short time periods (not very). The AR4 runs are more useful for that of course because there were many more simulations done for each scenario. - gavin]

  38. robert:

    Re: 8 … I applaud the efforts, Gavin. But George Will is with the Washington Post. Never know, a personal invitation might just charm the bowtie off him.

    By the way, I’m teaching a course in climate change at Utah State University this coming semester — for nonscience majors — using your book as the principle text.

    [Response: Yay! (Thanks.. and I hope it goes well - let me know.). -gavin]

  39. sidd:

    Thanx for getting back to the science. Looking at the grafs, i notice that ocean heat content jumps about the time surface temperatures fall below ensemble mean. But thats maybe, probably, just a coincidence…?

  40. Edward Greisch:

    Thank you, Gavin. The graphs look to me to prove that you have done a very good job of predicting. All of the real global temperatures are close enough to your predictions. You did better than Hansen, as expected, since Hansen’s forecast was made at an earlier date. Computing power was less then, and knowledge was less then, so Hansen did well for his time. Predicting climate change is necessarily a very difficult thing to do. Showing real data on the same graph as computer models is clear proof that this isn’t “just a model” thing.

    I conclude that we are in very deep trouble. I don’t see how anybody can disagree. The 2002 to 2009 nitpick is just that, a nitpick, no doubt caused by weather. There is no way to avoid the conclusion that something is going terribly wrong. There is no excuse for delay in doing something about it. I know my congressman is committed to the cause because I have talked directly to him about climate change at every opportunity. Senators are harder to get to see directly. Most people don’t want to hear about it. I don’t know what else I can do.

  41. Skip Smith:

    I’d like to get back to the pirate issue. What steps have the world’s leaders taken to increase the number of pirates to prevent global warming and save the planet? Was this even discussed at Copenhagen? How can we combat the disinformation of the pirate deniers?

  42. Patrick Caldon:

    Is the Hansen 1988 graph the one with the large CFC forcing? If so how much of the difference is accounted for by this?

  43. Gilles:

    I think that Graham is essentially right in reminding that a comparison between a model and data is meaningful only if the probability that the data would look like they look if the model were wrong is very low. This is obviously not the case with the “new” data, which are probably compatible with ANY reasonable model anyway. In other words, it would be IN ANY CASE very unlikely that the average temperature would have decreased enough to “exclude” the current GCM,whether they are right or wrong. So the piece of information brought by the addition of a single point is actually very low.

  44. sean:

    Fred @14,

    You fail to mention the significant point that pirate activity has fallen more in the Northern Hemisphere since 1800, and we’ve seen greater warming there. (and let’s just not mention the tropics vs polar thing, okay?)

    On a more serious note:
    I am profoundly grateful not to be doing a science where it can take 15 years data to corroborate a trend. Oh, exciting, we get our annual data-point now, just it time for Xmas! You poor bastards, what a difficult job…

  45. Martin Vermeer:

    Note too, that the Hansen et al projection had very clear skill compared to a null hypothesis of no further warming.

    …aka the ‘Ostrich Model’ ;-)

    Gavin, so true, so true. This points to a very common fallacy about model/hypothesis testing (perhaps a misreading of Popper?): you never test a hypothesis against ‘nothing’; you’re always testing hypotheses against each other. And the Ostrich is the worst of the lot…

    Jaynes (2003, p. 504) quotes Jeffreys: “Jeffreys (1939, p. 321) notes that there has never been a time in the history of gravitational theory when an orthodox significance test, which takes no note of alternatives, would not have rejected Newton’s law and left us with no law at all. …”
    ;-)

  46. FredT34:

    If some of you didn’t see Tamino’s post yet on “How current temperatures match former predictions”, it’s here: http://tamino.wordpress.com/2009/12/07/riddle-me-this/

  47. Mathieu Rouault:

    Nice work. Could you do it for precipitation ?

    [Response: You would only see noise on these kinds of spatial/time scales. - gavin]

  48. Fair weather cyclist:

    Apologies if the following question has been answered before.

    It seems that the models have somewhat overestimated the surface temperature this decade. My question is: where is the energy that would have been contained in the surface layer had the models been more accurate? Do the models show it somewhere else within their domain, e.g. in the upper atmosphere? If so, are such places now warmer than the models predict? Or, is the excess thermal energy, predicted to be in the surface layer, in outer space or the ocean depths (which I presume to be outside the domains of the models) instead?

    Thanks to anyone for taking the trouble to answer this.

  49. Sylvain:

    Instead of comparing past projection with what was speculative progression of GHS concentration, why not rerun those model with the actual value.

    Getting the right answer from the wrong value doesn’t validate anything.

  50. Simon Rika aka Karmakaze:

    I am actually quite amazed at just how well the models do. The machines those models are run on must be incredible to handle the calculations involved – wish I could get my sticky fingers on one :)

    A possibly off topic question based on the first graph (I am a high school drop-out, and probably don’t understand anomaly graphs, so please bear with me):

    In my discussions (more like arguments) with “skeptics”, would I be right in saying that even at the “coldest” point during the “current cooling phase” that global mean temperature was higher than at any point prior to 1998? Is that the correct interpretation of the 2008 data point?

    Any help would be appreciated.

    PS
    I love this site not least because it sometimes feels impossible to talk to the actual scientists in the fields I am interested in. I always feel slightly removed from the action. Yet here, I can talk to the actual people doing the science, and well, my little heart just goes pitter patter :)

    I would hate to see the denier types be cleaned out completely, but maybe a “wall of shame” type thread could be made where the denier posts could be sent, that can not be replied to, but the long list of repetitions of the same tired old talking points could be visible to everyone and show WHY they are not welcome in the actual discussion threads?

    It could also act as a sort of trendline, where we could see the talking points appear, run their course, then reappear the way they do over time, showing the seemingly contrived nature of them. Just an idea.

    Also, Not to be a nitpicker, para 3 last sentence:

    “different models would had the closest match.”

    I assume you meant “have the closest match.”

    [Response: thanks, fixed. - gavin]

  51. David Harrington:

    One question:

    Why exclude the satellite data from the analysis? The temperature sets quoted are predominantly surface based and their coverage is largely from the continental USA. They will also have been “homogenized” and “corrected”. What happen if the satellite data from UAH is added for example?

    [Response: The MSU diagnostic is a different metric and I don't have that handy for all the models. The size of the unforced variability is higher than in the surface temperatures and the structural uncertainty in the trends (UAH vs RSS vs Fu etc.) is larger too. Note too that there have been plenty of judgment calls in how to splice the different satellites together. - gavin]

  52. Edie:

    >As we get to the end of another year,

    Excuse me, but what does another (in your view Gregorian calendar) year have to do with climate? You know there are other man-made calendars besides Gregorian which a large part of (but not all of) the world uses. The climate suddenly seasonally stops and says “oh look at those humans, we should stop winter in its tracks because they have this Gregorian thing called New Years Eve”.

    What a crock of balderdash.

    [Response: Let me know when you've got the rest of the world to go along with that. In the meantime, I had annual mean model output, and I compare it with annual mean data. Feel free to do it differently if you think it matters. - gavin]

  53. Dave Salt:

    Dr schmidt mentions radiative transfer in the atmosphere in response to Graham (#9). However, my understanding is that it’s the dominance of positive feedbacks within the climate models that’s driving catastrophic global warming; the so-called ‘enhanced greenhouse effect’ (Cf. IPCC TAR Sect. 1.3.1).

    If true, then the important point is not the radiative transfer of CO2 but the rationale for and details of the positive feedback mechanisms. I assume this would also include the necessary real-world evidence to either support or falsify their existence/dominance.

  54. Edie:

    > [Response: It's possible that different parts of the ocean 'weather' will be predictable over
    > different timescales. ENSO might only be for six months, but the AMO might give useful info
    > a decade or so out. However, the about of variance that you might be able to explain could
    > still be small. It's an active research area. - gavin]

    All the king’s horses and all the king’s men couldn’t confidently predict the regime change from La Nina to El Nino in 2009. ENSO dynamical and statistical models? [edit]

    [Response: The current El Nino was predicted months ahead of time. - gavin]

  55. Edie:

    > Do we have an idea from vulcanolagists how often these (and stronger) eruptions might be
    > expected to occur?

    Um Douglas, you’ve been watching too much Star Trek. Spock was a Vulcan but not a volcanologist.

  56. Bill K:

    @Gavin 22: No, but what it means is that if the models are uniformly distributed amongst that degree of centigrade (which I’m sure they’re not), that they’re actually quite *inaccurate*, which demonstrates rather the opposite point of what you’re trying to make.

    Or to put it another way, I can claim I’m very accurate because my models predict a temperature between absolute zero and the surface temperature of the sun, but that error range is so large, it means I’m not really predicting anything.

    [Response: Agreed. If the range is too wide then the observation is not particularly useful in deciding whether models are any good. Thus short term trends are not useful (a point I've made repeatedly). But you can see that the longer temperature trends are going to start being useful, and the long term changes in OHC are clearly useful. Note that the OHC data has taken many years for all of the observational network problems to be dealt with (if indeed they all have been) and so were not available prior to the models being run and so have a higher utility. - gavin]

  57. Edie:

    > [Response: Perhaps you can point me to a subroutine that uses Mars bar concentrations in a
    > calculation of the radiative transfer in the atmosphere? And then show me the lab results that
    > calibrate it's effects? The radiative code involving CO2 is available here for comparison. - gavin]

    Graham is an obvious troll so not worth paying attention to him. However, it would be very interesting to see your group invite Roy Spencer for a debate (forget wasting time on Rupert Murdoch’s Wall St. Journal incompetent clowns who wouldn’t know how to parse a FORTRAN subroutine). Clearly Spencer is competent enough in the context of radiation fluxes and forces to intelligently discuss feedbacks such as from clouds. I think its ludicrous for anyone in climate science (and that goes for the IPCC) to be able to walk around with supreme confidence as to how clouds will play a role in GHG warming (and then to try and model these creatures we call clouds — good heavens, not even our operationally used NWP models such as the GFS, UK Met, or ECMWF used for synoptic weather forecasts can do anything more than parameterize clouds. LOL.

  58. Edie:

    > Douglas (7) — Big volcanoes erupt randomly so other than putting in some in model runs
    > following the power law distribution on VIX magnitude there is not much to do. But as Gavin
    > states, occasion eruptions won’t matter much and big ones are certainly only occasional.

    David Benson — but you forgot something. What about the omnipotent “plan B” geoengineers? Super wealthy Nathan Myhrvold was trying to capitalize on lame Copenhagen with some mass media fun and games by appearing on Fareed Zakaria’s CNN game show called GPS, doing a sales pitch to the incompetent public about how the world should pay Nathan (and his pal Bill Gates) a lot of cash for his geoengineering patents for example so we can begin preemptively injecting S02 into the stratosphere with a garden hose suspended by helium balloons to simulate volcanoes LOL — Mhyrvold and Gates, you can’t pull the wool over our eyes (take your money and write more crappy closed source proprietary Windows software).

  59. sod:

    very good post. thanks for all this time invested in educating those of us who want to learn and even those who don t.

  60. Paul UK:

    @16 and pirate cooling.

    Some anthropogenic intervention may reduce the number of pirates, resulting in some warming. It would seem that we need to make sure we have the correct number of pirates in the world if we are to maintain a habitable climate.

  61. Jim Cross:

    Since CO2 has been increasing since the 19th century, why would you (even recklessly) use only a 26 year period to estimate sensitivity?

    [Response: I like to live dangerously. - gavin]

  62. Nick:

    Gavin

    Response: Err.. no. Since none of these models were fit to any of these measures, this is perhaps more likely a case of you not wanting to pay attention to anything that might threaten your presupposition that models can’t possibly work? For graph 1, I used all the models with no picking to see which ones did better in the hindcast.

    Then Gavin you have misunderstood my post, but I’ll address your points.

    1. Selection bias. Unless you understand selection bias, you wouldn’t make statements that none of the models fit the historical data. If they didn’t you wouldn’t present the data. There’s a precedent for this in the ‘hide the decline’ email, because its about selection bias.

    Now to where you’ve misunderstood the post. It is all about a priori tests. You’re presenting a case where you know some of the results, and are giving the impression that the models were in place for the whole period.

    So a simple question.

    Why didn’t you start the graphs from the date of the forecast? Why did you also include historical data?

    Nick

    [Response: Because short term trends are not useful to look at and the earlier period has not been selected in any way. But if you want, here is a picture from 2002 onwards. Let me know if that tells you anything useful. - gavin]

  63. jyyh:

    well, pirates do lessen the need to transport goods, since they do it themselves. this in turn could lessen the profits made by the shipping companies, which then would be a proxy indicative of the number of pirates. actual pirate numbers are hard to measure, so this proxy might give some additional verification of the truth. then there’s of course the question of insurances, pirate transportations (so i’ve told) will not be insured, so use of a modifier in the form of incurance losses in the eq is justified.

  64. barry:

    Gavin, I’m sure this has been answered elsewhere on the site: why is the fit to the Pinatubo event so well reproduced in the ensemble? It suggestes to me this feature is deliberately simulated in all/most of the runs WRT hindcasting. I read Ch 8 and couldn’t find an unequivocal statement on that, although it does mention that model skill is tested by simulating Pinatubo-like events.

    [Response: The aerosols from Pinatubo were included in all of our runs for instance and many of the other groups as well. So it is unsurprising that they cool at the time (even in the ensemble mean). The details of that response (in regional temperatures, rainfall, wind patterns, stratospheric temperatures, radiation etc.) are very useful in evaluating model responses. - gavin]

    [you commented] “For graph 2, the ocean heat content numbers are new and were not used in any model training, and for graph 3, the true projections started in 1984 as stated. That gives 26 years for evaluation, something clearly not available for the AR4 models (projections starting from 2003 or 2000 depending on the modeling group)”.

    I’m wondering what empirical data are used for (tuning/tweaking/callibrating?) models pre-2000/2003 that get dropped when the models start projecting from 2000/2003.

    Hope the questions aren’t too dopey.

  65. Examinator:

    Hi,
    I’m sorry to go off topic but I don’t know how to contact any one.
    I’m not a scientist, however, have you scientists seen this article?
    http://insciences.org/article.php?article_id=8012 I’d be interested to hear your comments. To the uninitiated, like me, it seems as though it should be considered. Is it credible or just a loner.

    [Response: Not credible. - gavin]

    I’ve been recommending Davids lectures to all and sundry on an Australian web site http://forum.onlineopinion.com.au/ The owner is Graham Young. The other week they ran a discussion on the lectures and the science, unfortunately there were questions we couldn’t sort out.
    Specifically Graham has some issues regarding water in the atmosphere feedback that I can’t answer. I think it would be helpful maybe helpful if some scientist on this site were to write an article and help us out with proper feedback comments. One of the big problems we and others are facing is that we don’t fully understand the science and that informed discussion is thin on the ground to find. There is a lot of emotions and opinions, despite that there are a sizable group who DO want to understand the facts more thoroughly.

    Many thanks in anticipation
    examinator (lowly commenter) and regular reader of this site.

  66. TH:

    CO2 is running above the high end of estimates, so only the highest scenarios are relevant. It is absurd to pat yourself on the back for being close to low CO2 growth scenarios.

    [Response: Not true. CO2 concentrations are right in the middle and in any case the variations in scenarios are not important until ~2030. - gavin]

  67. Ray Ladbury:

    Simon@50
    It looks like the 1997 datapoint is also slightly higher than 2008, but the El Nino actually started in Fall 1997, I think. But yes, your interpretation is correct. In other words every year this decade will be among the top 10 warmest years except 2008.

  68. Ray Ladbury:

    Nick@62, your comment is an indication that you don’t understand how these models work. They are not fits to data as such. Rather they are dynamical physical models where one makes the best determination of the physical parameters and then validates the model against other data. There are good reasons for NOT TUNING the models against short-term data to get better agreement, as the goal is predictive power rather than mere explanatory power. The “Start Here” section has some good references on how the models work.

  69. Schlonz:

    Shouldn’t the world have long become uninhabitable if the postulated positive feedback processes existed?

    [Response: No. Positive feedbacks in climate are amplifications over a no-feedback situation, not a runaway unstable process. - gavin]

  70. Josh Cryer:

    Good stuff, Gavin. I’d like to point to your article written almost 5 years ago: http://www.realclimate.org/index.php/archives/2005/01/is-climate-modelling-science/

    It seems there is a lot of confusion here about models and “temperature fitting.” Fortunately GISS model code is available (and I assume the bits from ModelE that are left out will be available in due time; presumably after you guys write some nifty papers about them). So if anyone, especially internet pundits, have a problem, they are free to voice it.

    Unlike, say, Scafetta, who I learned in the news today is refusing to provide the source code for his “solar variance contributes 50% of warming” claims: http://www.newscientist.com/article/dn18307-sceptical-climate-researcher-wont-divulge-key-program.html

  71. Barton Paul Levenson:

    Dave Salt,

    The major positive feedback is water vapor. As the CO2 greenhouse effect heats the Earth, more water vapor evaporates and stays in the air. H2O is an even stronger greenhouse gas, so the temperature goes up further–a radiative effect. Radiative transfer is how most of the temperature changes are taking place.

  72. Dan L.:

    Dr. Hansen, in his latest book “Storms of My Children” says a Venus-like runaway is likely if we burn all reserves of oil, gas and coal, but the Earth has seen nearly 7000 ppm CO2 in the Cambrian Period. What stopped the runaway then?

  73. Icarus:

    Do we know whether the ‘wiggles’ on the curves of observational data represent real fluctuations, or just shortcomings in our measurement methods? For example, where there is a big spike in OHC from around 2002 – 2005, and then a levelling off, does that really mean that the oceans were somehow absorbing more heat for a few years and then absorbing less after that (e.g. by changes in cloud cover or radiation from oceans to space), or does it mean that the heat increase is steady and our measurements aren’t up to tracking how all that heat is moving around the planet? Also, in the short term could it look like the oceans aren’t warming much, when in fact the increased heat is there but it’s going into melting ice at the poles rather than raising the temperature of the water?

    Thanks in advance for any comments…

    [Response: It's not clear. No historical data product is perfect, and there may be more revisions to come. The best we can look for is consistency among independent measures (with independent problems). However, there clearly is interannual variability in OHC but exactly what the right number is, is as yet unlcear. The long term trends seem to be more robust though. -gavin]

  74. greg kai:

    @69,Gavin:
    Schlonz still raised a valid point imho: a strong positive feedback would still lead to an unstable system if it exceed the negative feedback of T^4 thermal radiation. I think it would be usefull to know at which point this happen, so we are able to “normalize” all feedback mechanism (for example, >1 is unstable, 0 is no feedback (effect of CO2 alone), <0 means some additional stabilizing effect besides the simple T^4 thermal radiation…

  75. Eli Rabett:

    Examinator @ 65 Eli has put up something on the Lu paper, and there are other points in the comments. There will be more at Rabett Run. It’s a pinata

  76. B.D.:

    [Response: The current El Nino was predicted months ahead of time. - gavin]

    Uh, no… The current El Nino began in May-June-July, but here are the synopses from CPC’s archive:

    January 2009:
    Synopsis: Developing La Niña conditions are likely to continue into Northern Hemisphere Spring 2009.

    February 2009:
    Synopsis: La Niña is expected to continue into Northern Hemisphere Spring 2009.

    March 2009:
    Synopsis: La Niña is expected to gradually weaken with increasing chances (greater than 50%) for ENSO-neutral conditions during the Northern Hemisphere Spring.

    April 2009:
    Synopsis: A transition to ENSO-neutral conditions is expected during April 2009.

    May 2009:
    Synopsis: ENSO-neutral conditions are expected to continue into the Northern Hemisphere Summer.

    June 2009:
    Synopsis: Conditions are favorable for a transition from ENSO-neutral to El Niño conditions during June − August 2009.

    July 2009:
    Synopsis: El Niño conditions will continue to develop and are expected to last through the Northern Hemisphere Winter 2009-2010.

    El Nino was not predicted until it was already happening.

  77. tamino:

    Re: #73 (Icarus)

    Gavin’s right that the best determinant of whether the wiggles are physical or observational fluctuations, is comparison of independent data sets.

    I don’t know about ocean heat content, but a comparison of GISS to RSS satellite temperature data indicates that much (even most?) of the wiggling is physical rather than observational fluctuation. The match is impressive, especially considering that the two data sets are measuring different things (GISS is surface temperature, RSS is lower-troposphere temperature).

  78. TH:

    The cone has widened to nearly a full degree and continues to widen. It would be almost impossible to miss. The skill level demonstrated is equivalent to a sportscaster forecasting either win, lose or draw.

    [Response: What would you have me do, pretend that there isn't a large spread in short term trends? I've said repeatedly that on these kinds of time periods trends are not very informative. With the Hansen projections (26 years) it's getting to be useful. For the time being the AR4 projection spread is interesting because it undermines the very frequent assumptions that IPCC apparently forecast monotonic increases in temperature, or that models somehow don't take internal variability into account. Modellers don't expect to win prizes for temperatures falling inside the cone after 5 or 10 years (at least not with these kinds of models), but people need to know there is a cone. It just is what it is. - gavin]

  79. Bill:

    Is it normal in the USA, that professionally employed scientific staff are allowed to continually post information and opinion on blogs like this ? Do such opinions have managerial approval as would usually be required in most organisations?

    [Response: NASA has strong policies in place to allow for scientists to discuss their science (or even their opinions about policy) with no restrictions. I doubt that you would want it any other way. - gavin]

  80. Hank Roberts:

    >> Schlonz
    > Greg Kai

    You misunderstand “positive feedback” I think. Try some of
    http://www.google.com/search?q=positive+feedback+converging+series+climate+runaway

    For example:
    http://www.skepticalscience.com/argument.php?p=2&t=80&&a=19
    From the comments there:
    “Tom Dayton at 04:30 AM on 3 December, 2009
    villar, you can demonstrate non-runaway positive feedback in a spreadsheet:
    Cell A1: 0
    Cell A2: 10
    Cell A3: =A2+0.5*(A2-A1)
    Cell A4: =A3+0.5*(A3-A2)
    Now copy and paste cell A4 into cell A5 and on down the column for about 15 cells. The formula should automatically adjust to each cell, so each cell’s value is the previous cell’s value plus 50% of the increase that the previous cell had experienced over its predecessor. The feedback is an increase of each increase, not of the total resulting amount.”

  81. TH:

    “Carbon dioxide (CO2) levels in the atmosphere have risen 35% faster than expected since 2000, says a study. International scientists found that inefficiency in the use of fossil fuels increased levels of CO2 by 17%.”
    http://news.bbc.co.uk/2/hi/7058074.stm

    That doesn’t sound like “in the middle.”

    [Response: That is emissions, not concentrations. - gavin]

  82. Ron Taylor:

    Graham (#9) provides an amusing example of someone who teaches simulation studies at university level, but does not know the difference between a physical simulation and a statistical correlation.

  83. Jim Eager:

    Re Schlonz @69: Shouldn’t the world have long become uninhabitable if the postulated positive feedback processes existed?

    Only if if the feedbacks formed an increasing series, as in 1 + 1.5 + 2 + 2.5 + 3…

    But they are instead a self-limiting decaying series, as in 1 + .75 + .5 + .25…

    To think of it another way, if the postulated positive feedback processes did not exist Earth would never have gone into an ice age, much less exited from one.

  84. pat:

    I am having difficulty understanding the graphs…can the Hansengraphs into two graphs, natural global warming and the anthropogenic part.

  85. Ron Taylor:

    sidd says: “Thanx for getting back to the science. Looking at the grafs, i notice that ocean heat content jumps about the time surface temperatures fall below ensemble mean. But thats maybe, probably, just a coincidence…?”

    Maybe not. This is my layman’s take on a possible reason. If there is an overturning circulation that brings cooler water to the surface and takes warmer surface water deeper, then two things happen: (1) the increased temperature difference at the ocean/atmosphere boundary will cause the ocean to absorb heat from the atmosphere more rapidly, and (2) the atmosphere will be cooled more rapidly as it gives up that increased heat.

  86. Lynn Vincentnathan:

    None of this makes me happy. Would that the denialists be right.

    As for Hansen’s projections, yesterday I read in his STORMS OF MY GRANDCHILDREN book (pp. 59-69) how that U.S. decided to put more of its money into studying outer space, and did not do the necessary for studying effects of aerosols (I guess that is some of the known unknowns talked about here).

    It’s like we’re flying almost blind and the clouds of aerosols are blocking a clear view of the mountain up ahead. We could fly higher (mitigate like crazy) to be sure and overpass the mountain, but the powers that be plus the average Joe in the streets say no, and just hope that behind those clouds of unknowing there is sky and not a solid mountain.

  87. Mike Cloghessy:

    Hey Gavin…when is NASA/GISS going to release its raw data for independent research? I know of the lawsuit filed by CEI and others, so when can we expect the release of the information under FOIA?

    [Response: What data are you talking about? All our model results are online, as is the code for GISS ModelE, as is the raw data that it is used in GISTEMP, as is the code that does that analysis. I thought that you guys were going to be playing nice once everything was online... ;) - gavin]

  88. Andrew:

    @ lamont: “when are scientists going to stop writing code in fortran?”

    They may already have for the most part. But “bad old” Fortran (e.g. f77) is like carbon dioxide. It hangs around for decades after it was originally emitted.

    To tell the truth, modern Fortran is actually quite useful for new projects. I just retired from decades of work including among many other things, supervising a large scale “linguistically diverse” scientific computing effort which did not actually have any Fortran left in it for the past ten years. I am free of constraints of the past in my new work, and after closely considering all the alternatives, most of which I am already fluent in, I have chosen (PGI) Fortran as the compiled language component because of the high level of support for vectorizing, parallelizing, and acceleration (in my case CUDA GPGPU).

    In less than a week I was able to build a machine from commodity parts (3x nVidia GTX 285 for those who want to keep score), install 64 bit Linux and PGI Workstation, neither of which I had personally been exposed to previously, develop, test, and run code which was an order of magnitude faster (on the 720 GPU core) than I could run on the host processor (Core i7 975 OC to 4.2 Ghz). All in, less than $4000. Without that Fortran compiler, the CUDA kernel in C (nvcc) took a lot longer to write, (I know, because I did that too). And the corresponding MATLAB version (even including the latest parallelism available) is another factor slower.

    So here we are in 2010, and an expert in scientific computing well versed in non-Fortran solutions, can honestly and reasonably come to the conclusion that in the circumstances, his best choice is Fortran, even without any need to interact with an old “dusty deck” code base.

    As a strange postscript, in 2008 my thesis adviser needed me to produce a figure from my (1984) thesis for a review paper, but with higher resolution to meet current publication standards. That code had been written in CDC Fortran (for a 6600), and I only have it on punched cards. In order to port the code to any machine I would have to type it one way or another, so I chose to rewrite the code in MATLAB, which had the advantage of allowing me to redevelop the code from the mathematical basics, which were quite clearly described in my thesis.

    So yes, Fortran is not always the best choice, but oddly enough, at this point in time, there actually can be reasonably general circumstances under which Fortran actually is the best choice.

    Back in the middle 1980s we used to say that it was impossible to predict what the language of scientific computing would look like in the next millenium, but we could predict with confidence that it would be called Fortran. We could have been more optimistic on the visibility.

  89. S. Molnar:

    Re El Nino predictions: I usually go with the Australians with this. Here is a prediction from the (latest and greatest experimental) POAMA model made last January that seems to predict El Nino about 6 months out, which is what happened:

    http://poama.bom.gov.au/experimental/poama15/plots/20090101/ssta_nino34.gif

    You can generate plots and find more information on this page:

    http://poama.bom.gov.au/experimental/poama15/sst_index_rt.html

  90. Hank Roberts:

    > pinata
    One hard whack and it spills everything?
    I bet Eli means it’s a cornucopia.
    Cornucopinata, maybe — keep whacking and it keeps spilling more?

  91. TRY:

    A few things: Gavin was kind enough to point me to the 1992 paper with predictions for the Pinatubo eruption.
    Hansen
    If I recall it had a variety of predictions, most predicting a somewhat larger temp drop than what actually occured. We now see that models “predict” the exact temp. decrease that actually occured. Call it back-fit, selection bias, or what have you, but it is there.

    Apart from Pinatubo, the general theme of this post and the supportive comments is that models are not particularly predictive in short (<15 year) time frame? That they reflect the underlying physics, but to the extent future temperature diverges from or matches models, it doesn't provide more or less evidence for AGW?

    Back to the physics, then, we're talking about radiative forcing.

    As Ray has explained, CO2 absorbs and emits IR in specific wavelengths (spread somewhat as a result of pressure, etc). He's also suggested that some of the IR absorbed is converted to kinetic energy through molecular collisions. As a system, then, should we expect an increase in blackbody-type radiation from the atmosphere as a result of CO2 IR absorption? Let's say 50% of the absorbed IR is re-emitted directly by CO2 at the same wavelength. 50% is passed to other molecules through collisions. Then those other molecules emit various other IR wavelengths?

    I keep coming back to the expected changes in outbound radiation signature we'd expect to see as a result of increased CO2 in the atmosphere. Can we predict this? Can we measure it?

    Ray posted this picture in response to these questions, but I'm not sure if it's model output or real observations – he didn't answer that followup question:
    http://www.atmosphere.mpg.de/media/archive/1460.jpg

    These seem like reasonable questions to me!

  92. AManuel:

    I have not run the numbers, but from my visual observation of your first graph the models are no better than a linear fit of the data from 1980 to 2001 (date of IPCC AR4) projected forward to 2010.

  93. wallruss:

    What is the point of this article given that “I’ve said repeatedly that on these kinds of time periods trends are not very informative?”. The only model made a period of time ago to be of interest in Hansens, which was not very good.

  94. Grabski:

    Why is the Hansen forecast below the ‘C’ scenario? It’s already 0.5 degrees below the ‘B’ scenario forecast (about 50%).

  95. Ray Ladbury:

    TRY, Again, a molecule can only emit radiative energy in wavelengths where it can also absorb radiative energy. So, there will be increases, but only those associated with increased thermal excitation of atmospheric gas molecules. Except for gasses that have such modes in the IR, this will be negligible (that is, the excited modes are “frozen out” at these cold temperatures). These are just the greenhouse gasses. For the most part, the energy goes into increasing the kinetic energy of atmospheric gas molecules. The solid/liquid Earth surface will be a much more efficient radiator.

    Yes the figure I posted was a theoretical calculation. I had previously linked to measurements. Here are both together:

    http://www.atmosphere.mpg.de/enid/20c.html

    Note that cooling and warming occur about where they are predicted.

  96. Ray Ladbury:

    AManuel, Almost. The way a scientist would say it is that the models are consistent with a roughly linear increase in temperature over the past 30 years.

  97. Bob Tisdale:

    What paper were the OHC models associated with? Hansen et al 2005 illustrates only a decade of OHC model data.

  98. John P. Reisman (OSS Foundation):

    #87 Mike Cloghessy

    Just for fun try this in Google including the quotes:

    “Here is all the super secret hidden data that has been available the entire time that everyone has claimed that the data and the code is hidden”

    While the phrase is not entirely accurate because some things came online over time, it does characterize the reality v. the whiny nature of those at CEI.

  99. David Miller:

    Dan L asks in #72 why 7000 PPM of CO2 didn’t cause runaway global warming, and how similar levels could now.

    I think the answer to that, Dan, is that the hundreds of millions of years ago when CO2 was that high the sun was younger and putting out less energy. Folks who study the sun assure us this is so; as time goes by and the sun turns H into He the density goes up. Because the density goes up conditions are hotter and the ions are closer so the amount of fusion goes up. Go back in time far enough and the output was at least 10% lower. With lower insolation you need more of a greenhouse effect to keep temperatures livable.

  100. Martin Vermeer:

    Dan L. #72:
    > …but the Earth has seen nearly 7000 ppm CO2 in the Cambrian Period. What stopped the runaway then?

    The fainter Sun back then was one factor…

    A very interesting talk worth watching on this is Richard Alley’s AGU Bjerknes talk:__

    http://www.agu.org/meetings/fm09/lectures/lecture_videos/A23A.shtml

  101. Robin Johnson:

    In defense of Fortran…

    I was surprised several years ago to find that the GCMs were mostly written in Fortran. I then looked at the code (available online for your viewing pleasure). After a number of hours, it became clear that the code was mostly just doing calculations. Without insult, I suspect I could program Excel to run a GCM if I was fully competent in the physics. Excel wouldn’t be fast enough of course (a matter of no small importance).

    Programming can be broken down into four basic parts: loops, conditionals, algebra (calculations) and housekeeping (management of memory, stack, code, i/o and other system resources).

    The GCMs need loops, algebra, a few conditionals and very basic housekeeping.

    Fortran (literally “Formula Translation” for the non-computer science folks) is excellent at doing algebra, okay with loops and conditionals but provides very primitive housekeeping.

    C/C++/Java are specifically designed around the “housekeeping” aspect and the ability to access ALL available computer resources with a fine level of control for the serious software engineer. Functions, objects, scope, namespaces, constructors, destructors, members, etc blah, blah, blah allow software engineers like myself to build and manage applications of enormous complexity with hundreds of objects, thousands of variables, thousands of unique functions dealing with sockets, threads, error handling, interprocess communication, sophisticated security, etc, etc.

    The Apache Webserver, Linux or Windows could not HOPE to be written in Fortran. But a program to calculate the overall National League batting average for each year since 1887 using box scores from every game could easily and simply be written in Fortran by anyone with minimal programming expertise. While I could write a C++ program to do the same thing (and rather quickly since that is what I do for a living), it wouldn’t be particularly faster or *better* at calculating those batting averages.

    A GCM Fortran program just doesn’t need all the sophisticated “handling” and “management” that many applications need. If Excel was fast and “large” enough, I suspect the climate scientists would use THAT instead.

    This is not to say the GCMs would not benefit from high quality software engineering (using appropriate tools) particularly with regard to data parsing, data handling, data presentation, data analysis, multi-threading the calculations across multiple systems (for scaling), error handling (to avoid wasted runs), etc. Indeed, if the Fortran code is bundled into a library, C++ code can CALL those same functions getting the same speed benefit and provide the ability to handle the input, output and processing in a more sophisticated manner.

    In the future, I can envision models that incorporate precise but modifiable land formations, ocean currents, etc where the additional elements creates enough complexity in the data handling and function handling that C++ will become mandatory. But until then…

    And when they say they can’t model ocean dynamics well – its not a COMPUTER problem – its a PHYSICS/DATA problem.

    PS A computer model is a misnomer of course, it really means a MODEL implemented with a computer. Technically, a computer model would model how a computer works…

  102. Hank Roberts:

    > what stopped the runaway then

    All of the factors combined, of course.
    A few might include:
    Fainter sun*
    Where the continents were.
    Where the ocean currents went.
    How fast heat was redistributed to the deep ocean.
    How fast biogeochemical cycling removed the CO2.
    _______________
    * “… we can find the habitable zone as the band of orbital distances from the Sun within which an Earth-like planet might enjoy moderate surface temperatures and CO2-partial pressures needed for advanced life forms. We calculate an optimum position at 1.08 astronomical units for an Earth-like planet at which the biosphere would realize the maximum life span. According to our results, an Earth-like planet at Martian distance would have been habitable up to about 500 Ma ago while the position of Venus was always outside the habitable zone.”

    http://dx.doi.org/10.1016/S0032-0633(00)00084-2
    Habitable zone for Earth-like planets in the solar system
    S. Franck, A. Block, W. von Bloh, C. Bounama, H. -J. Schellnhuber and Y. Svirezhev
    Potsdam Institute for Climate Impact Research

  103. Lynn Vincentnathan:

    #91, TRY, another source of info about what climate can do is paleoclimatology. For instance, during the end-Permian 251 million years ago, there was a great warming (over many thousands of year, bec it was due to natural, not man-made, forcings). Over 90% of life on earth died. One of the final blows, after the warming reached great heights, was the oceans became super-anoxic (oxygen depleted). That’s already happening to some extent today, both from the warming and from fertilizer run-off and eutrophication. In such conditions bacteria break down the methane into HS (hydrogen sulfide), a deadly gas, that is thought to have dealt a deadly blow during the end-Permian both to sea life and also to some extent outgassing and killing land life.

    A good book is Hansen’s, STORMS OF MY GRANCHILDREN — which explains both global warming and the politics (both Republican and Democrat) that has thwarted the needed efforts to mitigate climate change.

    It’s not in the book I don’t think (I haven’t read all of it), but during the 1992 elections both Bush Sr and Clinton received about the same contributions from the oil industry. I’m not sure about Obama, but I don’t think he would have become an IL senator without southern IL coal behind him.

    We have to look at the human climate forcings behind the non-human forcings. I sort of see us as in “The Matrix” (did you see the movie?) with our “umbilical cords” plugged into oil and coal. We live in various illusions, and have conflated subsistence in the ecological/environmental sphere with “the economy,” and fear any harm to the economy, thinking the environment is just a pretty, but unessential background picture. One way to understand the analytical distinction is that animals don’t have economies, but do just fine. Economics is instrumental, it facilitates; the ecological-biological-environmental sphere is fundamental to life.

    A helpful book re how we can reduce our GHGs by 75% without lowering productivity is NATURAL CAPITALISM – see http://www.natcap.org . Also http://www.rmi.org

  104. Lee:

    BD #76 claimed El Nino wasn’t predicted ahead of time with quotes from CPC’s archive. But Gavin said that it was “predicted months ahead”, not that everyone predicted it. S. Molnar #92 showed the Australian prediction 6 months out. There also is the GISS 2008 year end summation.

    “Natural dynamical variability: The largest contribution is the Southern Oscillation, the El Niño-La Niña cycle. The Niño 3.4 temperature anomaly (the bottom line in the top panel of Fig. 2), suggests that the La Niña may be almost over, but the anomaly fell back (cooled) to -0.7°C last month (December). It is conceivable that this tropical cycle could dip back into a strong La Niña, as happened, e.g., in 1975. However, for the tropical Pacific to stay in that mode for both 2009 and 2010 would require a longer La Niña phase than has existed in the past half century, so it is unlikely. Indeed, subsurface and surface tropical ocean temperatures suggest that the system is “recharged”, i.e., poised, for the next El Niño, so there is a good chance that one may occur in 2009. Global temperature anomalies tend to lag tropical anomalies by 3-6 months.”

    [Response: Yes and no. This is more of hand waving prediction than I was really referring to. The dynamical models were pretty clear that we would be in an El Nino event now months ago. - gavin]

  105. James Staples:

    Nice Item in American Scientist about Gilbert Plass (which Gavin Schmidt contributed to, I saw), the first Scientist to solidly identify the role of CO2 in anthro-CO2 forced climate change; it’s well worth reading!

  106. Barton Paul Levenson:

    Try,

    Are you looking for this?

    Chen, C., J. Harries, H. Brindley, and M. Ringer 2007. “Spectral signatures of climate change in the Earth’s infrared spectrum between 1970 and 2006.” EUMETSAT Conference and Workshop Proceedings 2007.

    Previously published work using satellite observations of the clear sky infrared emitted radiation by the Earth in 1970, 1997 and in 2003 showed the appearance of changes in the outgoing spectrum, which agreed with those expected from known changes in the concentrations of well-mixed greenhouse gases over this period. Thus, the greenhouse forcing of the Earth has been observed to change in response to these concentration changes. In the present work, this analysis is being extended to 2006 using the TES instrument on the AURA spacecraft. Additionally, simulated spectra have been calculated using LBLRTM with inputs from the HadGEM1 coupled model and compared to the observed satellite spectra.”

    Griggs, J.A. and J.E. Harries 2004. “Comparison of spectrally resolved outgoing longwave data between 1970 and present.” EUMETSAT Conference and Workshop Proceedings 2004.

    “Measurements of spectrally resolved outgoing longwave radiation allows signatures of many aspects of greenhouse warming to be distinguished without the need to amalgamate information from multiple measurements, allowing direct interpretation of the error characteristics. Here, data from three instruments measuring the spectrally resolved outgoing longwave radiation from satellites orbiting in 1970, 1997 and 2003 are compared. The data are calibrated to remove the effects of differing resolutions and fields of view so that a direct comparison can be made. Comparisons are made of the average spectrum of clear sky outgoing longwave radiation over the oceans in the months of April, May and June. Di®erence spectra are compared to simulations created using the known changes in greenhouse gases such as CH4, CO2 and O3 over the time period. This provides direct evidence for significant changes in the greenhouse gases over the last 34 years, consistent with concerns over the changes in radiative forcing of the climate.”

    Griggs, J. A., and J. E. Harries 2007. “Comparison of spectrally resolved outgoing longwave radiation over the tropical Pacific between 1970 and 2003 using IRIS, IMG, and AIRS.” Journal of Climate 20, 3982-4001.

    Hanel, R. A., and B. J. Conrath 1970. “Thermal Emission Spectra of Earth and Atmosphere from Nimbus-4 Michelson Interferometer Experiment.” Nature 228, 143-&.

    Harries, J.E., H.E. Brindley, P.J. Sagoo, and R.J. Bantges 2001. “Increases in greenhouse forcing inferred from the outgoing longwave radiation spectra of the Earth in 1970 and 1997.” Letter, Nature, 410, 355-357.

    “The evolution of the Earth’s climate has been extensively studied1, 2, and a strong link between increases in surface temperatures and greenhouse gases has been established3, 4. But this relationship is complicated by several feedback processes—most importantly the hydrological cycle—that are not well understood5, 6, 7. Changes in the Earth’s greenhouse effect can be detected from variations in the spectrum of outgoing longwave radiation8, 9, 10, which is a measure of how the Earth cools to space and carries the imprint of the gases that are responsible for the greenhouse effect11, 12, 13. Here we analyse the difference between the spectra of the outgoing longwave radiation of the Earth as measured by orbiting spacecraft in 1970 and 1997. We find differences in the spectra that point to long-term changes in atmospheric CH4, CO2 and O3 as well as CFC-11 and CFC-12. Our results provide direct experimental evidence for a significant increase in the Earth’s greenhouse effect that is consistent with concerns over radiative forcing of climate.”

    Emphasis mine.

  107. Hank Roberts:

    PS, for anyone–including those skeptical about climate science, as long as you can consider evolution and the age of the Earth– I also highly recommend the video:
    http://www.agu.org/meetings/fm09/lectures/lecture_videos/A23A.shtml

    Once you see the pictures of cliffs showing rocks dropped by icebergs, and on top of them rocks made out of marine animal shells — rock made out of carbon dioxide by biogeochemical cycling — you’ll have a better understanding of how this has worked over deep time.

    From the slides displayed alongside the speaker, you can pick out search terms worth trying in Scholar, e.g.
    http://scholar.google.com/scholar?sourceid=Mozilla-search&q=paleobarometers

  108. Ron Broberg:

    Hey Gavin…when is NASA/GISS going to release its raw data for independent research? I know of the lawsuit filed by CEI and others, so when can we expect the release of the information under FOIA?

    It’s like playing whack-a-mole. Maybe whack-a-troll? ;-)

    Original source and internal data: http://data.giss.nasa.gov/gistemp/
    Recompiled and run on linux: http://rhinohide.cx/co2/gistemp/

  109. Andy:

    Gavin, care to speculate if GCMs will ever migrate to schemes that are fully coupled to carbon models? Seems like it’d be nice to move towards models that include things like keeping track of the amount of inorganic C in the oceans (weakening the ocean sink) or calculating high latitude soil respiration? Pie in the sky thinking? Anybody suggest a good paper that covers this?

    [Response: These models already exist and will be used extensively for the AR5 simulations. Cox et al (2000) was an early pioneer, and there was a good review by Friedlingstein, P. et al. 2006, ‘Climate–Carbon Cycle Feedback Analysis: Results from the C4MIP Model Intercomparison’, Journal of Climate, Vol. 19, 15 July, pp. 3337 – 3353. - gavin]

  110. Timothy Chase:

    TRY asked in 91:

    I keep coming back to the expected changes in outbound radiation signature we’d expect to see as a result of increased CO2 in the atmosphere. Can we predict this? Can we measure it?

    Yes and yes.

    We know the absorption spectra of carbon dioxide, of water vapor, methane and other greenhouse gases. We are able to measure them in laboratories. We are able to predict them on the basis of quantum mechanics and we are able to predict the intensity of the lines based upon partial pressure and temperature.

    See for example:

    Pressure broadening
    THURSDAY, JULY 05, 2007
    http://rabett.blogspot.com/2007/07/pressure-broadening-eli-has-been-happy.html

    Temperature
    WEDNESDAY, JULY 04, 2007
    http://rabett.blogspot.com/2007/07/temperature-anonymice-gave-eli-new.html

    A radiative transfer brain teaser
    THURSDAY, DECEMBER 03, 2009
    http://rabett.blogspot.com/2009/12/radiative-transfer-brain-teaser-here.html

    for example, the different absorption lines around 4.3 μm and of carbon dioxide correspond to different vibrational modes (which are quantized states of molecular excitation) and bending modes at 15&mu.

    We are able to analyze the downwelling solar radiation into the blackbody radiation of the sun and the absorption lines due to specific greenhouse gases, and we are able to analyze the upwelling thermal radiation from the earth into the same.

    Please see for example:

    Atmospheric Transmission
    http://www.globalwarmingart.com/wiki/File:Atmospheric_Transmission_png

    Through the analysis of upwelling with satellites and downwelling radiation with ground instruments we are able to show where changes in the levels of specific greenhouse gases from different years are responsible for changes in the spectra of the thermal radiation that makes it to space and is re-emitted by the atmosphere at the ground.

    Please see:

    How do we know CO2 is causing warming?
    Thursday, 8 October, 2009
    http://www.skepticalscience.com/How-do-we-know-CO2-is-causing-warming.html

    While it absorbs thermal radiation from the surface, it radiates thermal radiation as a function of its own temperature — in all directions, much of which makes it back to the surface. Therefore it reduces the rate at which thermal radiation makes it to space. Moreover, there are infrared images of it doing exactly this over western and eastern seaboards of the US due to higher population density, traffic and carbon dioxide emissions.

    In fact you can see it in this image:

    AIRS Carbon Dioxide Data
    A 7-year global carbon dioxide data set based solely on observations
    http://airs.jpl.nasa.gov/AIRS_CO2_Data/

    The dark orange off the east and west coasts of the United States? That is carbon dioxide at roughly 8 km altitude — infrared at 15 μm in wavelength has been absorbed and emitted at lower levels of the atmosphere, but this is where it gets emitted for the last time before escaping to space — and as such the brightness temperature at that wavelength reflects the cooler temperature at a somewhat higher altitude than the surrounding areas.

    Radiation transfer is one the best understood facets of climatology. And if you know that radiation coming in from the sun has been more or less constant (e.g., satellite measurements since the early 1960s show that but for the solar cycle solar radiation has remained nearly constant over this period) but that the amount of thermal radiation making it to space is being reduced by greenhouse gases, then by the principle of the conservation of energy you know that the amount of heat in the climate system is increasing. The only way that the rate at which energy entering the system and energy leaving the system may once again be brought into balance is by decreasing the rate at which energy enters the system or increasing the rate at which energy leaves the system.

    We can’t control the sun, so we have to look at the other side of the equation. To increase the rate at which energy leaves the system either you reduce the opacity of the atmosphere — or you increase the temperature and thus infrared brightness of the surface to compensate for the increased opacity of the atmosphere. And to slow and ultimately stop the rate of temperature increase you have to stop increasing the opacity of the atmosphere — which means bringing our greenhouse gas emissions under control.

  111. Terry:

    Re the self limiting positive feedback issue raised above, that would be true if it were solely dependent on CO2 or other GHG increments that are constrained by their finite concentrations (and the IR absorption cross section). But there is also a non self limiting feedback from dH20/dT that is exponential and is not finite. I wonder if Gavin would have the time to explain in “relatively” simple terms what boundary conditions the (typical) models use to prevent the H20 positive feedback from runaway. Cheers

  112. TH:

    “Carbon dioxide (CO2) levels in the atmosphere have risen 35% faster than expected since 2000″

    Gavin, they are referring to concentration, not emissions. Temperature should be in the upper half of the cone, not the lower half.

    [Response: The statement is wrong then (I guarantee they meant emissions). I showed you the actual data for concentrations - there is no dramatic increase over what was expected. Note that this isn't contradictory because a) concentrations average over a long period of emissions, and b) there are quite large variations in terrestrial and ocean uptake year by year. - gavin]

  113. Andy:

    RE: #76 BD

    You’re looking at the wrong web page for El Nino predictions. What you’ve read is an update of current conditions and near term conditions. Try this link instead. GISS predicted the El Nino back in 2008. Read the last sentence of this December 2008 report.

    http://data.giss.nasa.gov/gistemp/2008/

  114. robert:

    Re: #81 — TH…

    I understand your confusion. The BBC article you cite does say “levels”. However, the actual paper they are referencing (http://www.pnas.org/content/104/24/10288) discusses only emissions. In other words, in a rare slip, the press got it wrong. :)

  115. Windguy:

    I do like these graphs and their predictions, but ultimately we really need to talk with overall energy heat content increase. That includes ocean and atmosphere energy changes as well as measured ice changes as well in one simple graph.

    1998 may be the hottest year on record, but that is only on the surface and is only with the HadCRUT3 data. We really need to wake up these politicians with an overall energy increase, rather than playing the denialist games of presenting cherry picked data. If we show the ocean heat changes with the atmosphere changes in one go, and show those changes compared to our energy usage, it would shock anyone. The ocean alone has heated up by 16*10^22J! since measurements started. I normally ask them how many nuclear bombs that is.

  116. Simon Rika aka Karmakaze:

    @Ray Ladbury #76

    Thanks for the confirmation Ray. Another question so that I am not flying blind: What is the reason that anomaly graphs are used rather than absolute temperature graphs? I am sure there is a good reason, but I would rather give the right one, than what I *think* is the right reason, in my arguments.

    @B.D #76

    “El Nino was not predicted until it was already happening.”

    I believe that currently there is a lag between the actual start of an El Nino, and the time when we can say an El Nino has started. So if a someone were to say “Yesterday an El Nino started” and a month later we find that it did indeed start, that would still be a prediction even if made after the actual beginning. Others will correct me I am sure, but that is my understanding.

    Re: pat #84

    “I am having difficulty understanding the graphs…can the Hansengraphs into two graphs, natural global warming and the anthropogenic part.”

    This raises another question for the scientists. Are there any model runs where the model is exactly the same as these ones except starting from the assumption that CO2 is not a Greenhouse Gas? Can a similar graph be made where such a run is compared to the others to see which more closely resembles reality?

    I suspect that a lot of problem people have is not understanding just how wrong the models would get it if they assume that CO2 is not a factor, all else being equal. This would highlight, I feel, the need for the ‘skeptics’ to identify what ELSE has to be added to replace CO2, assuming their view is correct.

    I would understand of course if no such run has been done – it is physically wrong, and could be considered a waste of very valuable computing resources – but it can’t hurt to ask.

    Another thing about models that I think a lot of people fail to understand, is the model is NOT trying to PREDICT the actual temperatures at any period of time – they are simply trying to SIMULATE an environment running under the same conditions as the real one, sort of as a check to our understanding of how the real one works, and as a way to determine where we may need to improve. The fact they so closely follow reality indicates that we know a whole hell of a lot about how the real one works. Would that be a fair assessment?

  117. Geoff Wexler:

    TRY at #91

    50% is passed to other molecules through collisions. Then those other molecules emit various other IR wavelengths?

    You have been answered before here:

    http://www.realclimate.org/index.php/archives/2009/12/unforced-variations/comment-page-20/#comment-151628

    and by Ray Ladbury at #979 of the same thread and again now on this page at #95.

    Isn’t it time that you acknowledge these replies rather than repeating your point/question?.

  118. Timothy Chase:

    Lynn Vincentnathan wrote in 103:

    We have to look at the human climate forcings behind the non-human forcings. I sort of see us as in “The Matrix” (did you see the movie?) with our “umbilical cords” plugged into oil and coal. We live in various illusions, and have conflated subsistence in the ecological/environmental sphere with “the economy,” and fear any harm to the economy, thinking the environment is just a pretty, but unessential background picture. One way to understand the analytical distinction is that animals don’t have economies, but do just fine. Economics is instrumental, it facilitates; the ecological-biological-environmental sphere is fundamental to life.

    I like that. An environmentalist interpretation of “The Matrix.”

    There could also easily be a marxist or libertarian interpretation. Undoubtedly there are. Or an interpretation by an artist rebelling or against convention. I have heard of a labor union member interpretting it as applying to labor unions and of christian interpretations. A metaphor that can be interpretted along many lines.

    My own interpretation is that it is about the human condition, the ever-present possibility of existential or cognitive failure where cognitive failure results in our being trapped in a world of illusion, how we define ourselves in relation to that world, and of the necessity of undergoing a process of shedding that world of illusion, the story of our rebirth — whereby we re-establish our proper relationship with reality. Others might say its fountainhead. Regardless, the need to act in the face of the ever-present possibility of existential failure and the need to be open to recognizing and correcting our mistakes is always with us, each at every moment of our lives — we can be engaged in a process of constant rebirth, always be following the path of the hero — as it is told through human myths throughout many human cultures.

    In my view, this interpretation more or less subsumes the others — they are applications of its abstract principles within specific contexts. However, in my view we should also be open to the possibility that our application of it within a specific context is itself a form of illusion that we should shed. That how we have applied it so far may itself be a kind of metaphor that we mistook for reality. A world of illusion that we have yet to escape.

  119. Hank Roberts:

    > here is also a non self limiting feedback from dH20/dT
    Says who, Terry? I searched both Google and Scholar and found nobody suggesting this. Where did you get that idea?
    Not from the Wikipedia people, I hope? Stoat has covered it:
    http://scienceblogs.com/stoat/2009/02/runaway_climate_change.php

  120. David B. Benson:

    Eli Rabett (31) — The 1988 model is what it is with a measured climate sensitivity which now seems kinda high. But putting in more of the physics, it evolved into the current ModelE which hass a measured climate sensitivity of less than 3 K.

    pat — On the centennial scale, all of the warming is anthropogenic. Without (significant) human influences, the climate should hae been very slowly cooling due to the change in orbital forcing.

    Terry (111) — The air can only would so much water before clouds form and precipitation occurs. Try Ray Pierrehumbert’s
    http://geosci.uchicago.edu/~rtp1/ClimateBook/ClimateBook.html

  121. Mike Cloghessy:

    Ron Broberg wrote…

    Hey Gavin…when is NASA/GISS going to release its raw data for independent research? I know of the lawsuit filed by CEI and others, so when can we expect the release of the information under FOIA?

    It’s like playing whack-a-mole. Maybe whack-a-troll? ;-)

    Original source and internal data: http://data.giss.nasa.gov/gistemp/
    Recompiled and run on linux: http://rhinohide.cx/co2/gistemp/

    Is this raw data or has this data been adjusted, homogenized and re-adjusted. We already know how GHCN adjusted the data in Australia and Antarctica. I am a big fan of fudge, but not with climate data.

  122. Ernst K:

    112, Comment by TH — 29 December 2009 @ 2:49 PM: “Carbon dioxide (CO2) levels in the atmosphere have risen 35% faster than expected since 2000″

    Gavin, they are referring to concentration, not emissions. Temperature should be in the upper half of the cone, not the lower half.
    ____________________________________

    Read it again. It says “levels … have risen 35% faster than expected”. The rate at which CO2 rises is basically a linear function of the emission rate, so this is the same thing as saying the emissions are rising 35% faster than previously expected. Because we’re talking about a relatively short time period, it doesn’t translate into a big difference in CO2 concentrations … not yet anyway.

    [Response: Sorry, but read one of the preceeding comments. This is an error in the news piece - they meant to say emissions, not levels - which have not risen 35% more than expected. - gavin]

  123. Terry:

    Re D Benson (@120)and Hank (@119) my question was not whether runaway would happen (and clearly it doesnt), but how the MODELS deal with limiting the exponential increase in H2O (and thus forcing) with increments in T. If constant RH is assumed then the total amount of H2O is still unlimited in the vapour phase as it approaches 100%RH combined with increasing T. If constant SpH is assumed then that is limiting, but constant RH is not limiting. I also understand that convection to higher altitude and rain out is a limiting factor, but for a given mass of air and a relatively unlimited amount of H2O(l) increase in T results in and increase in RH with no limits. Again my query relates to how the models limit H2O(g).

  124. Anonymous Coward:

    re: several posts on a runaway greenhouse effect on Earth

    Pierrehumbert said here and elsewhere (in Nature for instance) that a runaway greenhouse was essentially impossible on Earth considering the amount of absorbed solar radiation. According to his figures, CO2 from fossil fuels could not trigger a runaway on Earth, except possibly through some highly unlikely indirect cloud effect (or something even more exotic).
    I made this point on an earlier RealClimate thread. For some reason, fellow commenters seem to believe that CO2 from fossil fuels could actually trigger a runaway. Now as before, my question is: does Hansen substantiate his claim anywhere? If not, I will continue to abide in the bliss of Kombayashi-Ingersoll.

  125. enough:

    Why no discussion concerning the XBT to Argos data set jump around 2003/2004 ?????

  126. dhogaza:

    Mike Cloghessy says:

    Is this raw data or has this data been adjusted, homogenized and re-adjusted. We already know how GHCN adjusted the data in Australia and Antarctica. I am a big fan of fudge, but not with climate data.

    Is this raw enough for you?.

    Have fun.

  127. Hank Roberts:

    TRY, see also:
    http://ams.confex.com/ams/Annual2006/techprogram/paper_100737.htm

  128. David Johansen:

    Hey gavin i wanted to make sure you saw this. Anyway i am having this discussion with this certain person on a danish climate debate forum, and he pulled this
    http://wattsupwiththat.com/2009/04/11/making-holocene-spaghetti-sauce-by-proxy/

    Out, an article which he wrote in where he argues that proxies are cherry picked or something like that, and that proxy studies do not show what climate scientists argue. Anyway he has a number of impressive graphs and i don’t really know how to respond. It seems quite impressive but i think he may be pulling some numbers out of his ass.

    Please help.

  129. Alw:

    It seems disingenuous to show a comparison from the AR4 (which was produced in 2007) that compares how well it does from 1980-2008.

    Now picking data from the predictions made on page 70 of the IPCC Third Assessment Report (TAR – 2001). We can see that warming predictions for the period from 2001 to 2010 range from 0.3 to 0.4 for the model ensemble all SRES envelope. If we compare this to the actual warming of between 0 and 0.5 from your graph above it doesn’t appear that the models are doing too well.

  130. Hank Roberts:

    > watts, spaghetti made with cherries
    > a number of impressive graphs

    This is what I keep seeing — any climate question, do a Google image search, and the septic sites dominate the results, page after page. They’re overwhelmingly represented in any image search on climate.

    To get the attention of the people who don’t read but look at pictures (and vote on that basis) the scientists need to go kick their PR departments, and drastically increase the number of simple, illustrative graphics put out online.

    Please. Go shake up _your_ public relations officers today.
    Show them what Google Image finds, on any subject related to climate or your own research field. Make them afraid for their own and their university’s budget if they don’t get better at this.

    David, pick the keywords out of whatever you read, do a text search for science sites, and _read_ instead of looking at the pictures. It’ll help far more.

    Here’s one place to start. Just one. Search for more.

    http://www.realclimate.org/index.php/archives/2008/09/progress-in-millennial-reconstructions/

  131. Hank Roberts:

    Terry, why not ask about some specific model? Here for example: http://www.ukca.ac.uk/documents/igac.pdf

    I don’t understand why you expect increasing humidity without limit. This may help:
    http://geog-www.sbs.ohio-state.edu/courses/G230/hobgood/ASP230Lecture14.ppt

    “… Saturation does not mean that air is holding all the water vapor it can!
    Air is mostly empty space. If there were no dust or other nuclei for water to condense on, then we could evaporate much more water vapor into the air before it started to condense into liquid water.”

  132. David B. Benson:

    Terry (123) — The models just put in the known physics and crank away. Not sure want you really need, but try
    http://bartonpaullevenson.com/Greenhouse101.html
    http://bartonpaullevenson.com/NewPlanetTemps.html

  133. David Johansen:

    Yeah i do read a lot. I am by all means trusting in the current paradigm in climate science. But i can’t respond to his text nonetheless, because i am not very well educated as of yet. I cannot see if what he is doing is good “science” or if he has any valid complaints, and of course i read the article he posted. I also google search man! come on. I was born with the internet basically wired into my brain.

    But of course you are right Hank. Thank you for the link. Now if gavin or you could help me out with the article?

  134. Dano:

    @130 Hank:

    Bingo.

    Best,

    D

  135. KLR:

    Hank Roberts @ 130 – you wrote how search results were dominated by “septic sites.” ;) Nice Freudian keystroke!

    Actually just this morning I was asking at tamino’s blog how to filter out WattsandMcIntrye etc from blog searches. Did a little more research and figured out that you can do that easy enough with an Advanced blog search, by entering in the names of the authors you’re interested in. For instance, these are the authors linked to in Open Mind’s blogroll: DeepClimate|Tamino|chriscolose|climatesight|greenfyre|SimonD|fergusbrown

    Much the same could be done with Google Image search, just subtract out the domains of your denier crew “-wattsupwiththat.com,” etc. It would be a simple matter to compile the resulting URLs for these restrictive searches and post them in a FAQ here and elsewhere.

  136. KLR:

    Another fun correlation (?): Graph compares rock music quality with US oil production 1949-2007. And also Bush & gas, approval ratings and gasoline prices that is.

    Time for a Mars bar!

  137. Ken W:

    Alw (129):
    “It seems disingenuous to …”

    It seems disingenuous that people repeatedly make the same bogus accusations without making any effort to understand the context of the subject matter (or “bother” to read the answers already presented). Go back and read posts # 17, 36, and 78 in this thread. Then read these articles:

    http://www.realclimate.org/index.php/archives/2008/11/faq-on-climate-models/
    http://www.realclimate.org/index.php/archives/2009/01/faq-on-climate-models-part-ii/

  138. Pekka Kostamo:

    Terry (111): There is no water runaway, as there is a stable mechanism of eliminating the excess from the atmosphere, as David says. Some other runaways are possible, eventually limited by other factors. Runaways often die when a key resource is exhausted.

    I.e. someday the global warming initiates a rapid thaw of the permafrost. Then large quantities of methane and CO2 are liberated causing more warming (with all the known feedbacks, like increasing water vapor etc.). This vicious cycle runs until all the permafrost has melted.

    Possibly some other vicious circle will kick in concurrently, like thawing of the undersea clathrates. The process will then run until also this resource is exhausted. Then some other stable state may eventually be established. Risk of an inhabitable earth (as we know it) is very high or at least non-negligible, a few thousand years from now.

    Anyway, what is the time frame we would like to evaluate? Agriculture was invented some 12000 years ago, right after the latest ice age. Written history goes back some 4000 years. Many kids born today will experience the year 2100, would that be adequate? No, it is meaningless. Just an arbitrary point on a ramp-up curve (political input added to the forecast).

    Maybe cloning the dinos is a good idea. They would feel at home, again. In one of the imaginative dino-world shows the “reporter” was wearing an oxygen mask…

  139. Jason:

    I also like comparing models and observations, but I remain deeply skeptical about the models and their predictive capabilities, most likely for several reasons:

    1. I think that models should be tested on whether or not they replicate observations made AFTER the model is published. As you are no doubt aware, the models used in AR3 do not perform well when compared to observations made after their publication date. Of course, it is too early to draw a conclusion about AR3 and too early to even look at AR4. But its hardly an argument in favor of the models.

    2. Although you didn’t have the OHC model data handy, the models did not predict that upper ocean heat content would suddenly stop increasing in 2004. You accurately display this change, but the data is rescued by a sudden spike in ocean heat content in 2002-2003. This is most likely due to a splicing artifact, and not “real”. If you believe otherwise, I’d love a reference. [The NOAA data appears to be from Levitus et al which quite explicitly relied on splicing different data sets at that very point].

    3. You don’t compare recent tropical tropospheric temperatures to the model runs. As you are probably aware, when Santer 08 is extended to use recent data (you stopped at 1999 for some reason), the models falsify.

    In the long run, none of this matters. Very little time has passed since AR3 was produced. Either the models are largely correct, or they are not. In ten years, I’ll feel comfortable drawing conclusions. If the models are correct then in 2020:

    1. The model ensemble will be consistent with observed surface temperatures (since AR3) while a random zero trend prediction (with equal variance) will not.

    2. Trends in the upper tropical troposphere since AR3 will also be consistent with observed data (using the methodology of Santer ’08 or equivalent), while zero trend predictions are not.

    3. Upper ocean heat content will resume its rise and, over the period beginning in 2004 (when we have reliable ARGO data) to 2019 will be consistent with the model predictions (and again, zero trend predictions will not be).

    I am, obviously, a skeptic. I agree that additional CO2 will tend to warm the planet, but I think that climate modelers are incredibly arrogant to think that they can actually model our planet. Simon Rika gushes that “I am actually quite amazed at just how well the models do” but doesn’t appear to realize that the predictions in the first graph are from AR4 (2007). The real test is whether or not the models continue to be accurate AFTER they are published.

    In data I trust. If mother earth starts following the models, I will be convinced. If not, the models are just an object lesson in scientific arrogance.

    Meteorologists would be supremely confident in their models too, if they didn’t have to suffer the routine indignity of being proven wrong. By making predictions that can only be tested over a span of decades, climate modelers are just delaying the inevitable.

    [Response: Again, what would you rather we do? We are stuck with the fact that there is very little predictability on short time scales because of the magnitude of the intrinsic variability. Thus predictions only narrow to something useful after a decade or two. We do hindcasts, but we are then accused of tuning to the data. We can do experiments to match paleo-climates but then we are accused of irrelevance. We can do experiments for specific short term events like Pinatubo or the impacts of ENSO, but we are still accused of somehow fixing things. None of these criticisms are valid, and the models do quite well on each of these tests. At what point might you think there is enough information to accept that their projections are pointing in the right direction? (If the answer is never, then there is no point discussing things further). - gavin]

  140. Josh Cryer:

    #87 Mike Cloghessy, and if you’re not satisfied with GISS releasing all of its data, you can get the truly crazy raw station history data directly from the NCDC. The data that is behind most of the world historical temperatures is there, documented by hundreds and hundreds of climatologists or weather people. And if you’re dismayed that you have to pay for it, just hit up your local university library and ask for a guest account, which will give you completely free access to everything going back to your grandparents or earlier!

  141. pat:

    Eli,

    Since we have been warming from the 1600′s (or cooling since the Holocene Optimum), when did it switch from natural to anthropogenic? And why can’t the man made warming overcome the trivial effects of the cold phase PDO.

    Pat

  142. Steve Bloom:

    Gavin, having just read this new paper on mid-Pliocene Arctic Ocean temps, I would be very interested in a discussion (a new post perhaps) on efforts to model that period, or perhaps on the entire PRISM project since I don’t recall it ever being discussed here. As the paper notes, at present the models don’t seem to be able to warm the Arctic sufficiently, and this may be related to their inability to get the current Arctic sea ice reduction right. I find the confluence of very warm Arctic temperatures with CO2 levels approximately the same as today’s on a planet virtually identical to ours to be striking evidence.

  143. Hank Roberts:

    That should be “septicTM Stoat”
    http://mustelid.blogspot.com/2004/12/septics-and-skeptics-denialists-and.html

    David, it’s not worth pursuing stuff at places like Watts, especially old topics like that, where people have already tried to make comments on it; you can see they gave up. But there’s no end to sites like that claiming wonderful discoveries that would win them Nobel prizes if they only wanted to publish them. Lots of pictures and assertions, characteristically, but nothing solid.

    Read the real science. You won’t “win” a “debate” with anyone who’s relying on the PR picture sites. That’s my best advice. Perhaps someone who’s gagged all the way through that stuff will have something helpful to say.

  144. Dano:

    @135 KLR:

    The overarching issue is the dominance of the information by replacing it with…with…well, preferred information.

    This surely is weakening whatever democracy we have left in the US of A, as curious individuals aren’t going to go to such lengths on The Google, esp if they don’t know what to filter.

    Best,

    D

  145. Eli Rabett:

    KLR, the point is what someone new to the area, such as David Johansen sees.

  146. Terry:

    Re Hank (@131) ““… Saturation does not mean that air is holding all the water vapor it can!” Thanks but I am well versed in standard water vapour physics/chemistry, and my question was related to how the model constrains it. I had hoped for a simple quick explanation, a bit of digging and http://physics.nmt.edu/~krm/minschwaner_dessler_jcli2004.pdf outlines the combination of RH, SH, convective detrainment and radiative cooling etc that limit H2O(g)in the models, and it is not a simple boundary condition (perhaps why Gavin decided to not reply) I will keep looking for other examples. Cheers

  147. Andrew:

    @Hank Roberts: “any climate question, do a Google image search, and the septic sites dominate the results”

    Septic indeed.

    Isn’t the septic dominance a simple consequence of the large effort of the denialists to position their view in search engines as opposed to what an honest census might provide? Google ain’t exactly Nate Silber, and doesn’t try to be.

  148. Steve Bloom:

    Re #133: David, at a quick glance even I (being no expert) noticed that weird hinging at 1950, which invalidates everything else he did. One thing we can be quite sure of is that the proxies don’t all agree in 1950 or on any other date, so forcing them to do so will throw off everything else. Scanning through the comments, I noticed a Tom P (don’t know who he is, but Watts identified him as working for NASA) who identified that and some other problems.

    In general, there’s no shortage of this sort of crankery on the toobs, and one thing I can guarantee you is that the authors of such things are entirely unpersuadable by even the most expert input. As Ray Ladbury can tell you, physics journals get submissions all the time purporting to overturn the consensus on things like relativity. Being a very prominent field at the moment, climate science gets more than its fair share of such material.

  149. David B. Benson:

    pat (140) __ Please do read climatologist W.F. Ruddiman’s popular “Plows, Plagues and Petroleum”; you might care to read his guest post here on RealClimate.

  150. Ron Broberg:

    @Mike Cloghessy#121: Is this raw data or has this data been adjusted, homogenized and re-adjusted.

    In other words, you don’t have a clue and are parroting the talking points fed to you. To bad you didn’t take the time to understand those talking points.

    Here’s a clue:

    GHCN takes daily CLIMAT reports and compiles them into monthly averages for Tmax, Tmin, and Tmean. The Tmean file is named v2.mean. For most purposes, this is considered the raw data. The GHCN value added data is in a file named v2.adj. See the difference? v2.mean is raw. v2.adj is value-added. The GISS team uses v2.mean (the raw data) and does their own value added adjustments. They do those adjustments right out in the open – the complete code is available. Many people have taken this code and recompiled it.

    That is the rough outline. If you want detail (for instance on the use of the adjusted USHCN in GISTEMP) see the references below.

    Of course, no station reports monthly Tmax, Tmin, and Tmean. This is compiled from daily sources and therefore (gasp) not raw, but compiled. Additional QA is provided as described here – but you won’t find the TOB or UHI adjustments here, that is in the v2.adj data set.

    I didn’t catch the Antarctica reference, but if your Australia reference was to the recent post by Willis Eschenbach on WUWT, his initial post was either deliberately obscuring the differences between GHCN v2.mean, v2.adj, GISS ds1, ds2, ds3, CRUTEM, and IPCC – or he has a poor understanding of the differences himself. His blog post was a prime example of misleading, poorly edited commentary. Knowing how long he as been around the climate blogs, I lean towards the possibility that he was deliberately being misleading. Too bad you were suckered in.

    (Rereading his blog post just now, I see that he has severely edited out much of the confusing cross-references to GISS, CRU, and IPCC. So maybe he is just that poor of a writer. Too bad it took him days or weeks to get to a readable version.) -rb

    References if you are actually interested in getting off the teleprompter:
    http://www.ncdc.noaa.gov/oa/climate/ghcn-monthly/images/ghcn_temp_overview.pdf
    http://www.ncdc.noaa.gov/oa/climate/ghcn-monthly/images/ghcn_temp_qc.pdf
    ftp://ftp.ncdc.noaa.gov/pub/data/ghcn/v2
    ftp://ftp.ncdc.noaa.gov/pub/data/ushcn/v2/monthly/readme.txt
    http://data.giss.nasa.gov/gistemp/sources/gistemp.html

  151. Silk:

    #129 – Like the man said, 8 years of data has pretty high signal to noise. The trend is clearly upwards, and the 30 year trend in line with what the models predicted.

    In any case, your eyeballing is not correct. I pulled the figure out from page 70 and blew it up. The model ensemble between 2000 and 2010 (scale in 10 yearly intervals) shows a warming of between 0.1 and 0.3 degrees in that 10 year period.

    Which matches pretty darn well with 0.06+/-0.14 ºC/dec or -0.04+/-0.23 ºC/dec (take your pick)

    Why not go back further? SAR predicted a mid-range increase of 2 degrees this century. Which is, roughly, 0.2 ºC/dec

    Remarkably skillful I’d say, for old fellas.

    As a policymaker, I’d say that climate models clearly give a range of outputs, and it is currently not possible to reduce the range of climate sensitivity from the 1.5 to 4.5 95% confidence interval range. However, as a policymaker, that is sufficient certainty to begin to take actions to reduce emissions, especially given that there are numerous actions I can take at low cost, and many of these have significant co-benefits in terms of energy security and improved air quality.

    The science isn’t ‘finished’ but anyone who looks at this and says “no problem there” has their head in the sand.

  152. Joel Upchurch:

    Re# 51
    Most of the historical differences between UAH and RSS have been resolved and the data recomputed where there were errors in the previous computations. There is slight differences in how they do thier computations, but I think no more than HADCRU and GISS.

    I happened to download the monthly corrections for UAH from here: http://vortex.nsstc.uah.edu/data/msu/t2lt/uahncdc.lt
    the other day. I did a linear trend fit through the monthly temperature anomalies from 1984 and ended up with a trend of 0.17 degrees per decade. This seems quite close to the 0.19 that GISS and HADCRU produced, when you consider that UAH is for the mid-troposphere and not the surface temperatures.

    [Response: MSU-LT is the lower-troposphere, not the 'mid', and should be running slightly warmer than the surface temperatures. RSS is more consistent that way, but there are still structural uncertainties in the MSU-LT trend analyses that are larger than the anomalies. - gavin]

  153. Silk:

    “I am, obviously, a skeptic. I agree that additional CO2 will tend to warm the planet, but I think that climate modelers are incredibly arrogant to think that they can actually model our planet.”

    I find it rather arrogant (and I’m not modeler) to come on here and tell established scientists they don’t know what their doing.

    You want to be skeptical? Go away and do some paleoclimatology that shows that climate sensitivity to CO2 is lower than 2 degrees. /That/ would be a real scientific discovery, and one that would have a massive impact on scientific knowledge.

    “In ten years, I’ll feel comfortable drawing conclusions”

    In 10 years we’ll have locked into an emissions trajectory that takes us to 550ppm CO2 or higher.

    How about we take a range of sensible actions now to avoid that, and if the models turn out to be over-predicting warming 10 years from now, we can turn our attention to something else. Risk management?

  154. Geoff Wexler:

    Questions
    The second graph is most interesting.
    Noise in graphs for overall heat content.

    1. One of the curves shows a lot of high frequency and large amplitude noise. Is this the one labeled ‘Global OHC’ ? Is it possible to explain what causes this?

    [Response: It is 3 monthly data, so there will be more real variation, but also possibly more sampling errors than in the annual mean observations or model output. - gavin]

    2. A very different question refers to the red and blue curves obtained from the models. Is it possible to use the models to interpret the causes of the dips which occur? Do these refer to a loss of energy to other energy stores (e.g. deep oceans, atmosphere, land?) or to outer space?

    [Response: Good question. Some of the dips are associated with volcanic eruptions (post 1963, post 1991), but I haven't seen an analysis that answers your question in general. - gavin]

  155. Alw:

    Re Ken W (137). I have read the comments, I would say that if we are looking at how well the PROJECTIONS are shaping up it is disingenuous to include hindcasts within the graphs. An honest method would show the comparison at the point that the prediction was made.

    Also I made a mistake in my original post – the TAR projections were for warming of 0.3 to 0.4 with the actual measured warming being between 0 to 0.05 (not 0.5 as I initially said)

  156. Ernst K:

    [Response: Sorry, but read one of the preceeding comments. This is an error in the news piece - they meant to say emissions, not levels - which have not risen 35% more than expected. - gavin]

    Sorry, you’re obviously correct that the opening sentence in the BBC article is a mistake. However, even if you assume the sentence from the BBC article was correct, it still would only be saying that CO2 levels are rising 35% faster than expected, which is not at all the same thing as CO2 levels are 35% higher than expected (which is what the original commenter was apparently suggesting).

    That’s all I was trying to say.

  157. Hank Roberts:

    Terry, I think you need to inquire about some particular model; here’s an example of a discussion of handling humidity in a particular model (you can reach the author via Grist, among other places he regularly posts blog comments):
    http://physics.nmt.edu/~krm/minschwaner_dessler_jcli2004.pdf

  158. gavin:

    I see that we have awakened the ‘consistent with’ bot in Colorado

    FWIW, 1980-2009 trends in the AR4 ensemble are 0.20+/-0.13 degC/dec (2 sig) – total envelope [0.08,0.34] degC/dec. This is very clearly inconsistent with no temperature change from 1980. Observations are 0.16+/-0.04 degC/dec. The skill of the ensemble mean relative to the ‘no change’ forecast in predicting that trend is very clearly positive.

  159. Terry:

    Thanks Hank @154, I already used my fingers to do the walking, got the same result. See my earlier post @146. Rgds Terry

  160. David B. Benson:

    Geoff Wexler (154) — For your second question, I’ll suggest variations in tropical cyclone activity which is modulated in part by El Nino. Similarly, I suppose, other means of transporting heat landward and poleward and thence to space.

  161. Hank Roberts:

    It might be worth inviting an ecologist to comment on how their predictions are holding up.
    http://www.desdemonadespair.net/2009/12/it-going-to-get-lot-quieter-in-dutch.html

  162. Ernst K:

    Comment by Alw — 29 December 2009 @ 6:55 PM

    I have read the comments, I would say that if we are looking at how well the PROJECTIONS are shaping up it is disingenuous to include hindcasts within the graphs.

    It would be “disingenuous” if the models were calibrated to fit the historical mean temperature data. On the other hand, if the models are not calibrated to fit the observed mean temperature data, then a historical hindcast is perfectly valid.

    This is done all the time in the Earth Sciences (for example, my own field of Hydrology). The key rule is: clearly state what the calibration period was (if there is any – not all models need to be calibrated) and don’t use this period as part of your verification period.

    From what I understand, GCMs require little to no calibration because the models are physically based and most (if not all) of the parameters are defined a priori. As mentioned earlier, this is an important feature for climate change studies because calibration limits a model’s ability to predict behaviour under conditions different from the calibration period.

    I dare say that I would expect the historical fits would be much better if GCMs were calibrated to historical data. It’s really not that hard to make a calibrated model fit historical data. What’s difficult is building a model that can reproduce historical data with virtually no calibration – and that’s what GCMs do.

  163. TRY:

    Geoff #117
    Believe it or not, I’m genuinely interested in actual answers. If you look at my postings, I’ve responded in every case! People certainly have great confidence in their answers, but unfortunately they all disagree!
    Q: Can we measure global radiation signature over time? here are some of the answers I’ve gotten:
    1) No, we need to distinguish by hemispheres, too complicated.
    2) No, we need a fleet of satellites, too complicated.
    3) Yes, we just need one satellite, but it’s in storage due to Bush tax cuts.
    4) Yes, it’s already been done, here’s the link: (pointer to 2001 study comparing 1997 to 1970 – but study was site specific and clear skies only, not really a global assessment – then a more recent study comparing 2003 to 1997 shows no changes)
    5) Yes, it’s already been done, here’s the link: (pointer to downward radiation – interesting, but it seems like they used a model to get final results)

    Q: Can we predict global radiation signature over time? Have we?
    1) no one has answered this

    Should I give all of these answers equal weight?

    Then someone linked me to this
    http://airs.jpl.nasa.gov/AIRS_CO2_Data/ which shows CO2 globally using a satellite IR sensor. Clearly they are getting some global IR data? How should I think about this existing data in relation to the various answers above?

    I guess I came here for the “consensus science” view on this question, and would still like to get one.

    Then the question that is actually more interesting to me! CO2 energy issues in the atmosphere. We know CO2 is a small proportion of greenhouse gases, the largest being water vapor, and others including methane, etc. So it’s certainly likely that a CO2 will absorb a wavelength, then transfer a portion of that energy to a water molecule via collision path through non-IR-emitting atmosphere components, which water molecule may then emit a IR photon at a different wavelength? A very interesting systems question to my mind. And of course the answer will vary with atmospheric pressure and makeup. So feed x photons into the atmosphere that are absorbed by CO2 – what % are re-emitted by CO2, what % are transferred to other molecules, what % of those eventually cause IR emissions by H2O, CH4, vs transfer to ground via convection, etc.

  164. Don Shor:

    So, just to make sure I understand this correctly: the actual data corresponds most closely to Hansen’s Scenario C, with an actual warming of less than 2 degrees C per century?

    By the way, good luck buying a Mars bar in the USA. Your correlation will end abruptly in 2002.

  165. Andy:

    Thanks Gavin @109 – I guess this leads me to this question: ultimately, will earth system models replace GCMs in the long run? Or are they too hard to parameratize? Seems like the ocean components are more possible than the terrestrial components.

    [Response: That's already happening - but it's not a replacement. It all depends on the application. For our AR5 simulations, we will have fully interactive chemistry and aerosols as well for instance. The ocean and terrestrial carbon components will also be used in some experiments. - gavin]

  166. TRY:

    Ray #95: I’ve mentioned some specific items in a response to another poster. Briefly, there are other greenhouse gases including H2O a higher %. Photons are absorbed by CO2, on average what % are re-emitted vs passed via kinetic collisions to other molecules? Where does that kinetic energy ultimately go? Assume some portion to H2O, then emitted as IR? That’s certainly one pathway. Anyway, goes to impact of CO2 on radiation signature. Again, different than this idea that 100% of the energy that CO2 absorbs in a specific wavelength is emitted in that same wavelength, right?

    [Response: Not at all. The emission is related to the local temperature and occurs at all the relevant wavelengths. Absorption is dependent on the incoming flux of IR (from wherever). If there is no flux at the key wavelength, there will be no absorption, but there will still be emission. - gavin]

    The linke to actual measurements:
    http://www.atmosphere.mpg.de/enid/20c.html

    Just makes a really, really weak claim:
    The conclusion in total:
    “We now know that stratospheric cooling and tropospheric warming are intimately connected and that carbon dioxide plays a part in both processes. At present, however, our understanding of stratospheric cooling is not complete and further research has to be done. We do, however, already know that observed and predicted cooling in the stratosphere makes the formation of an Arctic ozone hole more likely.”

  167. dhogaza:

    Scanning through the comments, I noticed a Tom P (don’t know who he is, but Watts identified him as working for NASA) who identified that and some other problems.

    OT, but partial or complete “outing” of people who prefer to post anonymously is one of the intimidation techniques used by Watts to limit comments from non-denialists (he doesn’t do it to those in the amen chorus).

    I thought it was sleazy even before he started doing it to me.

  168. Jim Eager:

    Re Jason @139: “In data I trust. If mother earth starts following the models, I will be convinced.”

    And in the mean time the area under the curve will continue to grow, said area representing the total amount of carbon added to the atmosphere and to the active carbon cycle.

    Do you have a plan for how we will draw down the increase in that reservoir once you are convinced?
    Or a plan for how we will cope with the consequences for the next millennium, or will you just cross that bridge once you are convinced?

  169. Jim Eager:

    Re Pat @141, “Since we have been warming from the 1600’s (or cooling since the Holocene Optimum), when did it switch from natural to anthropogenic?”

    Since both CO2 and CH4 not only stopped falling but began rising soon after the Holocene Climate Optimum, anthropogenic forcing appears to have begun when humans invented agriculture, particularly the growing of rice in artificial wetlands, allowing human population to grow exponentially.

  170. TRY:

    Again, different than this idea that 100% of the energy that CO2 absorbs in a specific wavelength is emitted in that same wavelength, right?

    [Response: Not at all. The emission is related to the local temperature and occurs at all the relevant wavelengths. Absorption is dependent on the incoming flux of IR (from wherever). If there is no flux at the key wavelength, there will be no absorption, but there will still be emission. - gavin]

    I don’t see why you say “not at all”. Your statement agrees entirely with mine, doesn’t it? I mean, where does “local temperature” come from anyway? Essentially from radiation absorption and emission across the entire system. CO2 absorbs, converts to kinetic, at some point that kinetic is converted to radiation by another molecule and emitted (yes, not the only pathway). Thought experiment. Assume there’s an IR wavelength that only CO2 absorbs. Create an environment that replicates the ground level tropical atmosphere. Radiate the environment with just that wavelength. You will not see CO2 emitting 100% of that energy in the same wavelength. You will instead see a relatively broad band of emissions from H2O, CH4, etc, etc. As you say, local temperature goes up and the system radiates at all “relevant wavelengths”. I think we agree on this one!

    [Response: Sorry, I thought you were claiming that 100% of the energy absorbed in one wavelength is emitted in that same wavelength. My bad. - gavin]

  171. Ray Ladbury:

    Simon @116, Anomaly data is used to remove the average seasonal variation so that the trend is easier to spot.

  172. Ray Ladbury:

    Try @163, 166, First, I think you need to learn to ask your question more clearly. Clearly there are satellites that can measure the outgoing IR and which show the big bite taken out by CO2. The thing is that this is a snapshot. The signature of greenhouse warming would take years, if not decades, of detailed satellite measurements to tease out–just like the signature in terrestrial data.
    DISCOVR/Triana would have been an excellent addition to our arsenal of measurement tools, but L1 is a very long way from Earth. Likewise, IR instruments on GEO birds (e.g. GOES, etc.) are good, but look only at one hemisphere and have little visibility at the poles. Low-Earth-Orbit birds in a polar orbit traverse the entire globe, but each orbit is brief (minutes to a few hours), and the next pass over the same spot won’t be for weeks at least.

    So, we can make the measurements. We are making the measurements. They look very much like you’d expect for a world warming due to a greenhouse mechanism. It is just that YOU are looking for a single quick and dirty measurement that will remove all doubt, and that doesn’t exist for climate.

    As to the tropospheric warming/stratospheric cooling, you really should be more impressed by that. It shows that we have warming and cooling about where we expect AND of about the expected magnitude. THAT is really impressive, because THAT is a signature of a greenhouse mechanism.

    The evidence for anthropogenic causation is really overwhelming. However, it is evidence that comes from many, many separate, independent sources and phenomena. The denialists will focus on a single study (e.g. Mann et al. 98), just as the creationists will focus on a single fossil. Removed from its context, they can distort its meaning and make it look more problematic than it is. That simply is not how science works. You have to look at ALL the evidence. You don’t get to cherrypick only the studies that support you.

  173. Joe S:

    One quick question: are all models in the CMIP3 archive included in the IPCC ensemble above?

    And one more: how are multiple runs for a given model weighted in the ensemble average vs. the weighting for each individual model? For instance, are all runs for a given model first averaged to create an ensemble average that is then used for calculating the inter-model (pseudo) ensemble average? Or is some other weighting used?

    [Response: This consists of 55 simulations that were available at some point a couple of years ago. Every simulation is given an equal weight - which is not how IPCC did it or how I would do it in a publication - but it's probably ok for a blog post. - gavin]

  174. KLR:

    Hank, thanks for the clarification on…septicism?

    Dano @144 – that’s my point in a nutshell, I think of the average working stiff with 2 hours of commuting and screaming kids and 8 hours of drudgery at work, they come home and if they go online they just want to look at YouTubes of dancing bananas et al. Perhaps their curiosity’s been piqued by something they heard at work or from a friend about AGW; they conduct a search for whatever issue, and what do they get but WalltowallWatts. You need to nip that in the bud right from the start.

    I’ve been discussing energy issues online for years now, have always been on board with the AGW argument, and lately have been wanting to research things in more depth, and was pretty staggered by the amount of frustration you get attempting to find a balanced assessment of anything. Knowing how to find the information you seek should be step A for newcomers to this site. Many people don’t know how to do a site-specific search, even; I bookmarked that for RC years ago, that’s easy, but sometimes there’s a dearth of discussion on whatever topic – last night I was trying to find out more about V.K. Raina’s independent study of Himalayan glaciers, which your opponents were in a veritable froth over. And it was a real chore digging up real info on the total number of glaciers, how many have been under satellite observation, which ones are critical for feeding the major rivers, how long the studies had been conducted, and so forth.

    Beyond that, something I’ve been interested in for a while as well is a better way to present the veracity of either side’s arguments. Perhaps giving each researcher, septic or otherwise, a score, in the case of a real researcher, say, assigning negative marks for having multiple studies passed on due to not meeting editorial standards, or having a slew of opposing studies contradicting its conclusions. In the case of bloggers and pundits, well, where do you begin? You did this in the case of Plimer; the RC Wiki is a great start.

  175. Hank Roberts:

    TRY — all the answers you got are parts of the puzzle.

    For a consensus answer you will have to wait til the measurements have been made and evaluated.

    This is a question related to the one you ask repeatedly:
    http://www.realclimate.org/index.php/archives/2007/03/does-a-global-temperature-exist/
    (which will point you toward:
    http://rabett.blogspot.com/2007/03/once-more-dear-prof.html )

    And this one:
    http://www.realclimate.org/index.php/archives/2009/07/warminginterrupted-much-ado-about-natural-variability/

    Raypierre is commenting there that even assuming Triana goes up it would be reporting only visible light albedo, not infrared, and we’d need another instrument (on the night side, in the infrared) along with it to get the needed data on the total energy flux in and out, all from one fixed location pair of instruments, in a long time series, assuming everything worked and kept working.

    What you’re asking for is something that the climate scientists have been trying to get — for a very long time.

    Remember — data first, _then_ analysis, and eventually some kind of consensus. And most consensus statements* are annual summaries, changing with each new set of papers published. The IPCC’s coming out every five years.
    ___________
    * http://scholar.google.com/scholar?sourceid=Mozilla-search&q=consensus+statement

  176. sHx:

    Scanning through the comments, I noticed a Tom P (don’t know who he is, but Watts identified him as working for NASA) who identified that and some other problems.

    OT, but partial or complete “outing” of people who prefer to post anonymously is one of the intimidation techniques used by Watts to limit comments from non-denialists (he doesn’t do it to those in the amen chorus).

    I thought it was sleazy even before he started doing it to me.

    I don’t know if there is a Tom P working for NASA. Nor do I know anything about the alleged “outing” other than what was said above. But if a Tom P wants to remain anonymous online, he ought to call himself Peeping Tom. This is not rocket science.

  177. caerbannog:


    @Mike Cloghessy#121: Is this raw data or has this data been adjusted, homogenized and re-adjusted.

    A quick google-search on “Mike Cloghessy” turned up this:

    By Mike Cloghessy on Aug 10, 2009 | Reply
    Carbon offsets are like global warming…alarmists would have you pay for something that does not exist.

    Anybody want to place odds on how likely it is that Cloghessy will actually look at any of the data that he’s been pointed to?

  178. Hank Roberts:

    TRY, look through these archives for more.
    Google search:
    DSCOVR site:http://bobpark.physics.umd.edu

    (remembering Raypierre’s comment that an infrared sensor, and a dark side instrument, are also needed)

  179. sierra117:

    Hi

    Im fairly new to this debate but I have been watching this site and a number of the skeptics sites closely over the past few months.

    My background is in statistics and computer science; so I know a little about the techniques used in climate science.

    I am hear to learn about climate science; not to proffer an opinion. You might consider me a fence sitter whose own view about AGW has switched on more than one occasion.

    So, to the subject matter. IMHO, the conclusions re the charts seem to be valid, but, if you look at chart 1 and chart 3; the instrumental records from around 1998 onwards (as was mentioned) are trending negative. There doesn’t seem to be any other 10 year period in the instrumental record where the trend has been negative.

    [Response: There is a lot of variance in short term trends in the data- but you have to be careful because the period over which the expected warming is around the same as now is relatively short, and there are volcanoes every now and again which mess up the analogy. If you look at model simulations for the same period, you generally find negative 10 year trends happening at about the 10% level. Thus it isn't likely to be happening at any one period, but it is likely to happen if you look over a 100 year period. What we have seen in the last ten years doesn't stand out in that context. - gavin]

    Gavin, you mentioned that a trend of 15 years or less is insignificant statistically. I am curious to understand why you say that.

    [Response: From model simulations which show that initial condition ensembles need that long to have their trends clearly come out of the weather noise. '15 years' is not a hard and fast number though and there is always some uncertainty as to whether the character of the intrinsic variability in the models is close enough to that of the real world. - gavin]

    In relation to El Nino; we are in an El Nino pattern at present which is past its peak as I understand. Shouldn’t we therefore have seen a spike in this years data like the one that occurred in 1998?

    [Response: The very large El Nino in 1997-1998 gave rise to a record year in 1998. The (smaller) El Nino of 2009-2010 will likely give a spike in 2010. In the GISTEMP and NCDC records, the El Nino of 2004-2005 allowed 2005 to break the 1998 record. - gavin]

    Moreover, does that not also mean that temperature trend for the next few years is likely to continue downwards? And I know that this is speculation, but if the trend does continue downwards for say another 3 years, what does that say about the models?

    [Response: I very much doubt the next three years will trend downwards. - gavin]

    I understand there is another temperature record maintained by the University of Huntsille, Alabama (known as UAH?). I am curious to know how that stacks up to the same kind of analysis.

    [Response: It's a different metric. The MSU-LT series is an average of temperatures from the lower troposphere and is calculated by two groups (RSS and UAH) whose trends differ quite significantly. Which (if any) is more correct is still unclear. - gavin]

    As I said already, I am here to try and understand the science so please dont jump on me. The instrumental record of the past 10 years is something that skeptics point to as an indicator that AGW theory is incorrect.

    [Response: That is because they don't understand that there is unforced variability in the system. The year to year sigma in surface temperature is about 0.1 to 0.2 degC. The expected trend for this decade is 0.2 degC per decade. The signal to noise ratio implies you need more than ten years to see the trend clearly. There are however other measures that have less noise - stratospheric temperatures, or Arctic sea ice - the signals are stronger there. - gavin]

  180. Tony O'Brien:

    I do like Tamino’s quote “All models are wrong but some are usefull”. Models are usefull, they reduce but not eliminate surprises. We are facing droughts, reduced snowpack, higher sea levels and a higher incidence of extreme events.

    If we use the information provided, by models, preparatory adaption can reduce the untold devastation we are facing. Or do we wait until planes are trying to land on water to build levees around runways.

    The biggest impediment to the usefullness of models is our collective unwillingness to prepare in advance.

  181. Sepilok:

    Hank (161),
    Which predictions in particular?

    In many of the biodiversity-rich parts of the world we are still trying to work out what the impacts of CC will be and how it will interact with other threats to Biodiversity.

    In the tropics it’s not simple as we have multiple interacting threats (habitat fragmentation, invasive species etc.), too many habitat/species to look at and not many people/resources.

  182. Hank Roberts:

    One nitpick

    > in a polar orbit … each orbit is
    > brief (minutes to a few hours)

    Nope, each pass over a point on the ground is brief, minutes; each orbit is very close to exactly the same length of time (call it 90 minutes or so, the exact number depending on its altitude).

    An engineer explained to me that the reason we can’t predict passes overhead precisely for the ISS more than a week or so in advance, is that the satellite will experience some perturbation on each orbit from mass variations in its ground track. An equatorial orbit passes over exactly the same masses on each orbit; a polar orbit passes over a different slice on each orbit.

  183. Hank Roberts:

    > Which predictions in particular?
    Dunno. Ask the experts.
    http://www.google.com/search?q=biology+prediction+flowering+warming

  184. mommycalled:

    Andrew (post #88) is absolutely correct. I am fluent in enough programming languages that I can pick the right tool for the job. Fortran is the correct tool for numerical work. Lamont falls into the hammer trap: I have a hammer so everything is a nail

  185. Jiminmpls:

    Why do people have such a hard time understanding that the climate models in question aren’t forecasting interannual or interdecadal temperature changes? The models are concerned with longer time scales. NO ONE has predicted a linear warming over decadal time scales. These “the models have failed” posts are just signs of ignorance: Arrogant, willful ignorance.

    There are people working at shorter term climate models that factor in shorter-term natural variability. At least a couple of them say that natural forcings may overwhelm AGW forcings and “stall” or even reverse warming for the next decade or two. That does NOT mean that AGW isn’t occuring, even though their work has been misrepresented by denialist conspirators.

    Ya don’t have to be a scientist to understand this.

  186. Sepilok:

    Most of the predictions are for well into the future (2050-2080), so I’m not sure how we can assess at thiss stage how well the predictions are holding up.
    That said there are some effect of CC already obvious – i.e. shifts in species distributions, changes in flowering periods etc.

  187. John:

    I have been reading this site for the last couple of months and have found it to be very helpful. I will be honest, I am disturbed by this post and I have some comments / points to make:

    1) The first sentence is: “It’s worth going back every so often to see how projections made back in the day are shaping up.” But the graphs you then discuss aren’t that at all. The graphs start well before when the projections were made which simply shows that the model matches history (not surprising). I know this point has been made in the comments but the post itself remains very misleading. It should be either fixed or clarified.

    2) For the first graph, the comments state that the actuals versus the projections are since 2002 and you have provided a graph of just that period. In that period, actual termperature is down versus the projection that it would be up. While I agree with your point that not much can be drawn from this, why show the graph at all then? Since you don’t think that the actuals are significant at this point, why write the post at all?

    3) I am not sure what the point of second graph is. It doesn’t have any information on actual versus projection for the last six years.

    4) The last graph shows the actuals versus the oldest model. If I am reading this right, the actuals are below all three scenarios. In your commentary, you make the point that the actuals are within the standard error, but the graph doesn’t show that standard error. It would be helpful to see the size of that error and how close the actuals are to violating it (similar to the first graph).

    5) Would I wrong to say that according to this the actual termperatures have consistently been below the projections of the GCMs although within the standard error?

  188. Chad:

    Gavin,
    I’ve got a question about the pre-industrial control runs. On the PCMDI website, I found that it says that “the control should allow us to subtract any residual, unforced drift from all perturbation simulations.” So the 20C3M data is basically: drift + forced change + intrinsic variability. By subtracting the control run the data then becomes: forced change + intrinsic variability. Is it appropriate to compare such data to observational data? I wouldn’t think so because the observational data is an anomaly relative to some climatology whereas the model run minus the control run is an ‘anomaly’ relative to an unperturbed climate.

    [Response: The drift in surface temperature by the end of the 20th C is very small, so the issue is moot for the SAT projections. For ocean heat content it is more important and I plotted the drift corrected values in the second figure. You still need to baseline things (as I did in figure 1, following IPCC), but I'm still not sure what the OHC data are anomalies with regard to, and so I haven't done any more processing for that. As it stands the spread in the OHC numbers is related to absolute differences in total heat content over the 20th C - if you just wanted the change in heat content since the 1960s or something, the figure would be a little different. - gavin]

  189. pat:

    This is a central Pacific El Nino, the atmosphere vice the eastern Pacific El Nino of 1998; the atmosphere responds differently resulting in westward shift of Aleutian low.

  190. Jason:

    Gavin said: “At what point might you think there is enough information to accept that their projections are pointing in the right direction?”

    I actually think I’ve defined some very specific tests which, if the current models are reasonably accurate, will be sufficient to convince me of this fact within a decade.

    I’d like to see Real Climate do likewise. Suppose that the observed trends that I mentioned are less than half what the models predict (starting at AR3 for surface, or from the switch to all Argo data for OHC) is less than half of what the models predict. For how many years would this have to persist before you concluded that the models substantially exaggerate climate sensitivity.

    [Response: For us to be able to constrain sensitivity from transient changes you need to make some pretty reckless assumptions (see the main post). You need accurate estimates of the forcing for a start, and you need to be able to connect the transient sensitivity to the long term sensitivity. As you can see I did that for the Hansen et al runs and got a sensitivity of just above 3 deg C (though rather poorly constrained). That is very close to the mean sensitivity of the AR4 models. So you could do this with 20 odd years of data. But since I can do this already for the Hansen simulation, and also show that the AR4 models do as good a job for the same period (0.21+/-0.16 degC/dec), why isn't that sufficient for you? - gavin]

  191. tamino:

    Re: #179 (sierra117)

    http://tamino.wordpress.com/2009/12/15/how-long/

    http://tamino.wordpress.com/2009/12/07/riddle-me-this/

    http://tamino.wordpress.com/2008/09/12/dont-get-fooled-again/

  192. Jason:

    #168: “And in the mean time the area under the curve will continue to grow, said area representing the total amount of carbon added to the atmosphere and to the active carbon cycle.

    Do you have a plan for how we will draw down the increase in that reservoir once you are convinced?
    Or a plan for how we will cope with the consequences for the next millennium, or will you just cross that bridge once you are convinced?”

    I do have a plan. Lets replace all us taxes on income with a tax on carbon. If CO2 is a big problem, then this will fix it (at least as far as the US contribution is concerned). If not, swapping the income tax for a carbon tax is likely have a strongly positive impact on growth (especially if the carbon invested in imports and exports is properly accounted for), and certainly not a negative impact.

    If Democrats seriously believed Al Gore’s brand of alarmism, they would implement this immediately. Republicans would be happy to end the income tax. And which is worse “frying the planet” or sacrificing income redistribution?

    The problem, for those who favor immediate action, is that even the most liberal Democrats on capitol hill don’t believe that climate change is such an immediate problem that they should sacrifice their legislative agenda in order to do something about it.

  193. Thomas:

    If I can get back to the runaway feedbacks. This free textbook has a decent introduction to planetary climate, although it is a bit long, it requires roughly undergrad physics level understanding:
    http://geosci.uchicago.edu/~rtp1/ClimateBook/ClimateVol1.pdf
    Its been several months since I read it. The question concerns the fact that water vapor feedback becomes stronger as temperatures rise. IIRC correctly the following results are seen:
    At some level of solar radiation, which I think corresponds to an average surface temperature of 50C the runaway effect sets in. I think it is also true that if we were able to wall off the equatorial regions, that they would undergoe the runaway feedback effect. But for the planet, it is not thought to become runaway until the total solar input is considerably higher -perhaps 500M to a billion years from now. But with todays solar luminosity no serious climate scientists thinks we are in danger of setting the runaway effect.

    For those that are interested the rate of increase of solar luminosity is about 1% per hundred million years. This rate is slowly increasing, but a simple linear rate of increase will be pretty decent over a period of a few hundred million years.

  194. Timothy Chase:

    Ray Ladbury wrote in 172:

    Try @163, 166, First, I think you need to learn to ask your question more clearly.

    I don’t know about that. As oftentimes stresses, he’s very curious. And if his questions can be interpretted along different lines, he may get more answers — a bit like this fisherman:

    http://www.haverodwilltravel.com/images/Trolling%202.jpg

  195. Matthew:

    45, Martin Vermeer: Jaynes (2003, p. 504) quotes Jeffreys: “Jeffreys (1939, p. 321) notes that there has never been a time in the history of gravitational theory when an orthodox significance test, which takes no note of alternatives, would not have rejected Newton’s law and left us with no law at all. …”
    ;-)

    True enough. But if we had decided for some reason to spend a trillion dollars to “stabilize” the precession of the perihelion of Mercury, we’d have wasted our money. Newton’s laws do very well for interplantetary travel, but not for that purpose. Right now, they may fail to account properly for the relationship of mass to gravity or of mass, force and acceleration (or, there might really be large amounts of cold dark matter, or enourmous masses just beyond the vision of the Hubble telescope, or something.)

    The possibly oscillatory nature of the warming of the last 1 1/2 centuries may be the functional equivalent of the precession of the perihelion of Mercury: the evidence that the theory has a major omission, or flaw. That we don’t know it’s cause (or don’t agree that it is solar cycling) is not evidence that it is negligible.

    As you know from debates among Neyman, Pearson, and Fisher, there is an operational distinction between having enough information to substantiate belief and having enough information to support a huge investment.

  196. Leo G:

    Hank @ 143 – Actually, when WUWT gets on a real scientific thread, a lot of very good scientists tend to show up, Svelguaard, Spencer, aana v, etc.

    My favourite Svalgaard quote is this, “It is a pity for the scientific integrity of this blog that it be marred by your nonsense.”

    I find that at most blogs, pro or con, when a real scientist shows up, They take no prisoners.

    Now back to my homework! :)

  197. Sigurdur:

    For Gavin:
    Thank you for cleaning up RC. I had totally given up on this site as a source of useful information, but with the new tone I will be back.
    As a farmer I watch grow lines, (North America), and they have not moved north at all during the time of increased global temp.

    I would make a recommendation that you check in with your source writers at various papers and media outlets. The catastophic predictions are falling on deaf ears as there have been numerous droughts/floods etc throughout the Holocene period.

    The actual science, as of yet, seems a bit tenuous but is improving I would hope.

    Mainly, thank you for the change here.

    Regards,
    Sig

  198. Andrew:

    @ Jason: “Lets replace all us taxes on income with a tax on carbon.”

    A couple years ago, the top 1% of U.S. earners pay a total of about 35%-40% of the federal income tax. Do you think they accounted for 35%-40% of the carbon use?

    The median income is about $40K, the top 1% earners make about $1.25M. The tax rates would be 25% and 35% respectively for single filers. That means that the rich guy pays $440K and the median pays $10K. Now change to carbon. The rich guy isn’t using anything like 30 times the median carbon footprint. 30 times median is a gigantic carbon footprint. So let’s say highest 1% of earners use four times the carbon as everyone else (which I think would actually be somewhat high). What that means is cutting that high earners’ tax down to say, four times the median, then everyone else gets something like a 40% tax increase, with the lower income people getting a good deal more than that. Taking into account that there are incomes low enough to not pay income tax at all, then it only makes the burden worse on people who do pay taxes.

    Well yes, that would um, do something.

    Not really too hard to figure out why that isn’t the Democrats first guess though, is it?

    Maybe you can run some numbers for your next idea.

  199. Andy:

    RE: #161 Hank:

    The biggest terrestrial ecological disruptions are likely to occur through massive, abrupt loss of forest and other habitats. In my opinion, it’s pretty easy to see that forest cover will disappear as quickly and unexpectedly as artic sea ice and that this will take a lot of plant and animal species down. Forest loss is likely to occur from longer drought periods as well as increased pests and fire. This is already happening in the western US and Canada.

    Predictions in the literature seem to concentrate on how increased temperatures require biota to migrate and whether or not it is capable of it. But this assumes an orderly march to the poles by all species. Totally unreal asusmptions are being made here in my opinion. I see a world of rapidly shrinking forest cover with biota for the most part standing still and meeting their doom.

  200. Ken W:

    ALW (155):
    “I would say that if we are looking at how well the PROJECTIONS are shaping up it is disingenuous to include hindcasts within the graphs”

    You still don’t get it. If you had read the Realclimate model FAQ articles I linked too, you would understand the difference between a statistical model and a physics based model. If the plot were based on a statistical model (i.e. one that merely tried to fit itself to the existing temperature data record) then it would be a pretty useless graph. But that’s not the case. Here are the links again:

    http://www.realclimate.org/index.php/archives/2008/11/faq-on-climate-models/
    http://www.realclimate.org/index.php/archives/2009/01/faq-on-climate-models-part-ii/

  201. TRY:

    194 – Hey, finding pictures online is a great contribution! Gold star.

    If you bothered to read my previous comments you’d see that I asked the exact same question. The fact is, it’s an interesting question and one worth discussing.

    You’re exactly right. Warming is a result of an imbalance between inbound and outbound radiation. Your opponents claim that inbound radiation varies over time. Surely there is some variation, however slight? Are we tracking this outside the earth’s atmosphere?

    And what about outbound radiation? The AIRS system does seem capable of tracking radiation at some level. What’s it going to take to track that data across a wide IR range seasonally? We have data from at least 1997. No change to 2003. What about to now? Where are those studies? We should in theory see a change in radiation signature over time. Wouldn’t this go a long way towards addressing the issue of actual impact of increasing/decreasing CO2 in the atmosphere. We’re working hard to track temperatures – why not actual radiation output, the first degree, measurable impact of CO2?

    Your opponents claim that in fact CO2 does not have the claimed impact on outbound radiation: clouds, overlapping absorption bands, saturation, less positive feedback than expected from water vapor, etc, etc. Lots of discussion on boths sides.

    I have zero interest in rehashing all of these secondary issues. I particularly could care less about these “angels on the head of a pin” statistical discussions of temperature measurements and trends. Is it decadel? 15 years? Is there selection bias in what gets studied, funded, published? Does the north pole ice signal have less noise, or the south pole ice signal? Again, zero interest.

    Also, Hank Roberts, I’ll quote you
    “Please. Go shake up _your_ public relations officers today.
    Show them what Google Image finds, on any subject related to climate or your own research field. Make them afraid for their own and their university’s budget if they don’t get better at this.”

    Seriously?

  202. Doug Bostrom:

    #187 John:

    Unless I’m missing your thrust it does not seem as though you read Gavin’s text, starting with the title of the post: “Updates to model-data comparisons”.

  203. Nicolas Nierenberg:

    Gavin,

    It doesn’t really matter if the runs were done in 2004 or 2006. I’ll accept that they are a forecast starting in 2004 instead of 2006, it doesn’t change my point. The modelers knew what the actual results were for the earlier periods, so these types of models can’t be judged based on anything before that time.

    Show me a model of the economy that matches up until this year and I will say that’s nice. Give me a model today that matches the next ten years and I’ll say that’s impressive.

  204. sierra117:

    re @191

    Thank you Gavin. I went to the NOAA website and found a chart of the El Nino oscillations which confirmed your remark (re El Nino). I didn’t realise how big the 98 (and 83) El Nino events were by comparison to this years.

    Thank you Tamino; I have read through your articles.

    Has anyone undertaken any research to see how well the El Nino/La Nina oscillations correlate with variances from the global temperature trend line? Seems to me just by looking at the peaks and troughs in these charts there is a good correlation; but appearances can be deceptive and I know there is not substitute for a descent mathematical analysis.

  205. Hank Roberts:

    Leo, can you find that quote again? Google doesn’t find it.

    > Sigurdur
    > Grow lines
    Say what? What does that mean? I tried to look it up and found wackiness.
    Are you thinking about the change in plant hardiness zones?
    http://www.arborday.org/media/mapchanges.cfm

  206. TRY:

    A reason this radiation analysis might be interesting. Not much warming trend this decade compared to last – why? No impact from CO2 warming, or CO2 warming overwhelmed by a source of cooling? It seems these two scenarios would involve somewhat different radiation output. Do we know what these differences might look like? And can we measure them. I assume, bottom line, that the answers are no. Does seem worthwhile, however.

  207. Don Shor:

    [The implied claim] “…that no model produced any realisation of the internal variability that gave short term trends similar to what we’ve seen … is simply not true.”

    Given the very wide range of possible outcomes shown in the first graph, anything – including a decline in temperature nearly every year from 1980 to the present – would have been within the model estimates. So that may put the lie to George Will’s claim, but it also doesn’t speak very well for the utility of the models.

    [Response: On short timescales, absolutely. On long timescales they all warm strongly and that is the risk they are highlighting. However, a decline in temperatures since 1980 would definitely be outside the model envelope (see comment 158). - gavin]

    “So to conclude, despite the fact these are relatively crude metrics against which to judge the models, and there is a substantial degree of unforced variability, the matches to observations are still pretty good…”

    In the third graph, the data came in 27% below Dr. Hansen’s Scenario B, and even below his most conservative Scenario C. That is “pretty good?” What would be “not so good?”

    [Response: The forcing from Scenario B is the one closest to what happened - 'A' and 'C' are therefore moot for deciding whether the model has skill. You can quantify skill of a prediction by comparing it with a reference ('naive') hypothesis of 'no warming' say. The skill is calculated as 1-MSE_pred/MSE_ref (MSE=Mean Square Error), and positive numbers indicate skill. If you were doing it on the trend, the skill of the B simulation compared to a no warming case is 0.86. The skill is similar if you take each annual anomaly (0.75). So yes, that's pretty good - the model told us something we didn't know before. 'Not so good' would have been a linear extrapolation from pre-1984 temperatures, for instance. Obviously ahead of time we don't know which scenario is going to be best (though we might have an opinion). If you felt the scenarios were equally likely, you might think that the average over all of them would be your forecast. That too would have had skill. - gavin]

  208. Martin Vermeer:

    Matthew #45

    … there is an operational distinction between having enough information to
    substantiate belief and having enough information to support a huge investment.

    Matthew, you’re illustrating the fallacy I was describing. The point (Jeffreys’s point) you’re missing is that hypotheses need to be intercompared, not proven true in isolation. Your ‘operational distinction’ doesn’t really exist: valid decision making is based on valid inference.
    As it is, we’re betting the farm (as in, worst case, the continued existence of our civilization) on the correctness of the ‘Ostrich Hypothesis’, which violates textbook physics and is flatly contradicted by multiple independent lines of evidence. Can you say ‘wishful thinking’?
    There is no way not to bet. Responsible betters use the best info available, warts and all.
    Welcome to decision making under uncertainty, AKA risk management.

  209. Silk:

    Re #155 “Also I made a mistake in my original post – the TAR projections were for warming of 0.3 to 0.4 with the actual measured warming being between 0 to 0.05 (not 0.5 as I initially said)”

    No, you made more than one mistake in your original post. Your claim that TAR predicted a 0.3 to 0.4 deg temperature increase this decade is false

    See

    http://www.grida.no/publications/other/ipcc_tar/

    The MAXIMUM increase suggested (not predicted – SRES are not predictions) was 0.24 degrees.

    Th A1B scenario, which (so far as I recall) is closest, in emissions terms, to what actually happened, suggested an increase of 0.14 degrees this decade.

    Which is a pretty darn good estimate, taking which ever trend you want (0.06+/-0.14 ºC/dec or -0.04+/-0.23 ºC/dec)

    So, skeptics, we have a decade of reasonably successful prediction of global temperature change, and now we have better models.

    Next.

  210. Martin Vermeer:

    Matthew #195 (eh, mistake in previous, should be #195)

    But if we had decided for some reason to spend a trillion dollars to “stabilize” the precession of the perihelion of Mercury, we’d have wasted our money.

    At first I didn’t understand this metaphor at all… but perhaps it is relevant after all, but in the reverse direction :-)

    The situation we’re in is not the analog of your metaphor, where we are unaware of General Relativity; on the contrary, we know both that AGW is real and what causes it; only, some folks don’t like that reality. We know too much, not too little.

    Proposing a better metaphor: GR is known, and validly explains the anomalous precession of Mercury’s line of apsides — but some influential folks don’t like it, for ideological or vested-interest reasons. They just know — KNOW, I tell you — that this is ‘degenerate physics’ foisted upon the world by a global conspiracy of physicists, who also suppress observational data on the planet Vulcan / the inner asteroid belt / the flattening of the Sun / the deviation from inverse-square [take your pick, never mind they cannot all be true]. And anyway, 42 arc seconds per century is very, very small. It’s less than 1% of the total precession — are those “scientists” really claiming that you can measure such a small quantity reliably? And the godless materialists pushing GR also believe in a Big Bang, denying divine creation. It’s all part of a plot to corrupt our youth.

    (I can’t think of a realistic way in which a very large amount of money would be riding on this; but it shouldn’t have to matter, should it. The truth is the truth.)

  211. Dappled Water:

    #197 – What the heck are grow lines?. Are you referring to hardiness zones?.

    http://www.arborday.org/media/mapchanges.cfm

  212. Jim:

    Just curious, how do most models ‘model’ the atmosphere? I see in the AR4 it’s “~100 km (T106)”, what does that mean for the size of each block or individual unit of atmosphere?

    Is it calculated in spherical coordinates (e.g. radius, angle z, angle x) or translated into a sort of 3d brick version of a map of the Earth?

    Do they cover all layers from the ground/ocean to the tropo/strato/meso/thermo -spheres?

    For the troposphere is it modeled as flattened at the poles, and bulging at the equator?

    Is there accounting for the Coriolis force? Or the hemispheric prevailing winds (Polar easterlies, prevailing westerlies, trade winds)?

    I think I read somewhere they are struggling with cloud cover and albedo, is there some progress on that task?

    Thanks,

  213. Geoff Wexler:

    TRY
    #163

    So feed x photons into the atmosphere that are absorbed by CO2 – what % are re-emitted by CO2, what % are transferred to other molecules, what % of those eventually cause IR emissions by H2O, CH4, vs transfer to ground via convection, etc.

    #166 and #170

    Again, different than this idea that 100% of the energy that CO2 absorbs in a specific wavelength is emitted in that same wavelength, right?

    This is how I see it now:
    Try to separate off the greenhouse discussion from convection, by considering a time so short i.e. a small fraction of a second, that there is certainly no weather and no significant drift (convection) and so long that there is a large number of absorptions, emissions and collisions, i.e. radiation transfer and greenhouse effect.

    In that case the local temperature , density, pressure etc. will be constant and there will be local themodynamiuc equilibrium at a constant temperature and the proposition that 100% of the energy absorbed by CO2 in a specific wavelength is emitted in that same wavelength becomes exact . If this were not true then the CO2 would either cool or warm in contradiction to the hypothesis of constant temperature. It remains true even when other greenhouse gases such as H2O and CH4 are taken into account. This is because the energy transfers from CO2 to e.g. H2O and in the opposite direction have to balance.

    That result is very probably an example of the principle of detailed balance which you can read up. If this balance were violated you could probably apply it to violate the second law of thermodynamics. For the same reason, there will be no net energy lost to the non greenhouse gases such as O2 , and N2. Their role is to help maintain thermodynamic equilibrium by acting as a heat reservoir.

  214. Ray Ladbury:

    One of the fallacies we are hearing from the denialosphere is the presentation of the choices available to us. We do not face a choice between “doing nothing” and “investing trillions”. The next few decades will of necessity see a revolution in our energy infrastructure quite independent of anything we do about climate change. The era of cheap petroleum is over. The choice is whether we invest in a sustainable, clean energy infrastructure or whether we invest slightly less in a dirty and temporary fix relying on coal, oil shale, tar sands, etc. The choice is whether we invest as science counsels us or whether we do exactly the opposite–in other words, the choices are science and anti-science.

    We are also told that in order to justify the extra investment in clean energy infrastructure, we need to hold the science to some higher standard than mere scientific truth? Really? Should the standards of scientific truth depend on the desirability of its implications? Should we really be willing to bet the future of human civilization on a 20:1 longshot to avoid an investment that amounts to about 1-2% of global economic output over a few decades?

    Of course what is happening here is a conflation of scientific truth with probabilistic risk assessment(PRA). The flaw here is making acceptance of the risk contingent on its consequences–and that violates every tenet of both science and PRA. Scientific truth is scientific truth. You can take 90-95% CL to the bank. The key is to accept the best science we have and then formulate policies that take into account both costs and consequences of action and inaction.

    The level of scrutiny climate science has sustained is unprecedented. Its methods and conclusions have survived not just internal review, but review by National Academies, Professional Societies and even hostile legislative committees. Not one such review panel has dissented from the consensus position–that we are warming the planet and that we need to do something about it. Even the theory of Evolution has not been subjected to such scrutiny! There is still room for debate, but the legitimate debate now concerns what to do about this crisis, not about whether the crisis is real.

  215. Ray Ladbury:

    TRY, I work building satellites (could ya’ tell?), so when you ask me, you will tend to get a much more detailed and technical answer than when you ask others. I start thinking “How?” rather than “What?”. Keep in mind that the phenomenon we are discussing is “climate”. That is true whether our “eyes” are in the sky of on the ground. You still need to look at long-term, global behavior.
    I strongly favor this sort of program. DISCOVR would have been a good start–but a read on the history of this program is educational as to the influence of denialist elements on climate science:
    http://www.desmogblog.com/a-desmogblog-exclusive-investigation-into-nasas-dscovr-climate-station

  216. Simon Rika aka Karmakaze:

    @Ray Ladbury #171

    Is it easier to see the trend because of the use of a reference average temp (ie “1970-1999 average”)? I mean if you showed absulute temps the variability is so much that it basically looks like noise? I am just trying to wrap my head around why a graph that shows an absolute temp is harder to evaluate.

    In case I’m not making myself clear, say we have a graph of annual mean temp, and the average annual mean temp for the period 1970 to 1999 was 14.5C and this years’ annual mean temp was 14.6c would that not show the trend as clearly as this year being +0.1C anomaly compared to the 1970-1990 average?

    Thanks for the help, I appreciate it.

    I know this is off-topic, but it is a question that has been bouncing around my head for awhile now, and I just thought I’d ask.

  217. Barton Paul Levenson:

    Pat: Since we have been warming from the 1600’s (or cooling since the Holocene Optimum), when did it switch from natural to anthropogenic?

    BPL: We passed the peak of the interglacial 6,000 years ago and have been cooling, on average, since then–until the industrial revolution started.

    Pat: And why can’t the man made warming overcome the trivial effects of the cold phase PDO.

    BPL: WHAT effects? Be specific, please. Do you mean on temperature? Try here:

    http://BartonPaulLevenson.com/Ball.html

    http://BartonPaulLevenson.com/Reber.html

    http://BartonPaulLevenson.com/VV.html

  218. Barton Paul Levenson:

    Terry,

    Relative humidity stays fixed on global average:

    Gettelman, A. and Q. Fu 2008. “Observed and Simulated Upper-Tropospheric Water Vapor Feedback.” J. Clim. 21, 3282-3289.

    “Satellite measurements from the Atmospheric Infrared Sounder (AIRS) in the upper troposphere over 4.5 yr are used to assess the covariation of upper-tropospheric humidity and temperature with surface temperatures, which can be used to constrain the upper-tropospheric moistening due to the water vapor feedback. Results are compared to simulations from a general circulation model, the NCAR Community Atmosphere Model (CAM), to see if the model can reproduce the variations. Results indicate that the upper troposphere maintains nearly constant relative humidity for observed perturbations to ocean surface temperatures over the observed period, with increases in temperature ~1.5 times the changes at the surface, and corresponding increases in water vapor (specific humidity) of 10%–25% °C^-1. Increases in water vapor are largest at pressures below 400 hPa, but they have a double peak structure. Simulations reproduce these changes quantitatively and qualitatively. Agreement is best when the model is sorted for satellite sampling thresholds. This indicates that the model reproduces the moistening associated with the observed uppertropospheric water vapor feedback. The results are not qualitatively sensitive to model resolution or model physics.”

    Manabe, S. and R.T. Wetherall 1967. “Thermal Equilibrium of the Atmosphere with a Given Distribution of Relative Humidity.” J. Atmos. Sci. 24, 241-259.

    Minschwaner, K., and A. E. Dessler, 2004. “Water vapor feedback in the tropical upper troposphere: Model results and observations.” J. Climate, 17, 1272–1282.

    Soden, B.J., D. L. Jackson, V. Ramaswamy, M. D. Schwarzkopf, and X. Huang, 2005. “The radiative signature of upper tropospheric moistening.” Science, 310, 841–844.

  219. Barton Paul Levenson:

    sierra117: My background is in statistics and computer science; so I know a little about the techniques used in climate science… Gavin, you mentioned that a trend of 15 years or less is insignificant statistically. I am curious to understand why you say that.

    BPL: Your “background is in statistics” but you don’t understand why a trend of less than 15 years in annual temperature figures is useless? I find that hard to believe.

    Try this: Do a linear regression of mean annual global temperature anomalies on time. Use the past 5 years, 6, years, 7 years, etc. up to 30 years. Then tell me where the t-statistics on the time term hit the 95% confidence level.

    Let me know if you don’t understand what I mean by “linear regression,” “t-statistic,” or “confidence level.”

  220. Barton Paul Levenson:

    TRY: We should in theory see a change in radiation signature over time.

    BPL: I listed the studies for you which found exactly that. You completely ignored them. [edit]

  221. Barton Paul Levenson:

    TRY: No impact from CO2 warming, or CO2 warming overwhelmed by a source of cooling? It seems these two scenarios would involve somewhat different radiation output. Do we know what these differences might look like? And can we measure them. I assume, bottom line, that the answers are no.

    BPL: I showed you, bottom line, that it had already been done. You showed no response to my rather long post with complete citations. You’re just going to keep repeating this false point, sometimes phrasing it as a question, to give the impression that there’s a big fat hole in our empirical knowledge which invalidates AGW theory. [edit]

  222. Barton Paul Levenson:

    Gavin: The skill is calculated as 1-MSE_pred/MSE_ref (MSE=Mean Square Error),

    BPL: I don’t get it–wouldn’t the MSE for a prediction of “no warming” always be zero (MSE for a flat line)? How are you calculating MSE_ref?

    [Response: It's the mean square difference from what actually happened. - gavin]

  223. Richard Steckis:

    “As you can see, now that we have come out of the recent La Niña-induced slump, temperatures are back in the middle of the model estimates. If the current El Niño event continues into the spring, we can expect 2010 to be warmer still.”

    1. The current temperatures are not in the middle of the model estimate but close to the lower third of the model estimates.

    2. Of course you are assuming no future La Nina slumps?

    3. I think the El Nino has to extend into the NH summer to make 2010 the warmest year of the decade (the new decade does not start till 2011). Current modelling of this El Nino by Australia’s BOM still has this one dissipating during March which is the usual month for these events to start breaking down.

  224. wil:

    #40 “I conclude that we are in very deep trouble. I don’t see how anybody can disagree. The 2002 to 2009 nitpick is just that, a nitpick, no doubt caused by weather.”
    You can go back much further than 2002. You can also start in 2001, 2000, 1999, 1998, 1997 or 1996. Take for instance the NOAA-NCDC data from 1996 to 2009 (that is 14 years!) and you still will find that the slope is not significantly different from zero (p=0.09). Isn’t that a reason for serious doubt? How long can you blame the weather for the discrepancy?
    If you want to convince people who have an open mind but are not willing to believe just anything you will need better arguments.

  225. sierra117:

    @219

    BPL….I understand the maths…where can I get hold of the data?

    [Response: Here. - gavin]

  226. Rob:

    What would the output of the GCMs look like if there were no CO2 increase? Any links to a graph? thanks!

    [Response: Assuming you mean no forcings of any kind, then the ensemble mean would be flat, but you'd still see excursions of the same magnitude as the grey bands above. - gavin]

  227. Anonymous Coward:

    Thomas (#193) wrote: “No serious climate scientists thinks we are in danger of setting the runaway affect”.
    The thing is, Hansen claims there is a clear (if not quite present yet) danger. He may not be “serious” but he’s too big a name to be dismissed out of hand. So, again, my question is: did Hansen substantiate his extraordinary claim publically?
    An H2O runaway greenhouse would be the worst catastrophe ever. There is no risk humanity has a handle on that’s more serious so I do not understand Hansen’s seemingly flippant way of bringing it up.

    The minimum amount of absorbed solar radiation for a runaway effect on Earth seems to be close to 290W/m^2. Thankfully, the albedo of the Earth isn’t going get close to 15% any time soon so we seem to be well under the danger zone (barring weird cloud effects). I don’t see how such an amount of absorbed solar radiation would translate to a global average temperature of 50C (as Thomas wrote).

  228. Grabski:

    a > 25% underestimate for scenario C (from the 2007 review)
    The forcing from Scenario B is the one closest to what happened – ‘A’ and ‘C’ are therefore moot for deciding whether the model has skill.

    But the data are 0.5 degrees below B scenario, and in fact are below the C scenario. So forcings in C are 25% less than actual and temps are below Scenario C; why is that moot? There’s a lot of information from that miss about the models.

  229. Ray Ladbury:

    wil@224 There’s a reason why climate is considered 30 years or longer. See here:
    http://tamino.wordpress.com/2009/12/15/how-long/

    I’ve always found it astounding that people want to draw conclusions on a decade of information while 1)ignoring the current decade is the warmest on record; and 2)ignoring the previous 3 decades.

  230. Ray Ladbury:

    Simon@216. Try looking at monthly data–lots of up and down, right? Hard to spot a trend. Now average over a year. Still lots of up and down, but the trend is easier to see. Now try looking at 5 year averages and the trend becomes quite clear. Essentially, if you remove known sources of noise (like annual variation in absolute temperature) the trend becomes easier to see.

  231. Geoff Wexler:

    #201 TRY (again)

    “Your opponents claim that ……..

    I have zero interest in rehashing all of these secondary issues….”

    Really? Then why have you just listed them all? Far from being secondary many were of crucial importance, but were settled years ago.

    Lots of discussion on boths sides.

    Thats just what the pro-CO2 lobby want everyone to believe; just non-rigorous discussion, every single step uncertain and no conclusions.

  232. Dale Power:

    The Mars Bar theory holds some merit if you are willing to look outside the strict scientific box for a bit.

    Same with the Pirate index.

    1. The Mars Bar theory indicates that increased non-essential product production (one major sign of the industrial/consumer age) tracks well with increased Global Temperatures. It is not the direct cause of course, but rather a sign of what is going on with the overall societal complex in a given time period. It is actually valuable to note this, as it demonstrates the relationship between human activity and Temperature increase over time.

    2. The Pirate Index shows how an increase in societal input, in the form of policing, shows some relationship to the above mentioned Mars Bar Theory.

    As wealth increased due to the industrial age, resources were more available to combat Piracy on the high seas. Both the policing and the funds available to pay for it track with temperature increases and proceed those increases, showing a cause and effect relationship in potential.

    Yes, this is far from real science, but it is the kind of thing that catches the public imagination!

    People do NOT want to take responsibility for, well, almost anything in life! You have to show people what is going on in many different ways if you want them to believe you.

    Who has the scientific background to actually write this up? (Provided it honestly holds up data wise.)

    This is the kind of “device” (I almost said “trick”!) that will actually impact the minds of people, so is worth doing!

  233. John E. Pearson:

    sierra117: Here is a very simple argument that explains why there ought to be some time scale before which trends cannot be ascertained. Think of a random walker with a deterministic component to his walk, a constant drift speed v. If the variance of the stochastic motion is D t (t is time) then the distribution function for the walker’s position will be Gaussian with mean v t and variance D t . At early times the width of the distribution (w = sqrt(D t) is much bigger than the walker’s mean position (v t) and one cannot ascertain the trend (i.e. v) from data (i.e. time series of the walkers position). The width w=sqrt(D t) is equal to the mean (v t) at time T: sqrt(D T)=vT so that T = D/v^2. For times small compared to T =D/v^2 the trend cannot be learned with any accuracy. It has often been misstated here that this is an issue of the amount of data that one has. This is not quite correct. It doesn’t matter how much data you have for early times. Even if you could collect continuous time and position data (an infinite amount of data) you still would not be able to learn the trend v at times small compared to T. The noise itself (which is characterized by “D”) sets a limit on how well v can be ascertained for short times.

  234. Hank Roberts:

    > Simon 216

    Try moving the slider on the little applet on this page:
    http://hot-topic.co.nz/keep-out-of-the-kitchen/

  235. Howard S.:

    Yes Ray, 229. There’s a reason why climate is considered 30 years or longer. See here:

    http://www.youtube.com/watch?v=8mxmo9DskYE&feature=player_embedded

  236. Jim Eager:

    Jason @192, I actually agree with you that a carbon tax would be far preferable to a cap & trade regime, as does James Hansen, btw, but you missed the meaning of my question: just halting CO2 emissions will not be enough to prevent global warming induced climate change since a halt will not reduce the amount of extra carbon that has been added to the active carbon cycle on any meaningful human time scale.

    Putting a price on carbon will certainly spur investment and research into developing methods to actually remove excess carbon from the atmosphere, but given that a good deal of energy is released by burning fossil carbon, not to mention the energy expended on digging up, pumping and refining that carbon, basic physics dictates that removing that carbon and sequestering it from the active carbon cycle will require an amount of energy of at least the same magnitude. Where will that energy come from?

    It took over two centuries from a near standing start to liberate the 300+Gt of carbon that we have added to the atmosphere and active carbon cycle. It is thus reasonable that it will take a similar time scale from a standing start to sequester enough C to reduce the carbon reservoir to a level that will avert the full consequences of the climate change that we have set in motion.

    By diverting your comment into political accusations you avoided both answering my questions and dealing with the physical reality of our situation.

  237. wil:

    @Ray Ladbury #229
    “I’ve always found it astounding that people want to draw conclusions on a decade of information while 1)ignoring the current decade is the warmest on record; and 2)ignoring the previous 3 decades”.
    If you read my words carefully (#224): I was talking about 14 years which is really more than a decade. And of course I am not ignoring the previous decades, but precisely because of the strong upward trend in those years the shift in the trend during the last 15 years is so remarkabl. It is too simple to blame it all on “the weather”, and I am looking (on sites like this one) for a better explanation. Can someone convince me that we can just ignore the last 15 years? And how much longer can we go on ignoring?

    [Response: Don't be ridiculous. No-one is 'ignoring' anything - unless it is commenters who keep on ignoring evidence that demonstrates that short term trends have less significance than they think. - gavin]

  238. Ray Ladbury:

    Wil says, “And of course I am not ignoring the previous decades, but precisely because of the strong upward trend in those years the shift in the trend during the last 15 years is so remarkabl.”

    http://tamino.wordpress.com/2009/12/07/riddle-me-this/

    Uh, you were saying?

  239. Edward Greisch:

    What is OHC? Over Head Cam? Maybe you mean Ocean Heat Content? Acronyms need to be spelled out more often, please, everybody.

    [Response: Sorry. Check out the acronym index though. - gavin]

  240. RB:

    @203 Nierenberg

    I’ll take a stab at the stock market. It is currently priced to return 6% annually over the next ten years with a yearly standard deviation of 20%. That is, at the end of 10 years, the stock market will be (1.8 +/- 1.1) times current S&P 500 of ~1100. This methodology was actually successful based on 1999 projections leading up to 2009.
    http://www.hussmanfunds.com/wmc/wmc091214.htm

  241. Ike Solem:

    What, no mention of the paucity of oceanic data for comparison purposes?

    To be more clear, consider this phrase from the end of this article:

    “The model used in the mid-1980s had a very simple representation of the ocean – it simply allowed the temperatures in the mixed layer to change based on the changing the fluxes at the surface. It did not contain any dynamic ocean variability – no El Niño events, no Atlantic multidecadal variability etc. and thus the variance from year to year was less than one would expect. Models today have dynamic ocean components and more ocean variability of various sorts, and I think that is clearly closer to reality…”

    But with such poor collection of ocean subsurface data over the 1984-2009 period, how can you be sure what “reality” consists of? Imagine, for example, that atmospheric radiosonde temperature data was a spotty as ocean subsurface data – what kind of conclusions could you then draw?

    Obviously, it’s a total failure of NASA’s earth-monitoring job – but hey, whatever, let’s launch another deep space microwave background probe – that’s interesting, and since it won’t generate data that will annoy the fossil fuel lobby, it’s far more likely to be launched than Triana! Yes, that’s how you succeed in science these days – focus on topics that are safe and likely to be funded by the complex – and for goodness sake, don’t criticize your “colleagues.” That creates bad feelings, you know.

  242. honorable:

    The cavalier way with which you block comments that might appear critical is simply disgusting. I’m very disturbed by climategate and the way RealClimate is managed. More science and less activism, please. Criticism is the essence of the scientific approach. In my scientific research, I have always welcomed criticism, [edit]

    By the way, I am a professor of Medicine in a first rate North American university.

    [Response: Oh please. People repeating the same old tired nonsense add nothing to a comment thread and I make no apology for trying to maintain the signal to noise ratio. Not every letter to the editor gets published either. - gavin]

  243. David Watt:

    Aren’t you working the data just a little Gavin.

    If you take the data from any post 2000 start point I don’t think the correlation looks very good at all and the post 2007 onwards section (i.e. the bit where AR4 became a prediction) looks pretty terrible.

    How can you be sure that the 2007 downward blip can all be pinned on La Nina? Given the way this winter is shaping up right now, wouldn’t it be wiser to wait and see if the (so far) rather fragile recovery continues.

    [Response: There is always noise. No point in 'waiting to see' if it disappears because it won't. But keeping these kinds of comparisons up-to-date still seems worthwhile. - gavin]

  244. Jason:

    “But since I can do this already for the Hansen simulation, and also show that the AR4 models do as good a job for the same period (0.21+/-0.16 degC/dec), why isn’t that sufficient for you?”

    Pielke Jr.’s points 1,2, and 3 in http://rogerpielkejr.blogspot.com/2009/12/consistent-with-fallacy-how-not-to.html do a good job of defining how to make a prediction such that it robust against the appearance of ex-post facto criteria selection.

    Your comparison with Hansen 1988 (which I’ve seen interpreted differently especially regarding the comparison of actual and (then) expected forcings) is not robust in this regard.

    A “luke-warmer” climate model crafted in 1988 with dramatically lower sensitivity than Hansen’s would also (today) appear consistent with observations. Would I be correct to assume that you agree with Hansen’s error bars on his modern estimate of sensitivity? (+/-0.5 deg) and therefore consider such a low sensitivity to be improbable?

    As for the AR4 models, while accurate hind-casting is obviously important, it is the ability of climate models to forecast that I am interested in.

    [Response: Assuming that the 26 year trend scales linearly with the equilibrium sensitivity and forcing (big assumption), any model that had a sensitivity of below 2.1 deg C would have done worse (lower skill) than the Hansen et al model (that would be 1.9 deg C without a 10% correction for the high forcing). There is plenty of other evidence that sensitivity is greater than 2 deg C, and so this is somewhat confirming of that. As for Roger, I was not part of the team that made those early runs, so according to his no-post-facto rule, I'm apparently not allowed to analyse them since I didn't make a statement about what they did while I was still in high school. Brilliant. - gavin]

  245. Jason:

    #198: “Not really too hard to figure out why that isn’t the Democrats first guess though, is it?”

    My point was this:

    Democrats could right now get enormous Republican support for a plan to dramatically reduce US CO2 emissions to a level that even Hansen would approve of.

    If Democrats actually believed that failing to act decisively _now_ would result in catastrophe, then they would do so. Asking people (even the poor) to pay for the carbon they use isn’t such a terrible thing. It certainly won’t doom civilization as we know it.

    Democrats don’t actually believe that there is anything pressing about climate change which is why we wound up with a pork laden bill which does nothing to reduce emissions, and probably won’t even become law.

  246. Dave Salt:

    Plots comparing modelled ‘scenarios’ with real-world data can, undoubtedly, be considered as evidence that the implicit assumptions and mechanisms incorporated within the climate models are correct. However, hard sciences like physics, chemistry or biology also require that a theory should show how it can be falsified and, in so doing, provide a means to test its fidelity against real-world behaviour.

    Based upon my limited understanding of climate science and the theory of catastrophic anthropogenic global warming (AGW), I see little evidence to suggest that this key step in the Scientific Method has been applied or even that it is considered important. I know about the predicted “hot spot” above the equatorial troposphere but am lead to believe that current observations are, at best, insufficient to support the theory or, at worst, appear to falsify it. Given this situation, I can fully understand why some regard climate science as more akin to what Richard Feynman described as a ‘Cargo Cult Science’ rather than a hard science.

    Nevertheless, still think that there may be genuine reasons to believe that the current AWG narrative is correct and so would be grateful for any pointers as to what they may be. More specifically, I’d be very interested to hear of any real-world evidence that proves the dominance of positive feedbacks within the Earth’s climate system since this appears to be the key mechanism behind the so-called ‘enhanced greenhouse effect’ (Cf. IPCC TAR, Section 1.3.1), which amplifies the impact of a doubling of CO2 levels from a less than 2C to more than 4C and so raises the spectre of world-wide catastrophe.

  247. David Watt:

    My problem is that I don’t really think it is “noise”.

    The UK Met Office obviously thinks like you that it is and has seen each tranche of cooling since 2007 as “anomalous” and about to return to the “trend”.

    Perhaps that is why its last four attempts at a seasonal forecast have all turned out to be drastically wrong and why Vicky Pope now says it is much easier to forecast 30 years ahead than it is for three months.

    [Response: Vicky may well be right. But don't misunderstand my use of the term 'noise'. It is only noise for people looking for trends in climate driven by external processes. It isn't noise for people doing seasonal forecasts, or people trying to understand El Nino, or the AMO or the PDO or the NAO or blocking events, or storm dynamics, or cloud formation etc. The main issue here is to what extent those drivers will affect climate in the long-term, and so that is what I'm discussing. - gavin]

  248. Hank Roberts:

    > Jason says: 30 December 2009 at 1:0 PM
    > …
    > … Democrats could right now get enormous Republican
    > support for a plan to dramatically reduce US CO2 emissions

    Please post that plan, and get the enormous Republican to sign up to support it. That support would be good to see.

    (*Not here*– pick a website known to attract attention, for example Deltoid, which always welcomes promising ideas, or maybe ClimateProgress.)

  249. John E. Pearson:

    Wel @224.

    I ran regressions on this data: http://data.giss.nasa.gov/gistemp/graphs/Fig.A2.txt

    starting in 1970,1975,1980,1985,1990,1995 & 1998 (the hot year) and found the following.

    start N trend t-score P(T < t_score)
    year (K/yr)
    1970 40 .016 12.1 *
    1975 35 .017 10.5 *
    1980 30 .016 7.8 *
    1985 25 .018 6.94 *
    1990 20 .018 4.69 .9999
    1995 15 .015 2.92 .99
    1998 12 .011 1.4 .9

    *The P-value calculator I used gave unity for these.

    It sure looks significant to me. I don't see how you are concluding there isn't a significant trend.

  250. Ernst K:

    Comment by Nicolas Nierenberg — 30 December 2009 @ 12:20 AM (203)

    It doesn’t really matter if the runs were done in 2004 or 2006. I’ll accept that they are a forecast starting in 2004 instead of 2006, it doesn’t change my point. The modelers knew what the actual results were for the earlier periods, so these types of models can’t be judged based on anything before that time.

    Show me a model of the economy that matches up until this year and I will say that’s nice. Give me a model today that matches the next ten years and I’ll say that’s impressive.

    As I tried to explain back in comment 162, GCMs are physical models (i.e. built on established physics). Obviously, Economic models aren’t based on physics – you’d deserve a few hundred, if not several thousand, Nobel Prizes if you could pull off an economic model from physics alone.

    I actually thought of commenting that many apparently well educated “skeptics” don’t seem to understand the difference between physical and conceptual models, but I didn’t want to insult them. So much for that.

    Nicolas, your comment here betrays your complete lack of understanding of even the most basic concepts of physical modeling. Either that or you’re being completely disingenuous yourself.

  251. Ray Ladbury:

    Dave Salt, Barton Paul Levenson has provided several references that show evidence for positive feedback. I also commend to you the excellent review article by Knutti and Hegerl, along with the other papers by the same authors
    http://www.iac.ethz.ch/people/knuttir/papers/

    Here you will find very strong evidence (at least 10 independent lines) that CO2 forcing is at least 2 degrees per doubling of CO2. It is encouraging to see that all of these lines of evidence favor a sensitivity of about 3 degrees per doubling, but if the analyses are wrong, it is much more likely that sensitivity is higher, rather than lower.

    And as to falsifiability, you really need to read up on philosophy of science. Strictly speaking, falsifiability applies more to relatively simple hypotheses rather than complex physical models. In such models, it is quite possible to falsify one aspect of the model and have the model remain mostly intact otherwise. Presumably, the tenet of the consensus model of Earth’s climate you would like to see falsified is the importance of CO2 as a greenhouse gas. That could certainly be done, but the easiest way to do it would be to come up with an alternative model that explains the data better than the current model. No such model has been proposed.

  252. Andrew:

    @jason: “My point was this:

    Democrats could right now get enormous Republican support for a plan to dramatically reduce US CO2 emissions to a level that even Hansen would approve of.”

    Putting aside for the moment what Republicans right now actually believe about climate science, let us consider how they are acting vis a vis the Democrats.

    From http://www.politico.com/news/stories/1209/30083.html:

    “Kirk is one of a growing group of Republican candidates flip-flopping away from cap and trade as they stare down more-conservative primary challengers. Republicans who once flouted their green bona fides are tacking right, to the point of questioning the science behind global warming, believing it’s politically toxic within the conservative base to favor anything Democrats want to do about the climate.”

    This is not a political blog, though. I suppose the question of what sort of carbon tax might work is important and germane. However the politics of “right now” are probably less important for climate, since, painful as it is to consider, the politics of the current election cycle will not last as long as the climate problems. Maybe it is better to put aside Democrats and Republicans as they stand now (huge intradecadal oscillations there) and consider only the policy options which can persist long enough to be effective on climate time scales.

  253. Jason:

    #236, “just halting CO2 emissions will not be enough to prevent global warming induced climate change since a halt will not reduce the amount of extra carbon that has been added to the active carbon cycle on any meaningful human time scale.”

    First, I don’t have any problem with the earth getting warmer, especially if it only gets a little warmer, and if the pace of that warming is slower than the IPCC forecasts. I only favor action to reduce atmospheric concentrations of CO2 in those situations where the uncertain benefits exceed the uncertain costs. I think that 350ppm in 2100 is an unrealistic pipe dream.

    “Putting a price on carbon will certainly spur investment and research into developing methods to actually remove excess carbon from the atmosphere, but given that a good deal of energy is released by burning fossil carbon, not to mention the energy expended on digging up, pumping and refining that carbon, basic physics dictates that removing that carbon and sequestering it from the active carbon cycle will require an amount of energy of at least the same magnitude.”

    That is not at all clear to me. In fact, I’ve seen outwardly credible estimates explicitly suggesting that it will be possible to build carbon sequestration technology that removes many times more carbon from the atmosphere than is emitted during the production of the required energy. Can you direct me to an argument explaining why this physically is impossible?

    “Where will that energy come from?”

    Personally, I think we should move aggressively back towards nuclear power, passing federal laws that streamline and consolidate the approval of new power plants and power lines. There is no reason why all safety and environmental concerns can’t be addressed by one or two panels.

    “It took over two centuries from a near standing start to liberate the 300+Gt of carbon that we have added to the atmosphere and active carbon cycle. It is thus reasonable that it will take a similar time scale from a standing start to sequester enough C to reduce the carbon reservoir to a level that will avert the full consequences of the climate change that we have set in motion.”

    What level would that be? I neither agree nor disagree with the reasonableness of your assertion, but there seem to be a fair number of credible researchers who believe otherwise.

    “By diverting your comment into political accusations you avoided both answering my questions and dealing with the physical reality of our situation.”

    You missed the point. You asked me “Do you have a plan for how we will draw down the increase in that reservoir once you are convinced?”

    My response is:

    We don’t have to wait until I am convinced.

    There are options for limiting CO2 right now which, even if AGW is completely wrong [which I don't think it is] will be a net positive for the economy.

    We are not implementing these options because even the liberal wing of the Democratic party is not seriously committed to climate change. Which is OK. But lets not suggest that convincing the center and right of the scientific merits of AGW is somehow holding things up. As long as Democrats are sufficiently committed to fighting climate change that they are willing to negotiate away part of their agenda, we can do something serious about emissions right now.

    You can convince me later.

  254. John E. Pearson:

    246 on falsifiability.

    Dave, it is trivial to falsify the models that predict global warming. The models are based on physical theory going back to the early 1800′s. All you have to do to falsify the models is to falsify any of the underlying physical theory on which they are based: the heat equation, the Navier-Stokes equations, the Planck distribution, quantum mechanics, the laws of thermodynamics, etc. Your claim that the models aren’t falsifiable is nonsense.

  255. Andrew:

    @ Ray Ladbury: One of the fallacies we are hearing from the denialosphere is the presentation of the choices available to us. We do not face a choice between “doing nothing” and “investing trillions”.

    What would be wrong with INVESTING trillions? All that is needed to justify that is a decent rate of return. With what U.S. stocks did in the past decade, the bar is set pretty low at the moment. Let’s consider what the rate of return on power production will be in the future. What if it becomes clear that the climate is threatened – even by less than many current estimates? If you have the lead on a non-carbon power economy, that will be worth a huge amount. Purely in economic terms, there is huge upside as well as huge downside risk; exactly the kind of environment which rewards informed investors and punishes ostriches.

  256. TRY:

    BPL – I did see your post and mentioned that papers you linked to in my followup posts.

    I didn’t respond directly to you because – when I asked you for papers supporting your model prediction successes post, you sent me a list that was primarily a paper from 1896 that was full of incorrect predictions. I questioned this, and you never responded, so it seems like a waste of time to respond to you directly, no?

    Restating what I’ve said in other posts, the studies you link to show no change from 1997 to 2003, and no followup studies of any kind. 1997-1970 is interesting, but site-specific, clear sky, etc.

    Surely you understand, as I’ve said several times, that the really interesting thing is global radiation signature – that’s the core claim and something that presumably is worth monitoring and modeling.

  257. Kevin McKinney:

    Simon, you asked: “Would I be right in saying that even at the “coldest” point during the “current cooling phase” that global mean temperature was higher than at any point prior to 1998?”

    Layman’s answer FWIW:

    Yes, provided you were talking about annual mean anomaly for GISS or NCDC (aka Smith & Reynolds 05.) It’s likely that there was more variability at smaller intervals–for example, December 1997 may well have been warmer than some more recent December. (I’m not as sure about the Hadley data rankings.)

  258. Jason:

    #250: “As I tried to explain back in comment 162, GCMs are physical models (i.e. built on established physics).”

    There is a long history of physical models accurately modeling the past, but being completely wrong. The Epicycles of early Copernican (and even Ptolemaic) astronomy come to mind.

    If climate models were a deterministic application of well defined physics then:

    1. They would agree with each other and
    2. We would not have problems like the current “pause” in warming that Gavin alluded to.

    Very few of the thousands of assumptions that go into climate models would somehow invalidate physics if they were proven false.

    It is therefore an extreme stretch to suggest that physics implies the results of the climate models. The climate models depend on physics, and must be validated by successfully predicting events that occur after their publication.

    [Response: Actually there is more scope for validation than that. You can also use a) information about the past that you weren't aware of, or has only recently been published or b) relationships in existing data that had previously not been noticed or calculated. Either of these count as predictions in the methodological sense (i.e. it doesn't just have to be about something that happens in the future). Cosmology would be in dire straits if that was the case! - gavin]

  259. Ernst K:

    I suppose there is one other possible explanation for not accepting hindcasts from physical models as an acceptable form of model verification: one might simply think the modelers are making the whole thing up, that they don’t really have physically based models, that the models have actually been calibrated to match the historical global surface temperature record (even though the modelers claim they haven’t), and/or that the presented results are not the actual output from the models.

    But if that’s the case, just come out and say it and stop hiding behind the “hindcasts don’t count” smoke screen.

    If I’m missing something, please tell us exactly why you think hindcasts are not an acceptable way to verify a GCM.

  260. Edward Greisch:

    102 Hank Roberts: You have the Earth at Mars times backwards.

  261. Jason:

    #254: Is it your contention the models are predicated only on: “the heat equation, the Navier-Stokes equations, the Planck distribution, quantum mechanics, the laws of thermodynamics, etc.”?

    The models contain hundreds or thousands of additional unproven assumptions. These range from the response of upper tropospheric humidity to global temperature changes, to the impacts on cloud formation, to the historical forcing from aerosols (which to many skeptics appears to be the product of circular reasoning).

    No skeptic is suggesting that physics is wrong.

    To my knowledge, no credible climate scientist is suggesting that these basic principles of science are sufficient to imply the results of the AR4 model ensemble. Necessary, yes. Sufficient, no.

    All of the principles you mention are likely to be right, yet the GCMs may be horribly wrong.

  262. caerbannog:

    Off-topic (Dr. Schmidt, feel free to s***can this post if you think that it’s too far off-base here)

    Folks who consider Steve Mosher to be one of the more serious AGW skeptics might be interested in seeing him show his true colors here: http://biggovernment.com/2009/12/29/the-green-religion-and-climategate-interview-with-steven-mosher/

  263. Nicolas Nierenberg:

    re 250,

    Thanks for the kind words Ernst. It is this kind of polite exchange that leads to greater understanding.

    I was obviously only using an example to make a point. You may be surprised to learn that there are basic laws of economics that work fairly well. However in the real world there are so many confounding factors that it is difficult to build accurate models.

    Similarly the laws of physics are quite clear, but there a huge number of confounding factors in climate. So there is not such a huge gap between climate models and economic models in my opinion. If it were just physics then we pretty much would have been done when the JASONs built there model of the world.

    So I will restate my opinion. The ability to model climate can only be measured by skill in measuring periods after the model run. Not in the ability to model periods known to the modeler.

  264. TRY:

    Geoff #213 – There’s a nice symmetry to your suggestion, but I don’t think it holds for the general case. In your scenario, constant temperature implies an equilibrium state. Going back to my thought experiment, steadily radiate an atmosphere with an IR wavelength that only CO2 absorbs, wait for system to reach equilibrium. This situation meets your constant temperature requirement, but involves CO2 radiating less than it absorbs. I agree, the atmosphere won’t radiate at wavelenghts that it *can’t* absorb, but it will radiate at wavelengths that it’s *not currently* absorbing. Because I describe an environment with an external forcing (specific wavelength IR), I don’t think detailed balance applies, as that would only apply to a closed system at thermodynamic equilibrium? Or mayby I misunderstand the principle! Regardless, the thought experiment I describe seems clear and unambibuous.

    Re the other issues – my point is that all this argument about second-, third-, fourth-degree effects is potentially endless. Yes, sheer volume counts for something, but the volume of potential second-degree effects of claimed CO2 impact is vast order of magnitudes higher than what’s actually been published. So why not spend some time looking at first-degree effects at a global scale? I’d rather leave the politics/business/etc for another discussion, personally.

  265. Nicolas Nierenberg:

    Or as Gavin pointed out in a subsequent post, potentially by other information not known to the modeler. But that only works once, obviously.

  266. John E. Pearson:

    257: wrote “No skeptic is suggesting that physics is wrong.”

    Nonsense. There are skeptics that argue the stupidest stuff imaginable. I’ve seen all sorts of stuff from skeptics. You don’t have to look long to find skeptics writing down mathematical “proofs” that purport to prove global warming from CO2 is impossible. If you want to falsify global warming and leave all the relevant physical theory intact you’ll have a much harder time. It’s worth noting that Popper wasn’t a scientist and didn’t think very hard about what constitutes a scientific statement. You can’t falsify the statement (in Popper’s sense) that a given coin has a probability p=0.5 of coming up heads. What you can do is perform a long sequence of experiments which will provide evidence either for or against the statement. Eventually you might convince yourself and any reasonable person whether the coin is fair or not, but you certainly can’t falsify the statement; “The probability of this coin coming up heads is 1/2″ with Popperian certainty. That doesn’t mean that a probabilistic statement is devoid of scientific meaning. I have yet to hear a skeptic that was whining about falsifiability acknowledge that probabilistic statements are part of science. If skeptics would face this fact it would be easier to take them seriously.

  267. wil:

    @249 and @228 (Gavin response):
    I have used the NOAA-NCDC data and I am willing to believe that using GISS-data the answer will be slightly different (as it would be different again when using for instance the RSS satellite data). But that is not my point. The trend has been strongly positive from 1970 till around 2000. Now suppose for simplicity’s sake that all temperatures starting from 2000 are exactly the same and they would remain exactly at that same (high) level for several more years (for instance 10 years). Obviously, the trend value starting from 1970 would remain positive during all those years, and even maintain statistical significance for many years. But still, after 20 years of unchanged temperature, I suppose that most people would agree that a shift had occurred from rising temperatures to a flat line.
    So basically my question is when does “insignificant, short term” change to something relevant? This is what I meant with the term “ignore”, it was in no way meant to be offensive.

  268. Edward Greisch:

    103 Lynn Vincentnathan: Methane is CH4, no sulfur in it. Hydrogen sulfide is H2S. The sulfur comes from another source. Oxygen kills sulfur bacteria. Without oxygen in the ocean, sulfur bacteria take over and make H2S. Otherwise true, and H2S reacts with water to form H2SO4 [sulfuric acid] in your lungs, I think. H2S gas is poison and kills all humans equally.
    http://www.sciam.com/article.cfm?articleID=00037A5D-A938-150E-A93883414B7F0000&sc=I100322
    Yes, Homo Sapiens will probably go extinct if global warming continues.

  269. Ron Taylor:

    Jason says: “Democrats could right now get enormous Republican support for a plan to dramatically reduce US CO2 emissions to a level that even Hansen would approve of.”

    What on earth are you smoking? That is the most improbable political prediction I have heard in years.

  270. Thomas Lee Elifritz:

    If climate models were a deterministic application of well defined physics then:

    Computer models are deterministic numerical representations of physical models that execute of finite von Neumann machines. As such the output that they produce is used as data for the testing and verification of the models against the empirical evidence – measurements and observations performed by instruments, which they themselves are also produced by the use of computer models of physical systems, namely semiconductor and condensed matter physics and the associated electrical and mechanical engineering necessary to produce the devices used in modern science.

    Thus models are ‘tools’ and ‘methods’ used by scientists and engineers in the study of nature, and the application of the information and knowledge derived by that endeavor, and are a small part of the large repertoire of techniques available to YOU in your search for truth, profit or comfort.

    Scientists and engineers are no different than you or anyone else, you have access to most if not all of the same resources they have – nature.

  271. Jason:

    #259: “I suppose there is one other possible explanation for not accepting hindcasts from physical models as an acceptable form of model verification: one might simply think the modelers are making the whole thing up, that they don’t really have physically based models, that the models have actually been calibrated to match the historical global surface temperature record (even though the modelers claim they haven’t), and/or that the presented results are not the actual output from the models.”

    I don’t think that the models can reasonably be called physically based. They use physics, but the physics can be right and the models could still be wrong.

    I do NOT believe that the modelers are just “making things up”. But it is undeniably the case that numerous assumptions and inputs go into these models.

    Obviously the modelers’ decisions when making these assumptions are affected by their pre-conceived notions about climate sensitivity.

    [Response: This is nonsense. If I set a parameter related to sea ice, I do it in order to improve the simulation of the sea-ice - usually on a seasonal cycle. The net effect on climate sensitivity is unknown. Same with cloud parameters, or land surface functions. These kinds of models just aren't built the way you imagine - and we don't test what the sensitivity is every time we change some minor thing. We certainly don't optimise the model for some specific 'pre-conceived' notion of what sensitivity is. We just don't. - gavin]

    Moreover, I think that after these assumptions are made, the models are analyzed and debated in an environment where it is easier to get money, get published and get get tenure if your models show higher sensitivity.

    [Response: Complete BS. (Sorry, but really? you think tenure is granted or not because you have a higher climate sensitivity? Get real). The GISS model used to have a sensitivity of 4.2 deg C, the AR4 model had a sensitivity of 2.7 deg C. Can you discern a difference in our publication rate? or budget? This is beyond ridiculous. - gavin]

    Even if no researcher ever allows these concerns to impact his model, models showing less warming are still less likely to get published, get discussed, or get used by the IPCC. These models are more likely to be abandoned, or to have their assumptions reconsidered.

    [Response: No. No. No. Where is there any evidence for this in the slightest? This is simply a fantasy. If there were such models, don't you think the 'skpetics' would be all over them? - gavin]

    In summary:

    Nobody credible has alleged that modelers are making things up BUT

    Skeptics suspect that those modeling decisions which are NOT based on physics (and there are many) are biased towards showing greater warming.

    Forecasting (but not hindcasting) will reveal (or not reveal) this bias.

    [Response: You are arguing from a completely false premise that has no connection to reality. - gavin]

  272. Timothy Chase:

    TRY wote in 201:

    194 – Hey, finding pictures online is a great contribution! Gold star.

    You mean that actually was you?

    TRY wote in 201:

    If you bothered to read my previous comments you’d see that I asked the exact same question. The fact is, it’s an interesting question and one worth discussing.

    Bull.

    To take just one example, you asked in 91:

    I keep coming back to the expected changes in outbound radiation signature we’d expect to see as a result of increased CO2 in the atmosphere. Can we predict this? Can we measure it?

    However, in 163 you state that your question is:

    Can we measure global radiation signature over time?

    I pointed out that we can measure the delta, the difference between 1970 and 1997. But this is the difference in terms of spectra and only at specific points in that spectra. And it isn’t on a yearly, monthly or daily basis. Your initial question suggested a mere delta between years would be more than enough to satisfy you. It suggested that simply looking for the finger print of change in the spectra — based upon specific wavelengths in the same way that a fingerprint identification is often based upon a dozen or so points in the fingerprint — would be more than enough to satisfy you.

    In 110 I gave you what you were asking for. In 91.

    But in 163 the language has changed, such that what you are asking for is “global radiation signature” and “over time.”

    The words “radiation signature” still sounds like a few points in the spectra would be more than enough to satisfy you. But looking back at the word “global” it already sounds like what you are looking for is broad spectrum — not just a few channels. And then when you state:

    You’re exactly right. Warming is a result of an imbalance between inbound and outbound radiation. Your opponents claim that inbound radiation varies over time.

    … so it would appear that what you are looking for is something approximating a total acounting of radiation entering the system and radiation leaving the system such that we can show a surplus based upon that accounting. Perhaps you want to make sure that all that surplus energy isn’t somehow leaking out at a wavelength no one thought to look at? Well-established principles of physics like Planck’s radiation law might not well-established enough for you? Our ability to explain how greenhouse gases interact with radiation right down to the vibrational and rotational and rovibrational quantized states of molecular excitation and principles of quantum mechanics not quite enough?

    By the time that we get to the phrase “over time” it begins to look like you aren’t looking for a mere delta between two different and widely spaced years, but for continuous measurement. Your concern with seasonal measurements would seem to suggest this as well. But then what day of the week did we take the measurements? Maybe all that excess energy we seem to have been accumulating slipped out on weekends.

    No matter how much information we get you and no matter how advanced the technology gets, the information will be limited. It is the nature of the beast. There will always be one more level of detail that we could go. And you can point out that we haven’t made it to the next moving-the-goal-post level yet and say, not good enough.
    *
    No, you weren’t asking the same exact question, and your questions are not exact. Therefore you get different answers from different people who are either responding to different questions or who are responding to different interpretations of the same vaguely stated question. And at that point you can state that you are getting different answers to the same question and that therefore “there isn’t any consensus.”

    I quote from 163:

    I guess I came here for the “consensus science” view on this question, and would still like to get one.

    Furthermore, you stated in 163:

    5)… (pointer to downward radiation – interesting, but it seems like they used a model to get final results)

    … it would seem that one of your gambits is to dismiss anything that is the least bit tainted by being partly dependent upon models or theories. But anything that isn’t the direct reporting of sensory data may be regarded as theory-laden.

    In fact, if one goes all Cartesian, you can doubt the existence of your own hand. And had Descartes been more rigorous in his application of doubt — relying only upon that which was truly indubitable, he would have realized that in a state of truly radical skepticism one has no theoretical foundation for distinguishing between thought and imagination, perception and hallucination or memory and fantasy. All knowledge is — at one level or another — theory-laden. And on this basis you will always have plenty of room in which to move those goal-posts so that you can continue to stare disbelievingly at your hand or study your belly-button.

    TRY wote in 201:

    Your opponents claim that in fact CO2 does not have the claimed impact on outbound radiation…

    As I pointed out in comment 855 of the Unforced Variations thread:

    Doubt is our product, since it is the best means of competing with the “body of fact” that exists in the mind of the general public. It is also the means of establishing a controversy.

    Smoking and Health Proposal (1969)
    http://tobaccodocuments.org/landman/332506.html

    … our “opponents” are into selling doubt, not dealing in facts, and as a matter of fact I have identified 32 different organizations (in the same comment) that were involved in both the denial campaign surrounding tobacco and the denial campaign surrounding antropogenic global warming. In contrast, every major scientific organization and peer-reviewed which has seen fit take a position on anthropogenic global warming has said that global warming is taking place, we’re causing it, and its serious.

    Please see:

    The Consensus on Global Warming:
    From Science to Industry & Religion
    http://www.logicalscience.com/consensus/consensusD1.htm

  273. Dave Salt:

    Thanks, Ray Ladbury (#251) and John E. Pearson (#254).

    Yes, I’m well aware that there are positive feedbacks and that they have the potential to amplify the basic CO2 greenhouse mechanism; hence my reference to the ‘enhanced greenhouse effect’, as described in Section 1.3.1 of the IPCC TAR. What I was enquiring about was real-world evidence that proves the Earth’s climate system is dominated by them, which is what appears to be needed for current climate models to ‘simulate’ past recorded trends. Maybe the evidence I seek is buried within the long list of references you and others have indicated, but I was sort of expecting a more thoughtful explanation from people who, I assume, are extremely knowledgeable of the subject and can therefore explain the salient points to a layman like myself.

    As my first degree was in physics, I’m somewhat familiar with the Scientific Method and the associated philosophy behind it, hence my reference to Richard Feynman’s description (http://en.wikipedia.org/wiki/Cargo_cult_science). Similarly, I’m also aware of the basic mechanism by which CO2 can act as a greenhouse gas (i.e. via infra-red absorption) and the underlying physics upon which it is based, along with the IPCC’s assessment that this alone would cause a rise of less than 2C rise in response to a doubling of CO2. However, the IPCC are clear that this mechanism is insufficient to raise temperatures to catastrophic levels, which is why the understanding of – and real-world evidence for – the dominance of positive feedbacks is so crucial to the current AGW narrative.

    Note that I wrote my post because I’m rather reluctant to believe things simply on the basis of rhetoric and exaggerated claims from either side of the ‘debate’. I also don’t respect argument by authority (i.e. trust me, I’m a scientist) but am more than willing to be educated by clear and logical reasoning.

  274. Mike Cloghessy:

    caerbannog wrote…

    @Mike Cloghessy#121: Is this raw data or has this data been adjusted, homogenized and re-adjusted.

    A quick google-search on “Mike Cloghessy” turned up this:

    By Mike Cloghessy on Aug 10, 2009 | Reply
    Carbon offsets are like global warming…alarmists would have you pay for something that does not exist.

    Anybody want to place odds on how likely it is that Cloghessy will actually look at any of the data that he’s been pointed to?

    Since my response to Ron Broberg was 86ed…and likely this post will not see the light of day on this website, I thought I would try again to point out that I have looked at some of the data. The issue is what happens to the data after the raw data is analyzed. With the leaked docs from CRU, with the allegations by the Russians re CRU, the HGCN data of Antarctica and Australia, the redefining of “peer review”, and again (it appears) the problems I have posting on this website it is becoming clear that the AGW camp has no desire for debate, no desire for opposing views, which by default weakens their “science”.

    IMO the AGW scare of the 1990s (and early 2000s) will go the way of the coming ice age of the 1970s.

    Until then… Hey caerbannog I have some carbon offsets for sale…you interested?

  275. Ernst K:

    Comment by Jason — 30 December 2009 @ 2:28 PM:

    The models contain hundreds or thousands of additional unproven assumptions. These range from the response of upper tropospheric humidity to global temperature changes, to the impacts on cloud formation, to the historical forcing from aerosols (which to many skeptics appears to be the product of circular reasoning).

    No skeptic is suggesting that physics is wrong.

    First, I doubt that last sentence is correct, unless you put “credible” between “No” and “skeptic”.

    But back to the first paragraph. Are these examples supposed to be just a snapshot of a much longer list or are you suggesting that these are the three biggest “assumptions” that could conceivably compensate (either individually or collectively) for the well established effect of radiative forcing due to greenhouse gasses such as CO2?

    Now my understanding is that where physical processes are not based directly on extremely well established science (such as Navier-Stokes etc.) they are based on process models. For process that need to be parameterized, for example due to resolved scale issues in the case of cumulus clouds or turbulence, the parameters are defined a priori (i.e. in advance) based on field or lab experiments. The parameters are not calibrated in order to match the historically observed surface temperature record.

    Please set me straight if I’m misinformed about this. I have worked with Mesoscale atmospheric models (such as MM5 and GEM – which can be run with no calibration whatsoever) but never with a proper GCM.

  276. Alw:

    Ken W (200)

    I understand your references – but the this post is regarding looking back on how predictions are faring, as the first line puts it; “It’s worth going back every so often to see how projections made back in the day are shaping up”.

    It is disingenuous to include the hindcasts within a historical looking back at how well the models have done as the accuracy of the hindcasts was known at the time!

    The graphs should only be showing the changes that have happened since the point of production of the paper. Or at the least should show a line or point demarking when the projection was made.

  277. Terry:

    Paul @ 218
    Thanks very much for the refs. The early Manabe et al 1967 and 1964 papers are exactly what I was looking for. Some good holiday reading (perhaps I need to get out more). Cheers

  278. Hank Roberts:

    > 102, 260
    > Edward
    That’s not my paper–I pointed to the abstract and quoted a bit from it.
    http://dx.doi.org/10.1016/S0032-0633(00)00084-2
    That abstract refers to a hypothetical Earthlike planet, at Mars’s current distance (looking at how far the habitability zone extends on either side of Earth’s orbit, and for what time spans). They’re talking about an Earthlike planet That made sense to me when I read the abstract; I imagine they’re addressing how long hypothetical Earthlike planet could have held its heat and volatiles at that distance, at the far outside edge of the habitability zone, as they compare it to the other extreme at Venus —I’ve been looking for more on the subject.

    I don’t see any sign anyone else thought it a mistake, looking at the brief links on citing papers. But I did scratch my head about it for a while before thinking it made sense as written.

  279. Ernst K:

    Re 263:

    “Thanks for the kind words Ernst. It is this kind of polite exchange that leads to greater understanding.”

    I was as kind as your comment made it possible for me to be.

    “I was obviously only using an example to make a point.”

    The problem was that it was a horrible example to use to make a virtually meaningless point.

    “You may be surprised to learn that there are basic laws of economics that work fairly well.”

    I understand this quite well, but you are overreaching to suggest that they can be reasonably compared with a physically based climate model. Perhaps you could point me to a macroeconomics model that doesn’t require calibration with historical macroeconomic data. This is not a slight on economics, it’s a reflection of the fact that the field is so far removed from the current limits of our understanding of physics.

    “The ability to model climate can only be measured by skill in measuring periods after the model run. Not in the ability to model periods known to the modeler.”

    This argument would be valid if the models were calibrated to match historical data, if the modelers were obfuscating their calibration and verification periods, or if you thought the modelers were fixing the results outright.

    Your argument implies that the modelers (from all the modeling groups) are either unaware of, hiding, or lying about something pretty basic even though their code and input data is (at least for the most part) in the public domain.

  280. Doug Bostrom:

    Nicolas Nierenberg says: 30 December 2009 at 2:42 PM

    “The ability to model climate can only be measured by skill in measuring periods after the model run. Not in the ability to model periods known to the modeler.”

    Nicholas, what you say is only true if you assume that persons running the models are either dishonest or for some reason completely incapable of divorcing the construction of the model from observations.

    If the output of a model is faithful to observed behavior of an actual system being modeled, do you believe that as that skill is observed the very success of the model is thus invalidated?

    That’s what you’re effectively saying, unless your assumption is that dishonesty or rank incompetence is at play.

    Do you believe the same of other models of complex, dynamic systems? No model is correct once it is validated against observations?

  281. Thomas Lee Elifritz:

    trust me, I’m a scientist

    Actually, Dave, we know exactly who you are and exactly what your internet comment history id. and what that reveals about your knowledge of planetary science and radiative transfer. You are no stranger to climate denialism.

  282. Jason:

    #275: “‘No skeptic is suggesting that physics is wrong.’ First, I doubt that last sentence is correct, unless you put ‘credible’ between ‘No’ and ‘skeptic’”

    Which skeptics are saying that physics is wrong?

    “Are these examples supposed to be just a snapshot of a much longer list are the three biggest ‘assumptions’ that could conceivably compensate (either individually or collectively) for the well established effect of radiative forcing due to greenhouse gasses such as CO2?”

    Those are the first three that came into my head, but they are part of a much longer list (hence my use of the words: “The models contain hundreds or thousands of additional unproven assumptions.”)

    That said, those are three good choices. Each of them individually could change the predicted warming by 25% or more. A majority of the assumptions are both less controversial and less impactful.

    “Now my understanding is that where physical processes are not based directly on extremely well established science (such as Navier-Stokes etc.) they are based on process models. For process that need to be parameterized, for example due to resolved scale issues in the case of cumulus clouds or turbulence, the parameters are defined a priori (i.e. in advance) based on field or lab experiments. The parameters are not calibrated in order to match the historically observed surface temperature record.”

    Neither of these extremes are accurate. The GCMs were not designed solely to replicate historical temperatures. But neither are they restricted to using values determined a priori.

    In many cases the GCMs have gradually evolved over long periods of time. Perceived weaknesses are addressed by changing assumptions and inputs. Not matching the historical record is, of course, a weakness.

    In the eyes of many skeptics, myself included, some of the input data (like historical aerosols) have co-evolved with the models.

    There is an interesting email written by Tom Wigley to Phil Jones on September 27th of this year: http://www.eastangliaemails.com/emails.php?eid=1016&filename=1254108338.txt

    As you probably know, due to methodological changes in the collection of SST measurements, there were significant errors in the WW2 SST record.

    Correcting for these errors naturally introduces some uncertainty.

    In this email, Tom Wigley suggests adjusting historical temperatures by selecting values which fit the models.

    Please note that I see nothing unethical about his behavior. Tom thinks his models are right. The temperature record is uncertain and appears to disagree with his models. He recommends fixing the value he has less confidence in, in this case the historical temperature record.

    But if model output is allowed to influence historical data and/or model assumptions, then a sort of circular reasoning results, with assumptions and historical data being selectively chosen to make the models look good.

    In this case, all the participants are aware of this potential (and there is no evidence that I am aware of that models have actually been used to modify the historical temperature record). But it would be easy to imagine a similar situation in which a more complicated network of collaborators prevents any individual participant from even recognizing the potential for circularity.

    My aim is not to prove that climate models have been compromised in this manner. I honestly don’t know if they have.

    But I suspect it, and I therefore require validation by forecast to allay my suspicions.

    Climate modelers should demand the same.

  283. Jason:

    #269: “What on earth are you smoking? That is the most improbable political prediction I have heard in years.”

    Is it improbable because Republicans do not want to repeal or reduce the income tax?

    Or is it improbable because Democrats do not view climate change as a sufficiently serious issue to make such a trade?

    I am saying the latter. Just as Republican Lindsey Graham has jumped all over Waxman Markey thanks to the prospect of off-shore drilling, a great many Republicans would support climate change legislation if it resulted in the repeal of substantial reduction of the income tax.

  284. Dave Salt:

    Hello, Thomas (#281).

    Yes, I remember our brief ‘discussions’ on several space policy boards and so am not surprised by the manner of your reply. Nevertheless, I’d still be interested to hear any reasoned reply you may be able to provide in response to my inquiry.

  285. Ray Ladbury:

    Dave Salt,
    Chris Colose gives a pretty good treatment of feedback here, with some good references:
    http://chriscolose.wordpress.com/2009/10/08/re-visiting-cff/

    However, the bottom line is that it does not seem to be possible to get an Earthlike climate with a CO2 sensitivity less than ~2.1 degrees per doubling. Despite copious efforts at constructing a model with low sensitivity (very interesting for its inherent properties independent of its implications for climate change), no one has succeeded. That is a strongly constrained lower limit unless you can come up with something that overturns a whole boatload of evidence.

    Now as to your cargo-cult reference, THAT, sir is unwarranted and merely serves to call attention to your ignorance. Climate science has been subjected to an unprecedented level of external scrutiny–ranging from review of the science by National Academy Panels, to reviews by societies of scientific professionals and even hearings by hostile legislative panels. None of these bodies have dissented from the consensus position, and in in fact the vast majority have endorsed it. You are impugning the integrity not just of climate scientists, but of the entire scientific establishment with your cavalier calumny. Did it ever occur to you that the reason it is so hard to “falsify” the science is because the evidence supports it?

  286. Ken W:

    ALW (276):
    “It is disingenuous to include the hindcasts within a historical looking back at how well the models have done as the accuracy of the hindcasts was known at the time! ”

    No it isn’t! Showing the fit of a GCM’s computed temperatures (whether in the future, in the past, or during the present) to actual measured values (which were not used for tuning) is a very useful gauge of model accuracy. If the model didn’t fit with the instrumental record, that would falsify the model or instrumental record. If the model didn’t fit with historic proxy records, that would either falsify the model or the proxy technique. In any case, those comparisons must be done to establish confidence in the models.

    Donald Rumsfeld once said “we go to war with the army we have, not the army we wish we had”. Science is no different, we progress our knowledge based on what we have or can get. While it would be great to sit around doing nothing for another 20 or 30 years to demonstrate our current models accuracy to every skeptics satisfaction (if that were even possible), we don’t really have the luxury.

    I wonder what skeptics would say if climate scientists didn’t compare model outputs with the instrumentation record (past, present, and future)?

    Gavin shows 26 years of Hansens model future projection vs. instrumetal record, along with an additional (and useful) 20+ years hindcast. And he shows 6 – 9 years of the AR4 future projections, along with an additional (and useful) 20+ years of hindcast. As subsequent years come to past, I’m sure he’ll be glad to add additional points. But to accuse him of being disingenous says more about you than him.

  287. Completely Fed Up:

    Jason: “If Democrats actually believed that failing to act decisively _now_ would result in catastrophe, then they would do so.”

    Nope. No more than since you know that drinking alcohol is bad for you, nobody drinks alcohol.

    It is SOMEONE ELSE who gets it in the shorts.

    Just like short-term thinking in corporations on the stock market. How many companies outsourced to save money short-term to tick the options up? And how many found out they spent more for worse service some time later?

    But did they get the money back from the ones who exercised the options?

    No.

    Yours is a commonly appearing current fallacy.

    “Asking people (even the poor) to pay for the carbon they use isn’t such a terrible thing. It certainly won’t doom civilization as we know it.”

    This is definitely NOT what the denialist alarmists catawailing imply. Apparently even the thought of AGW mitigation will ruin the West and send us back to the caves.

  288. Larry:

    Re: In #239, [ "... Check out the acronym index ... gavin ]:

    The index is great! Hadn’t spotted it before. Thanks to Steve Fish, and the group for posting it.

    It would also be wonderful to have a similar index (or listing) of the various models, both old and new, and their variants. It could perhaps provide some brief explanation of each, and a link to a relevant specific site.

    I have also often wished that there were a spreadsheet (a wide one I suppose) that lists the various models, with columns for indicating what factors are or aren’t implemented in each (or perhaps even whether the implementations are simplistic or sophisticated).

    Just a wish-list — I know you are all busy.

  289. Ray Ladbury:

    Jason, I am hoping that your implication that the surface station record was changed to reflect model output is unintentional on your part, because no one has in fact done this.

    As to your implication that the models are tweaked to achieve agreement with the historical record, that is also incorrect. Any changes that are made must be motivated by the physics. It is valid to increase fidelity of the model–e.g. by adding a treatment of ocean currents around Antartica. It is not valid to tweak that ’til you get best agreement with temperature.

    Jason, have you ever done any dynamical modeling? Do you even understand how it differs from statistical modeling? Because your comments sure do not indicate any such understanding.

  290. Jason:

    “[Response: This is nonsense. If I set a parameter related to sea ice, I do it in order to improve the simulation of the sea-ice - usually on a seasonal cycle. The net effect on climate sensitivity is unknown. Same with cloud parameters, or land surface functions. These kinds of models just aren't built the way you imagine - and we don't test what the sensitivity is every time we change some minor thing. We certainly don't optimise the model for some specific 'pre-conceived' notion of what sensitivity is. We just don't. - gavin]”

    Ernst asked if data that is not known a priori is used to tune climate models.

    As I understand it, Gavin’s answer is: We do attempt to tune our models to observed data using information that is not available a prior BUT we never ever consider the impact on climate sensitivity or temperature.

    I didn’t think that you calculated climate sensitivity at each step. If I wanted to accuse you of engineering modelE specifically to maximize climate sensitivity, I would have. I do not believe this is the case and did not mean to imply it.

    BUT surely it is reasonable to suppose that in the process of adjusting the model, your mental expectations about the intermediate results have an influence!

    I’m no stranger to (non-climate) complex modeling myself, and I can tell you that it would be very hard for me to approach the process and not be thinking about the consequences of each change. Fortunately, in my case, it is very easy to acquire additional data against which I can validate my changes. But without this additional validation, I would be very concerned indeed. I would probably feel obliged to sequester a portion of the data, and/or take other preventative measures.

    “[Sorry, but really? you think tenure is granted or not because you have a higher climate sensitivity? Get real.]”

    Are you seriously going to claim that a scientist whose work supported a lower climate sensitivity would have the same chance of getting tenure as a scientist who work supported a higher sensitivity?

    Tenure is the end result of one of the most ruthlessly political processes on planet earth. The same sort of hardball political science that was on display in the CRU emails occurs routinely in the tenure process of every department of every university of any significance. The notion that disagreeing with the consensus scientific position does not have a strongly negative effect on tenure proceedings is laughable.

    I can think of several examples in other fields. Climate science is surely not immune.

    [Response: I imagine that tenure is indeed tough (I've never gone through it). But tenure is generally granted by the university not your scientific colleagues - and most of them wouldn't know the difference between climate sensitivity and a hole in the ground. They look at publications, letters, honours, teaching assessments and the like. It doesn't matter how high or low your climate sensitivity number is if you haven't got a decent track record. Name one single person who's been denied tenure on the basis of their climate modelling results (of what ever sort !). Just one. And when you can't, come back and apologise for letting your prejudice get in the way of the facts. - gavin]

  291. TRY:

    Timothy Chase – oh, please – that’s a lot of ridiculous text that is just a mish-mash. Let’s stick to the science! Let me make it nice and simple for you.

    You claim, I assume: CO2 added to the existing atmosphere will absorb more outbound IR at certain wavelengths than would otherwise be absorbed. This will result in the global system moving to a new equilibrium, during which time the global system will retain more energy. As a result of this energy retention, overall water vapor in the atmosphere will tend to increase, which will have a similar impact in terms of system energy retention. More CO2 leads to more water vapor, which together lead to energy retention until the system reaches it’s new equilibrium – a moving target if CO2 continues to be added to the atmosphere. Actually pretty straightforward, right?

    Your opponents claim that, in general, the impact of CO2 is much less significant than you claim it is. Overlapping absorption bands and saturation are two common claims. Bottom line, CO2 does not have the impact on outbound radiation that you claim it does.

    Now, you may claim that you have omniscient knowledge of the very, very complex global energy system, or that you don’t need it because a few simple equations absolutely define our entire global system. The problem with that is that we use simple equations to make predictions, then we test those predictions. Once you start looking at second-order or third-order impacts, you get into a morass of claims and counter-claims.

    So, why not look at first-orderimpacts? Specifically, actual out-bound radiation globally. Seasonal matters because CO2 varies seasonally. And of course time matters. Now do you understand why the papers you posted don’t address this?

    They are a good start, but where is the followup? What would the overall IR signature look like if CO2 absorbs/emits at the levels you claim? What would the overall IR signature look like if CO2 absorbs/emits at the levels your opponent claims? Then, hey, look at the data.

    As for the rest of it, argue with someone else about tobacco.

  292. Completely Fed Up:

    Jason says:

    “First, I don’t have any problem with the earth getting warmer, especially if it only gets a little warmer, and if the pace of that warming is slower than the IPCC forecasts.”

    So will you be fine when you have to take those displaced from marginally livable land that is now far too hot?

    Will you be fine when the refugees come around looking for homes, food, jobs, education and all the things you have where you are?

    Will you?

    No.

  293. Completely Fed Up:

    wil whines:
    “So basically my question is when does “insignificant, short term” change to something relevant?”

    Never.

    When it changes to something significant, it’s no longer insignificant.

    If you wait longer to get more data, it’s no longer short term.

  294. Ernst K:

    Re 282:

    “Which skeptics are saying that physics is wrong?”

    For starters, how about anyone who says that CO2 doesn’t matter because water vapor is responsible for 98% of the greenhouse effect, or that “CO2 lags warming”? Perhaps you feel that such cranks don’t deserve a label as honorable as “skeptic”. If so, I wouldn’t disagree.

    “In this email, Tom Wigley suggests adjusting historical temperatures by selecting values which fit the models.”

    Is there any evidence to suggest that this adjustment was ever applied to the final CRU data? Or are we only talking about a possible explanation for a short term divergence between the observed temperature record and the model predictions? From my reading of that email, I don’t see any suggestion that the CRU numbers should be changed to better match the models. If no adjustment was made to the CRU data, then there is no circle.

    “My aim is not to prove that climate models have been compromised in this manner. I honestly don’t know if they have.

    But I suspect it, and I therefore require validation by forecast to allay my suspicions.”

    At least I now know that you fall into the “climate science conspiracy” camp (even if you only “suspect” it might have happened). Personally, I find it hard to believe these people wouldn’t recognize that it would be wrong to change the observed record to match the models and then use the same record to validate the models. That’s why I’m left with conspiracy, because they really must know better.

    The problem with such a point of view is that you won’t be able to settle such a doubt until there has been so much warming that it’s probably too late to do anything about it.

    Now perhaps you’re just “infected” with a brand of extreme skeptical philosophy. I like to call this paralyzed skepticism, because ones doubt is so extreme that it makes it impossible for one to make informed decisions with incomplete information.

    That’s fine for an individual, but such people should not be put in positions to make policy decisions. Of course, the same could be said of the other extreme, “faddists”.

  295. Ray Ladbury:

    TRY@264 The situation you describe is not one of equilibrium. Indeed, if you irradiate the atmosphere your source, it will immediately begin to heat up. You are no longer in equilibrium, so your temperature is time dependent.

    I agree we need a detailed climate monitoring network. (Hell, for fun, I was even starting to think about what kinds of sensors you’d want!) I suggest contacting your representatives and telling them of your opinion. Know, however that it isn’t cheap, easy or uncontroversial. This is a slog, not a walk in the park. Science is the best guide, though, for keeping us on the path rather than in the swamp.

  296. dhogaza:

    No it isn’t! Showing the fit of a GCM’s computed temperatures (whether in the future, in the past, or during the present) to actual measured values (which were not used for tuning) is a very useful gauge of model accuracy. If the model didn’t fit with the instrumental record, that would falsify the model or instrumental record.

    Something like this happened when the first UAH satellite temperature reconstructions were published, supposedly showing the planet was actually cooling, not warming, in the 1990s. The WSJ even proclaimed these results to be the “wooden stake through the heart of AGW” or some such.

    Surface temps and expectations from modeling both disagreed with the UAH results …

    What had to be fixed? Hint: wasn’t the models.

  297. S. Molnar:

    I’m having trouble with Gavin’s reply to “honorable” @242. If what we’re seeing is the output of his “same old tired nonsense” filter, I really can’t picture the items that don’t get through. It must be very nonsensical indeed. Maybe he could set aside some of the best for a post; say, next April 1.

  298. dhogaza:

    Jason asks:

    Which skeptics are saying that physics is wrong?

    Fellow denialist TRY obliges:

    Your opponents claim that, in general, the impact of CO2 is much less significant than you claim it is. Overlapping absorption bands and saturation are two common claims. Bottom line, CO2 does not have the impact on outbound radiation that you claim it does.

  299. Ray Ladbury:

    TRY, Do you understand that a mere snapshot of the outgoing IR spectrum with a huge bite taken out right at the absorption line of CO2 is not sufficient to establish increased greenhouse warming? You have to look at the system over time–integrate the effect. You have to look at energy in and energy out (in the IR and visible). We have lots of snapshots. We don’t have enough eyes in the sky to integrate over time (~30 years) and separate climate from noise?

    I’m all for doing it. The opposition comes from other quarters than the scientific community. There are some folks who really don’t want to know (viz. my desmogblog reference to Triana/DISCOVR–a situation with which I am intimately familiar).

  300. Nicolas Nierenberg:

    RE: 280,

    Doug, I’m discussing a basic rule of modeling, it has nothing to do with climate scientists or honesty. And I want to make it clear that I don’t believe in these weird divisions of skeptics, and well whatever the others are.

    A model has to be tested with out of sample data. In a model as complex as these the knowledge of the existing result has to influence the person writing and testing the model. Therefore even though Gavin believes that he his building only on first principles it isn’t, in my opinion, possible. It is the same reason why drugs have to be tested using double blind experiments. It isn’t that the physicians who are administering the tests and noting the results are dishonest, it is just the way the world works.

    And looking at Gavin’s example of sea-ice modeling. I understand that he is doing it on first principles. But if a new module suddenly increased climate sensitivity so that 2009 was five degrees C warmer than present, I can assure you that he would first look for a bug, and then second rethink the model because obviously that isn’t what happened. That isn’t dishonest, that’s just makes sense. The result of a hundred decisions like that is something that will be very close to the historical record. Particularly if you average all the climate models. (Which may be a sociological explanation of why the average of all climate models has proven more accurate than any one.)

  301. Doug Bostrom:

    “The same sort of hardball political science that was on display in the CRU emails occurs routinely in the tenure process of every department of every university of any significance.”

    Oh, bullshit. Politics plays a role in tenure decisions, a little bit more or less in many though still not most cases, but it’s social politics that trips up candidates. Political tenure trouble results from poor social skills on the part of the candidate, not science. If somebody’s pleasant to get along with, they’ll get cut some slack and that’s about the extent of it.

    This sort of bankrupt hysteria about the fundamental legitimacy of scientific inquiry is becoming all too common of late, even as the actual scientific case in question becomes less controversial. Legitimacy is a handy qualitative escape hatch to dive into when all else fails.

    Undermining the legitimacy of scientists with broad attacks on the entire academy is a nauseating and repugnant scorched earth tactic smacking of desperation. The collateral damage this approach causes will feed into other areas of inquiry, and worse it’ll foster such other disasters as reluctance to vaccinate against measles, abstinence programs as a less squeamish approach to sex education, etc. Shameful, truly.

  302. Barton Paul Levenson:

    Jason: even the liberal wing of the Democratic party is not seriously committed to climate change.

    BPL: Your telepathy is malfunctioning. I’m a liberal Democrat and I know AGW is real, and the greatest problem our civilization has ever faced outside of nuclear war. Your proposed tax plan would wreck the economy by suddenly imposing huge taxes on most working people. We do NOT have to wreck the economy to stop AGW. It’s a straw man argument. It’s not the Democrats who are blocking action on AGW, it’s the GOP, with its general anti-science attitude that rejects AGW theory, evolution, ozone damage to the CFC layer, health problems from smoking, and in general any scientific finding at all that might somehow result in more regulation of big business.

  303. Dave Salt:

    Thanks again, Ray Ladbury (#285)

    Though very interesting and highly educational, the linked posting only discusses feedback concepts, as per its title “Re-visiting climate forcing/feedback concepts…”, but appears to provide no direct evidence (i.e. from real-world observations) that these mechanisms actually dominate the Earth’s climate system, which was the subject of my original enquiry. Your other comment would be acceptable if the climate models included every possible mechanism and associated couplings with a high degree of certainty but, as the IPCC admits, there appears to be some factors that are not yet sufficiently well understood (e.g. those relating to clouds) to justify this statement. Please correct me if I’m wrong here and, in fact, the models no longer include any assumptions or ‘plugs’ to match their output to past historical trends. Simply saying, in effect, that “we’ve tried everything else so it must be that” seems insufficient to justify a hypothesis that could have a massive influence upon the world’s future social and economic development.

    As for my reference to Cargo Cult Science, you’ll note I was suggesting that a true lack of real-world evidence would likely lead to this conclusion and that my original post was, therefore, a sincere attempt to refute this through a simple enquiry. If your only means of reply is via ad hominid comments or argument by authority, I can only conclude that you are either unable or unwilling to discuss the issue in a civilised and rational manner; an unfortunate tendency that afflicts BOTH sides of this particular debate. Nevertheless, I refuse to believe both you and Mr Elifritz are true representative of this blog and so am still more than willing to learn from people with a more civilised and rational approach to science.

  304. Andrew:

    @ Jason: “Is it improbable because Republicans do not want to repeal or reduce the income tax?

    Or is it improbable because Democrats do not view climate change as a sufficiently serious issue to make such a trade?”

    Strange as it seems, there is even another possibility.

    Replacing income tax with carbon tax is totally unworkable. In 2007, the income taxes paid by the top 1% earners was 40% of all income taxes paid – more than the bottom 95% of earners COMBINED (just under 40%).

    So your carbon denominated income tax replacement must increase the taxes on 95% of the population. By a lot, actually – something like double.

    You believe that BOTH Democrats and Republicans would eagerly line up to roughly double the income tax bill on 95% of the population and drastically slash the income tax bill for the highest earners?

    I think most people reading this can figure out why this proposal is not part of any solution to anything.

  305. Jason:

    #289: “Jason, I am hoping that your implication that the surface station record was changed to reflect model output is unintentional on your part, because no one has in fact done this.”

    I am saying that Tom Wigley in an email to Phil Jones dated September 27th 2009 recommended that this be done.

    I explicitly stated that I did not think that this had occurred, and that the request itself was not, in my eyes, an ethical breach.

    But considering how casually Wigley made this request, it doesn’t seem completely out of the realm of possibility. If you and Gavin say that this has never ever happened at GISS, then I believe you.

    [Response: You have completely misunderstood what Wigley was doing. Given the issues unearthed by Thompson et al (2007), Wigley wanted to know what impact that might have on his detection and attribution work and what the magnitude of the change in the ocean SST might be. No-body is going to just shift the actual record in the ad hoc way you appear to think Wigley was suggesting. - gavin]

    “As to your implication that the models are tweaked to achieve agreement with the historical record, that is also incorrect. Any changes that are made must be motivated by the physics. It is valid to increase fidelity of the model–e.g. by adding a treatment of ocean currents around Antartica. It is not valid to tweak that ’til you get best agreement with temperature.”

    Here is what Gavin said: “If I set a parameter related to sea ice, I do it in order to improve the simulation of the sea-ice – usually on a seasonal cycle.”

    It sure sounds like Gavin is comparing the output of the model to observed data and modifying the model with the intent of matching the observations.

    I would never suspect that Gavin deliberately biases his own model. What would be the point?

    But there is a world of difference between not deliberately sabotaging your own model, and having a model that is free of bias [a term I am using in the colloquial sense].

    I was asked why I think that validation of forecasts is necessary and validation of hindcasts insufficient. I think that validation of forecasts is necessary because I believe that the models have been indirectly biased by the historical data they purport to predict.

    “Jason, have you ever done any dynamical modeling? Do you even understand how it differs from statistical modeling? Because your comments sure do not indicate any such understanding.”

    Almost entirely dynamical. But clearly my experience is very different from what goes on in climate modeling. I find some of the statements that you and Gavin have made equally perplexing.

    [Response: If you read our papers (and my comments) we are completely up front about what we tune to - the climatology (average annual values), the seasonal cycle, the diurnal cycle and the energy in patterns like the standing wave fields etc. We do not tune to the trends or the sensitivity. - gavin]

  306. Doug Bostrom:

    Nicolas Nierenberg says: 30 December 2009 at 6:33 PM

    Nicholas I see your point but I believe you’re investing too much confidence in your assumptions. If true in the literal sense I took from your statement, it would have wide repercussions extending into numerous fields beyond the one under discussion here.

    Based on some of my own experience (not climate modeling of course but attempting to adjust variables in isolation in complex systems) I also suspect that such efforts– particularly if unintentional– would be reasonably likely to blow up the model.

    But of course Gavin would know better.

  307. Jason:

    “[Response: I imagine that tenure is indeed tough (I've never gone through it). But tenure is generally granted by the university not your scientific colleagues - and most of them wouldn't know the difference between climate sensitivity and a hole in the ground. They look at publications, letters, honours, teaching assessments and the like. It doesn't matter how high or low your climate sensitivity number is if you haven't got a decent track record. Name one single person who's been denied tenure on the basis of the climate modelling results (of what ever sort !). Just one. And when you can't, come back and apologise for letting your prejudice get in the way of the facts. - gavin]”

    I know of none. I also know of no professors with climate models that predicted substantially lower sensitivity than the consensus who were granted tenure, so I don’t consider this a particularly meaningful measure.

    I do, however, have some useful data to add. I have taken (over the past 3 years) to asking climate science grad students the following question:

    If your research produced results that tended to disagree with the consensus, what impact do you think it would have on your ability to: Get a job/Get a grant/Get tenured.

    Unfortunately, I’ve changed the wording around and only have 6-7 responses. But thus far the universal response of climate science grad students a major universities is that research disputing the consensus would be severely detrimental. The word “impossible” was used twice.

    I imagine that you could trivially repeat this experiment. I would wager that you get the same result.

    [Response: But you are testing people's opinions, not actual facts. And frankly, your question is ill-posed. What does 'the consensus' even mean in your context? That CO2 is a greenhouse gas? That it's rising? That there has been warming over the last century? That these things are likely connected? Or something else completely? The quality of someones career is much more tied to the quality of their work - not the specific results. And that is something you should be stressing to your students. - gavin]

  308. John P. Reisman (OSS Foundation):

    #242 honorable

    ‘Honorable’, not even close.

    Honorable people are not afraid to post their real names (due cause excepted).
    Honorable people don’t make uninformed claims without cautionary statements.

    Your anonymous post is absolutely not “characterized by integrity”, thus using the moniker honorable is incorrect in your case.

    Your claim of being “a professor of medicine in a first rate North American university” means nothing here. The subject is climate change and anthropogenic global warming. If you want to participate in the discussion in a productive fashion you will need to get up to speed.

    http://www.realclimate.org/index.php/archives/2007/05/start-here/

    and for some dumbed down explanations

    http://www.ossfoundation.us/projects/environment/global-warming

    As to your unfair accusation of ‘cavalier’ comment blocking. Poppycock.

    Why are you disturbed by climategate? It does not overturn the science though you may feel personally offended by the fact that people in private conversations have opinions, which I might add is entirely un-American.

    http://www.ossfoundation.us/projects/environment/global-warming/myths/climategate

    Criticism is the essence of the scientific approach if the criticism is scientific. Random BS form the bleachers is not scientific criticism.

  309. RB:

    @300 Nierenberg.
    I accept your basis for out-of-sample testing – behavioral biases and pattern seeking behavior by the human mind are well understood in finance. Systems traders understand this as well.
    http://oldprof.typepad.com/a_dash_of_insight/2007/08/developing-and-.html

    I recently saw Richard Alley’s talk where he mentioned a CO2 sensitivity of 2.8C per doubling in line with IPCC’s 3C number. Would that qualify as out-of-sample corroboration of CO2 sensitivity for you – hindcasting of course?

  310. Nicolas Nierenberg:

    Re: 305,

    Doug, I don’t understand your point.

    To use my previous example if you were building a climate model, and you made a change resulting in 2009 (or 1975, or 1998) being 5C warmer than the 1961-1990 average are you saying that you wouldn’t look for a bug, or assume that you had made some kind of other error? Conversely if you made the change and now 2009 was closer to the actual than your previous model wouldn’t you be more likely to accept the result without looking for a problem? I know I would.

    But I would do it with the full knowledge that the true test would be to see if my model was predictive of future periods. Or alternatively of some period that had been held back from me.

    At the risk of boring everyone I have recently had a similar experience building algorithms for determining location of RFID (radio frequency) tags inside buildings. First principles say you can use signal strength to do triangulation. But in fact there are a number of confounding factors having to do with reflection etc. So we had to try different kinds of models. We made numerous recordings of signal strength so that we could test our models. This helped. But frequently improvements that worked against dozens of our recorded experiments failed when we tested in an actual new environment, or simply in an new time period in an old environment. (In the end we developed quite a nice solution which is patented, but it isn’t perfect.)

  311. John P. Reisman (OSS Foundation):

    #246 Dave Salt

    You want real world evidence of a positive feedback?

    Put a pot of water on a counter top at room temperature and measure how much it evaporates over time. Then take another pot of water and put it on a stove and put a flame under it.

    One of these pots will evaporate faster. They are both evidence that water evaporates…. oh, by the way, water is a green house gas. and the oceans are getting warmer. Add 2+2 and tell me it does not add up to 4.

    Now, here’s another experiment for you. Go out in a parking lot on a hot summer day and place your hand on the surface of a black car and hold it there for one minute. Hurts doesn’t it. Now go to a white car and repeat the experiment. Notice a difference?

    Now, take a look at the ice extent reduction trend in the Arctic and try to imagine what will happen to the heat energy that hits the region as more and more summer ice extent disappears (don’t forget the hand on car experiment and take into account that white ice is like the white car and dark water exposed to the sun is like the black car).

    It’s really not that hard to understand Dave. Now, you have your proof of positive feed back and reasonable expectations. What say you?

  312. Jason:

    #294: “The problem with such a point of view is that you won’t be able to settle such a doubt until there has been so much warming that it’s probably too late to do anything about it.”

    In #139 I gave specific measurable criteria that will, within ten years cause me to become convinced (assuming this “pause” ends and the warming resumes).

    Since Waxman Markey makes no meaningful reductions in emissions, we won’t lose anything by waiting. (Arguably we gain since implementing Waxman Markey now will have the effect of creating entrenched interests that oppose change ten years from now).

    As I said in #139:

    “In data I trust. If mother earth starts following the models, I will be convinced. If not, the models are just an object lesson in scientific arrogance.”

  313. Hank Roberts:

    TRY, “A paper Trenberth published this year complained about our inability to monitor energy flows associated with short-term climate variability.” — Bob Parks

    The scientists have been pointing out the need for better monitoring, for years. You should call your congressperson.

    https://listserv.umd.edu/cgi-bin/wa?A2=ind0912&L=bobparks-whatsnew&D=1&T=0&H=1&O=D&F=P&P=424

  314. Geoff Wexler:

    Jason.

    Forecasts preferable to hindcasts? How about forecasters like Callendar, Plass and others, who, resting on the shoulders of earlier scientists like Fourier, Tyndall and Arrhenius, forecast the emergence of observable anthropogenic global warming ? It seems to me that they did rather better than the early GW skeptics like Angstrom’s son (about 1900) even though his position was quite a plausible one given the evidence available at that time.

    Hindcasts are not worth much? How about Bardeen , Schrieffer and Cooper, who hindcast the occurrence of superconductivity about 50 years after it was observed. I notice that the Nobel commitee did not share the view that they should be barred from receiving a prize for being so tardy.

    Was the validation of Ptolemy’s theory really flawed because it was based on hindcasts? I thought that it was also good at forecasts , at least until Galileo observed the phases of Venus. After that it was still good at some kinds of forecast and similar kinds of hindcast.

    So what was wrong with Ptolemy’s theory? It had no serious foundations but was just a brilliant form of curve fitting. In some ways it resembled the cyclical theory of climate which is now one of the alternatives to the consensus version.But it seems to me that Ptolemy’s theory was far more useful. As for climate model theory, unlike Ptolemy’s, it is almost certainly strongly constrained by its foundations in science, in spite of the fact that not all of it is based on calculations from first principles. Even the conservation of energy cuts down a lot on the range of possible answers and that is just one constraint.

    Your super-skeptical attitude, Jason, to climate models reminds me of Lindzen. You write of thousands of assumptions but provide just three examples, of which one refers to the constancy of relative humidity. It is true that Arrhenious used this as a working assumption in his 1895 model but that does not mean that modern climate models follow his example. According to Realclimate (somewhere) this is not an assumption at all, but an emergent property of the models. So that would be one less assumption out of the thousands. . Which models and which papers about them were you discussing when you made that allegation? Anyway this behaviour can be understood better now , starting from the physics. This is discussed in Raymond Pierrehumbert’s book (on line).

    The next example you give concerns aerosols which you assert involves circular reasoning. That may depend on the problem being tackled. I have serious doubts about the circularity which would imply that there is no independent knowledge about aerosols. I suspect that some denialist arguments depend on a hidden assumption of disregarding the aerosols altogether, which could of course be justified by suggesting that it is the usual practice to choose their properties arbitrarily.

    The next example involves the lack of a first principles theory of cloud formation. Over to the experts. But I gather that there is a range of plausible cloud properties leading to a range of plausible answers. In order for the “horribly wrong” option to come true I suspect that it would be necessary to input some obviously wrong cloud data.

    Rejection of the validation of the models because of a supposed problem with the “current pause in warming”? Isn’t that the same old misuse of short term trends discussed so many times or does it refer to the climate models inability to reproduce the details of the short term wiggles which would be based on an unrealistic demand for lots more detailed initial conditions? Neither constitutes a reason for rejecting the validation which depends on being able to get the right statistically meaningful trend.

  315. dhogaza:

    Dave Salt:

    Please correct me if I’m wrong here and, in fact, the models no longer include any assumptions or ‘plugs’ to match their output to past historical trends. Simply saying, in effect, that “we’ve tried everything else so it must be that” seems insufficient to justify a hypothesis that could have a massive influence upon the world’s future social and economic development.

    With all respect, you’re the one making contrarian assertions. It’s up to you to provide positive support for your assertions, in particular the claim that climate models boil down to “we’ve tried everything else so it must be that” or that they’re fit to the historical record. It’s not up to us to prove you wrong. GISS Model E and documentation is online, including references to papers describing the model’s physics and general implementation, and various modules reference the papers containing the physics upon which they’re based. I’m sure that if you put in the energy to dig out information to support your case that you’ll find some very interested readers here.

    We’re all aware that your appendage waving (reader assert appendage of their choice) has convinced *you* of *your* superior understanding, but it ain’t likely to have much of an affect on a practicing physicist like Ray, or a mere BS math type like myself.

  316. RB:

    And yes, I also note Gavin’s comment above:
    [We do not tune to the trends or the sensitivity. - gavin]

  317. Ernst K:

    Re: 290

    “Ernst asked if data that is not known a priori is used to tune climate models.

    As I understand it, Gavin’s answer is: We do attempt to tune our models to observed data using information that is not available a prior BUT we never ever consider the impact on climate sensitivity or temperature.”

    Not quite, at least to my understanding, which is something like the following:

    1) The models are built on well established basic physics (Navier-Stokes, the laws of thermodynamics, etc.) at the resolved scale of the model.

    2) Physical processes that operate at scales smaller than can be resolved in the model are modeled with parametrization schemes. These schemes usually require at least on parameter that must be supplied by the modeler. So the question becomes, “where do you get an appropriate parameter value from”?

    One answer would be to optimize the parameters to match a portion of the historical record, and then verify the values by comparing the model predictions with a different period. This is an acceptable approach but it can be problematic if you intend to build a model that can predict behavior under conditions that are significantly different from the period you used to calibrate. It also means you can’t use at least a portion of the observed record to verify your data.

    Another approach would be to conduct field experiments of each individual physical process to estimate an appropriate value. For example, you could measure the latent and sensible heat fluxes over a test plot to estimate parameters that are appropriate for calculation of the rate of evapotranspiration from a boreal forest. This is the better approach because it makes for a more robust model and it parameter estimation procedure is independent of the global temperature record.

    3) Because there are usually a number of competing process schems
    es, how do you select which scheme to use in your model?

    The correct answer to this questions is definitely not, “the scheme that lets my model match the historical temperature record better”, it’s “the scheme that the literature suggests is better at simulationg the process behavior.

    For example, studies might show that snow albedo and melt rates can be better simulated if you include snow models with multiple snow layers. You therefore should include such a methodology in your GCM even if it means the GCM gets a little worse at predicting the average surface temperature.

    In other words, you don’t calibrate the roughness height of a boreal conifer forest to best fit the global mean surface temperature record, you use the value that provides the best simulation of the rate of evapotranspiration as measured in a real boreal forest.

    That’s the way it should be done, and as far as I know that’s the way it is done.

  318. Ernst K:

    Re 300:

    “And looking at Gavin’s example of sea-ice modeling. I understand that he is doing it on first principles. But if a new module suddenly increased climate sensitivity so that 2009 was five degrees C warmer than present, I can assure you that he would first look for a bug, and then second rethink the model because obviously that isn’t what happened. That isn’t dishonest, that’s just makes sense. The result of a hundred decisions like that is something that will be very close to the historical record. Particularly if you average all the climate models.”

    This would be a legitimate concern if the uncertainty in our understanding of any one process could lead to such a large change in model behavior. If GCMs really were anywhere near that sensitive to such changes in process parametrization I wouldn’t have any confidence in their predictions either. However, unlike conceptual economics models, GCMs don’t behave like that.

    My understanding is that the kind of “tweeks” we are talking about mostly improve the simulation of seasonal and annual variability and how warming and precipitation changes are distributed over Earth. This is demonstrated by the fact that the only way to make the GCMs completely fail to match the historical record is to remove the components that deal with the increase in greenhouse gas concentrations.

  319. TRY:

    298 dhogoza – You’re kidding, right? Did you not read the whole post, or are you in the business of selectively quoting to mislead? Gee, who else does that?

    295 Ray – sure, but as I said, wait until the system reaches equilibrium. At some point, surely, it will be emitting as much energy as is coming in. Agree with this now? re 298 – regardless of mechanics, there certainly seems to be some benefit in looking at first-order impacts.

  320. Ray Ladbury:

    Dave Salt says, “As for my reference to Cargo Cult Science, you’ll note I was suggesting that a true lack of real-world evidence would likely lead to this conclusion and that my original post was, therefore, a sincere attempt to refute this through a simple enquiry.”

    Dude, there are MOUNTAINS of evidence, both literal and figurative. The climate senstitivities are constrained by evidence–more than 10 separate lines of it! The successful predictions of the models provide evidence. The paleoclimate provides evidence. Volcanic eruptions provide evidence. Satellite measurements provide evidence. Groundbased measurements. Hell, we’ve even got recorded dates of the first bloom of cherry blossoms on Mt Fuji going back to the 17th century that provides evidence. There are TONS of evidence. YOU merely refuse to look at it. You didn’t even bother to look at the references in Chris’s blog post, even though I specifically commended them to you. Now why would that be, I wonder?

    And with regard to my tone, I think I have been more than civil given that you are alleging either massive corruption or massive incompetence by the entire global science community without even the vaguest hint of evidence! I’ve made nothing that even by the most liberal stretching of definitions could be considered an ad hominem attack.

    OK, Dave, since you won’t look at any of the evidence I’ve provided, what evidence would you actually accept?

  321. Ray Ladbury:

    Nicholas Nierenberg says, “A model has to be tested with out of sample data. In a model as complex as these the knowledge of the existing result has to influence the person writing and testing the model. ”

    No, it does not! In my field (radiation effects in electronics) we often have to do simulations where we know many of the answers up front. In my former life, we had to do complicated analyses to extract tiny signals from huge backgrounds. It is not just possible to do so without biasing the analysis, it is routinely done! Physics is your friend. Use it!

    [Response: Actually I agree with Nicholas. Sensitivity of the models needs to be tested on 'out of sample' data - which wasn't used in building the model. I have been pushing for increased use of paleo tests for precisely this reason. But the 20th C trend is also 'out of sample', as was the post 1984 trend in 1984, as was the OHC change in 2005. Your kinds of tests are of course needed in model construction but aren't sufficient. - gavin]

  322. TRY:

    And dhogaza – surely you would acknowledge that “the physics” allows generally for two different molecules in the atmosphere to absorb the same IR wavelength? And that given a constant influx of energy in a mixed gas environment, how much energy one type of gas absorbs can be dependent on how much energy other gas molecules have absorbed?

    Let’s leave AGW out of it entirely and just address that pretty well-defined science question.

  323. Aaron Lewis:

    Re 91: TRY (With sincerest apologies to all the computer guys that like formal statements)

    The system is planet with liquid oceans and gaseous atmosphere including traces of CO2. The planet receives electromagnetic radiation from a nearby sun. The CO2 absorbs some radiation, vibrates, and transmits that energy to other gases in the atmosphere via collision. Those gases transfer that energy to the surface of the planet/ocean which circulates, exchanges energy with the atmosphere and radiates energy through the atmosphere to space.

    The question then becomes: Can we use radiation signatures to detect a change in the heat of the system? And, are there extant observers?

    Yes and yes.

    Energy will be absorbed by the CO2, transferred to the other gases in the atmosphere, and thence to the ocean producing a radiation signature. See for example: http://www.osdpd.noaa.gov/data/sst/fields/FS_km5000.gif
    This is a measure of outbound radiation detected above the Earth’s atmosphere. It is measured on a routine basis and the data is available. Another sample is: http://discover.itsc.uah.edu/amsutemps/AAT_Browse.php?chan=03&satnum=15&aord=a which is a graphic of the energy in water at various levels in the atmosphere.

    Theory says that the temperature of the ocean surface will rise as CO2 rises. Given various heat transfer mechanisms most of the heat will end up in the ocean. If the radiation signature of the ocean changes, we know heat has accumulated and global warming has occurred. Here we can see an analysis of changes in the temperature of the surface of the oceans as detected by the ocean’s radiation signatures: http://www.osdpd.noaa.gov/data/sst/anomaly/2009/anomnight.12.28.2009.gif.

    Note that much of the ocean’s surface is yellow or orange or red denoting a rise in the temperature of the surface of the ocean and hence the predicted change in the radiation signature. Yes, as predicted the oceans warm as CO2 increases, and the data is all available.

    It is not the answer that you want, but it is fast, easy, and 71% correct.

  324. Charlie S:

    Re #50 Simon … it’s not a climate model in the any sense of the ones in this post … but it can be interesting to play with the Interactive Java Climate Model — and it doesn’t take a supercomputer or knowledge of FORTRAN (or any programming).

    http://www.astr.ucl.ac.be/users/matthews/jcm/index.html

  325. Andy:

    Gavin: Re: response to #5 – does the AMO exist? I haven’t read anything definitive. If so, then what are the expected mechanisms for such a long duration change in ocean circulation?

    [Response: Well there is clearly evidence for variability in the overturning circulation - both in paleo data and in models. The models produce patterns that have (varied) multi-decadal frequnecies and so it's not silly to be looking for this in the modern observations. However, our ability to distinguish internal variability from forced changes in indicies like the 'AMO Index' is poor. So while it probably exists, we probably don't know what it's done (or is doing). - gavin]

  326. Matthew:

    #208, Martin Vermeer. I did not miss the point of Jeffreys’ comment, I pointed out that not everyone who writes of statistical inference agrees with the point.

    There is no way not to bet.

    I agree with you there, but I think that you underestimate the cost of betting huge sums of money on current technology with current knowledge. Money spent now will not be available 20 years from now when better technology is available, and will not be available for desalination projects, which the world really could use. Too much money spent too soon can do more harm than good, and will do no good whatsoever if some other theory than AGW turns out to be more accurate. In terms of controlling risk (loss times probability of loss), there is more than one risk.

    “All models are false, some are useful.” I do not know the original source, but the textbook by Bates and Watts on estimation of nonlinear models has it as a chapter epigraph. Another chapter has a nice quote from Bertrand Russell on the fact that all scientific theories are approximations. All the specific relationships that are ingredients in the GCMs are simplifications of complex relationships with parameters estimated from noisy data of some sort. Take all of these approximations glommed together, and you have models that are potentially less accurate than simple models estimated from time series trend analyses. The evidence to date, summarized at the head of this thread, is that the climate models agree rather coarsely with observed data, not very precisely.

  327. Spencer:

    Anyone looking at the first graph can see clear as day that the hindcast data is much closer to reality then the futurecast data. Even the error bar are smaller. It may be selection bias, fitting the model to the data, it really doesn’t matter.

    [Response: Not quite. It's because the data is baselined to the beginning part of the curve so that the mean of each model is the same as the data over 1980-1999. The width of the bar is then due only to the size of internal variability. As you go into the future, you still have this kind of uncertainty, but you also start to see a little spread related to differing sensitivities of the models. As you go further out, the spread related to sensitivity will increase, and we will be able to winnow the models. But for the moment the internal variability is the dominant uncertainty in the AR4 simulations. - gavin]

  328. Jim Eager:

    Jason @ 253: First, I don’t have any problem with the earth getting warmer, especially if it only gets a little warmer, and if the pace of that warming is slower than the IPCC forecasts.

    Well, considering that the current level of atmospheric CO2 without including future growth is already higher than it has been at any time in at least the last 3 million years (i.e. before the start of the current glacial-interglacial cycle) and perhaps as long as the last 20 million years [Tripati et al, Science 4 December 2009], then it seems clear that we can safely rule out your first caveat, while much paleoclimate research shows evidence of rapid changes in ice sheet dynamics and sea level during emergence from a glacial stade, your second caveat is on shaky ground.

    J: I’ve seen outwardly credible estimates explicitly suggesting that it will be possible to build carbon sequestration technology that removes many times more carbon from the atmosphere than is emitted during the production of the required energy. Can you direct me to an argument explaining why this physically is impossible?

    Surely, it’s called the First Law of Thermodynamics, which apparently has something to do with conservation of energy.

    Let’s leave aside the capture and sequestration of CO2 from fossil fuel power plant flue gasses, which will obviously require almost as much energy as is usably generated and will remove not a single molecule of existing carbon from the active carbon cycle. Instead, let’s look at potential methods to sequester much less concentrated COe directly form the atmosphere. Even though photosynthesis provides the energy required for the production of biochar feed stock, turning it into char and getting it into the soil on the necessary scale will require a lot of additional energy. Although energy-free once in place, quarrying, crushing, grinding and distribution of periodite will require a good deal of energy.

    J: What level would that be?

    Oh, I don’t know, somewhere between the level that allowed the last glacial stade to start growing and the level that existed prior to the last time sea level was 25 to 40 meters higher [Tripati et al, Science 4 December 2009, again], i.e. definitely somewhere much closer to 350 ppmv than 387 ppmv.

  329. Stephen Pruett:

    What do you make of the following quote from a CRU e-mail, “Hi Tom How come you do not agree with a statement that says we are no where close to knowing where energy is going or whether clouds are changing to make the planet brighter. We are not close to balancing the energy budget. The fact that we can not account for what is happening in the climate system makes any consideration of geoengineering quite hopeless as we will never be able to tell if it is successful or not! It is a travesty!
    Kevin (Trenberth)

    Just on the basis of his credentials and involvement in the IPCC process, one would think that if anyone knows the current state of the science, it would be Dr. Trenberth. I suspect you will not agree with his conclusion, and it may be that your models do not attempt to account for the entire energy budget, so this comment may not apply directly to your work. In any case, I would be interested in your take on this.

    [Response: He's talking about the uncertainties in our current observing system which are too large to enable us to work out exactly where all the energy goes on a year by year basis (and no one is in disagreement about that). He's even written a paper about it. - gavin]

  330. Joseph:

    A model has to be tested with out of sample data. In a model as complex as these the knowledge of the existing result has to influence the person writing and testing the model. Therefore even though Gavin believes that he his building only on first principles it isn’t, in my opinion, possible. It is the same reason why drugs have to be tested using double blind experiments. It isn’t that the physicians who are administering the tests and noting the results are dishonest, it is just the way the world works.

    A model should be tested with data that was not used to “train” the model, but the analogy with drug trials doesn’t apply. It’s not human bias that is the problem. The issue is that there can be overfitting, and you could be trying to model noise, or perhaps your model is not a reflection of how the world works (e.g. a 3rd-order polynomial model might fit a series pretty well, but it doesn’t forecast.)

  331. Leo G:

    From Tamino’s site –

    {quote} The trend lines from 2000 to 2010 (actually to the present since 2009 hasn’t ended yet) are all positive:

    •For GISS data, the trend from 2000 to the present is +0.0115 +/- 0.018 deg.C/yr.
    •For RSS data, the trend from 2000 to the present is +0.0017 +/- 0.030 deg.C/yr.
    •For UAH data, the trend from 2000 to the present is +0.0052 +/- 0.043 deg.C/yr. {end quote}

    Am I reading this right?

    GISS, with the error factor could be neg/flat/pos

    RSS, also could be neg/flat/pos

    Only UAH is absolutely positive.

    If true, how ironic :)~

  332. Leo G:

    Whoops, just realized that my eyes missed the decimal place on the UHA

    “never mind!”

  333. TimTheToolMan:

    With regards to the Real Climate article “Why greenhouse gases heat the ocean”, has this been resolved? I’ve not found a paper that has quantified the effect so I’m wondering what mechanism the models use? Or have I simply not found the science that has quantified ocean heating from anthropogenic CO2 yet?

  334. Mark A.:

    I’ve found the discussion on how the GCM’s were built intriguing. One of the main reasons i’ve been skeptical about the predictability of the models is that I was under the impression that they had been largely “tuned” using historical temperature data when they were built. If the models were tainted by historical data, their value would largely be dependent only upon their ability to forecast – which so far doesn’t appear to be very good. (although I concede that one decade is hardly enough to come to any conclusions)

    However, it sounds as though Gavin and others are claiming that the GCM’s were constructed almost entirely based upon principles of physics and without any bias from historical data. If this is true, then the fact that the models predict so well the actual temperature records of the past up to the recent present would be cause for any skeptic to double take.

    But then, this too makes me pause. Are we to believe that a hodgepodge of physical principles were coded into these models, and yet when these principles were pooled together, models were able to be created that so closely resemble the actual temperature record from the last century?

    With so many complex unknowns as there are in the equation that climatologists admit are either poorly understood or completely unaccounted for in the models, could such accurate results have really been obtained without the models being tainted by the historical temperature data in some way? For one, i’m lead to believe that the positive and particularly the negative feedback mechanisms are left largely unaccounted for in the models, especially older ones, yet these models were still able to produce accurate results that followed actual temperature records? I would expect that even leaving one minor forcing or feedback mechanism unaccounted for in the models would create a cumulative effect over time exaggerating either a warming or cooling effect that would cause the model’s results to greatly diverge from actual temperature records over a significant period of time. Yet this doesn’t seem to be the case, at least in the public models, seeing as how they cross and follow historical temperatures repeatedly as time progresses, showing little deviation on a long time scale. Gavin, et. all: can you provide an explanation for this?

  335. Martin Vermeer:

    Nicholas #300, two things. Firstly, the situation in medicine is very different because of the placebo effect, which is very real and occurs also in “honest” patients.
    Secondly, a large error of the kind you describe would, as Gavin described in #271, be found well before getting around to trying to replicate the instrumental record, by looking at the phenomenon that module is actually trying to describe. Implying that Gavin’s description is not what really happens, does come close to an accusation of less than full honesty. And actually some of the models in AR4 don’t do a very good job with the instrumental record (were those the more “honest” modellers?).

    I understand that in adversarial situations (like trying to convince a skeptic public) you want to have “hard” blind testing, which means in practice that only old and currently obsolete models like Hansen 1988 can qualify. But, once the existence of minimally skillful models has been thus established, for production work, please let’s use the best and give the researchers a little credit for knowing what they are doing.

  336. Edward Greisch:

    The problem is: People listen to Rush Limbaugh on their car radios while going to and from work. There are no graphs to see on the radio. Rush says AGW is a hoax so many times that the average person believes it. They aren’t going to look at any graphs that they wouldn’t understand anyway.
    RC needs to get a talk radio show that airs when the most people are driving. RC needs to include the same psychological hooks that Rush uses. Quit being Mr. Nice Guy. [edit]

  337. wil:

    @ 293 In answer to my question”:
    “So basically my question is when does “insignificant, short term” change to something relevant?”
    ‘Completely Fed Up’ answered:
    Never. When it changes to something significant, it’s no longer insignificant. If you wait longer to get more data, it’s no longer short term.

    If you carefully read my original contribution (#224) you can see that the NCDC data indicate there is no significant temperature increase even since 1996. So the ‘significance’ is there (increasing in strength every year after 1996), but it is at a statistical level and every time the answer from the CO2-adepts is, well it’s only short term. Therefore I asked when it would be considered RELEVANT.
    I am afraid that the answers given so far are really not convincing, at least not to me and probably a lot of others that have difficulty with the divergence.

  338. Dave Salt:

    Concerning Thomas Lee Elifritz (#281) responding to my post (#273), it dawns on me that he may have misinterpreted my statement “I also don’t respect argument by authority (i.e. trust me, I’m a scientist)”, which was an attempt to illustrate a point and not a statement about my professional status.

    Just for the record, I am not a scientist nor do I pretend to be one on the internet.

  339. Simon Rika aka Karmakaze:

    @Ray Ladbury #229

    “Try looking at monthly data–lots of up and down, right? Hard to spot a trend. Now average over a year. Still lots of up and down, but the trend is easier to see. Now try looking at 5 year averages and the trend becomes quite clear. Essentially, if you remove known sources of noise (like annual variation in absolute temperature) the trend becomes easier to see.”

    I know I’m dense in this respect, because of my lack of formal education, so please bear with me:

    Say we have a series of “annual mean temperature” datapoints. We select a representative period and average the annual means to get an average annual mean (kind of a double average).

    So say that gets us the average annual mean of 14.1C. Is that how that part works?

    Next we get each annual mean temperature for each year and plot its difference from that average annual mean. Is that what an anomaly graph is showing? Like:

    Average for 1970-1999: 14.1C

    2001: +0.1C
    2002: +0.2C
    2003: +0.1C
    2004: +0.3C

    Is that the sort of data that is being plotted? Have I got that right so far?

    So wouldn’t:

    Average for 1970-1999: 14.1C

    2001: 14.2C
    2002: 14.3C
    2003: 14.2C
    2004: 14.4C

    Show the trend just as clearly? If not, what am I missing?

    Don’t take this as meaning I am questioning the scientists, I am just trying to understand what the difference is.

  340. Simon Rika aka Karmakaze:

    Sorry Gavin or whoever is modding. I would understand if you want to delete this post but if you do, could you add the following request (or fill it for me) to the previous post somehow – I thought of it after I hit submit, and I don’t want to derail this thread.

    Could you perhaps point me to a good source where I can learn the basics of this sort stuff. I looked at “start here”, but that seems to be talking about the climate science rather than what I know are the real basics – how to read and plot the graphs etc. used in climate science. Or maybe I’ve missed it.

    Basically, I left high school at 15, and so my knowledge of even the basic stuff like the maths etc is only what I’ve picked up along the way, and I am wondering if I have any clue what I’m looking at.

    [Response: With respect to temperature anomalies, read this piece on the Elusive Absolute Surface Temperature, but for a real intro, you probably want to read a book (Cough). ;) - gavin]

  341. Timothy Chase:

    TRY wrote in 291:

    Let’s stick to the science! …

    Your opponents claim that, …

    TRY,

    You are the one who keeps on bringing in “my opponents” — and that’s not sticking to the science.

    Additionally, they aren’t “my opponents.” For one thing, I am a philosophy major turned computer programmer in a field that is unrelated to climatology. So if anything, these opponents are opponents of the scientific consensus, a consensus that includes every major organization that has seen fit to take a position on whether climate change exists, whats causing it, and the apparent seriousness of the consequences of climate change. Or perhaps they are opponents of climatology, of science, or simply opponents of doing anything about climate change until it is too late.

    But they aren’t my opponents.

    And while you are more than happy to bring in these opponents, you treat their opposition as some sort of irreducible primary. You don’t ask or want to consider any relevant questions regarding the nature of their opposition.

    What are their qualifications?

    Judging from some of the “x number of scientists who oppose ‘global warming theory’” lists, they would appear to be TV weathermen, economists, sociologists, and an occasional ‘climatologist. Spencer, Christy, Lindzen. A few others — but almost none of any prominence in the field.

    Have they published their opposition to the consensus in relevant peer-reviewed journals where people who are familiar with the issues in the field are able to judge their papers — and where certain standards of quality are presumably applied prior to the article being published?

    Typically, no. If they are climatologists their opposition to the consensus appears in op-eds, or a newsletter, or in a speech before an audience who knows very little about climatology. But occasionally a really bad paper will make it through — and have all of its flaws dissected in later articles — articles which make one ask how the original paper ever made it through the peer review process.

    What are the strengths of their arguments? Do they have any alternate, testable explanations for the same phenomena?

    Nothing that has stood up to the evidence.

    Do they have an alternate climate model — based upon known physics?

    Heck, do they have a specific mechanism based upon known or at least testable principles of physics that will explain why warming has taken place since the mid seventies — and — are they able to explain why the well-known and well-understood physical mechanism which is generally regarded as being responsible for global warming in the later half of the twentieth century was somehow cancelled out?

    Zip.

    In no significant, scientifically relevant sense is there any opposition at all to the consensus regarding anthropogenic global warming. And in that sense it is meaningless to speak of opponents to the scientific consensus on anthropogenic global warming.

    What do they have? The very same organizations often have a history of supporting scientifically indefensible positions — in tobacco and other areas. In fact as I pointed out and as you try to brush off, 32 of the organizations involved in the denial campaign surrounding anthropogenic global warming were also involved in the denial campaign surrouding tobacco. Its well-documented.

    And if you bring up the opponents of the scientific consensus in AGW and I will point out other areas in which they were opponents of the scientific consensus.

    *

    TRY wrote in 291:

    Your opponents claim that, in general, the impact of CO2 is much less significant than you claim it is. Overlapping absorption bands and saturation are two common claims.

    “Overlapping absorption bands”? I presume you mean overlapping with water vapor. Yes, at the surface any relevant wavelength is already saturated. Adding more carbon dioxide there won’t make any difference. However, water vapor has a low “scale height” or “e-folding distance” — which means essentially that unlike other gases it tends to stay close to the ground. The mean e-folding distance (where the partial pressure of water vapor is divided by the base of the natural logarithm (~2.7) relative to the surface is roughly 2 km. It tends to fall out as precipitation rather than going much higher. The level of carbon dioxide in the atmosphere falls off much more slowly with altitude. And as such carbon dioxide is an effective greenhouse gas where water vapor is no longer an issue.

    “Saturation”? Even if the center of the absorption band is saturated, the wings won’t be. And as the spectral range over which saturation exists expands there will always be more distant parts of the wing that are undersaturated.

    This is afterall what pressure broadening is all about.

    Please see:

    Pressure broadening
    THURSDAY, JULY 05, 2007
    http://rabett.blogspot.com/2007/07/pressure-broadening-eli-has-been-happy.html

    … which I refered you to back in 110.

    Furthermore, even if lower altitudes are saturated, infrared radiation will get through. Half of the radiation that is emitted go down, half goes up, and no matter how many times the energy is passed by emission, conduction or convection it will eventually escape to thinner parts of the atmosphere that are no longer saturated. And increasing carbon dioxide levels will increase the degree of saturation at those layers and the layers above them.

    See:

    Part II: What Ångström didn’t know
    26 June 2007
    http://www.realclimate.org/index.php/archives/2007/06/a-saturated-gassy-argument-part-ii/

    TRY wrote in 291:

    Bottom line, [they claim] CO2 does not have the impact on outbound radiation that you claim it does.

    The physics says otherwise. The images showing a reduction in infrared brightness (in those parts of the spectra that carbon dioxide is opaque to) where carbon dioxide concentrations are higher says that they are wrong.

    I gave you one of those, too.

    Here:

    AIRS Carbon Dioxide Data
    A 7-year global carbon dioxide data set based solely on observations
    http://airs.jpl.nasa.gov/AIRS_CO2_Data/

    … and please also see the increasing opacity of the atmosphere due to carbon dioxide levels here:

    Aqua/AIRS Carbon Dioxide with Mauna Loa Carbon Dioxide Overlaid
    http://svs.gsfc.nasa.gov/vis/a000000/a003500/a003562/index.html

    … for the period from September 2002 to July 2008.

    As I explained in 110 in relation to the earlier image:

    The dark orange off the east and west coasts of the United States? That is carbon dioxide at roughly 8 km altitude — infrared at 15 μm in wavelength has been absorbed and emitted at lower levels of the atmosphere, but this is where it gets emitted for the last time before escaping to space — and as such the brightness temperature at that wavelength reflects the cooler temperature at a somewhat higher altitude than the surrounding areas.

    TRY wrote in 291:

    So, why not look at first-orderimpacts? Specifically, actual out-bound radiation globally. Seasonal matters because CO2 varies seasonally. And of course time matters. Now do you understand why the papers you posted don’t address this?

    Dealt with that already. In detail. 272.

    As for feedbacks that go beyond the radiative properties of greenhouse gases — none of our current models are able to get a climate sensitivity as low as 1.5°C, and moreover, the feedbacks to the sun are the same as the the feedbacks to greenhouse gases, and you can’t explain the behavior of the earth’s climate system over the past half million years with a low climate sensitivity. Solar forcing alone won’t get you the glacials and interglacials.
    *
    TRY wrote in 291:

    What would the overall IR signature look like if CO2 absorbs/emits at the levels you claim? What would the overall IR signature look like if CO2 absorbs/emits at the levels your opponent claims?

    What co2 absorbs/emits at the levels I/”my opponent” claim?

    It isn’t a matter of opinion. We know the absorption spectra of carbon dioxide. We know the absorption spectra of other greenhouse gases.

    See:

    The HITRAN Database
    http://www.cfa.harvard.edu/hitran/

    They are established facts — as are the effects of pressure and temperature upon their absorption spectra. As I pointed out when I linked to:

    Pressure broadening
    THURSDAY, JULY 05, 2007
    http://rabett.blogspot.com/2007/07/pressure-broadening-eli-has-been-happy.html

    Temperature
    WEDNESDAY, JULY 04, 2007
    http://rabett.blogspot.com/2007/07/temperature-anonymice-gave-eli-new.html

    … in 110.

    People who are interested can check out and play with Modtran for themselves for total atmospheric column calculations here:

    Modtran
    http://geoflop.uchicago.edu/forecast/docs/Projects/modtran.doc.html

    TRY wrote in 291:

    As for the rest of it, argue with someone else about tobacco.

    Don’t need to — your champions already lost that war.

    But they and their tactics:

    Doubt is our product, since it is the best means of competing with the “body of fact” that exists in the mind of the general public. It is also the means of establishing a controversy.

    Smoking and Health Proposal (1969)
    http://tobaccodocuments.org/landman/332506.html

    … continue, and your being here and your tactics are entirely in line with that.

  342. Simon Rika aka Karmakaze:

    @Hank Roberts #234

    I’m sorry Hank, but I think you and Ray misunderstand me. Let me explain for you and anyone else who might have the wrong idea.

    I am not questioning the data. I have no doubt that it shows what it shows and why, I am simply wondering why that method of showing it – a graph of anomalies – is better than another method – a graph of absolute temperatures.

    I left school with above average marks in math and science at 15, but that is the extent of my formal education. I am simply trying to figure out what I am looking at, and why it couldn’t be shown in another way – I am by no means questioning the data.

  343. Completely Fed Up:

    Another way to post Doug’s message in #306 is: there’s an infinite number of ways to get it wrong, and non-infinite ways of getting it right. The chances of getting it right randomly is infinitesimal.

  344. Completely Fed Up:

    Andrew #304: the richest people have a tax rate of less than 20%. The tax rate for those too poor to set up a Cayman Islands account and pay accountants to find tax loopholes is double that.

    The rich already avoid tax.

    This doesn’t make carbon taxing replacing income tax a good idea, but the rich already avoid taxes and they’ll avoid this one too.

    [edit - general taxation and capitalism is off topic]

  345. Josh Cryer:

    I built some n-body simulation code for a video game. While trying to understand the physics I found that I was matching what I believed to be proper n-body movements most of the time.

    Now the code itself had collision detection, and the n-bodies would glance off each other in a way that didn’t seem right. They were too “sticky.” I tweaked the code many times, basic trial and error stuff, trying to figure out what was wrong. I thought it was initially in the collision detection code, because the n-body (Euler) formula is easy enough for a high schooler to understand. Also, visibly, that’s what it looked like was happening. The collisions were too sticky. It had to be the collision code, because the physics were “correct.”

    Wrong. I spent days trying to figure it out, tweaking parameters into the gravity of the n-bodies, tweaking initial velocities, tweaking the virtual diameter of the bodies (Euler’s formula relies on the square of the distance to the body center). They still stuck to one another. It still moved like a chaotic system, but the bodies were glued to one another.

    It turns out at the end of my n-body gravity routine I failed to reinitialize the gravity. Each iteration it built up and built up until the bodies all became one. The collision detection code, though it was imparting directional velocity (which was supposed to be completely inelastic), was inconsequential to the gravity that the bodies had. It was a tiny itty bitty mistake on my part.

    The point I’m trying to make is that chaotic systems cannot be easily “tweaked” to represent some “preconceived version” of reality. If the physics are not good enough you will not get the results you expect, you must therefore improve (or in my case, fix) the physics. People accuse modelers of “pattern matching” to make the models fit the data, but I would be amazed to meet someone who was smart enough to be able to intuit model output from a chaotic system. All I see with the models is that they are improved by known (empirical) mechanisms and generalized physics of those mechanisms. Frankly that’s the only way I see that it can be done.

  346. Josh Cryer:

    Oops, “completely inelastic” should have been “completely or perfectly elastic” in my above post there. Sorry for the double post!

  347. wallruss:

    “However, the bottom line is that it does not seem to be possible to get an Earthlike climate with a CO2 sensitivity less than ~2.1 degrees per doubling. Despite copious efforts at constructing a model with low sensitivity (very interesting for its inherent properties independent of its implications for climate change), no one has succeeded. That is a strongly constrained lower limit unless you can come up with something that overturns a whole boatload of evidence.”

    Does this mean, as it seems to imply, that the CO2 feedback parameter used in the models, is itself based on how well the models do? If so this doesn’t seem to fit with the statement that:

    “As to your implication that the models are tweaked to achieve agreement with the historical record, that is also incorrect. Any changes that are made must be motivated by the physics. It is valid to increase fidelity of the model–e.g. by adding a treatment of ocean currents around Antartica. It is not valid to tweak that ’til you get best agreement with temperature”

  348. mark:

    I am neither a skeptic/denier nor a advocate of AGW, but someone who is trying to learn and understand – I have only a basic school level understanding of general science.

    What does amaze me about this issue, on both sides of the fence, is the zealous religious type view. Surely this is about the science, facts and figures and how it is interpreted. Why do those not aligning to a particular view become either ‘deniers’ or ‘alarmist’. where is the option to debate to understand?

    Prime example

    Simon Rika aka Karmakaze
    would hate to see the denier types be cleaned out completely, but maybe a “wall of shame” type thread could be made where the denier posts could be sent, that can not be replied to, but the long list of repetitions of the same tired old talking points could be visible to everyone and show WHY they are not welcome in the actual discussion threads? ”

    Why a ‘wall of shame’ for holding a different view? I see the same sentiment on the other side of the fence.

    About time we all grew up, listened, understood and debated.

    Sorry for the rant, but as a self confessed layman, I feel I will never have the confidence to believe either side of the argument when everyone involved seems to have tunnel vision. I think this is the problem reflected in the general public that will only lead to apathy with the whole debate….and therefore no actions.

  349. CM:

    Dave Salt (#303), however unintentionally delicious your accusation of “ad hominid” arguments, shouldn’t that be ad hominidem? Anyway, Ray plainly did not commit an ad hom. He inferred the ignorance of the speaker from the quality of the argument, not the other way around. And an argument from the scientific process hardly reduces to an argument from authority. There was a reason why the medieval humanists insisted students begin with the trivium

    BTW, here’s the abstract of Dessler et al. 2008, to which BPL already pointed you.

    Between 2003 and 2008, the global-average surface temperature of the Earth varied by 0.6°C. We analyze here the response of tropospheric water vapor to these variations. Height-resolved measurements of specific humidity (q) and relative humidity (RH) are obtained from NASA’s satellite-borne Atmospheric Infrared Sounder (AIRS). Over most of the troposphere, q increased with increasing global-average surface temperature, although some regions showed the opposite response. RH increased in some regions and decreased in others, with the global average remaining nearly constant at most altitudes. The water-vapor feedback implied by these observations is strongly positive, with an average magnitude of λ q = 2.04 W/m2/K, similar to that simulated by climate models. The magnitude is similar to that obtained if the atmosphere maintained constant RH everywhere.

    Does this help answer your question? If I were you, I’d look up the abstracts of the other papers people here have helpfully pointed you to.

  350. Stephen:

    For figure 1 when you say “For example, here is an update of the graph showing the annual mean anomalies from the IPCC AR4 models plotted against the surface temperature records from the HadCRUT3v and GISTEMP products (it really doesn’t matter which). Everything has been baselined to 1980-1999 (as in the 2007 IPCC report) and the envelope in grey encloses 95% of the model runs. The 2009 number is the Jan-Nov average.”

    Can you refer me to the corresponding figure in the IPCC AR4? I’m curious if one can compare the figure posted here to Chapter 8′s FAQ Figure 8.1, and Chapter 9′s figure 9.5.

    Thanks for your help…

    [Response: This is a pretty good comparison to those figures - the baseline is different, and you are seeing the individual runs, and they calculated the ensemble mean slightly differently - but apart from that... I'll try and do a more exact match if I get time. - gavin]

  351. Grabski:

    What if it becomes clear that the climate is threatened

    What if, what if, what if it becomes clear that the climate is threatened by continued cooling? Then trillions will have been wasted.

  352. Jaydee:

    179. sierra117

    1968 – 1978 gives a decade with a downward trend
    http://www.woodfortrees.org/plot/gistemp/from:1968/to:1978/plot/gistemp/from:1968/to:1978/trend

    A nine year sequence from 1986 to 1995 also has a downward trend

    http://www.woodfortrees.org/plot/gistemp/from:1986/to:1995/plot/gistemp/from:1986/to:1995/trend

    1977 to 1986 is pretty flat but does have a slight upward trend
    http://www.woodfortrees.org/plot/gistemp/from:1977/to:1986/plot/gistemp/from:1977/to:1986/trend

    As these periods are contiguous, you might conclude that temperature had declined, but no…
    http://www.woodfortrees.org/plot/gistemp/from:1968/to:1995/plot/gistemp/from:1968/to:1995/trend

  353. Completely Fed Up:

    Maybe the way to deal with Pruett’s request isn’t to post the text at all. Just replace it with “your answer is HERE $HTTP$”.

    If nothing else, it’ll up the link count to the answers. Note how any climate term sent to google comes up with 80% hits to denialist blogs rather than, say, the IPCC or the national met services.

    Because they seed other blogs with references to the denialist blog sites.

  354. Completely Fed Up:

    “Take all of these approximations glommed together, and you have models that are potentially less accurate than simple models estimated from time series trend analyses.”

    Except you don’t have a model if you take a time series trend analysis.

    After all, even if you fit 100% by including enough wavelets, you do not know if there are any other wavelets and so your “model” is far more flawed than you think.

    After all, Max sees a 60 year cycle, but who’s to say there’s not a 100 year cycle still going up? And then a 1000 year cycle still going up, etc?

    Trend analysis is NOT A MODEL.

    It allows you to check to see if the trend in the data is in agreement with your REAL model (the physical one that you proclaim fatally flawed).

    And please explain how so many climate models that leave out different things you INSIST are the death knell to accuracy still manage to get so many things the same? After all, there’s an infinite supply of wrong numbers, so why are we seeing only a small and congruent set?

    Luck?

  355. Ray Ladbury:

    Jason says, “I do, however, have some useful data to add. I have taken (over the past 3 years) to asking climate science grad students the following question:
    If your research produced results that tended to disagree with the consensus, what impact do you think it would have on your ability to: Get a job/Get a grant/Get tenured.
    Unfortunately, I’ve changed the wording around and only have 6-7 responses. But thus far the universal response of climate science grad students a major universities is that research disputing the consensus would be severely detrimental. The word “impossible” was used twice.”

    Jason, either YOU are bullshitting or you are polling idiots. Do you think scientists establish their reputations and win Nobel prizes by blending in with the crowd? Do you think scientists are afraid of disagreeing with eachother on technical matters. Hell dude, we were the nerds in highschool, remember? We stood out. The absolute quickest way for a young researcher to become a superstar is to overturn a model that is well established. Good Lord, man, you don’t understand anything about the scientific process or scientists at all.

  356. Ray Ladbury:

    Matthew @323 “All Models are wrong; some models are useful”–George Box

    Matthes says, “Take all of these approximations glommed together, and you have models that are potentially less accurate than simple models estimated from time series trend analyses.”

    This is true only if you get the physics badly wrong–which shows up in the validation phase. If you get a physical model that is well validated, and suddenly it ceases to perform well, it is usually an indication that there is a physical process that is important for the new data that was not important for the calibration or validation datasets. You really ought to learn how these models work, don’t you think?

  357. Completely Fed Up:

    Simon:”I am simply wondering why that method of showing it – a graph of anomalies – is better than another method – a graph of absolute temperatures.”

    But what IS temperature?

    My body temperature is 98.

    My body temperature AT THE SAME TIME is 36.

    It is ALSO 303.

    Because temperature is not absolute. It is ONLY in relation to something else.

    My body is warm and a lizard is cold not because of any absolute temperature since the differences are practically the same when measured against absolute zero (both boiling hot) or when measured to the temperature of the sun (both freezing cold).

    So your request is nonsensical: there IS no absolute temperature. It’s all relative.

  358. Ray Ladbury:

    Simon@341, OK, let’s think about this. What are we interested in determining? Whether the climate is changing, right? Climate is a long-term process, so we’ll need to look at data over a period of several (~30) years. And then we will want to determine whether there is an upward slope, a downward slope, no slope, a nonlinear rise… We will also be interested in any seasonal effects–did winter warm more than summer, for instance?
    Exercise for the reader: Go try it yourself. Get some data. Graph absolute temperatures. Then graph anomalies. Which one makes it easier to see whether things are changing?

  359. Jason:

    #306: “Nicholas I see your point but I believe you’re investing too much confidence in your assumptions. If true in the literal sense I took from your statement, it would have wide repercussions extending into numerous fields beyond the one under discussion here.”

    In most other fields it is much easier to acquire new validating data.

    If, against this data, a model consistently makes more accurate predictions than its competitors, it is better.

    I am thus free to use my own understanding (or often enough misunderstanding) of the system being modeled without fear of biasing the results.

    GCMs do not have this luxury.

    I am deeply skeptical that humans can accurately forecast ANY system that is even remotely as complex and noisy as the earth’s climate without access to vast amounts of validating data.

    Cosmological models (which were previously mentioned, and which I would argue are _much_ simpler than GCMs) have the great advantage that they predict specific values. If a measured quantity differs substantially from what the models say it should be, you aren’t likely to hear about internal variability. Instead, the assumption is that the model is mistaken or incomplete or that the observations are wrong or misinterpreted.

    If GCMs _are_ as accurate as some of their proponents seem to believe, it would be the high water mark in the history of human modeling of complex systems; an extraordinary accomplishment of which I am (quite legitimately I think) deeply skeptical.

  360. John E. Pearson:

    344: Celso Grebogi, Ed Ott, and Jim Yorke, and their collaborators wrote papers on controlling chaos about 2 decades ago, so it can be done. (I’m not saying that climate modelers do this. They don’t. I am saying only that it is possible to tweak the parameters of a chaotic system in order to produce a desired output.) I haven’t thought about this stuff for a long time but I believe that this is the key paper. http://prola.aps.org/abstract/PRL/v64/i11/p1196_1

  361. Ray Ladbury:

    wallruss asks “Does this mean, as it seems to imply, that the CO2 feedback parameter used in the models, is itself based on how well the models do?”

    No it does not. It means that if you force your model to have a sensitivity less than this level, it doesn’t look like Earth. It fails. Is that clear.

  362. Ray Ladbury:

    Grabski asks, “What if, what if, what if it becomes clear that the climate is threatened by continued cooling? ”

    What an odd thing to ask at the end of the warmest decade on record. You have quite an imagination.

  363. Completely Fed Up:

    will #337, yes it would HAVE to be a careful reading since your post didn’t say anything of the sort.

    “If you carefully read my original contribution (#224) you can see that the NCDC data indicate there is no significant temperature increase even since 1996. So the ’significance’ is there ”

    How do you get from “no significant increase” to “significant”? The number I’m thinking of is not positive. Therefore it must be negative? No. Could be imaginary or zero.

    “and every time the answer from the CO2-adepts is, well it’s only short term.”

    And it is. When your timescale is “30 years” less than 10 years is short term.

    My answer was 100% correct and right. You just didn’t like it.

    Read it again.

  364. Completely Fed Up:

    John opines uselessly: “If GCMs _are_ as accurate as some of their proponents seem to believe, it would be the high water mark in the history of human modeling of complex systems”

    Nope, because climate is mostly an energetic proposal. After all, the solar system itself is chaotic (don’t believe me? let me know which side of the sun Pluto will be in 100 million years) but we can model it just fine for our needs.

    The climate is not a chaotic problem any more than the fairness or otherwise of a siz sided dice or hand of cards is a chaotic problem. Predicting what number will turn up in the next roll of the dice IS.

    But I guess you don’t know and don’t WANT to know. Because if you found out, you’d be discomfited.

    Tough.

    Reality doesn’t care if you like the consequences.

  365. sierra117:

    Does anyone know where I might find time series data of atmospheric CO2 concentrations?

  366. Lynn Vincentnathan:

    Hansen himself puts reliance on models in 3rd place in STORMS OF MY GRANDCHILDREN, after paleoclimatology and observations.

    However, since we don’t have a few earths — some as experimental in which we add GHGs and some control in which we don’t add GHGs — models are the next best thing for trying to figure out what might be coming up.

    I was myself looking at paleoclimatology for “what’s the worst that could happen” and looking at the end-Permian warming during which 90% of life on earth died. But that happened very slowly over many thousands of years, not at the lickity-split rate at which we’re emitting GHGs. And the sun was less bright then, as Hansen points out in his 2008 Bjerknes lecture — http://www.columbia.edu/~jeh1/2008/AGUBjerknes_20081217.pdf

    So I guess we have to look to Venus for “what’s the worst that could happen.”

  367. Completely Fed Up:

    “I am saying only that it is possible to tweak the parameters of a chaotic system in order to produce a desired output.) ”

    And such would give massively different results if you didn’t do EXACTLY the right tweaks.

    Which they managed to do despite no detailed description of how to do the tweak and how to change the tweak to fit a different model.

    (after all, a hoax IS required or you get the infinite number of wrong answers and if there had been any communication, the CRU hack would have shown it)

  368. caerbannog:

    #271 (Comment by Jason — 30 December 2009 @ 3:10 PM)

    Moreover, I think that after these assumptions are made, the models are analyzed and debated in an environment where it is easier to get money, get published and get get tenure if your models show higher sensitivity.

    [Response: Complete BS. (Sorry, but really? you think tenure is granted or not because you have a higher climate sensitivity? Get real). The GISS model used to have a sensitivity of 4.2 deg C, the AR4 model had a sensitivity of 2.7 deg C. Can you discern a difference in our publication rate? or budget? This is beyond ridiculous. - gavin]

    Uhh… Jason, here’s something for you to think about (presuming that you are inclined to do such things).

    When Svante Arrhenius calculated the climate sensitivity to CO2, what values did he come up with? Do today’s climate models show higher or lower sensitivity than Arrhenius’ original calculations? And how do those numbers square with your claim that scientists are encouraged to tweak their models to produce higher sensitivity numbers?

    If you don’t want to think about this, that’s fine. But I hope that some other folks here do.

  369. Lynn Vincentnathan:

    Here’s an interesting article about James Hoggan’s work on denialists, and I noticed it’s drawn out a lot of denialist bloggers: http://www.csmonitor.com/Environment/Bright-Green/2009/1228/James-Hoggan-talks-about-global-warming

    I wish I had had a good “model” for understanding denialists, so I wouldn’t be so shocked to see them still at it 20 years after I first started mitigating AGW. The human sciences really need to catch up on human behavior modelling.

    Now I’m thinking the last 2 people alive some hundreds or thousands of years from now when AGW really gets extremely bad will be 2 brothers, one a believer, one a denialist. Then one kills the other in a heated argument over AGW, and the last man standing not only has to suffer the horrors of AGW, but suffer them alone.

  370. Ray Ladbury:

    Jason@359, We simulate the collapse of neutron stars. We simulate the flow of air aroung supersonic jets. We simulate the paths and behavior of hurricanes with pretty good 5-day accuracy. We simulate the detonation of thermonuclear devices. And on and on. This is the poorest sort of “argument from ignorance”: You can’t understand how scientists can be so smart, so you refuse to even look at the evidence that climate models have substantial skill.

    And even if you were right, what then? All of the evidence we have strongly favors a climate sensitivity of at least 2.1 degrees per doubling–and it’s much more likely to be above 4.5 than below 2.1. That is sufficient to establish that we have a serious threat. Climate models are crucial to identifying and evaluating risks posed by that threat. If you cannot bound the risk, it doesn’t mean you are off the hook. An unbounded risk is something you absolutely cannot ignore–any risk assessment professional will tell you that! You are under the misimpression that somehow ignorance is your friend. It is not.

  371. Jason:

    #314: “Hindcasts are not worth much?”

    I actually think that hindcasts are very valuable, and have been exceptionally valuable to climate science.

    I argue that they are insufficient, not that they are useless.

    “So what was wrong with Ptolemy’s theory? It had no serious foundations but was just a brilliant form of curve fitting. In some ways it resembled the cyclical theory of climate which is now one of the alternatives to the consensus version.”

    The problem with Epicycle based models of our solar system, aside from surprisingly minor inaccuracies, is that they can not tell us anything about how the system would respond to a change in circumstances.

    If a massive object shot through the solar system, what impact would it have on the movement of the planets? This curve fitting exercise could tell us nothing.

    GCMs are being used to model the effects of a change in the system. To the extent that they are an exercise in fitting (or over-fitting) curves to hindcasts, they will not be able to inform us about the consequences of that change.

    [A discussion of the assumptions that I mentioned follows]

    I lack the knowledge necessary to tell climate scientists how to improve their assumptions. Even if I did possess the requisite knowledge and understanding, I doubt that I would have sufficient confidence in my own assumptions to put any faith in their results (absent some forward looking validation).

    “Rejection of the validation of the models because of a supposed problem with the “current pause in warming”? Isn’t that the same old misuse of short term trends discussed so many times or does it refer to the climate models inability to reproduce the details of the short term wiggles which would be based on an unrealistic demand for lots more detailed initial conditions? Neither constitutes a reason for rejecting the validation which depends on being able to get the right statistically meaningful trend.”

    As I previously mentioned, I will be convinced if the observed data resumes its previous trends. The inability to replicate short term wiggles does not concern me, provided that those wiggles turn out to be brief interruptions in a long term trend.

  372. Hank Roberts:

    > sierra 117
    > Does anyone know where I might find time series
    > data of atmospheric CO2 concentrations?

    The Start Here button at the top of the page is one good place to start.
    So is the first link under Science in the right sidebar.

    Or Google; here’s your question, with the magic letters in front of it:

    http://www.google.com/search?q=time+series+data+of+atmospheric+CO2+concentrations%3F

  373. Grabski:

    Ray Ladbury wrote: What an odd thing to ask at the end of the warmest decade on record. You have quite an imagination.

    Really? I can read the graphs in this article. For one, a change of zero is within the confidence bands of the chart labelled IPCC AR4 Realizations. So much for the confidence there.

    [Response: Over the whole period? No. a zero trend from 1979 to 2009 is well outside the modelled range. - gavin]

    Second, the Hansen graph is very rich. For one, it clearly shows that warming has stopped. In the words (paraphrased) of Dr Ternbreth: Where’s teh Warming? Why can’t we measure it? Yes, climate/weather blah blah; but after some time weather becomes climate and that’s happening right now. Temps do have an autocorrelation, meaning that it takes time to reverse field. So temps have to stop climbing (happened) before they start falling (looking like that in the most recent, short term trend).

    Third, the Hansen out of sample forecast shows that even though forcings are 25% above actuals, temps are below that forecast. That is, temps are below what was forecast even for a lower level of forcings (which didn’t, of course, happen). There’s a lot of info in that miss.

    [Response: Forcings are not '25% above' expectations. Where did you get that idea? Go back to the orginal post on the Hansen et al results to see what the forcings actually have done (they are lower than Scenario B). - gavin]

    [edit of tedium]

  374. Ray Ladbury:

    Simon@339 Ahh! I see the problem! You are taking yearly AVERAGE readings! In so doing, you are already removing the seasonal effect. In that case, the advantage of the anomaly numbers is merely that they correspond better to the physical parameter of interest–namely how much heat we have added to the system, rather than how much heat, total, is in the system. Make sense?

  375. Lynn Vincentnathan:

    #367, Completely Fed Up, I like your last phrase, “the CRU hack would have shown it.” That’s how we need to turn the CRU fiasco on its head. Let’s keep on using that phrase.

    Like, “If the climate scientists truly understood it was cosmic rays and not GHGs causing the warming, the CRU hack would have shown it.”

    Or, “If the climate scientists truly understood there was no global warming in the 20th-21st centuries, the CRU hack would have shown it.”

    We can just go down the laundry list on this one.

  376. Completely Fed Up:

    Jason proclaims: “As I previously mentioned, I will be convinced if the observed data resumes its previous trends.”

    Well were you for AGW until ~2003 then?

    No, I don’t think you were, Jason.

    And how will you know the trend when you don’t seem to be able to work out whether we have one (note: we don’t. 8-10 years isn’t long enough). So how will you change your mind? How will we even know?

  377. PeteB:

    Dave Salt,

    Re : Climate sensitivities and feedbacks

    There are a couple of good sections in AR4, both in the increased confidence in water vapour feedback, and the robustness of the combined water vapour / lapse rate feedback Section 8.6

    http://ipcc-wg1.ucar.edu/wg1/Report/AR4WG1_Print_Ch08.pdf

    And observational estimates of overall climate sensitivity Section 9.6

    http://ipcc-wg1.ucar.edu/wg1/Report/AR4WG1_Print_Ch09.pdf

  378. Completely Fed Up:

    Ray: “You are under the misimpression that somehow ignorance is your friend. It is not.”

    Well seeing as knowledge isn’t going to make him right, that’s not his friend either.

    And ignorance has the benefit of being easier to come across.

  379. Andrew:

    @John Pearson: “Celso Grebogi, Ed Ott, and Jim Yorke,”

    The climate has to be regarded as a system where the parameters have uncertainty; so the deterministic chaos approach is not likely to be safe. On the other hand, in the 1990s, the theory of H-infinity control was revolutionized by the work of Glover, Doyle, and others (based on AAK theory, etc.).

    What modern control theory would tell us about climate control is:

    1. It is possible to some extent; but we do not know enough about the precision of control that can be achieved.
    2. It is not at all clear what the minimum cost of the control for a given performance specification will be but it is clear that the minimum cost robust control will likely not be a policy which is all on one parameter and none on the others. This is the biggest complaint I have about people that think we can best solve climate problems with all CO2 control and ignore everything else, or all pumping aerosols and nothing else, or the hydrogen economy, or only use planning, etc. Unless you have a very strong L-1 like cost of control, you don’t see this sort of sparse control vector in a minimal control. And if there is one thing we really do know about the system is that there are strong uncertainties about the costs of control; this means at the very least the cost of control is bounded from below by a quadratic form (i.e. L-2 norm). I would bet the house that all-or-nothing is completely non-optimal at this point. This would also preclude “getting lucky” by using a deterministic chaotic control, too.

  380. Jason:

    #328: “J: I’ve seen outwardly credible estimates explicitly suggesting that it will be possible to build carbon sequestration technology that removes many times more carbon from the atmosphere than is emitted during the production of the required energy. Can you direct me to an argument explaining why this physically is impossible?

    Surely, it’s called the First Law of Thermodynamics, which apparently has something to do with conservation of energy.”

    Nobody is proposing that atmospheric CO2 be turned back into petroleum and pumped into the ground.

    There are numerous plausible methods of removing carbon from the atmosphere that require substantially less energy than was generated during the process of emitting the CO2 in the first place.

  381. Ray Ladbury:

    mark@348 asks “Why a ‘wall of shame’ for holding a different view?”

    Nope! Not for holding a different view, but rather for refusing to consider evidence, for digging up thrice-killed zombie arguments, for attempting character assassination of scientists for just trying to do their job or for asserting the existence of a massive conspiracy by the entire scientific community to take over the world.

    Scientists really aren’t that hard to get along with: Just don’t ignore the evidence and if you are going to accuse us of fraud, you better have something more substantial than quotes mined from stolen emails and taken out of context or post-modernist, anti-science claptrap.

  382. PeteB:

    Dave Salt

    Re Climate Sensitivity and Feedbacks

    Section 8.6 Climate Sensitivity and Feedbacks (including the robustness of the combined water vapour / lapse rate feedback)

    http://ipcc-wg1.ucar.edu/wg1/Report/AR4WG1_Print_Ch08.pdf

    Section 9.6 Observational constraints on climate sensitivity

    http://ipcc-wg1.ucar.edu/wg1/Report/AR4WG1_Print_Ch09.pdf

  383. Bill DeMott:

    If GCMs _are_ as accurate as some of their proponents seem to believe, it would be the high water mark in the history of human modeling of complex systems; an extraordinary accomplishment of which I am (quite legitimately I think) deeply skeptical.

    Comment by Jason — 31 December 2009 @ 10:13 AM

    Jason:

    I don’t see that GCMs are claiming or even attempting a “high degree of accuracy.” Rather, the goal is to show long term trends. As far as I can see, these general models are not attempting to predict el ninos and athey certainly don’t predict the occasional significant volcanic erruption. The point is that they predict the approximate slope of the long term trend. This is what we need to understand how humans are influencing climate and whether we need to do something about it.

  384. Hank Roberts:

    > I will be convinced if the observed data resumes its previous trends

    Please see the MetOffice page I quoted earlier.

  385. ADR:

    Thoughts?

    No Rise of Atmospheric Carbon Dioxide Fraction in Past 160 Years, New Research Finds: http://www.sciencedaily.com/releases/2009/12/091230184221.htm

    Controversial New Climate Change Data: Is Earth’s Capacity to Absorb CO2 Much Greater Than Expected: http://www.sciencedaily.com/releases/2009/11/091110141842.htm

  386. John E. Pearson:

    367: Huh? You need to chill. I was simply commenting that it is in fact possible to control chaotic systems, that it has been done, and I provided a hook into the literature. You wrote: “And such would give massively different results if you didn’t do EXACTLY the right tweaks.” This is simply false. The tweaks would constitute a set of measure zero and would be unachievable in practice. Besides the theory they constructed an experimental realization of the theory in collaboration with a bunch of guys from the Naval Surface Warfare center. If you want a trajectory that falls within some prescribed tolerances it is possible to achieve it. I have no idea what HAD CRU has to do with this. I suppose that you are writing this nonsense because you have decided I am an evil denialist because of a joke that I made the other day in which I used the phrase “alarmist”. Personally it made me laugh out loud as did the initial post that I was responding too with said joke in which it was claimed that a month to month change in the anomaly of .2degrees was a really big deal and somehow invalidated all of climate science.

    I hate it when people need it spelled out for them. Here goes. For starters I am no denialist. The top comment on this is me catching George Will in a blatant lie: http://www.washingtonpost.com/ac2/wp-dyn/comments/display?contentID=AR2006033101707 There, I’ve said it. Beyond that, people on this site really need to chill a bit. I’ve been insulted mildly and strongly on here on numerous occasions, always by people who had incorrectly concluded that I was trying to deny the science. Usually that was in response to questions. Hank has a tendency to type the question into google and tell me to read the papers. I use google all the time in my own research. It can take hours to find the important references. If I ask a question here it is simply a scientist asking a scientific question. I’ve asked questions on here and been called stupid for asking them. I may or may not have already googled for it. I may just want to hear what people think/know about a given subject. Sometimes I think out loud on here. That is simply the normal way that scientists communicate. You shouldn’t always jump on each and every remark that someone makes and one ought not to be so quick to insult people. It stifles intelligent discussion. If people say the same stupid shi* over and over it ceases being intelligent discussion. Don’t respond to them. Pearson’s first Law: Never argue with idiots.

  387. Jason:

    #355 “The absolute quickest way for a young researcher to become a superstar is to overturn a model that is well established.”

    That is true. If you could produce a result that empirically overturned a branch of science you would have it made.

    How often do you think this occurs? More to the point, what is the probability that a random MIT grad student (like the ones you called idiots) will make such a discovery?

    What is the probability that they will get a tenure track position as a consequence of decidedly more incremental work?

    If a PhD candidate hoping to snag a tenure tack position came to you for career advice, would you tell him to focus his research on proving the IPCC wrong?

    “Good Lord, man, you don’t understand anything about the scientific process or scientists at all.”

    I like your romantic view of how science works. Lone individuals producing results that overturn branches of science. But if you actually believe that this how the majority of science works, then I’m afraid it is you who is ignorant of the scientific process.

    As the editors of Nature and other top journals make it their mission to suppress evidence that “that obstructionist politicians in the US Senate will probably use [...] as an excuse to stiffen their opposition to the country’s much needed climate bill”, anyone who produces research that is not helpful to this agenda will find their work being published in lesser journals and being subject to considerable delays.

    Grad students seem to understand this. I again suggest that if you repeat my experiment independently you will get similar results.

    There is nothing even slightly subtle about the reception that awaits skeptical climate science research.

    [Response: First off there is no specific thing as 'skeptical climate science research'. There is plenty of skepticism throughout climate science. If you mean 'research that is perceived to go against the conventional wisdom' there is plenty of that - and most of it doesn't get any press at all. Scientists are challenging conventional wisdom all the time. If you are talking about the occasional paper that is based on bad statistics (Douglass et al, 2008), flawed logic (Soon and Baliunas, 2003), inappropriate models (Schwartz (2007)), fundamental misconceptions about what attribution is all about (Scafetta and West (2005, 2006, 2007, 2009)), or ignorance about the basics of paleoclimate (Loehle, 2006) , then sure - those papers will be criticised. The issue is not the conclusion, but the methodology. If the actual research does not support the claims made in the press releases and the senate floor speeches, then, yes, that will affect your scientific reputation (as it should). Note that there are some contrary papers that deserve publication - whether they end up being right or wrong - I count Lindzen and Choi (2009) in that group. I think it will be found wanting and not turn out to be a robust or useful result, but the research done in demonstrating this will be useful. It simply a fact of life that bad papers (defined as lacking in methodology/logic/etc - not on the basis of their conclusion) will get contrarian attention if they say that they have 'proved the consensus wrong'. That means that they also get more attention from the mainstream. Bad papers that go the other way generally just fade into obscurity - neither commented on nor cited. And in most other fields that is what happens to all of them. I'll make one addition comment, if a student follows a research path because they want to demonstrate that climate sensitivity is negligible then they are in severe danger of having their prejudices guide their analysis. People should research things they are interested in - that might have applications for climate sensitivity - but they need to be guided by the results, not their wishful thinking. - gavin]

  388. Jason:

    #368: “When Svante Arrhenius calculated the climate sensitivity to CO2, what values did he come up with? Do today’s climate models show higher or lower sensitivity than Arrhenius’ original calculations? And how do those numbers square with your claim that scientists are encouraged to tweak their models to produce higher sensitivity numbers?”

    Clearly there is a (recent) downward trend in climate sensitivity numbers. I think this is primarily a result of climate scientists looking at observations, observing that their models need improvement, and tweaking the models to achieve better results (ultimately resulting in a lower sensitivity).

    I have never accused the modelers of ignoring data; just not having enough of it.

    I suspect that the trend towards lower climate sensitivity numbers will continue during the new decade.

    [Response: On the basis of what? This is just your wishful thinking.- gavin]

  389. Jason:

    #370: “You are under the misimpression that somehow ignorance is your friend.”

    Ray Ladbury, you do your arguments no favor by behaving in such an ugly manner.

  390. jl:

    re 365
    ftp://ftp.cmdl.noaa.gov/ccg/co2/trends/co2_mm_mlo.txt

  391. Matthew:

    354, Completely fed up: Trend analysis is NOT A MODEL.

    It’s a statistical model, or a mathematical model, analogous to the pre-Newtonian models of planetary movement. Another example is the pre-Einstein Lorentz-Fitzgerald contractions.

    After all, Max sees a 60 year cycle, but who’s to say there’s not a 100 year cycle still going up? And then a 1000 year cycle still going up, etc?

    That’s why stringent testing, not lenient testing, is required. The Digital Orery showed that planetary movement is chaotic, not periodic, as far into the future as they were able to simulate. But the periodicity is a sufficiently accurate model for making calendars.

    And please explain how so many climate models that leave out different things you INSIST are the death knell to accuracy still manage to get so many things the same?

    “are the death knell to accuracy” is your formulation. I only claim, in a skeptical spirit, that they might be the sources of gross inaccuracy. The models make some common predictions because of what they have in common, which could be imprecise parameter values.

    356, Ray Ladbury: This is true only if you get the physics badly wrong–which shows up in the validation phase.

    No. Many tiny inaccuracies can accumulate to produce model predictions that are inaccurate on time scales of 10-30 years.

    359, Lynn Vincentnathan: I wish I had had a good “model” for understanding denialists, so I wouldn’t be so shocked to see them still at it 20 years after I first started mitigating AGW. The human sciences really need to catch up on human behavior modelling.

    It’s characteristic of some AGW credents that they overlook the need to understand how so much intense belief in AGW has been created from such incomplete and imprecise knowledge. Imagine the possibility that, 20 years hence, Indian and Chinese psychological scientists and historians of science write books and hold symposia about the decline of the EU and US that was precipitated by the AGW mass hysteria that swept them. Was it just a coincidence that the hysteria developed in parallel with the “Left Behind” religious movement? Or in parallel with the gross overinvestment in “end of life” medical care? In science, skepticism is the norm, and intense, motivated, skeptical debate is an ideal. A psychological problem, in general, is how do so many otherwise intelligent people develop such strong beliefs in stupid stuff? Maybe the AGW hysteria (that part, like believing Al Gore, that might be “hysteria”) is just another of many examples of fin de siecle disease.

  392. Didactylos:

    Completely Fed Up said:
    “So your request is nonsensical: there IS no absolute temperature. It’s all relative.”

    You are being confusing. Any measurement system is ultimately just a convention, so your “explanation” doesn’t really explain anything. Most importantly, it doesn’t even touch on any of the relevant science, which is all explained rather well in the link Gavin provided: http://data.giss.nasa.gov/gistemp/abs_temp.html

  393. John P. Reisman (OSS Foundation):

    #307 Jason

    If your research produced results that tended to disagree with the consensus, what impact do you think it would have on your ability to: Get a job/Get a grant/Get tenured.

    You do realize that your question has nothing to do with actual science… right?

    It’s similar to to saying 2+2=4 but if society believes that it is 5 and you want to get a job, you really should ignore the reality of the equation and go with what others think. That has nothing to do with the equation though. You are inferring a non sequitur argument regarding desire has relevance to scientific knowledge, bizarre at best. Straw-man arguments again… My niece eats ice cream and she’s not fat, so ice cream does not make people fat.

    Such obtuse logic spouted by those that attempt to compare opinion with science are one of the major problems of getting people to understand the relevance of context in debate. Adding yet another shadow of complexity into the minds of students without explaining the context, from a teacher (if you are a teacher/professor?), this is more easily considered nefarious if not argument from ignorance/authority.

    In other words it sounds like you are confusing your students more than educating them. No wonder America has so many critical thinking problems… or are you teaching critical thinking and not merely challenging the students to delve?

    If my assumptions are correct about you, I’m surprised you are a teacher. This is a serious problem. If you can’t even parse out the logic, and you’re a teacher, and if that may be endemic among teachers across the nation, that explains a lot about the confusion.

    I recommend you delve deeper into the science and leave the unrelated opinions aside.

  394. Andrew:

    @Jason: “If your research produced results that tended to disagree with the consensus, what impact do you think it would have on your ability to: Get a job/Get a grant/Get tenured.”

    It would help you get a job, get grants, and get tenured. If there’s one thing a graduate student prays for, it’s a clear demonstration of an unexpected result.

    Confirmation is tremendously important in science, but original discovery is what pulls down the prizes.

    The place where you get the prize for finally showing what everyone already knew? That’s mathematics, not science.

  395. Alan Millar:

    361. Comment by Ray Ladbury — 31 December 2009 @ 10:16 AM

    “It means that if you force your model to have a sensitivity less than this level, it doesn’t look like Earth. It fails. Is that clear.”

    I think you mean that it doesn’t look like the modelled Earth.

    That means one of two things :-

    Either it helps to validate the models or it helps to show that the models are no good!

    We hear that the models are not backfitted to match the data, that’s a laugh! Unless we are being led to believe that the models predicted the Mount Pinatubo eruption. That would be a good trick!

    The models were obviously backfitted to match the effects of this eruption and the assumptions and parameters used were almost certainly those that would cause the models to match the actual temperature record.

    If it was just the physics I would like to be pointed to the papers which have established the precise effects of aerosols on the global climate and how those agreed parameters were input into the models. As far as I am aware these are not well understood currently and are still being debated.

    Alan

  396. Lynn Vincentnathan:

    #351, Grabski & “what if it becomes clear that the climate is threatened by continued cooling? Then trillions will have been wasted.”

    Not at all — we would have become energy/resource efficient/conservative and on to really great alt energy — thus saving us money and strengthening our economic without loss of productivity. And we would have mitigated a host of other environmental and non-environmental problems to boot, saving us even more money and lives.

    And if truly we find the earth is cooling, then we could get out some of those fossil fuels we fortuitously left in the ground and burn them a bit (making sure their other pollutants don’t get emitted), and keep our climate just right for life as we know and love it.

    However, if you read Hansen’s STORMS OF MY GRANDCHILDREN, it seems very unlikely we will be going into an ice age. Ever!

  397. dhogaza:

    GCMs are being used to model the effects of a change in the system. To the extent that they are an exercise in fitting (or over-fitting) curves to hindcasts, they will not be able to inform us about the consequences of that change.

    I lack the knowledge necessary to tell climate scientists how to improve their assumptions.

    The first paragraph shows you don’t even know how the models work, despite various people including Gavin Schmidt telling you and others that they’re not “exercises in fitting curves to hindcasts”.

    And yet here you are spouting off about assumptions that need improvement, models that you don’t believe work sufficiently well to be useful, etc.

    Why don’t you just stay away until you’ve learned enough to stop embarrassing yourself in public?

  398. Completely Fed Up:

    Andrew procrastinates: “This is the biggest complaint I have about people that think we can best solve climate problems with all CO2 control and ignore everything else,”

    What is this “everything else” that is being ignored, Andy? And how do you know it’s being ignored?

    An example: I’m using a slow poison to kill my rich great aunt so I can inherit a wodge. I am, however, caught in the act.

    My rich aunt has the flu at the same time.

    Do they treat the flu symptoms but still let me give her the toxin?

    That’s what your complaint “Don’t stop CO2 production” wail is asking for: we continue to add a slow poison whilst working on, oh, poor people or something.

  399. Ray Ladbury:

    ADR@384, Note that the study is talking about what percentage of CO2 goes into the atmosphere as opposed to “elsewhere”. If true, it would be encouraging. However, it does seem to conflict with some other recent studies and I would think the further you go back, the greater would be the uncertainty in both emissions and atmospheric vs. oceanic fraction. It also adds concern for oceanic acidification, though. One to watch, I’d say, until someone more knowledgeable than me has a chance to peruse it.

  400. Blair Dowden:

    ADR at 384: The titles of both articles are misleading, at least to me. The content of both are about the same thing, and it is valid – the fraction of CO2 absorbed by the land and oceans has not changed significantly over the period we are able to measure. This is good news, this most important negative feedback is not decreasing so far. As for this invalidating climate models, I don’t really know, but I think that the predicted reductions in the ability of the earth to absorb CO2 will happen too slowly to show up in the current data.

  401. Completely Fed Up:

    Didactic: “You are being confusing. Any measurement system is ultimately just a convention, so your “explanation” doesn’t really explain anything. ”

    And 100% matched to the complaint. It meant nothing too and changing the “absolute” part doesn’t tell you naff all about the temperature.

    Why not use the kelvin scale?

    Of course, you’d start with a scale at about 288K and so all your plots would be relative to that value…

    hang on, that’s exactly the same plot as the poster was complaining about…

    So no, the answer was 100% correct for the query made.

  402. Completely Fed Up:

    “As far as I am aware these are not well understood currently and are still being debated.

    Alan”

    And does the debate change the result significantly?

    No.

    But you can look and see for yourself rather than just hand-wave the problem into existence.

    After all, according to quantum mechanics, you can’t know the position and velocity of anything to 100% accuracy and the nature of the macroscopic world in quantum terms is still being debated.

    Does this mean we can’t find out if a driver was speeding?

    No.

    Why?

    Because the known issues do not affect the answer we’re looking at.

  403. Josh Cryer:

    #385 John E. Pearson, thanks for the link, I hadn’t known you could coerce chaotic systems like this. Not having read the paper, could you explain what it does to the system? It seems as if their perturbations could break a system that is dependent upon chaotic runs, so any attempts to use their method with climate models would prove futile. Certainly if I were to use it in my n-body code it would cease to be an n-body code. (Note that I saw that you are not claiming that this is what is used with climate models, at least this claim cannot be made with regards to those where the code is readily available, such as GISS or CCSM.)

    And don’t let some commentators get to you, it gets bad on both sides of the isle. I like that it’s not as bad here on this site as it is on others (probably because they moderate out most of the noise).

  404. Completely Fed Up:

    ” Alan Millar says:
    31 December 2009 at 1:25 PM
    I think you mean that it doesn’t look like the modelled Earth.”

    Well, given we’re living on the Earth and we are interested in the climate of the Earth, I think that is rather the point, don’t you?

    And yes, the actual pinatubo eruption wasn’t modelled but what they did after the fact was change the eruption they presumed to happen with the actual measurements OF THAT VOLCANIC ERUPTION (which, remember, is not modeled, this is a climate model not a vulcanology one) and then run the same physical model again, untuned to that change, but the same parameterisations as the original had, so the ONLY new information is the measured event of Pinatubo.

    If the result was significantly different from the real record of the earth that had that eruption in it, then the model would have failed. If it was slightly different, it would show how much the models could be wrong.

    This is called “proving the models”.

    And it passed.

  405. Ray Ladbury:

    Matthew@390 says “No. Many tiny inaccuracies can accumulate to produce model predictions that are inaccurate on time scales of 10-30 years.”

    This presumes a systematic bias of “tiny inaccuracies”. It also presumes that the same bias does not prevail for the validation dataset–that is there must be a systematic shift in systematic biases. Yes, it’s possible to screw up a validation. Pray, what evidence do you have that the validation was in fact screwed up?

    Matthew then reveals his true colors: “Imagine the possibility that, 20 years hence, Indian and Chinese psychological scientists and historians of science write books and hold symposia about the decline of the EU and US that was precipitated by the AGW mass hysteria that swept them. Was it just a coincidence that the hysteria developed in parallel with the “Left Behind” religious movement?”

    Congratulations, Matthew, you have revealed yourself to be a tin-foil-hat-and-black-helicopter conspiracy theorist. Dude, did it ever occur to you that the reason scientists find the evidence persuasive is because the evidence is in fact persuasive? Isn’t that just a wee bit more plausible than the assumption that more than 95% of climate scientists and more than 90% of physicists, and more than 85% of chemists and… have all suddenly and simultaneously gone bat-shit crazy?

    Please, please, please, please, please and pretty, please with sugar on top, Matthew, read Spencer Weart’s history. It’s referenced on the Start Here page. ‘Cause, Dude, seeing you spout this conspiracy-theory stuff is embarrassing!

  406. Ray Ladbury:

    Alan Millar says “I think you mean that it doesn’t look like the modelled Earth.”

    I’m sorry. I didn’t realize it was possible to stutter in a written response. No, I mean what I said. A model with sensitivity below 2.1 degrees per doubling doesn’t look anything like Earth.

    As to the rest of your screed, the fact that you seem to think it is necessary for a climate model to predict volcanic eruptions would seem to indicate that you don’t have much of a grasp of the subject matter.

  407. Completely Fed Up:

    Mathew repeats: “354, Completely fed up: Trend analysis is NOT A MODEL.

    It’s a statistical model, or a mathematical model”

    It’s not a model where you can do any form of simulation.

    It is not the model that GCMs are a class of.

    And those form-fitting analyses are worse than the physical ones you want to avoid using (mostly because they can’t be made to fit the result you’d like to see).

    The form fitting is not a scientific model: you can’t say “and this causes that” because you haven’t EXPLAINED the origin of the wavelets you’ve fitted. All your intend will result in is “well, it goes up and down like this”. This doesn’t model the real world and it doesn’t model a hypothetical world (e.g. one where we tripled CO2 output or halted output of CO2 completely). It hasn’t explained anything.

    It’s just made a different way to say what the line did.

  408. Andrew:

    @Completely Fed Up: “344.Andrew #304: the richest people have a tax rate of less than 20%.”

    That’t not anywhere near as true as it was twenty years ago, but it is also irrelevant even if it were true.

    I am using data based on actual taxes paid – not taxes avoided or reduced.

    The taxes actually paid by the highest 1% earners in 2007 amounted to just over 40%. 2007 is the most recent year for which that data is available. 2008 will likely be a distorted picture, but 2009 should be relatively normal.

    Here is a link to a report containing the data:

    http://www.taxfoundation.org/news/show/250.html

    And of course if you want the straight government data you can get it from the IRS as Excel sheets:

    http://www.irs.gov/taxstats/indtaxstats/article/0,,id=133521,00.html

    Note that replacing income tax with carbon tax would mean replacing the tax collected – not the tax avoided. So if we were to suppose that rich people pay very low tax rates then it would only make replacing income tax with carbon tax even more burdensome for the average taxpayer.

    You can actually check for the most part people with high tax rates don’t easily reduce their tax rates – there’s 2.5 trillion dollars in tax free municipal bonds that are worthless to people who do not pay high tax rates. There is no point to buying munis if you don’t have a high tax rate. 2.5 trillion dollars is a lot of pointless.

    There are lots of other tax managed financial instruments ETFs, mutual funds – and things like overpaying life insurance premiums. If you are a high earner, all sorts of salesmen come knocking on your door with these ideas. Well if it was easy to just lower your tax rate by going offshore, then none of these guys would be in business. Yet their business thrives; only because the large majority of rich people end up paying high tax rates.

    I suppose I should point out I spent the last twenty years running offshore hedge funds, so the question is not new to me. If you live in the U.S. then you can invest offshore, but you are much better off reporting the income to the IRS, in which case it is taxed same as if you made it in the U.S. Now thousands of rich people were talked into trying tricks that amount to lying to the IRS about their offshore assets (and many of them are now in court trying to stay out of jail – Google “UBS tax evasion 2008″ for stories). But that’s thousands, not hundreds of thousands of people. Most rich people I knew are smart enough to stay clean with the IRS. Of course there will always be some dimwit who can’t control their greed, but many of those actually get caught. The offshore tax cheat does occur, but like the infamous welfare queen with two cadillacs? It’s the exception that fires the imagination, not the bulk of the statistics.

  409. John P. Reisman (OSS Foundation):

    #371 Jason

    Insufficient?

    Let’s try a thought experiment.

    Someone is holding a gun to your head. The majority of weapons experts believe that the bullets in the gun are real and powerful enough to blow your head clean off. You don’t think they are. You think they are insufficient and will do no harm.

    So you say, go ahead pull the trigger. After that you will decide if the bullets are real and sufficient to blow your head clean off.

    This is effectively what you are saying with your argument.

    More explicitly you are saying GCM’s and hindcasts are not really good enough yet, and you lack the knowledge needed to help experts improve their assumptions (second smart thing you said in your post, first was ‘hindcasts are very valuable’).

    We know greenhouse gases are actually greenhouse gases (GHG’s).

    We know industrial processes and land use changes have increased the levels of GHG’s in the atmosphere. We know albedo is changing.

    So, essentially, your logic, is that GHG’s are not GHG’s, thus, adding more will not have a meaningful effect.

    So you’re saying go ahead, pull the trigger… and if it destroys the global economy we will then know that the scientists were right and you were wrong.

    Man, I’m glad you’re not my dad. It would be rough for me to listen to such obtuse reasoning on even a semi regular basis. It’s hard enough as it is.

  410. Josh Cryer:

    Ray Ladbury, BTW, I saw that you mentioned DSCOVR a few pages back, I was wondering if you were aware of CLARREO: http://clarreo.larc.nasa.gov

    I wish it would happen sooner than 2016, but it should have such an accurate sampling ratio as to make land based temperature records obsolete (not that climatologists won’t still use them!).

  411. Joseph:

    I would expect that even leaving one minor forcing or feedback mechanism unaccounted for in the models would create a cumulative effect over time exaggerating either a warming or cooling effect that would cause the model’s results to greatly diverge from actual temperature records over a significant period of time.

    Without having looked at the code of the really complex physics-based models, I can tell you it wouldn’t work like this. If the predicted temperature deviates too much from where the equilibrium temperature should be (according to irradiance and forcings) the model will self-correct. So I don’t believe you’d have this “cumulative” error you’re speculating about in any significant way.

  412. Ken W:

    ADR (384):
    It’s important to understand that the total amount of CO2 in the atmosphere is increasing (nothing in this report challenges that) and that will in turn cause additional warming. It’s also important to understand that no single study is conclusive (the skeptics always like to jump on a single study that they think supports their position, while ignoring dozens of others that counter their position).

    Here’s a good brief analysis of that study:
    http://www.skepticalscience.com/Is-the-airborne-fraction-of-anthropogenic-CO2-emissions-increasing.html

  413. Edward Greisch:

    http://www.scientificamerican.com/article.cfm?id=local-nuclear-war&sc=DD_20091230
    Scientific American has just inadvertently published a new geo-engineering solution to global warming.

  414. SecularAnimist:

    Matthew wrote: “Imagine the possibility that, 20 years hence, Indian and Chinese psychological scientists and historians of science write books and hold symposia about the decline of the EU and US that was precipitated by the AGW mass hysteria that swept them.”

    Actually, they will be writing about how the decline of the USA was brought about by the death-grip of the fossil fuel industry on US energy policy, which kept the US mired in 19th century energy technologies, while China and India became the economic powerhouses of the world through massive investment in wind, solar and other renewable energy technologies that became the foundation of the New Industrial Revolution of the 21st Century.

    Actually, they are already writing about that now, since it is already happening. China is already the world leader in wind and solar manufacturing and exporting — both technologies that were invented in the USA.

  415. Doug Bostrom:

    Ray Ladbury says: 31 December 2009 at 2:01 PM

    “Please, please, please, please, please and pretty, please with sugar on top, Matthew, read Spencer Weart’s history.”

    Just in case finding the link was baffling:
    http://www.aip.org/history/climate/

    Suggestion to RC: script the site so that every five posts a machine-generated post links to Weart’s site.

    Tip for contrarians: read Weart’s history -before- posting here.

  416. SecularAnimist:

    My only comment about those graphs is that I admire the equanimity which seems to enable scientists to look at them dispassionately and analytically. I’m glad you can do that, because I cannot. They fill me with fear.

  417. Andrew:

    @CFU: “What is this “everything else” that is being ignored”

    If you look at the policies proposed on climate remediation, (e.g. Waxman-Markey, carbon tax etc.) then climate forcings other than CO2 are treated as CO2 equivalents. This means a one-dimensional measurement of the control parameter is used, despite the application of a multi-dimensional control. In those circumstances, it is likely (and expected) that the actual linear combination of the control that is applied will be determined by the economics of the controls (the arbitrage is via cap and trade). By setting up that arbitrage we know that we will be applying a one dimensional control. Then we are minimizing the instantaneous economic cost (and hoping without any serious credibility that has some sort of global optimality).

    Here is an analogy – you have several parameters for controlling your car – steering wheel and accelerator to name two. And if you make a gentle turn, you lose a little speed, so there is a sort of “equivalence” between the steering wheel and the accelerator over a small region of the parameter space. Now if you made a cap-and-trade style arbitrage between those two parameters, you might end up with the minizing combination being 20% steering and 80% accelerator. Imagine now that your car mechanically connects those two inputs with that scaling. Parallel parking might actually be possible in those circumstances. But it would be seriously more difficult than if you can use them independently.

  418. Martin Vermeer:

    Matthew #326

    … I think that you underestimate the cost
    of betting huge sums of money on current technology with current
    knowledge. Money spent now will not be available 20 years from now
    when better technology is available

    Ah… “wait for technology to save us.” Look, you don’t study mitigation scenarios much do you? The spending takes place over the whole time line, not all of it ‘now’. But what we do spend now, will have to be based on current technological realities. 20 years from now? Ask again then.
    …and please note that not investing now in mitigation is also a ‘bet’, or should I say ‘uninvestment’, collecting compound interest at a nasty rate until we wizen up.

    if some other theory than AGW turns out to be more accurate

    In your dreams.

  419. Completely Fed Up:

    “If you look at the policies proposed on climate remediation, (e.g. Waxman-Markey, carbon tax etc.) then climate forcings other than CO2 are treated as CO2 equivalents.”

    OK.

    “This means a one-dimensional measurement of the control parameter is used,”

    Uh, no. didn’t you read your statement:

    “forcings other than CO2 are treated as CO2 equivalents.”

    So it’s multidimensional. Assuming this means “adapting to change in one forcing” as one-dimensional.

    “Here is an analogy – you have several parameters for controlling your car – steering wheel and accelerator to name two.”

    And your engine when you accelerate produces torque that will cause the car to veer. This used to happen a LOT in older cars before they started working on complex controls that counter this effect by turning the wheels appropriately.

    Therefore your accelerator also has a steering wheel in it.

    But it doesn’t stop there!

    When you turn, old cars had the wheels spin the same speed and your inside driven wheel would skid because it was trying to move the same linear distance on the inside of a curve. So the steering wheel has a brake that slows down the inside wheel. It’s called a differential.

    Your steering wheel has a brake in it.

    The appropriate inclusion of one dimension into the other is warranted and makes driving both easier and simpler. Modern cars are a lot easier to drive than the Model T fords.

    “But it would be seriously more difficult than if you can use them independently.”

    Not in your car.

    Helicopters also have several problems that mean your collective is mixed with some rudder, your rudder is mixed with some collective and engine, and your engine is mixed with some rudder.

    Why?

    Because without that mix, the craft is much more difficult to manage.

    Cheap radio controlled helicopters are easier to fly than expensive ones BECAUSE they have fewer controls.

    Your choice of analogy was exemplary. Pity it actually undermines your “everything else is ignored” idea.

  420. Doug Bostrom:

    Nicolas Nierenberg says: 30 December 2009 at 7:23 PM

    Hmm, I’m not even sure at this point that we’re disagreeing, or not much, rather that I took exception to your original point after reading it too literally.

    I think we could probably both agree that a model can be built from first principles, can then show reasonable competence but of course can be improved by incorporating newly identified or previously ignored influences.

    I’d venture to say that if a model of a physical system can be compared to the real physical system being described by the model and that such comparisons can yield paths for improvement of the model is a validation of the model.

    We could probably also agree that if the fundamentals of the model were poorly understood to the point that the model was originally invalid, attempts to improve it based on hindsight comparisons would probably make the performance of the model against hindsight even worse.

    In any case, I think I did not read/understand your original post properly.

  421. Doug Bostrom:

    Oops:

    “I’d venture to say that if a model of a physical system can be compared to the real physical system being described by the model and that such comparisons can yield paths for improvement of the model is a validation of the model.”

    should be:

    “I’d venture to say that if a model of a physical system can be compared to the real physical system being described by the model and that such comparisons can yield paths for improvement of the model, that process itself is likely a validation of the original model.”

  422. Jim Bullis, Miastrada Co.:

    Partly related to the ocean heat content chart of the above article, but also related to the mitigation discussion, I wrote the following comment to an Economist Magazine article on Copenhagen:

    There is something very wrong with a developed world that wastes about 80% of the energy intended for transportation and about 60% of the energy intended to make electric power. Automobiles and trucks were designed for a world where fuel seemed unlimited. Electric power generating systems were also arranged to waste energy without seriously annoying large populations. The last hundred years have been a great ride — whoopee! Correcting this insanity is the task at hand. Global warming is a secondary issue that will be fixed only when we get the more fundamental problem solved.

    It seems that the campaign against global warming could actually be a distraction that leads to failure to solve anything. The very goal of a 2 degree C limit in the rise of global surface temperature is an example of how misdirected this campaign can be. While it is plausible that man made CO2 can offset the general heat balance of the earth, it seems entirely likely that this imbalance will be taken up by the deep ocean heat capacity. We could actually have serious global warming consequences with sea level increases while the surface temperature averages rise hardly at all. All the squabbling about the temperature record may be irrelevant.

    A good case can be made that the actual scientists that model the expected climate are serious people who have done very sophisticated work. Questioning their motives because they have tried to present a convincing popular case is simply wrong and mostly anti-intellectual in flavor. Still, it seems that the impending disaster of global warming is not as well understood as we might have been led to think.

    Perhaps more relevant is the apparent fact that serious planning decisions continue to ignore global warming alltogether, and opt instead to solve the energy dependence problem. The bamboozled public thinks that electric cars with futuristic batteries will cut CO2 when this development will actually result only in a shift to coal as the base fuel and actually increase CO2 compared to emissions from hybrid vehicles. Why do people with economic and political good sense want to bamboozle the public? The answer is, that shifting to coal will indeed help with the oil dependency problem which is a meaningful way to perpetuate prosperity and to change the power balance in the Middle East.

    Also we have great enthusiasm for the “smart grid” which promises only to slightly trim losses from the existing electric power system with the underlying result of perpetuating the system of central power plants where vast amounts of heat are wasted. The dream of wind and sun as power sources seems like a deception to justify new transmission links, when the continued uneconomic reality of these ideals shows nothing real should be expected here. The bamboozled public will wake to the reality that the new transmission links will simply enable wasteful power production practices by bringing power generated far away to the urban users. Imagine “mine-mouth” power plants in the coal regions of the USA, far out in the country alongside of windmills. Guess what the proportion of power coming from wind will be.

    The real goal should be to cut energy use with due concern for the functioning of industrial society.

    We have some examples of how to do better. The Aptera is a car that dramatically decreases the energy needed for personal transportation of the sort that people need, and might eventually come to believe looks good. Distributed cogeneration of electric power using natural gas, where the generators are at individual households that use the otherwise wasted heat, thus doubling or tripling the system efficiency of electric power production. Miastrada Company is also involved in such future developments. (I represent Miastrada Co.)

    By working to solve the fundamental problem as discussed above, we arrive at possible solutions that make economic sense in their own right. The appropriate test of any solution is whether it is economically sustainable without long term infusions of public money, whether it comes from the Treasury or through extra costs for fuel or electricity.

    The tragedy of Copenhagen is that the solutions depended on infusion of public money, whether to cap and trade or subsidize poorer countries. Overlaying all this is the incredible naivety that setting of goals and making pledges means anything at all. Realists should have stayed home once Presidents Obama and Hu agreed that neither would make binding commitments. President Obama knew with certainty that he could never get such a treaty ratified and President Hu was probably aware that he would also face intractable planners who know the real costs involved.

    So we can try to spin a meaningless exercise into something that might turn out to have some positive results. Or we could try to awaken to a real challenge to rethink the way we do things in a way that fixes the fundamental problem of extreme energy waste.

  423. Lynn Vincentnathan:

    Matthew (#391), I think the hysteria is on the part of the denialists. A reasonable person (I’m talking non-scientists) when faced with a decision, would choose wisely. When choosing between acting on the false-positive (mitigating AGW, when AGW is not happening) yielded great savings and better living, and failing to act given a false negative (not mitigating when AGW really is happening) yielded great disaster, perhaps even the Vensus syndrome as top climate scientistist, James Hansen suggests, a reasonable wise person would choose — now let’s think a while — yeh, they’d choose to mitigate, save money, and have a better life, hoping like crazy the climate scientists were wrong and AGW was not happening.

    So why all this hysteria about turning off lights not in use, or getting onto GreenMountain 100% wind generated electricity that costs less than polluting energy, or putting up a little investment in energy efficient appliances and products that save money in the long run, some even paying for themselves in savings and going on to save more, and certainly doing much much better than the stock market did this past decade. Why are people so scared to death about installing a $6 low-flow showerhead with off-on button that saves $2000 in hot water during its 20 year lifetime? BOO!

  424. Barton Paul Levenson:

    Sierra117 — I have CO2 concentrations from 1880 to 2007 here:

    http://BartonPaulLevenson.com/Correlation.html

    For more up to date information, google CDIAC.

  425. Barton Paul Levenson:

    Jason: The inability to replicate short term wiggles does not concern me, provided that those wiggles turn out to be brief interruptions in a long term trend.

    BPL: Why don’t you look at the trend over more than 120 years, then?

    http://BartonPaulLevenson.com/Correlation.html

    I give temperature anomalies from 1880 to 2007. Graph ‘em against time in Excel and tell me what you get.

  426. Alan Millar:

    Comment by Ray Ladbury — 31 December 2009 @ 2:05 PM

    “As to the rest of your screed, the fact that you seem to think it is necessary for a climate model to predict volcanic eruptions would seem to indicate that you don’t have much of a grasp of the subject matter.

    The point I am making is that the models are all adjusted to match past reality. Aerosols seem the favourite way to do this. In GCM reality aerosols are like Tinkerbells fairy dust they make the Models fly!

    Of course different amounts of ‘fairy dust’ are needed for each model to make them match but that is no problem as there is no agreed physics to falsify it. Very conveniant!

    We all know that the models have a problem with the 1940 – 1975 cooling period. However, that is all solved by inputting various parameters for aerosols and voila, we can match the data!

    Unfortunately Ray, this creates a rather large elephant in the room, the 1910 – 1940 period.

    One of the most interesting of the leaked e-mails is, to my eyes, the one which includes reference to the 1910 – 1940 ‘problem’

    “The other interesting thing is (as Foukal et al. note — from
    MAGICC) that the 1910-40 warming cannot be solar. The Sun can
    get at most 10% of this with Wang et al solar, less with Foukal
    solar. So this may well be NADW, as Sarah and I noted in 1987
    (and also Schlesinger later). A reduced SST blip in the 1940s
    makes the 1910-40 warming larger than the SH (which it
    currently is not) — but not really enough.

    So … why was the SH so cold around 1910? Another SST problem?”

    This 1910-1940 issue goes to the heart as to what level of confidence we can have in the AGW theory and the associated GCMs.

    Upto now it seems that certain AGW scientists and advocates have been happy to wave their hands a bit whilst muttering Solar and Aerosols as the answer as to why global temperatures increased at a similar rate during this period as compared to the latter part of the century, with little help from increasing CO2 levels.

    I have known all along that this is rubbish. If you believe in AGW then you can only allow a small fraction of the observed increase in temperatures to be attributable to increased solar activity. As far as aerosols go, this is a direct lie. Aerosols increased very sharply during this time. This is a fact confirmed by the Greenland ice cores.

    Now we can see, in writing, that this problem is unresolved by scientists at the heart of the AGW hypothesis and they do not believe the meme they have happily allowed to become established as the answer to this ‘problem’.

    So we know for certain that we have a situation where an unknown combination of climatic factors caused the global temperatures to rise at a significant rate comparable to the late 20th century and this remains unresolved.

    I am sure that most people here can see what this means for the AGW hypothesis. Logic dictates that if you cannot explain one rise over a similar period then you cannot explain another rise over a similar period. Unless you can identify and isolate the significant factors in the earlier period then you cannot know whether these unknown factors are driving the rise in the latter period, it is unarguable logic.

    So Ray, as you beleive that the science is basically settled, please identify, isolate and quantify the precise climatic factors that drove this rise so that I can compare them against the 1976 – 2000 period to see what the difference was if any.

    If you quote reduced volcanic activity as a reason, other than as a less precise analogy for aerosols which I have already shown to be false, please state the hypothesis which allows volcanic activity to warm the Earth outwith the aerosol effect.

    Alan

  427. Ray Ladbury:

    Alan Millar,
    The period 1910 to 1940 was also a period of low volcanic activity, rising solar intensity and increased industrial activity (CO2 production)–and this probably also contributed to the observed trend. What is more, the globe was not exactly bristling with instruments in the period, so it is not surprising there are uncertainties. The fact that we cannot account in detail for every tenth of a degree at every period in history does not negate the successes of the models in accounting for the majority of what we see in Earth’s climate.

    So, Alan, what do the denialist models say about 1910-1940. Oh, that’s right, there are no denialist models. No model at all in fact that has a sensitivity less than 2.1 degrees per doubling. Do let us know when you’ve got one, Alan.

  428. dhogaza:

    Alan Millar …

    Aerosols seem the favourite way to do this. In GCM reality aerosols are like Tinkerbells fairy dust they make the Models fly!

    As proven by this abstract …

    Oh, wait, the abstract highlights a laundry lists of model results compared to observational data, it doesn’t appear they’re just making stuff up in order to make the model fly after all …

    Lurkers: never trust anything a denialist says without checking up on it first.

  429. Doug Bostrom:

    Lynn Vincentnathan says: 31 December 2009 at 3:29 PM

    “Why are people so scared to death about installing a $6 low-flow showerhead with off-on button that saves $2000 in hot water during its 20 year lifetime?”

    Well, there’s ample evidence that fear in this case is being cultivated, as well as paralysis. Cognitive corruption is being generated and propagated by professionals skilled in the arts of public relations.

    “Fear, uncertainty, and doubt”. Compare those terms to misunderstandings you see coughed up every day on this site. The general fit is remarkably tight.

    The selective attention paid to this particular branch of scientific inquiry accompanied as it is by a steady undercurrent of accusations of fraud, malfeasance and incompetence is really quite aberrant, conspicuously so.

    There are a lot of interests who are quite keen on waste. They report to shareholders and are judged in part on their ability to make sure we continue being wasteful and shortsighted. Nothing new, really; it’s an old story about preserving the status quo.

    If the stakes were not so high, people like Gavin would be able to pursue their curiosity without being the target of character assassination campaigns and the like. As it stands, their course of inquiry has lead them into the crosshairs of powerful interests.

    Some of these researchers have felt compelled to raise their hands and point out the potential danger their findings appear to identify. That just makes the situation worse for them, leading to death threats and the like, the tip of the pyramid of greed-induced madness. That’s a big problem with PR of the kind driving the contrarian community: pound on fear hard enough and you’ll bring out the crazies. Same deal as the health care debate, etc.

  430. John E. Pearson:

    403: Josh, I don’t have access to that article until I go back to work so I can’t read it. Here’s what I think they did. First it is well-known that chaotic systems have a great many unstable periodic orbits. ROnnie Mainieri and Predrag Cvitanović wrote a fairly long book about this which was never published but is probably available on the internet somewhere. You can get approximations to many statistical objects of interest by doing appropriate averages over the unstable orbits. It’s pretty technical stuff and I never understood it deeply to begin with. What I think that Yorke and co did was take advantage of the unstable periodic orbits and stabilize them by perturbing the parameters. Think of balancing a broom in the upside down position by wiggling your hand. I know they did this with an experimental system but I don’t remember much about it. THey wrote: “It is shown that one can convert a chaotic attractor to any one of a large number of possible attracting time-periodic motions by making only small time-dependent perturbations of an available system parameter. The method utilizes delay coordinate embedding, and so is applicable to experimental situations in which a priori analytical knowledge of the system dynamics is not available.” I tried to make it clear in my original remark that I don’t think this has anything at all to do with controlling the climate nor with climatologists tuning their models to the data. Mathematically controlling climate is far easier than controlling a chaotic dynamical system because if you want to turn down the temperature of the earth all you have to do is reduce the forcing a bit which is what climatologists are advocating. It doesn’t require continuous perturbations as in Grebogi, Ott & York. Simply decrease atmospheric CO2 concentration and the temperature will eventually drop (or perhaps just stop increasing).

  431. Grabski:

    Ray Ladbury:

    This is where I got that idea. From this very blog:

    And finally, let’s revisit the oldest GCM projection of all, Hansen et al (1988). The Scenario B in that paper is running a little high compared with the actual forcings growth (by about 10%)

    Scenario C assumed no change in in forcings, 2000 forward. I admit I used this description of Scenario B and extrapolated. I may be a high, but the fact is that we are below Scenario C’s out of sample forecast, and it’s clear that forcings are more than 10% above that level (since that’s Scenario B’s overshoot” and they haven’t stabilized (per Scenario C)

    So we have temps below the level that this model said would require no further growth from 2000 – 2009.

  432. John P. Reisman (OSS Foundation):

    #426 Alan Millar

    You are confusing the legitimate pursuit of quantifiable answers and problem resolution… with ‘fairy dust’.

    I think there is a level of confidence in the 1910-1940 period for combined natural variation and imposed forcing. But the signal to noise is not so easy to parse.

    But that really is a red herring isn’t it.

    The current forcing, quantitative knowledge of GHG’s, land use albedo, ocean temps are clearly resolved in models and observations, for the most part. This event is human caused.

    Picking an email and saying it says we know nothing ‘now’ is pretty silly really. Context is key. Figuring out a problem is not the same as resolving other problems.

    As to your statement:

    I have known all along that this is rubbish. If you believe in AGW then you can only allow a small fraction of the observed increase in temperatures to be attributable to increased solar activity.

    Solar accounts for around +/- 0.2 W/m2 of current radiative forcing. The current forcing above pre-industrial is positive around 3.6 W/m2. What are you trying to say?

    Can you point me to the proof you are speaking of regarding GRIP cores?

    As to your assertion:

    Logic dictates that if you cannot explain one rise over a similar period then you cannot explain another rise over a similar period.

    This is a non sequitur. If someone punches you in the face and you don’t know why that would be different that in I punched you in the face and told you why. Your assertion that your logic in unarguable is ridiculous and arrogant… since I have just argued against it quite clearly.

  433. Spaceman Spiff:

    Alan Miller @395 said:
    “We hear that the models are not backfitted to match the data, that’s a laugh! Unless we are being led to believe that the models predicted the Mount Pinatubo eruption. That would be a good trick!

    The models were obviously backfitted to match the effects of this eruption and the assumptions and parameters used were almost certainly those that would cause the models to match the actual temperature record.”

    Could you imagine at all that what was done was to inject the measured ejecta (in mass, altitude, at the appropriate latitude of the eruption) from Pinatubo into the model atmosphere, and re-run the models? And the models’ reproduction of what did happen regarding the net forcing and resulting time-lagged change in temperature provided some affirmation of the treatment of aerosols. I’d say that was a worthwhile scientific test of the model.

    Saying that “aerosols” are not completely understood is pointless. So what? You wouldn’t find a climate or atmospheric scientist anywhere that would disagree with that statement. For that matter science doesn’t completely understand anything. You’ve mistaken not knowing everything with not knowing anything. None of this is terribly useful.

    Finally, there is a significant and growing literature on aerosols and their direct and indirect effects on climate. I suggest making a modest attempt to investigate this yourself before drawing conclusions.

  434. Matthew:

    418, Martin Vermeer: Look, you don’t study mitigation scenarios much do you? The spending takes place over the whole time line, not all of it ‘now’. But what we do spend now, will have to be based on current technological realities. 20 years from now? Ask again then.

    There are lots of mitigation strategies. $1 trillion spent over 10 years by the US and EU, if used (as some has been up till now) to finance construction in India and China, will not lead to CO2 reduction before 2050, and maybe not in this century. It gets worse: the US and EU combined produce only 1/3 of the annual anthropogenic CO2, and much less of the annual CO2 increase; we could shut down completely without affecting future global warming, as long as the rest of the world keeps growing its economies, unless the AGW theory is way off. China also, like the US and EU, is investing is CO2 capture and storage R&D. If that works well enough, which we may know in 5 years (though not with certainty) then the whole mitigation strategy will change.

    I support increased production of energy from all non-carbon sources for the US, at a rate that does not cost a reduction in GDP growth, and increased investment in reforestation world-wide. I noticed that you mocked, but did not deny, the claim that too much money spent now will mean that less money is available in 2 decades. Solarizing the US economy now, by purchasing PV cells made from coal-fired factories in China (as we are doing), will accomplish less than a much slower solarization based on PV cells made from solar-powered factories, but this would will be a slower process.

    Lynn Vincentnathan, I think that a motivational analysis is not the topic of this thread, but since you raised the issue you might want to look into the theory of cognitive dissonance and “post-decision dissonance reduction”. If you have been investing in reducing your carbon footprint for the last 2 decades, as you wrote, then you have a vested psychological interest in your beliefs. You can’t change your mind no matter how much evidence accumulates against AGW, according to the cognitive dissonance theorists, so you have no right to think of yourself as a more reasonable person than anybody else. Then there’s all that mythological Freudian stuff (projection, rationalization, denial, etc.) It’s sort of arrogant to think that only people who disagree with you have motivated beliefs.

    With the uncertainty about the AGW theory, and the imprecision in the diverse predictions, a wise strategy is to hedge bets, i.e. invest in a diversified portfolio with a long-term perspective: CC&S, solar, wind, all biofuels, nuclear, reforestation; if CC&S works, then synfuels (like the Great Plains synfuels plant, where the CO2 is sold to Canadian oil companies to increase recovery of oil from old wells.) If you are buying a car, you might consume more total energy by purchasing a Prius than by purchasing a Corolla; and you might consume the least by maintaining and driving an old Camaro. Use the money to fund reforestation in Ecuador instead.

  435. TRY:

    #410 Josh – Wow, thanks for the link to this –
    http://clarreo.larc.nasa.gov

    Pretty much exactly what I was interested in, at least going by the promotional copy. It would be great to see this get launched.

    Ray and Doug – great summary! this is an excellent overview
    http://www.aip.org/history/climate/

    Timothy #341 – If you read that link above you’ll see, as I did, how complex these issues are. And that complexity has increased over time, as the impacts of absorption, emission, saturation, convection, precipitation, cloud formation, are dealt with in more and more detail throughout the entire atmosphere – which really doesn’t have ‘layers’, just a constantly changing gas/h20 makeup, energy levels, emissions, etc. across three dimensions.

    Per that link above, we are far beyond the “simple physics” in that there are so many pertinent processes and interactions that we have to rely on complex models to take everything into account.

    So I guess the challenge is, that as we make these models more complex and presumably more accurate, our expectations of their predictive power go up. But without good short-term predictions, people are left jumping back and forth —
    – “climate processes are complicated, so we need sophisticated models to show sensitivity to CO2 and take all the potential feedbacks and proceses into account”
    – “well, the models aren’t that accurate in the 15 year time frame, so how can we rely on them in the longer term?”
    – “When we’re talking about climate change and sensitivity to CO2, the underlying physics and forcing is pretty straightforward – here are the short equations showing an obvious forcing and the associated move to a higher temperature equilibrium.”
    – “But those equations don’t take X into account.”
    – “Right – but these models do. As I said, we need big models to show sensitivity to CO2 and take all the potential feedbacks and proceses into account”

    So, maybe IR output signature is a predictable, testable item. Maybe not. Interesting question, I think.

  436. Ernst K:

    “So we have temps below the level that this model said would require no further growth from 2000 – 2009.”

    But scenarios B’s forcings from emissions were about 10% higher than what actually occurred, and scenario C had the same CO2 forcings until 2000 and lower forcings from CH4 etc., so you should expect B to have over-predicted the warming, with C lagging slightly behind until 2000 after which the 2 should diverge, which they do.

    If you go to the original Hansen et al 1988 paper (http://pubs.giss.nasa.gov/docs/1988/1988_Hansen_etal.pdf), then you’ll see that Scenario B and C used the following CO2 forcings:

    2000 CO2 = 377 ppmv for both scenarios (compare figure 2 with the equation in Appendix B)
    2010 CO2 = 400 ppmv for scenario B and 377 for scenario C

    Actual CO2 in 2000 was something like 365-370 and current CO2 is about 385. 377 wasn’t reached until about 2005 or so.

    So scenario C was pessimistic until 2000, and only became slightly optimistic in 2005. It really shouldn’t be a surprise that C fits the actual temperatures the best.

    Remember that these are climate models, not emissions models.

    It would be interesting to put our best estimates of the actual CO2, trace, and aerosol concentrations into the original 1988 model and show what they would predict. As long as you don’t change any of the formulations in the model itself, it would be a perfectly valid test of the original model.

    Would that be easy to do Gavin? Or would it take a lot of work to dust off the model and get it running again?

    [Response: It's the same model as EdGCM - so no, it shouldn't be hard and I vaguely remember someone trying to do this the last time we discussed this. Not sure if it ever got finished though.- gavin]

  437. Hank Roberts:

    Grabski — you’re posting a claim about 1988 that has been debunked here repeatedly.
    Please, use the search box. Look at the assumption made in 1988 for climate sensitivity. Please look things up first.

  438. Hank Roberts:

    Oh, why hope. Here, this is what you should have found:
    http://www.realclimate.org/index.php/archives/2007/05/hansens-1988-projections/

  439. Jason:

    “I suspect that the trend towards lower climate sensitivity numbers will continue during the new decade.

    [Response: On the basis of what? This is just your wishful thinking.- gavin]”

    Let me be clear then, I suspect that the current environment in climate science, which is rabidly hostile to anyone perceived as being skeptical, has biased your estimates by consistently elevating research which is perceived as being helpful to a particular political view point, and depressing results that are perceived as harmful.

    I suspect that the views expressed in the Nature editorial have long been widespread throughout the field of climate science and have had a very significant impact on critical decisions concerning the acceptance of papers, and the awarding of funding.

    In such an environment, I think it is inevitable that there will be an impact on the research that results, your good intentions notwithstanding.

    [Response: You are very wrong in your assessment, But I doubt you will be convinced otherwise. - gavin]

  440. Geoff Wexler:

    Re #426 Alan Millar

    This 1910-1940 issue goes to the heart as to what level of confidence we can have in the AGW theory

    Try Schlesinger 4th. figure here:

    http://www.climatewatch.noaa.gov/2009/articles/short-term-cooling-on-a-warming-planet

    [Thats a popular account, an easy read; for the serious version try Google Scholar]

    What do the experts here think about the AMO mechanism being part or all of the answer to Millar?

  441. Jason:

    #394 “It would help you get a job, get grants, and get tenured. If there’s one thing a graduate student prays for, it’s a clear demonstration of an unexpected result.”

    In most fields this is true, but not in Climate Science.

    In Climate Science, if the result is perceived as threatening the consensus political view, it is attacked without regard to its scientific merit. If it is published, an attempt is made to remove the journal editors responsible.

    [Response: This is the umpteenth time you've made this statement, and you have still to provide a scintilla of proof for it. It simply isn't true. Point to one paper that was 'attacked without regard to scientific merit' and one case where any editor has been removed for publishing such a paper. And before you start agitating - note that Hans von Storch resigned from Climate Research over poor peer-reviewing (and the actual editor involved in the relevant decision (de Freitas) was not removed), and Saiers served his full 3 year term as GRL editor. So either provide some proof for your claims, or stop making them (here at least). - gavin ]

  442. Jason:

    #397: “Why don’t you just stay away until you’ve learned enough to stop embarrassing yourself in public?”

    So if I parrot Gavin who says that GCMs are not “exercises in fitting curves to hindcasts”, my comments are welcome.

    But if I propose a test for whether or not Gavin (along his peers) has accidentally biased his models, I should stay away?

    [Response: While you were actually asking questions and bringing information to the table you were most welcome. Once you dipped into unjustified and (still) unsupported insinuations of malfeasance and bias, no, not so much. - gavin]

    Amusingly, my other posts in this thread concern the topic of whether or not grad students can enhance their career prospects by attempting to publish unexpected results that go against the prevailing political sentiment.

    There is a vast difference between post on a blog and submissions to peer reviewed journals. But a host of highly regarded climate scientists: Curry, Korhola, Lindzen, Von Storch, etc. have suggested the the highly politicized attitudes expressed here extend to much more serious scientific discourse.

    The only people who should be embarrassed are those who suggest that climate science, as it exists today, welcomes contributions that could result in Inhofe and his repugnant ilk scoring political points.

    [Response: You are, again, wrong. Scientists want the truth - or as close as we can get to that. This is not something that the 'repugnant ilk' are much concerned with and so they regularly misrepresent good science (even more often than they champion nonsense). We will not prevent misrepresentations however hard we try, but you still have not demonstrated any actual evidence that good science that undermines the mainstream view is being suppressed. Given that garbage like Chilingar, Miskolczi, Gerlich and Tscheuschner, McLean et al, does get published, why can't all these brilliant contrarians do so too? Where are the Arxiv preprints that are going to blow us all away? They simply don't exist, and your conspiracies are simply fantasy. - gavin]

  443. Simon Rika aka Karmakaze:

    @Gavin, Ray, Et Al.

    Thanks, I knew I was missing something obvious, LOL!

    I have figured out at least part of what it is I was missing and thought I’d just relay it for anyone who has been following and is still confused as I was/am.

    I was forgetting that “+0.2C” in January could still be far warmer as an absolute temperature than “+2.0C” in July (for my part of the world that is) and so the latter could appear to be “cooling” when it is in fact significantly warmer than the norm, this would mean plotting the actual mean temperature would make it very hard to see the changes.

    Likewise +2.0 during a La Nina could be colder than +0.2 during an El Nino, so plotting the aboslute temperature could make the warming during the La Nina seem insignificant compared to during the El Nino. Plotting them simply as +0.2 and +2.0 doesn’t remove any relevent information (as some people might think), it simply highlights it.

    Also, as a function of the fact that we can’t measure (or realistically handle the data from) every single molecule of air even in a single column in the atmosphere, no matter how many measurements we take, it will still only represent an average, not an absulte temperature. So, plotting it as this artificial (averaged) temperature would imply something we don’t or actually can’t realistically know to a certainty, so only the change in the artifical average is plotted to avoid confusion.

    This helps incorporate something I read somewhere (probably here): that the anomaly is consistent over larger regions than the actual temperature. For example at my house it could be 15.1C and down the road it could be 15.2C but for each location that represents +0.1C anomaly. A region can be warming due to global effects, but each location within that region varies considerably in actual temperature.

    Does that sound right to the experts?

    I know this is essentially what you were trying to explain, I was just having difficulty relating it to the plotting of the data – I sort of had to try picturing the graph as an absolute temperature series over time and imagine how hard it would be to see.

    Gavin’s links helped clarify that for me, I think, but perhaps an article in the Start Here section that shows two such graphs side-by-side so we can see how the same data can look very different depending on how it is plotted might still be helpful. As for your book, Gavin, I would very much like to read it – I shall have to find out if I can get it here in my corner of New Zealand :)

    As I said, my own education in even the basics such as this is severely lacking, and I am sure some of the other commenters (especially the deniers) have the same problem. I know it is not the job of the climate scientists to teach basic skills such as this, but perhaps if there was at least a page or link here to help out people like me, some of the more silly claims might fade away. I mean to say, maybe not everyone coming here and making silly claims is being a denier, maybe they are simply confused at a level that the experts don’t even think about and wouldn’t even question among themselves. This for example isn’t even a climate issue – it’s simply a data display issue and would be common in any field dealing with complex data.

    I know a simple webpage could never explain it all (that’s why we have schools and universities) but just the common stuff like why a temperature anomaly graph is better than an absolute temperature graph at accurately conveying the data, could clear up a lot of confusion and even show genuine doubters that these things are not done to “sell” the science, but to make it easier to see, and they are done for very good reason and those of us who are not experts in the field need to be sure we understand even simple stuff like this before we start assuming we even know what we are looking at.

    Thanks for all your help, guys.

    -

    @mark #348

    “Why a ‘wall of shame’ for holding a different view? I see the same sentiment on the other side of the fence.”

    Let me make myself clear. I wasn’t saying people with different views were deniers and had to be sent to a wall of shame – I am saying people who post the same old easily disproven claims that they picked up from some random blog on the net, and didn’t even bother to independently verify, but then come here and imply or outright accuse the scientists of commiting fraud based on them, belong on a wall of shame – especially in isolation, so we can see just how often and how contrived it is.

    If you don’t see it as shameful that someone would act like that… well, there’s your problem.

    “About time we all grew up, listened, understood and debated.”

    Nice sentiment – I wish they would – but instead, a wall of shame would be an approppriate response to such actions.

    Pick any thread on here and you will see people who hold contrary views do get on the board, but it seems to mostly be the ones who are saying something different from the tired old denier canards. More often than not they ignore the responses, repeating the same question over and over with slight changes in wording, until they then declare victory by saying the scientists refuse to answer, when in fact they got answered every time – but ignored it. Another kind of behaviour that should be highlighted on a wall of shame.

    You can lose the clear answers in a long thread like this, so if the conversation was pulled out and put on a seperate thread so you can see the ‘question, answer, ignore answwer, question again’ cycle clearly, people like you would see why these acts are so annoying.

    “Sorry for the rant, but as a self confessed layman, I feel I will never have the confidence to believe either side of the argument when everyone involved seems to have tunnel vision.”

    As one layman to another, let me give you a piece of advice – question your OWN assumptions BEFORE you question anyone else’s. I’ve just shown why I said what I did, but you assumed it was because of the reason you THOUGHT it was, rather than the REAL reason. If you had just questioned that assumption, you might have wondered if you were missing something and ASKED rather than RANTED.

    Make sense?

    -

    @Grabski #351

    Here is a case of needing to question your own assumptions first:

    “What if it becomes clear that the climate is threatened

    What if, what if, what if it becomes clear that the climate is threatened by continued cooling? Then trillions will have been wasted.”

    Here the assumption is that the ONLY benefit of advances in efficient renewable clean energy is a reduction (or halt) of global warming. However, even if AGW turned out to be totally wrong (it won’t, the scientists are not that stupid) the benefits to our species of being able to advance renewable energy techonology or energy efficiency (ie. cheaper energy in the long run) would far outweigh the costs incurred in the meantime, in my opinion.

    Wouldn’t you like to generate your own electricity from the Sun (for example) rather than having to pay some company to generate and transmit it to you, often over very long distances, with all the loss that entails (thus making the electricity you DO get more expensive)?

    So before you can say “trillions will have been wasted” you will have to show that there is no benefit, AT ALL, to a move away from fossil fuels other than reduced CO2 emmissions, and that is BEFORE we (meaning us interested laymen) even consider whether the science is valid or not.

    I may be wrong here, but it is my understanding that a very significant amount of the elecricity we generate is WASTED by attempting to transmit it very long distances. If we just removed or reduced that wastage, we would automatically increase the amount generated that we can actually use, and decrease the cost for it. That HAS to be a good thing, even if you don’t believe AGW is real, don’t you agree?

    -

    @Completely Fed Up #357
    @Ray Ladbury #358 and #374

    Yes, I understand that now. That was my problem as you see above – I hadn’t been able to visualise it, and because I hadn’t seen one, I was struggling to figure it out. I hope I understand correctly now. Yes, I probably should have tried graphing it myself to see, but my time is limited and this is a sort of hobby for me (increasing my knowledge of science and in general), rather than something I can devote a lot of time to.

    So I just thought it would be quicker to ask someone to explain it to me, rather than taking time to figure it out for myself. It seems I might have been fundamentally flawed in that assumption – I should have questioned it first :)

    (Yes, I know the delay was caused mostly by my inadequate description of my problem.)

  444. Jason:

    #409: “Someone is holding a gun to your head. The majority of weapons experts believe that the bullets in the gun are real and powerful enough to blow your head clean off. You don’t think they are. You think they are insufficient and will do no harm.

    So you say, go ahead pull the trigger. After that you will decide if the bullets are real and sufficient to blow your head clean off.

    This is effectively what you are saying with your argument.”

    Actually, if somebody points a gun at my head I am going to wait until I am convinced it is not real before giving them permission to pull the trigger.

    I’m a big fan of waiting until I am convinced, and I highly recommend that you do the same if you ever find yourself in a similar situation… especially your only alternative is putting on a Waxman-Markey brand tin foil hat and praying that it somehow stops the bullet.

    Maybe this would be a more interesting discussion if somebody proposed an alternative that, in the event the models are right, would actually have a significant impact on climate change.

    [Response: So now your criticism of the science is that politicians aren't doing enough? Goal-post shifting much? - gavin]

  445. Doug Bostrom:

    Looks as though Jason has finally and reluctantly conceded that he has no actual coherent argument against mainstream science, other than some sort of issue with the tenure process.

    After the dust settles, what did Jason leave us with? Nothing but ranting about how a promotional step can somehow corrupt entire fields of inquiry, inducing legions of researchers to ignore unbalanced equations in a conspiracy of silence. According to his initial spluttering on the topic, it’s not just climate science, either. What other topics we should worry about? Materials? Are composite aircraft going to come crashing down out of the sky because nobody wanted to upset the tenure applecart? How about astronomy? Should we take another look at that red shift?

    How about another take? Jason’s all wound up about climate science in particular because it’s a popular and accepted fad in certain political circles. If one’s ideology is a certain way, one has no choice but to be a contrarian.

  446. Jason:

    [Response: This is the umpteenth time you've made this statement, and you have still to provide a scintilla of proof for it. It simply isn't true. Point to one paper that was 'attacked without regard to scientific merit' and one case where any editor has been removed for publishing such a paper. And before you start agitating - note that Hans von Storch resigned from Climate Research over poor peer-reviewing (and the actual editor involved in the relevant decision (de Freitas) was not removed), and Saiers served his full 3 year term as GRL editor. So either provide some proof for your claims, or stop making them (here at least). - gavin ]

    Are you seriously going to claim that an attempt was not made to remove the editors involved with these papers?

    I would point to the M&M papers as an example of scientifically valid results being illegitimately criticized.

    [Response: Really, that's it? The invalid conclusion that the PCA centering mattered or the continual insinuations of scientific misconduct weren't worthy of crticism? Oh please. - gavin]

    And I wonder why McIntyre’s update of Santer et al ’08 is still being reviewed? I don’t have a scintilla of proof, but I’d bet that one of your coauthors is a reviewer and “went to town” on it. What do you think?

    As a coauthor of Santer 08, when you rerun the results using the exact same methodology but stopping at 2008 instead of 1999, what does your analysis show? Are the models consistent with observations?

    [Response: If you had any genuine interest, you'd actually read Santer et al (2008) and you would see that the extension to 2006 was indeed included in the supplemental material (experiment SENS2). If you'd bother to ask any of the authors about this instead simply taking McIntyre's word for anything, you would have been told that this had been in the main paper in the initial submission and was only moved to the supplemental material at the request of a reviewer who wanted us to stick to the same period used in Douglass et al. The idea that we were hiding some adverse result is, again, just a baseless smear. I have no knowledge of the status of McIntyre's comment, but if, like you, he hasn't read the supplemental material, I wouldn't be surprised if it is not well reviewed. - gavin]

    I try to avoid discussion of CA issues because I know those posts aren’t allowed. But come 2010 I’ll be more than happy to discuss them. My perception of bias is ultimately rooted in concrete examples of what i consider to be scientific malpractice.

    [Response: Which you have yet to demonstrate. - gavin]

  447. Andrew:

    @CFU: ““This means a one-dimensional measurement of the control parameter is used,”

    Uh, no. didn’t you read your statement:”

    Um, no, it means you don’t understand what it means.

    If you convert everything into carbon equivalents, the schedule of conversion determines that you measure the control in one direction. There are still many directions in which control can be exerted (which is apparently where you stop following the idea). But because of arbitrage between the control, the financial cost of the various controls is minimized in one direction, and the bulk of the control will be exerted in that one direction.

    So it’s a one dimensional control, with the direction of that control determined by the equivalence ratios and financial costs. Not Multidimensional.

    Oddly enough that you bring up helicopters is useful. One of the most common applications of H-infinity control theory is fly-by-wire helicopters, such as the Bell 205. (I suppose Ian Postlethwaite is the poster boy for this http://www2.le.ac.uk/departments/engineering/people/academic-staff/ian-postlethwaite)

    You are thinking of ways to control helicopters that are simple. But they are not the best performing controllers of helicopters. In very high performance helicopters, the controls are presented as mixed as the user interface, but the actual control is much more complex, and can only be performed by computer.

    Toy helicopters are easier to control mainly because they do not have exigent control specifications – you are not flying them with high precision at the extremes of their flight envelopes. So yes, if you want to have a lot of slop and waste in your controller, sure, don’t use a good theory and things might work OK.

    The EPFL “Toycopter” is a resonable example of a serious approach of modern control theory to a toy-like helicopter, and it’s not differentially flat; and cross-coupling is present.

    There is a good deal more uncertainty in the climate than in helicopter. It would be nice to think that we will be able to avoid any strong nonlinearities in the large scale quantities, but there are some large scale nonlinear variables known to be involved.

    I don’t see any reason to pretend that the seat of the pants approach to climate control has any particular merit.

  448. Clark Lampson:

    Any comments on one Wolfgang Knorr, of the Department of Earth Sciences at the University of Bristol, paper coming out in GRL claiming “no” increase in atmospheric CO2.

    [Response: That's a completely wrong reading of the paper. Read this instead. - gavin]

  449. Doug Bostrom:

    I’m beginning to wonder if “Jason” is perhaps somebody playing a practical joke, or just trying to make contrarians look ridiculous.

    In any case, for those who accuse RealClimate of censorship and plead for all posts to be heard, be careful what you wish for, heh!

    “My perception of bias is ultimately rooted in concrete examples of what i consider to be scientific malpractice.”

    “I have a gub”– Take the Money and Run

  450. Ernst K:

    All this has encouraged me to sit down and read Callendar (1938) (http://www.rmets.org/pdf/qjcallender38.pdf) in a bit more detail.

    What is especially interesting to me is the discussion at the end where the comments of a number of commentators question the methodology and conclusions of Callendar. It’s fascinating how several of the comments sound like they could have come from modern AGW “skeptics”, many of their key arguments are literally 70+ years old.

    But these commentators were not a skeptical fringe, they probably represent a sizable portion of the mainstream at the time (I suspect it’s the vast majority but it’s obviously hard for me to know for sure). To me, the comments clearly show how the “CO2 theory of climatic change” ran counter to the “scientific consensus” of the day. The current “consensus” wasn’t the natural default of the climate community at all, it had to be built up over decades. Callendar was actually congratulated for “his courage and perseverance” for presenting this work.

    Callendar’s work stands up remarkably well, but at the time there would be little further progress until Plass (1956) (another great read: http://onramp.nsdl.org/eserv/onramp:16572/n7._Plass__1956corrected.pdf). Which further suggests to me how climate scientists of the day were hardly jumping to develop Callendar’s work.

    I just wish I could find some contemporary responses to Plass’ work. Any links would be greatly appreciated.

    [Response: Actually I'm writing a post on this now. But if you have a library look up some letters between Lewis Kaplan and Plass in Tellus in 1960. - gavin]

  451. Chris W:

    Looking at the annual update, I am struck by the fact that there was a temperature uptick in 2009 in the AR4 graph. It occurs to me that this inflicts some damage to the denialist argument that the atmosphere has not warmed in the past few years (and that therefore the entire notion of climate change is bogus). The reply is now, “yes it has warmed, and the red and blue lines on the graph seem ready to rejoin the black line expressing the overall trend”. The overall trend heading, of course, up.

    Can we assume from this that the denialists will drop that argument and make up a new one, as is usual for them in such cases?

  452. Chris Wiegard:

    I notice the uptick in temperature on the AR4 graph. This event would tend to deflate the denialist argument that the warming trend has ended. No indeed, it has not ended, and the red and blue lines now are re-approaching the black line.

    Time for the denialists to shift to new ground, as is their wont?

  453. Timothy Chase:

    TRY wrote in 435:

    If you read that link above you’ll see, as I did, how complex these issues are. And that complexity has increased over time, as the impacts of absorption, emission, saturation, convection, precipitation, cloud formation, are dealt with in more and more detail throughout the entire atmosphere – which really doesn’t have ‘layers’, just a constantly changing gas/h20 makeup, energy levels, emissions, etc. across three dimensions.

    The models are already calculating things that way. But its always finite mathematics, and as far as I can tell always will be. What used to be divided into 20 layers gets divided into 40. what was divided into grids of 2 degrees by 2 degrees gets divided into 1.25 degrees by 1.25 degrees. Same with time — although that may get divided dynamically. And that is whether you are dealing with the atmosphere or the ocean. Always dividing into layers and boxes, but the grids get smaller and more processes get taken into account.

    Where radiation transfer calculations used to be based upon local thermodynamic equilibria and Kirchoff’s law we are now able to consider non-local thermodynamic equilibria and use Einstein coefficients. Where gids used to be static now they are dynamic, and in areas where flow and the transfer of momentum is greater than others the grid can be made finer. But computer power is always limited, and being limited the mathematics has to be finite, not continuous.

    TRY wrote in 435:

    So I guess the challenge is, that as we make these models more complex and presumably more accurate, our expectations of their predictive power go up.

    Don’t you think that has already been occuring? With the expansion of the Hadley cells and the dry subtropics, the expansion of the range over which hurricanes are forming and Catarina in 2004 off the coast of Brazil? Ocean circulation — which models have been fairly successful at for the past few years. How well do they model precipitation patterns, the trends we are seeing, the polar vortex? The rise of the tropopause, the that the warming trends during winter have been greater than the warming trends during summer, that nights have warmed more than days, that the stratosphere would cool as the troposphere warmed.

    TRY wrote in 435:

    But without good short-term predictions, people are left jumping back and forth –

    Short-term predictions are about weather, not climate. A model that is good at modeling weather is not necessarily good at modeling climate. In terms of weather, we can expand the time-frame over which we are able to make successful predictions from a few days to a couple of weeks, maybe longer. But the complexity involved in making longer term predictions grows as an exponential function of time.

    Climate models aren’t about that. They don’t try to predict what the weather will be on a certain day in a particular city twenty years from now. They do things in broader strokes. Will summers typically be warmer forty years from now, by how much and with what variability in the Northeast? Weather is a question of the specific path taken by the earth’s climate system through an attractor that evolves over time. Climate is about the shape of that attractor, its statistical properties and how it evolves over time. And while weather is chaotic, as near as we can tell climate is not — although there will be branching points.

    Moreover, given the fact that the models are based upon actual physical principles and actual emissions as best as they can be independently varified, it doesn’t make as much sense to distinguish between predicting the future as seeing how closely a model fits the past. But technically speaking, models don’t make predictions — as their runs have to assume different emission scenarios — which means what happens is dependent upon us and the choices that we make.

    TRY wrote in 435:

    So, maybe IR output signature is a predictable, testable item. Maybe not. Interesting question, I think.

    Are you speaking of upwelling radiation spectra or overall radiation balance?

    If you know the distribution of greenhouse gases, the aerosols, clouds and radiation entering an atmospheric column, calculating the radiation leaving the column is straightfoward. At the same time, knowing the balance of incoming over outgoing radiative energy is certainly something they are interested in, although there are other more roundabout ways of calculating it. But the feedbacks are where the real uncertainties lie, and therefore this is where the testing of climate models tends to focus. So for example there is a lot focus upon how well they model climate modes nowadays — which will be of considerable importance in terms of identifying mid-range trends.

    But none of this will change the minds of those who are repeatedly told that climate models are nothing more than statistical models and thus a fancy form of line-fitting, that our belief in the relationship between temperature and carbon dioxide levels is based upon nothing more than statistical correlation, that its the sun that is doing all of the warming, the greenhouse effect violates the second law of thermodynamics, that global warming isn’t really taking place but just so much urban heat island effect or scientists fudging their results, the whole AGW-thing is an international conspiracy to establish a world social-ist government. It won’t keep certain authors from testing climate models against data that we know is wrong or out of date (e.g., earlier versions of Raobcore for tropical mid-tropospheric warming) then claiming that the mismatch is a problem with the hypothesis that warming trends are due to an enhanced greenhouse effect when the “problem” would be there independently of the specific cause of warming trends.

    And it won’t in any way (at least directly) reduce the number of organizations that those authors belong to that receive funding from Exxon (Patrick J. Michaels (ExxonSecrets, SourceWatch) – 12, Fred Singer (ExxonSecrets, involved in the defense of tobacco, see: SourceWatch) – 13, Sallie Baliunas (ExxonSecrets, SourceWatch) – 11).

    Its not a lack of evidence or the “immaturity” of climate science that is standing in the way of the public’s acceptance of either anthropogenic global warming or its seriousness.

    Please see:

    The American Denial of Global Warming (58 minutes)
    Naomi Oreskes
    http://www.youtube.com/watch?v=2T4UF_Rmlio

    … and,

    Climate Cover-Up: The Crusade to Deny Global Warming (Paperback – 2009) by James Hoggan, Richard Littlemore

  454. Ray Ladbury:

    Jason @446. Oh dear. Just, oh dear.

  455. Ray Ladbury:

    Jason at 444 says “I’m a big fan of waiting until I am convinced, and I highly recommend that you do the same if you ever find yourself in a similar situation… especially your only alternative is putting on a Waxman-Markey brand tin foil hat and praying that it somehow stops the bullet.”

    Uh, Jason, given your most recent sputtering, maybe you want to ix-nay on-ay the in-tay-oil-fay hat-ay.

  456. Lynn Vincentnathan:

    #391, Matthew, I was indeed motivated to mitigate climate change. After seeing the docu “Is It Hot Enough for You?” in 1989 (and reading science articles on which it was based), and seeing that the droughts in the African Sahel over the past several decades fit what was expected with global warming, if and when AGW reached scientific certainty, which it did in 1995, I first thought, “Why don’t THEY (gov, people) do something about this?” Then I realized I was part of the problem and I had to do something. And I wasn’t going to wait around for science to reach the great .05 (95% confidence); even .50 p-value would be more than enough confidence for me. At first I was willing to sacrifice, but as it turned out I was able to mitigate cost-effectively without sacrificing living standards.

    As for my car, it is a 1997 Taurus we bought used in 2002, but we only drive about 2000 to 3000 miles per year, and I turn off the engine in drive-thrus, and run multiple errands, and carpool with my husband our 2 miles to work (I used to bicycle my 1 mile to work at our last place, but conditions here are not good for bicycling, and I’m getting old). Long ago, in the 70s, during the oil crunch, when I learned about entropy and finite resources, I decided we would always live as close as possible to work (so I don’t count that as part of my climate change mitigation, since I’ve already been doing that for 5 decades).

    We are, however, thinking we might need another car in the next couple of years, and I’m waiting for affordable EVs or plug-in hybrids (with a range of at least 20 miles) to come out in our area, so I can drive on the wind.

    But I do agree that people are not, as economists suggest, (completely) rational and economic. I would hope they would have a heart, a conscience. It is extremely demoralizing that many more people are so blinded and self-centered or ego-threatened that they can’t mitigate, even if they don’t completely agree with the science (as the U.S. Bishops and Popes JPII and BXVI have admonished us to do).

  457. Ray Ladbury:

    Simon@443, We’re all happy to have helped. Learning is what this blog is about for all of us readers–under the tutelage of St. Gavin and his equally patient(beatified, at least) entourage.

  458. Ike Solem:

    Face facts – the failure to collect data on the status of the ocean-atmosphere system puts the entire American scientific enterprise to shame – how is this any different from the Lysenkoism that dominatated Soviet science for decades? (Try applying Godwin’s Law to that statement, PR monkeys).

  459. Prof T Heidrick:

    Can I ask a few ? from this group, not to do my work for me but to give me links where I can find the answers if I Study them.
    1-On the temperature measurements-”average” and “mean” seem to be tossed out interchangably and of course they are different. Assuming we are talking “averages”-on surface averages-are these simple arithmetic averages, some kind of curve fit and integration or area weighted? Urbanization over tim could affect these depending on how you do it.. For “air temperatures” again are these simple or volume weighted averages? Also, why is the “average” the significant number? If I have my head in the freezer and feet in the oven I have an average temp.-but so what?

    2-On the models
    GAvin posted a subroutine which seemed to show the circumferencial elements based on longituede and latitude. IS this right and does this mean finite difference models not finite element. This would mean that interfaces between land and sea with steep T gradients would be difficult to handle.
    How is the “lumpiness ” in CO2 , i.e unveven distribution over the world reported by NASA handled?-now and previously when basically unknown.

    Sensitivity analysis. Has anyone done this in detail given that methane , water vapour etc. have a bigger incremental effect than CO2. These things can fool you . When we devloped complex models for nuclear reactor accidents, we found decay heat which we knew to .1% mattered to the result so much we needed to know it to .001% to get repeatable predictions. Other things we knew less well were less important.
    Boundary conditions-it would appear from the discussion on El Nino these are not handled well. Are there any discussions on the
    Initial conditions-errors multiplly over time-how are these handled. Any ionfo is greatly appreciated.

  460. Radge Havers:

    Clark Lampson@448

    At ScienceDaily “No Rise of Atmospheric Carbon Dioxide Fraction in Past 160 Years, New Research Finds.”

    Michael Savage is all over this on the radio. I’m guessing another sewer line is about to burst.

    A couple of paragraphs down at SkepticalScience is this: “Over this period, an average of 43% of each year’s CO2 emissions remained in the atmosphere…”

    Now maybe I’m missing something, but if that wording were used up front in reportage together with a sentence like “the emission rate and total global atmospheric CO2 continues to increase,” it would make it harder for the nutty to sow confusion. I find this very frustrating.

  461. Ernst K:

    [Response: Actually I'm writing a post on this now. But if you have a library look up some letters between Lewis Kaplan and Plass in Tellus in 1960. - gavin]

    Googling “Kaplan and Plass in Tellus” helped me find this:

    http://www.americanscientist.org/issues/feature/2010/1/carbon-dioxide-and-the-climate/1

    :)

    That will do for now since I still have university access to online journals (but not to Tellus A before 1990 – scan in your archives now!).

    Plus, I could also access all three of the related articles as well!

  462. Andrew:

    @Jason: “In most fields this is true, but not in Climate Science.”

    Um, I got my Ph. D. in a group of climate scientists, although I am not a climate scientist. I can tell you straight up, having seen the progress of the careers of my colleagues, that there is not really much difference at all in what it took to get ahead academically. And it is a reasonable approximation of what it is supposed to be.

    Frankly, one of the quickest routes to the top is to have the goods on a new idea that overturns a lot of established thinking. It’s the part about having the goods that the denialists are lacking.

    Frankly I would say that most fields are filled with enough people who have become somewhat bored with the same old same old, and there is actually a bias in favor of novelty over quality.

  463. Molnar:

    Jason(446):
    “And I wonder why McIntyre’s update of Santer et al ‘08 is still being reviewed? I don’t have a scintilla of proof, but I’d bet that one of your coauthors is a reviewer and “went to town” on it. What do you think?”

    This is pathetic. Do you have anything else to contribute to the discussion, besides (self-admitted) baseless accusations? Or are you just trolling?

  464. Lawrence Coleman:

    Great synopsis on what went wrong at copenhagen at http://news.ninemsn.com.au/article.aspx?id=989508
    an exerpt from the article..”They blame the complex UNFCCC process, a spider’s web of a thousand interlinked strands, where decision-making is driven by consensus among 194 nations. This offers plenty of room for delaying tactics or sabotage.” They also raise the point that future climate deals may be better acheived by forging a ‘coalition of the willing’..coz you are never going to get economically obsessed countries like china to agree to anything that might not be 100% in their own vested interest..God! sounds just like the US doesn’t it!. They mentioned that the outcome of copenhagen was the enevitable lowest common denominator..an outcome so utterly weak and unbinding that everyobne felt safe with it.
    Brazil shows hope in that they have legally comitted themselves into a 40% emissions reduction framework by 2030 I think it was. If anyone here can come up with a carefully thought out framework to convince me that a democratic process can work at establishing the required targets of CO2 reduction..please come forward..Those comments I have heard to date are very flawed in their knowledge of the democratic process and human nature and intention.
    In my opinion a binding agreement by the coalition of the willing (major polluters) exluding the minor players might be our best hope. The human race does not seem nearly advanced enough to have a coherent global consensus involving up to 200 countries..we need to keep it simple!

  465. Rattus Norvegicus:

    Skeptical arguments in a less contentious context:

    http://drboli.wordpress.com/2009/12/15/the-duck/

  466. Martin Vermeer:

    Good work Simon #443 — you’re getting there.

  467. Charles:

    With regard to Knorr’s paper, I note that in para. 22, he writes: “The possibility, however, presents itself and, given the evidence from oxygen data [Bopp et al., 2002], would mean that a larger proportion of emissions is taken up by the ocean than what has been previously assumed. The analysis also shows that recent trends after 2000 can be explained by re-scaling land use emissions within their uncertainty ranges.”

    Gavin is right, AFAICT: people are misinterpreting the paper.

    Gavin, your patience with Jason has been amazing. Jason, you’re making yourself look more and more foolish. One does begin to wonder if you’re just trolling.

  468. TimTheToolMan:

    Based on the RealClimate article “Why greenhouse gases heat the ocean” and the fact I cannot find any science to quantify the effect demonstrated in that article as far as actual ocean heating goes, I have serious doubts about the model’s abilities to model anthropogenic warming of oceans.

    So for the second time, can someone please tell me what mechanisms and assumptions the models (eg HadCM3) use to warm the oceans?

    [Response: I don't really know where you are coming from on this, but there is a demonstrable long-term rise in ocean heat content that is matched by the models. The actual mechanism is very straighforward - there is a net positive flux of heat at the surface which gets mixed through the mixed layer (mainly by wind stirring and convection) and which then is diffused and advected into the deep ocean. - gavin]

  469. Lynn Vincentnathan:

    #464, Lawrence, there is this idea of “contraction and convergence” — see: http://en.wikipedia.org/wiki/Contraction_and_Convergence

    The high per capita emitters contract, allowing the low emitters to economically develop and emit more, but the net emissions should continue to decrease.

    That is a good way to think about the problem — on a per capita basis (which puts the U.S. way above China in emissions per capita). Also, I think there has to be some way of figuring in global trade, which would put China at an even lower per capita level, since a lot of their emissions are from making products for the rich nations — I think I read somewhere that 20% of their emissions go into export products (or net export), and 8% additional emissions (Americans buying Chinese products) are attributable to Americans (not sure if they included the emissions in shipping the products). You can see why China was in a double bind. They understand this, but to demand that rich nations reduce, would actually harm their budding economy.

    Another plan promoted by Hansen it simply tax carbon emissions (or sales of fossil fuels), then return that money to the tax-payers (100% dividend) — see: http://www.columbia.edu/~jeh1/mailings/2009/20090226_WaysAndMeans.pdf . So a person pays a higher bill for coal-generated electricity and gasoline, but they in effect get that extra cost back as cash to spend any way they choose. Smart, economically minded people (even if they were not environmentally minded) would then figure out how to reduce consumption of fossil fuels — maybe go on wind-generated electricity, buy a fuel-efficient vehicle, move closer to work, spend vacations closer to home, etc., and have money left over to pay off their mort-gage, or whatever. Hypothetically their extra money would not go into buying fossil-fuel intensive products, since the emissions tax would also be included each step of the production/transportation process.

  470. Ray Ladbury:

    Prof. T. Heidrick,
    It would seem that most of your questions are answered here:
    http://www.aip.org/history/climate/index.html
    Also, try here:
    http://ipcc-wg1.ucar.edu/wg1/FAQ/wg1_faqIndex.html
    Also here:
    http://www.realclimate.org/index.php/archives/category/extras/faq/

    Climate science is not in its infancy.

  471. Bill:

    To move forward in 2010 there seemingly needs to be certain key steps taken in order to achieve better international consensus. I would suggest the following:
    1. A new international task-force set-up, charged with the responsibility of establising an officially recognised database for ‘Global temeprature’ to support all future policy planning.
    2. This database would be generated from an agreed set of globally-representative surface stations whose construction, siting and instrumentation would be documented to agreed standards and whose data would be available and auditable.This would be both retrospective and prospective.
    3.The global database creation ,management and reporting would be subject to internationally recognised quality standards.
    In essence, this is like moving a research project into development or production.
    Globally , we dont really need to keep on discussing the relative merits of one dataset v. another, or to keep on with the rather sterile debates about the fragmented ( including the changes in station numbers over time ) raw data and whether its available because of local national agreements. We need to move on with the bigger global picture.
    This type of international quality standardisation would be expected in many other fields of medicine, transport, construction etc, and with the global budgets being reported, amounting to ‘trillions’ if you believe Copenhagen, some structured cost-effective approach to underpin global policy decisions,seems long overdue.
    Or, we can sit here and ‘blog’ and call each other ‘names’ and dismiss any contrary views …”oh please ….” for the next years. Just a thought !

  472. Bill:

    Re#468, which datasets are you referring to ? Thanks

  473. Ray Ladbury:

    Bill,
    While I appreciate the sentiment of #471, I would point out that that we now have 4 independent datasets–2 terrestrial and 2 satellite–that have been investigated and reviewed out the ying-yang. And they all pretty much agree as far as trend. You only need to debate the merits of different datasets when they disagree significantly. This is manifestly not the case, and what is more, the trends shown in these databases are backed by qualitative and quantitative observations of ice melt and other temperature sensitive indicators. I do not see the point in reinventing the wheel when the vehicle has 4 good wheels already.
    I would also point out that the IPCC is just such an “international task force,” and look at how well that has been embraced by the denialists. It does not matter what standards we follow. It doesn’t matter how open we are. No matter what we do. No matter what evidence we have, the denialsophere will continue to denounce climate science and science in general as a fraud. Their position has never given consideration to such trivialities as evidence.

  474. dhogaza:

    Jason(446):
    “And I wonder why McIntyre’s update of Santer et al ‘08 is still being reviewed? I don’t have a scintilla of proof, but I’d bet that one of your coauthors is a reviewer and “went to town” on it. What do you think?”

    This is pathetic. Do you have anything else to contribute to the discussion, besides (self-admitted) baseless accusations? Or are you just trolling?

    Jason- since when is a reviewer “going to town” on shoddy work a *bad* thing? It’s a pathetic accusation because not only does he have any evidence, but if there *were* evidence it would be that …

    someone’s doing their job as a reviewer. Dismantling substandard work. That was the implication of that oh-so-evil e-mail that Jason’s snidely referring to. And this is now a bad thing, apparently.

  475. Barton Paul Levenson:

    TRY: maybe IR output signature is a predictable, testable item. Maybe not.

    BPL: Already tested. Against time. AGW confirmed. But you just keep refusing to acknowledge it.

  476. Bill:

    Ray, on #473.
    I appreciate your response but I’m concerned that we are not moving forward in a systematic way. The more I look into the ‘terrestrial’ datasets which we rely on for long-term data ( not just trends’ but absolute values), the more I worry about their real independence and their derivation from the numbers collected from a hugely varying number of ground stations. The real raw data,in other words.
    Secondly, some of this data is questionable, and in other fields of science, the best way to resolve this is to set-up an independent group to investigate and report, the IPCC has lost public credibility now…
    I’m absolutely not suggesting reinventing wheels, but checking and tuning the engine, and then producing a certificate of airworthiness’ , so to speak

  477. dhogaza:

    Secondly, some of this data is questionable, and in other fields of science, the best way to resolve this is to set-up an independent group to investigate and report, the IPCC has lost public credibility now…

    I’m absolutely not suggesting reinventing wheels

    Yet, that’s exactly what your first sentence suggests.

    Ray’s right, it doesn’t matter how research, review, and reporting is structured, denialists will deny, and claim it’s all fraudulent.

  478. John E. Pearson:

    461: Gavin. In your comments on Plass’s paper you wrote: “First, although the residence time for carbon dioxide in the atmosphere (the total amount of CO2 divided by the flux in and out of the ocean) is on the order of a few years, the perturbation time is much longer—even up to a few tens of thousands of years—because of the slow uptake in the deep ocean and the buffering effects of the ocean chemistry.”

    I’m trying to understand what you meant by “perturbation time”. If we write Co2_O for the concentration of CO2 in the ocean and Co2_A for that in the atmosphere and there were no chemistry one might write

    d Co2_A/dt = (Co2_O-Co2_A)/tau_R

    where tau_R is the residence time for CO2 in the atmosphere. In this case the perturbation time would be the residence time. But if you include ocean chemistry which involves Co2_O going up and down as well, that the evolution of a perturbation to atmospheric CO2 would take much longer than tau__R to equlibrate because of all these additional reactions? You might write:

    d Co2_A/dt = (Co2_O-Co2_A)/tau_R + f(Co2_A,Co2_O, … )
    d Co2_O/dt = (Co2_A-Co2_O)/tau_R + …

    and now you ask on what time scales do perturbations to this system die out?
    Or were you talking about something else entirely?

  479. Bill:

    re#477.The resolution of source data questions should not be seen as denying or supporting . If you cannot accept that their is widespread public perception of ‘questioniable ‘about data ,policy and process, I dont know where you have been.
    Any future global policy clearly needs widespread public support and what may swing that could be a credible new and independent approach using internationally acceptable standards for data quality in support of policy decisions. We are far from that today……..

  480. Ray Ladbury:

    Bill@476, One might accuse science of many things, but lack of systematic progress is not one of them.

    You say you are disturbed by problems you see in raw data from terrestrial stations. Do you contend that the folks who process such data for a living (and have been doing so, I note, for decades) are unaware of these problems? They certainly go to great lengths to correct for any problems they do know about. I would say that evidently they are fairly successful, too, since the entire network of stations yields trends consistent with those using only “known good” stations:
    http://www.skepticalscience.com/Is-the-US-Surface-Temperature-Record-Reliable.html

    This coupled with the facts that:
    1)Independent errors at over 1000 stations are unlikely to yield a “trend” but instead result in increased noise
    2)Both independently processed terrestrial datasets yield consistent trends, and these trends are consistent with those revealed by satellite-based datasets.
    3)The temperature trends we see in all 4 of these datasets are consistent with qualitative changes we see taking place globally today.

    So, I think what you have is a solution in search of a problem. Remember, all data have errors. What matters is 1)whether you can correct or othewise mitigate them; and 2)whether the errors significantly affect results of the investigation.

    Now as to your proposal for an independent body, who would you suggest. Clearly, given the villification of the IPCC, the UN would not be seen as an acceptable overseer. The science has already been reviewed by National Academies in every major industrial nation on the globe. Professional and honorific scientific societies have also looked in detail at the evidence and methods of climate science, and not one dissents from the consensus science. Hostile legislative committees have been over the whole enterprise and found nothing they could trumpet as a serious flaw.

    So, I ask you, who is left?

  481. Hank Roberts:

    Watch for this news, which will hit hard at the concern about verifying honest reporting of carbon controls, I expect.

    http://www.google.com/search?q=chinese+stock+market+ponzi+scheme

  482. Completely Fed Up:

    Matthew states boldly: “There are lots of mitigation strategies. $1 trillion spent over 10 years by the US and EU, if used (as some has been up till now) to finance construction in India and China, will not lead to CO2 reduction before 2050, and maybe not in this century”

    Please prove this or be ignored.

  483. Pekka Kostamo:

    476 Bill. Its a done deal:
    http://www.wmo.int/pages/gfcs/index_en.html

    Standards of observation and data management have applied for about 100 years already, coordinated by agreements between the various governments.

    A simplified standard accessing system is being added. It just takes some time as there are those 190-odd national governments involved.

  484. Bill:

    Re #483, it looks like the WHO in medicine when we actually need a FDA !

  485. Molnar:

    dhogaza (474):
    “Jason- since when is a reviewer “going to town” on shoddy work a *bad* thing?”

    Well, we don’t know yet if it is shoddy work or not. It seems to me from the context of his post that he is suggesting that somebody is abusing the review process to keep McIntyre’s comment out of the literature no matter what.

    I certainly agree that letting rubbish get published just to appease someone is nonsense.

  486. Matthew:

    469, Lynn Vincentnathan

    I am in favor of lots of personal and societal investments to reduce energy use and address the possible consequences of CO2 accumulation, but not all proposed investments, and not without considering accurate computations of actual trade-offs. Beginning 20 years ago or so, I gradually replaced all my incandescent lightbulbs with compact fluorescents; now I am gradually replacing my compact fluorescents with full-spectrum LEDs. Doing so too rapidly would be a bad idea because the full-spectrum LEDs are manufactured in China using electricity from fossil fuels (or possibly nuclear, which I do not regard as bad.)

    I also pay the premiums on term life insurance. But that does not mean that I actually believe that I shall die this year, or that I try to prove to all my friends that I shall die.

    My real point in addressing the issue of motive is that every adult has multiple motives, and these ideas about motivated beliefs should be omitted from the discussion of the science of AGW. I hope I did not seem to impugn your motives personally.

    482, Completely Fed Up: Please prove this or be ignored.

    Which, that the EU is using its carbon offsets to finance the construction of CO2-spewing industries in China and India, or that CO2 production in China and India will not start to decline before mid-century, or that $1trillion could be wasted? I don’t care much if people ignore me, but evidence related to these possibilities is published every week, and available online. If there is a thread here devoted to public policies related to AGW, instead of evidence for and against AGW, then I’ll elaborate. For one example, the state of California subsidizes the purchase of PV cells, almost all of which are manufactured in other places, a majority of them in China; that does not reduce the carbon footprint of California, it merely moves it to China, which is in fact building its coal-fired electricity generating capacity faster than at any previous time in Chinese history. China is also building its non-fossil fuel power industry, but Chinese CO2 output will increase for decades.

    What China does with coal and oil does not affect the evidentiary status of AGW (pending the Earth’s response to increased “Sinogenic” CO2), but it should affect the way Americans think about policy choices.

  487. Matthew:

    103, Lynn Vincentnathan: A helpful book re how we can reduce our GHGs by 75% without lowering productivity is NATURAL CAPITALISM – see http://www.natcap.org . Also http://www.rmi.org

    Some of the debate is about timing, some is about goals (e.g., for some an important goal is to preserve/expand American military power, which is at serious risk if the military depends on oil shipping slowly across the oceans), some is about financing, some is about which technologies to use (e.g., some oppose nuclear but others support nuclear), and some is about government mandates.

  488. Matthew:

    210, Martin Vermeer: We know too much, not too little.

    If that were true, the models would be exact over all time scales.

  489. dhogaza:

    Well, we don’t know yet if it is shoddy work or not. It seems to me from the context of his post that he is suggesting that somebody is abusing the review process to keep McIntyre’s comment out of the literature no matter what.

    Background is that one of the purloined e-mails written by a reviewer used the phrase “going to town” describing the review task awaiting him. In the context it’s obvious the reviewer thought he was being asked to review crap, and by going to town he meant he was going to dismantle it thoroughly to back up his rejection.

    And Jason would appear to think this is a bad thing.

  490. TimTheToolMan:

    [Response: I don't really know where you are coming from on this, but there is a demonstrable long-term rise in ocean heat content that is matched by the models. The actual mechanism is very straighforward - there is a net positive flux of heat at the surface which gets mixed through the mixed layer (mainly by wind stirring and convection) and which then is diffused and advected into the deep ocean. - gavin]

    If that long term rise in ocean heat cannot quantitatively be attributed anthropogenic causes then AGW science has a huge hole in it. The oceans are potentially free to both cool and warm as they like and take the global temperatures along with them.

    In that case any AGW “effect” could be a small increment to an otherwise naturally varying climate and the case for continued increases at the observed rates diminishes considerably.

    Currently to my knowledge there has been no work done to quantify the effect demonstrated in “Why greenhouse gases heat the ocean” and so I’m wondering what the models use as the basis for their heating but particularly with respect to any “forcing” from anthropogenic CO2.

    [Response: Still don't get the point you are making. People have been measuring heat fluxes, turbulence, mixed layer dynamics and the like for decades. Peter Minnett (who wrote that article) is a very active ocean-going scientist. The models warm the ocean when you increase the forcing, not through some special physics that only has to do with CO2, but because the net impact of increasing heating at the surface serves to warm the ocean. I don't see why that is at all problematic. Perhaps if you were more explicit in what it is you don't get, then I could be more use. - gavin]

  491. David B. Benson:

    Mark A. (344) & others — Here is some reading about GCMs:
    “A Climate Modelling Primer” by Henderson-Sellers
    Introduction to Three-Dimensional Climate Modeling 2nd Edition
    Warren M. Washington and Claire Parkinson
    http://www.palgrave.com/products/title.aspx?PID=270908
    http://www.realclimate.org/index.php/archives/2008/11/faq-on-climate-models/
    http://www.realclimate.org/index.php/archives/2009/01/faq-on-climate-models-part-ii/langswitch_lang/tk
    http://www.climatescience.gov/Library/sap/sap3-1/final-report/sap3-1-final-all.pdf
    http://bartonpaullevenson.com/ModelsReliable.html

  492. TimTheToolMan:

    [Response: ...The models warm the ocean when you increase the forcing, not through some special physics that only has to do with CO2, but because the net impact of increasing heating at the surface serves to warm the ocean. I don't see why that is at all problematic.... - gavin]

    The effect is described in that article as a mechanism to “keep the heat in” and again as far as I’m aware there is no science that quantifies the effect. How can this not be problematic if it turned out that the effect could not account for the observed warming when it was further analysed?

    It is those assumptions the models make and mechanisms they use to warm the ocean that I’m interested in. The oceans dont simply “warm” from CO2 downward longwave radiation as per the article and I’d like to see what the models DO use as far as anthropogenic forcings are concerned.

    There must be a finite number of inputs to ocean heating and I’d like to know what they are. Can you please provide that?

    [Response: The heat budget at the surface is made up of the latent heat of evaporation, sensible heat exchange, downwelling solar radiation, downwelling long wave, upwelling long-wave, and small terms associated with the temperature and state of any fresh water flux (rainfall or ice melt/formation). - gavin]

  493. Richard Steckis:

    “Response: I don’t really know where you are coming from on this, but there is a demonstrable long-term rise in ocean heat content that is matched by the models. The actual mechanism is very straighforward – there is a net positive flux of heat at the surface which gets mixed through the mixed layer (mainly by wind stirring and convection) and which then is diffused and advected into the deep ocean. – gavin”

    Is this theoretical or has it been observed empirically? Are you trying to tell us that heating of the oceans by this process is greater than the absorption of heat from direct solar radiation?

    Please explain the advection process to the deeper layers. Have the deeper layers exhibited a significant increase in heat content as a result (Ref. please).

  494. Hank Roberts:

    Tim, is this what you’re looking for? Oceans are more complex, but the basic mechanism of warmer air transferring heat to surface water happens in lakes too:

    http://www.agu.org/pubs/crossref/2009/2009GL040846.shtml

    Satellite observations indicate rapid warming trend for lakes in California and Nevada

    “Large lake temperatures are excellent indicators of climate change; however, their usefulness is limited by the paucity of in situ measurements and lack of long-term data records. Thermal infrared satellite imagery has the potential to provide frequent and accurate retrievals of lake surface temperatures spanning several decades on a global scale. Analysis of seventeen years of data from the Along-Track Scanning Radiometer series of sensors and data from the Moderate Resolution Imaging Spectroradiometer shows that six lakes situated in California and Nevada have exhibited average summer nighttime warming trends of 0.11 ± 0.02°C yr−1 (p < 0.002) since 1992. A comparison with air temperature observations suggests that the lake surface temperature is warming approximately twice as fast as the average minimum surface air temperature."

    Or are you looking for an explanation of why warm air transfers heat to water?

  495. Richard Lawson:

    I have a question about long term solar cycles.
    I understand that GISS includes the ~11year sunspot cycle, which has a minor effect. There is also a longer term variation, with a periodicity of about 200-300 years, shown here:
    http://www.globalwarmingart.com/wiki/File:Carbon_Derived_Solar_Change_png

    It seems from this that we are just passing the peak of the modern solar maximum, and that for the next 50-100 years we should hopefully be in a period of solar decline. There does seem to be a visual correlation between these solar declines and lower global temperatures.
    http://www.globalwarmingart.com/wiki/File:Carbon_Derived_Solar_Change_png
    (second figure down, apologies for crude nature of the work)

    So the question is, can we run the models with these longer solar cycles included?

    Dare we hope that a few decades of solar decline may give us much needed time to decarbonise the global economy effectively? Or would less severe projections simply give the denialists an opportunity to persuade the politicians to continue BAU?

  496. Geoff Wexler:

    As I see it now
    Energy conservation in a single wavelength. The italicised conclusion in the penultimate paragraph of my comment (as I saw it then):

    http://www.realclimate.org/index.php/archives/2009/12/updates-to-model-data-comparisons/comment-page-5/#comment-152066

    was wrong. Energy cannot be conserved at a single wavelength. (Gavin response at #170 covered this more concisely). Although it appears at first sight that the radiation transfer equation decouples the wavelengths from each other an extra condition such as energy conservation cannot be applied to individual wavelengths without producing a contradiction. It is first necessary to integrate over all wavelengths. This allows energy to be transferred from one wavelength to another as TRY suggested.

    But what about the rest of TRY’s argument? (S)he invoked a thought experiment in which a narrow band of wavelengths was fired upward into the atmosphere. Suppose that this was all there was, i.e the black body spectrum from the surface was replaced by a highly concentrated beam. Asssume that the wavelengths were chosen within the absorption bands of e.g. CO2. This may be a highly artificial experiment and many things would change. But for the sake of argument suppose that it happened for a brief interval of time.

    Would this affect the downward greenhouse radiation? I don’t see why? Wouldn’t we still see the CO2 signature , as well as the CH4 signature and the H2O signatures just as before? If this downward flux changed with time wouldn’t it still be possible to attribute it to an increase of CO2, CH4 etc? Thermalisation is equivalent to a loss of memory of the character of the exciting radiation from the ground. You would still have a problem with overlapping absorption bands, which could be unravelled by doing the radiation transfer calculations.

    TRY also enquired as to the ultimate fate of the energy of absorption. In the highly simplifed case of neglecting local heating it would all go into the energy of the downward flux of greenhouse emissions. But to answer it better you would need e.g Raypierre’s book and some runs with the radiation transfer programs.

    Was TRY trying to throw doubt on these calculations? I wouldn’t be surprised. But I suspect that he would have to try really hard indeed.

  497. TimTheToolMan:

    [Response: The heat budget at the surface is made up of the latent heat of evaporation, sensible heat exchange, downwelling solar radiation, downwelling long wave, upwelling long-wave, and small terms associated with the temperature and state of any fresh water flux (rainfall or ice melt/formation). - gavin]

    So am I to assume the downwelling long wave term is an approximation for the actual effect described in the article “Why greenhouse gases heat the ocean”?

    Could you quote where the values used for term have come from?

    [Response: Each term is calculated as a function of the temperatures, composition, cloud cover, etc at each time step in the model. Downward LW increases with higher CO2 and water vapour, but all of the terms vary with climate change and the net change is positive down. - gavin]

  498. Ray Ladbury:

    TimtheTool, If you’ve ever been diving, you know that visible light penetrates the water to at least about 10 meters, right? You know that as you go deeper, the light is extinguished, indicating that it is being absorbed, right?
    You know the skin surface effect occurs and about what magnitude it is, right? We know that decreased gradients decrease heat loss, right?

    And we certainly know the ocean is warming, right?

    So, we have a mechanism that we can put in the models. We have model results that agree pretty well with observations. What is missing?

    As you can see from Peter Minnett’s site, he’s been busy looking at stuff like this. http://www.rsmas.miami.edu/personal/pminnett/Complete_List/complete_list.html

  499. Ray Ladbury:

    Geoff,
    I see no reason to doubt TRY’s bona fides. He/She was at least asking interesting questions that illuminated the physics–as evidenced by the fact that they helped you understand it better. I find equipartition to be a very powerful concept in understanding things. If you start out with an situation far from equilibrium–e.g. all radiative energy in a single wavelength–the system will move toward what it would look like at equilibrium if at all possible.
    In the case you posit, the outgoing IR line will excite CO2 molecuses. These will relax–partly radiatively in the same line, but probably broadened by collision, but mostly collisionally. This will impart kinetic energy to other molecules, shift the distribution of energies upward, and any other modes that aren’t frozen out (e.g water vapor, CO2, N20,…) will also be excited.

    My caveat wrt TRY’s suggestion is that we’re looking at a climatic process, so a mere snapshot will not be sufficient to demonstrate the long-term trend of warming. Snapshots taken at different times will give slightly different results. We have these snapshots. They look like what you’d expect from a world warming due to greenhouse effects. What we really need is to turn the snapshots into a movie covering 30 years.

  500. JasonB:

    486, Matthew:

    “For one example, the state of California subsidizes the purchase of PV cells, almost all of which are manufactured in other places, a majority of them in China; that does not reduce the carbon footprint of California, it merely moves it to China, which is in fact building its coal-fired electricity generating capacity faster than at any previous time in Chinese history.”

    I think it is worth noting that with an energy payback time of 1-4 years and consequently an Energy Returned on Energy Invested ratio of between 10 and 30, it does reduce the carbon footprint of California even while shifting it to China. It doesn’t really matter if the PV cells are manufactured using coal-fired electricity — it would still be a win to make them as quickly as possible (and therefore increase their contribution to the energy mix as rapidly as possible) rather than wait until there was sufficient “PV power” to manufacture them.

    The EROEI ratio would have to be 1 or less for the net effect to be nothing more than shifting California’s emissions to China.

    As an aside, China is also increasing its wind power electricity generating capacity faster than at any previous time in Chinese history — it looks like they hit 22.5 GW at the end on 2009 and are on target to beat their 2020 target of 30 GW by the end of this year. (If those figures are correct, they added 10.3 GW in 2009 alone.)

    NB: I posted as “Jason” in the “CRU Hack: More context” thread. I’m sure you’ll forgive me if I change moniker at this point. :-)

  501. John P. Reisman (OSS Foundation):

    497 TimTheToolMan

    If you want to do a ‘simple’ experiment on ocean heating… in the winter, pour two glasses of cold water from your tap, put a glass of water outside your house and one inside. Assuming you have your heater on, you will notice that the water glass outside will get cooler, or turn to ice, depending on temperature, while the water glass inside will heat up to room temperature.

    Oceans are more complex and this is an oversimplified explanation, but heat does move in and out of water bodies.

  502. Matthew:

    500, JasonB: I think it is worth noting that with an energy payback time of 1-4 years and consequently an Energy Returned on Energy Invested ratio of between 10 and 30, it does reduce the carbon footprint of California even while shifting it to China. It doesn’t really matter if the PV cells are manufactured using coal-fired electricity — it would still be a win to make them as quickly as possible (and therefore increase their contribution to the energy mix as rapidly as possible) rather than wait until there was sufficient “PV power” to manufacture them.

    I think that you are overoptimistic on the payback time, or else the big subsidies would not be necessary. I could be wrong. The economics are rapidly changing, and if you are not right now, you will be in five years time or less.

    It is true that China is investing in alternative/renewable energy, but if the question is when China will reduce its CO2 emissions, then the fact that they continue to increase CO2 emissions matters. Like the US, they see alternative/renewable energy partly in military terms, and they are vulnerable right now to having their fossil fuel supplies interrupted in time of war.

    For both China and the US, it could turn out to be that CC&S is a more cost-effective intermediate-term strategy than solar. China and the US are building large scale installations at an unprecedented rate.

  503. Ray Ladbury:

    Matthew says, “It is true that China is investing in alternative/renewable energy…”

    No, they are kicking our collective buts in alternative/renewable energy. They are doing the smart thing and developing production capability in advance of the huge increase in demand as the rest of the world begins to realize just how deep we are in the soup. And the US…well, we’re still arguing over 50-year old science.

  504. Geoff Wexler:

    Ray.
    Thanks for your comment. My modifed version’s of TRY’s thought experiment was too sloppy to take very seriously or to take any further. For example an unintended consequence would have been that part of the black body spectrum emitted from the surface which would have fallen in the atmospheric window (no absorption lines) would have to be moved into an absorbing region of the spectrum. This would lead to additional energy being supplied to the gases and that would show up as an upward shift of the occupied gas levels, as you say.

    The non-trivial point that remains, is that the terms in the downward IR radiation which describe the emission after thermalisation should not depend on the nature of the exciting radiation or whether the original excitation was of CO2 say or CH4. Thus the detailed flow path for the energy might be of little interest. Doesn’t that take care of most of the greenhouse emission? As an example, you might look at the spectrum and identify part of it, very approximately , as having come from methane at about 200K (invented value).

  505. Rod B:

    re 497: “[Response: Each term is calculated as a function of the temperatures, composition, cloud cover, etc at each time step in the model. Downward LW increases with higher CO2 and water vapour, but all of the terms vary with climate change and the net change is positive down. - gavin]”

    A clarification question from way back basics: Is the downward LW radiation all and only from CO2 and H2O and other GHG molecules? Or is the LW downwelling for the atmosphere as a whole but triggered by CO2 and H2O?

    [Response: From everything - H2O, clouds, CO2, aerosols, ozone etc. - gavin]

  506. Steve Fish:

    Comment by Matthew — 2 January 2010 @ 11:31 AM:

    Embodied energy and cost estimates for PV are based on current electricity rates, but increasing costs of fossil fuels due to future scarcity and competition from emerging nations could reduce these dramatically. Depending upon ones circumstances, PV can be a pretty good bet. I think the biggest problem in the U.S. has to do with the current attitudes against buying quality up front in order to save in the long term. “I want it now” as opposed to delayed gratification. When carbon capture and sequestration from fossil power plants becomes available, PV will become an overwhelming bargain.

    Steve

  507. Matthew:

    503, Ray Ladbury: They are doing the smart thing and developing production capability in advance of the huge increase in demand as the rest of the world begins to realize just how deep we are in the soup. And the US…well, we’re still arguing over 50-year old science.

    I share your respect for China, and I think that we should, as they do, subsidize PV cell manufacture instead of PV cell purchase, and we should speed up construction of new nuclear power. As to payback time on investment, the payback time for nuclear power is much shorter than the payback time for solar.

    But as long as we are discussing policies with respect to AGW, it should be noted that China is continuing to increase its CO2 production. According to their minister at the COP15 meeting, they will continue to do so for decades.

  508. Mark C:

    I have two questions?

    Where do you get this Hadcrut3 data for 2009 from?

    You state The 2009 number is the Jan-Nov average- are all the previous points on the HadCrut3 and GISTEMP curves Jan-Nov averages as well- I dont see how a Jan-Nov average can be representative of the year when it is excluding one fo the coldest months of the year?

    [Response: It's the anomaly value, it has nothing to do with whether Dec is cold in absolute terms or not. The data came from here, and when the Dec numbers get posted, I'll update the figure. - gavin]

  509. Brian Dodge:

    “The oceans are potentially free to both cool and warm as they like and take the global temperatures along with them.”
    I actually laughed out loud when I read this; It’s clear that TimTheToolMan — 1 January 2010 @ 5:54 PM either doesn’t understand cause and effect, or is choosing to ignore it for political/social/religious/trolling reasons. No doubt some people believe that the ocean can choose to cool or warm, just like the electorate can choose to vote Republican or Democratic*, but it’s probably not wise to let them control policy debates, or handle sharp instruments.

    “TimtheTool, If you’ve ever been diving, you know that visible light penetrates the water to at least about 10 meters, right? You know that as you go deeper, the light is extinguished, indicating that it is being absorbed, right?
    You know the skin surface effect occurs and about what magnitude it is, right? We know that decreased gradients decrease heat loss, right?
    And we certainly know the ocean is warming, right?”
    Ray, I wouldn’t count on Tim understanding this, or admitting it if he does; his head might explode.

    [*] Of course, if the ocean did have an irrational mind of its own, like Wall Street investors, it would mean that climatology is as hamstrung as economic forecasting; maybe that’s the new denialist meme?

  510. TimTheToolMan:

    [Response: Each term is calculated as a function of the temperatures, composition, cloud cover, etc at each time step in the model. Downward LW increases with higher CO2 and water vapour, but all of the terms vary with climate change and the net change is positive down. - gavin]

    Of course, but I am interested in the one term attributed to downward LW radiation and its assumed warming effect on the ocean, not so much interested in the calculation of its magnitude by clouds/water vapour/CO2 and so on at each step, which I’m sure science has quite a good handle on…

    When the downward LW radiation is actually applied to the ocean to warm it, what is the mechanism used?

    [Response: I still don't know what you are after. The net heat flux is applied at the surface of the ocean and then the mixing in the ocean mixed layer determines how that is distributed. - gavin]

  511. Rod B:

    Gavin (505): [Response: From everything - H2O, clouds, CO2, aerosols, ozone etc. - gavin]

    Thanks. Any from N2, Argon, or O2?

    [Response: No. They aren't LW emitters. - gavin]

  512. Hank Roberts:

    Tim, are you wondering how heat can go from the sky to the ocean?
    How infrared photons heat water?

    Can you ask a simple clear question?
    Make a clear statement of what you believe is true?
    Give us a pointer to whatever you’re reading?
    What do you trust as a source, that leads you to ask what you’re asking?

    It sounds like you’ve read something somewhere that uses words in a way you think everyone understands — but it appears your source may be using the words differently.

  513. TimTheToolMan:

    [Response: I still don't know what you are after. The net heat flux is applied at the surface of the ocean and then the mixing in the ocean mixed layer determines how that is distributed. - gavin]

    So are you saying that the LW radiation heats the “surface” and this is mixed into the upper layers?

    That is not described in “Why greenhouse gases heat the ocean” for LW radiation to heat the oceans though is it? Indeed there is a recongition that mixing from the surface is NOT the mechanism used to heat the oceans.

    Can you explain how the science supports this change in mechanism and how the magnitude of its effect is justified?

  514. JasonB:

    502, Matthew:

    “I think that you are overoptimistic on the payback time, or else the big subsidies would not be necessary. I could be wrong. The economics are rapidly changing, and if you are not right now, you will be in five years time or less.”

    I said energy payback time, not investment payback time. Investment payback time is still in the order of 10 years or so, but that is irrelevant to your suggestion that California’s PV investments simply amount to shipping emissions to China; the fact that it takes much less energy to make the PVs than they will generate over their lifetime means that the emissions that are “shipped” to China are far less, even if coal-fired power is used to make them.

    “Like the US, they see alternative/renewable energy partly in military terms, and they are vulnerable right now to having their fossil fuel supplies interrupted in time of war.”

    That’s part of it, although their response to that vulnerability is primarily to diversify their portfolio rather than try to guarantee fossil fuel supplies. (In addition to coal, nuclear, natural gas, and wind, China also has 50% of the world’s small hydro capacity and has the largest hydroelectric capacity in the world — 172 GW, about 20 times their current nuclear capacity.)

    Another part, however, is that they recognise that there’s a lot of money to be made in selling those technologies. Witness how quickly they have become manufacturing powerhouses in the wind and solar PV arenas, neither of which are indigenous technologies.

    “For both China and the US, it could turn out to be that CC&S is a more cost-effective intermediate-term strategy than solar. China and the US are building large scale installations at an unprecedented rate.”

    It could turn out to be, but it doesn’t seem likely, especially for existing powerplants who’s location wasn’t decided upon based on the convenience of implementing CCS.

    Also, don’t confuse the cost-effectiveness of PV with concentrating solar thermal, and, in the latter case, don’t forget there is a wide range of technologies from Stirling engines in dishes through to towers, parabolic troughs, and compact Linear Fresnel Reflectors — the latter being especially cost-effective and compact although less developed than the more expensive parabolic troughs.

    507, Matthew:

    “I share your respect for China, and I think that we should, as they do, subsidize PV cell manufacture instead of PV cell purchase, and we should speed up construction of new nuclear power.”

    I haven’t seen any reports suggesting that China subsidises PV cell manufacture.

    “As to payback time on investment, the payback time for nuclear power is much shorter than the payback time for solar.”

    Care to cite references? The best figures I could come up with showed nuclear power actually being pretty similar to solar thermal (not PV) right now, with solar having the advantage that you could add to it incrementally and so start earning revenue from the investment very quickly with no real risk that you would make an enormous up-front investment and have your chance to earn income from it delayed or lost entirely. (It also has the advantage, for countries like the US, of making them completely independent of fuel imports.) This is despite the fact that nuclear has had half a century of prior development and total subsidies of ~$150 billion and solar thermal is still in its infancy.

    Wind power, of course, is currently cheaper than both, and, as China demonstrates, you can add a lot of wind capacity very quickly while waiting for nuclear powerplants to come online. They look like exceeding the targets they set for 2020 just three years ago by the end of this year. The rate of growth of wind in China is truly remarkable. Although there aren’t enough wind resources in total for wind to be the primary long-term solution, it’s a very useful stop-gap.

  515. Doug Bostrom:

    TimTheToolMan says: 2 January 2010 at 6:32 PM

    TimTheToolMan, earlier with regard to increasing ocean heat content you said “…any AGW “effect” could be a small increment to an otherwise naturally varying climate and the case for continued increases at the observed rates diminishes considerably.”

    Presumably you have no problem with the data describing ocean temperature since you’re prepared to hypothesize a mechanism to explain why the oceans are becoming warmer. I’m wondering from where you believe that energy may be arriving?

  516. Hank Roberts:

    This, perhaps?

    http://www.whoi.edu/science/PO/people/jprice/ekman/price86.pdf
    That’s field work done with a research vessel built to actuall stand itself in a vertical position; was or is called “RV Flip” — don’t know if it’s still in service. This paper is from the research into how the warm surface water mixes into deeper ocean water.

    Found by finding one of the early papers on this kind of work, clicking for citing papers and going through them.

    http://www.scopus.com/results/citedbyresults.url?sort=plf-f&cite=2-s2.0-0020098315&src=s&imp=t&sid=GZHbmRmUePTuf4VU_I_Rvoc%3a30&sot=cite&sdt=a&sl=0&origin=inward&txGid=GZHbmRmUePTuf4VU_I_Rvoc%3a2

    I’m just guessing this may be on point, I haven’t a clue about what Tim is trying to ask about.

    Tim, if you can, please ask a clear question. Tell us what “mechanism” means to you? Do you mean in a computer model? In actual measured behavior in the ocean? Some kind of machine? Something else?

  517. Dave Salt:

    Thanks, John P. Reisman (#311).

    I much appreciate your efforts to describe examples of positive feedbacks. However, my question was about their dominance within the Earth’s climate system and the real-world evidence that would support this assertion.

    Identifying some jig-saw pieces is a first step; showing they can fit together to form a coherent picture is another; demonstrating that this picture is a true reflection of the real-world is the final step of this scientific puzzle. Your information relates to the first step while my question relates to the final one.

    Concerning the type of evidence I’m looking for, my earlier post (#246) included the one and only example that I’m aware of (i.e. the predicted “hot spot” above the equatorial troposphere) and my hope was that someone here could provide more. Obviously, absence of evidence is not evidence of absence, so I’ll try to keep an open mind and continue to ask the question in the hope that someone out there can better enlighten me.

    Thanks, dhogaza (#315)
    I’m not making assertions but simply drawing a conclusion, based upon what I read in the IPCC reports and some of the references provided in this thread (see attached ‘clippings’ concerning model uncertainties).

    Thanks, CM (#349)
    I appreciate the spelling correction and the didactic comments. I hope my reply to Ray Ladbury (below) answers most of your concerns/criticism.

    Thanks, Ray Ladbury (#320)
    I took some time out between family celebrations to look at the “MOUNTAINS of evidence” that you and others here have referred to and was astonished by what I read.

    In summary, there’s not one example of a ‘prediction’, let alone one verified by real-world evidence. However, there’s an absolutely HUGE amount of candidness about the uncertainties within all of the models and, more importantly, that the biggest and most important of them is the uncertainty over the effect of clouds (see attached clippings).

    I did come across one link listing model predictions that it claimed were verified by real-world observations (http://bartonpaullevenson.com/ModelsReliable.html). However, this was rather unconvincing because it contained no references or supporting evidence and included the trophospheric ‘hot spot’, which current data seems unable to verify.

    You say that the “climate senstitivities are constrained by evidence” but the references all show that these constraints are rather wide and, more importantly, include a significant range that would imply non-catastrophic AGW (i.e. less than 2C). Moreover, as the models used by these sensitivity assessments contain ‘structural uncertainties’, the confidence in these derived constraints may well be questionable. Are you telling me that these uncertainties have now been resolved and that the effects of clouds are now sufficiently well understood so that we can confidently remove any reasonable doubt about model results?

    I’m actually very grateful for the pointers that everyone here has provided, although they weren’t exactly what I was expecting. Nevertheless, they’ve helped to clarify many of my previous ideas about this subject and lead me to draw the following set of conclusions:

    1) The low-level IPCC documents provide a candid and thorough summary of the current status of climate science. They are an honest attempt to tell a complex story where some of the most significant details are still poorly understood.

    2) Much of the ‘basic’ physics could be classed as “settled science” (e.g. the IR absorption of CO2) but it would be naive in the extreme to describe the system-level interactions that the models try to simulate as “settled science” because many of the basic mechanisms have yet to be fully accounted and/or there interactions are still not sufficiently well understood (e.g. clouds, aerosols, vegetation).

    3) The controversy that rages over this issue appears to derive from the way that the low-level details are ‘interpreted’ for policy makers. Worst case scenarios seem to be highlighted, while the associated uncertainties appear to lack the necessary emphasis.

    I suspect these conclusions will be unacceptable by many here and so attach the following selected ‘clippings’ for those who may be interested. If you feel they have been taken out of context or that I’ve omitted details that show they are not that important, please let me know.

    ——————————————————-
    http://ipcc-wg1.ucar.edu/wg1/Report/AR4WG1_Print_Ch08.pdf
    8.6.2.3 What Explains the Current Spread in Models’ Climate Sensitivity Estimates?

    Using feedback parameters from Figure 8.14, it can be estimated that in the presence of water vapour, lapse rate and surface albedo feedbacks, but in the absence of cloud feedbacks, current GCMs would predict a climate sensitivity (±1 standard deviation) of roughly 1.9°C ± 0.15°C (ignoring spread from radiative forcing differences). The mean and standard deviation of climate sensitivity estimates derived from current GCMs are larger (3.2°C ± 0.7°C) essentially because the GCMs all predict a positive cloud feedback (Figure 8.14) but strongly disagree on its magnitude.

    8.6.3.2 Clouds

    In the current climate, clouds exert a cooling effect on climate (the global mean CRF is negative). In response to global warming, the cooling effect of clouds on climate might be enhanced or weakened, thereby producing a radiative feedback to climate warming.

    Therefore, cloud feedbacks remain the largest source of uncertainty in climate sensitivity estimates.

    8.6.3.2.1 Understanding of the physical processes involved in cloud feedbacks

    The sign of the climate change radiative feedback associated with the combined effects of dynamical and temperature changes on extratropical clouds is still unknown.

    The role of polar cloud feedbacks in climate sensitivity has been emphasized by Holland and Bitz (2003) and Vavrus (2004). However, these feedbacks remain poorly understood.

    8.6.3.2.4 Conclusion on cloud feedbacks

    Despite some advances in the understanding of the physical processes that control the cloud response to climate change and in the evaluation of some components of cloud feedbacks in current models, it is not yet possible to assess which of the model estimates of cloud feedback is the most reliable.

    8.6.4 How to Assess Our Relative Confidence in Feedbacks Simulated by Different Models?

    A number of diagnostic tests have been proposed since the TAR (see Section 8.6.3), but few of them have been applied to a majority of the models currently in use. Moreover, it is not yet clear which tests are critical for constraining future projections. Consequently, a set of model metrics that might be used to narrow the range of plausible climate change feedbacks and climate sensitivity has yet to be developed.
    ——————————————————-
    http://ipcc-wg1.ucar.edu/wg1/Report/AR4WG1_Print_Ch09.pdf
    9.6.4 Summary of Observational Constraints for Climate Sensitivity

    Structural uncertainties in the models, for example, in the representation of cloud feedback processes (Chapter 8) or the physics of ocean mixing, will affect results for climate sensitivity and are very difficult to quantify.
    ——————————————————-
    http://www.climatescience.gov/Library/sap/sap3-1/final-report/sap3-1-final-all.pdf
    4.1.1 Equilibrium Sensitivity and Transient Climate Response

    We understand in much more detail why models differ in their equilibrium climate sensitivities: the source of much of this spread lies in differences in how clouds are modeled in AOGCMs.

    4.2.1 Cloud Feedbacks

    Differences in cloud feedbacks in climate models have been identified repeatedly as the leading source of spread in model-derived estimates of climate sensitivity (beginning with Cess et al. 1990). The fidelity of cloud feedbacks in climate models therefore is important to the reliability of their prediction of future climate change.
    ——————————————————-
    http://www.iac.ethz.ch/people/knuttir/papers/knutti08natgeo.pdf
    Structural problems in the models, for example in the representation of cloud feedback processes or the physics of ocean mixing, in particular in cases in which all models make similar simplifications, will also affect results for climate sensitivity and are very difficult to quantify.
    ——————————————————-
    http://chriscolose.wordpress.com/2009/10/08/re-visiting-cff/
    Clouds are the largest source of uncertainty in quantifying the extent of climate feedbacks.

    clouds have competing effects between reflecting sunlight (low clouds mostly) and influencing the outgoing infrared radiation (high clouds mostly). It is still not clear how these two effects will balance out, and thus the magnitude and even the sign of the feedback is not well constrained.
    ——————————————————-

  518. David B. Benson:

    TimTheToolMan (513) — Mixing certainly occurs in the upper ocean. For example, the top 10 or so meters are rapidly mixed by wave action. In addition, some tiny marine animals swim up at night to eat and then down during the day (I suppose to avoid being eaten); there is a significant amount of energy added to the ocean and it seems likely this activity promotes mixing as well as the means Gavin Schmidt mentioned in a reply to you.

  519. phil c:

    A couple papers with some interesting statistical analysis of some of the temperature datasets.(with a reference for those of us who aren’t statisticians: http://web.duke.edu/~rnau/411home.htm). The most interesting observation is that the temperature datasets are nonstationary. That means the data can’t be used for forecasting, without transforming it to get it at least approximately stationarity. I haven’t ever seen a reference to that process in any of the climate forecasting/models. The most typical “forecast” is a linear regression over a period, which is the worst possible predictor of the future. To quote Neils Bohr(and Yogi Berra) “Making predictions is very difficult, especially about the future”.

    Environmental Modeling and Assessment
    Nonstationary, long memory and anti-persistence in several climatological time series data.
    Luis A. Gil-Alana
    Contact Information
    Faculty of Economics, Edificio Biblioteca, Entrada Este, University of Navarra, E-31080 Pamplona, Spain

    Received: 27 August 2004 Accepted: 26 July 2005 Published online: 2 November 2005
    Abstract In this article we examine the stochastic behaviour of several daily datasets describing sun (total irradiance at the top of the atmosphere and sunspot numbers) and various climatological anomaly series by looking at their orders of integration. We use a testing procedure that permits us to consider fractional degrees of integration. The tests are valid under general forms of serial correlation and deterministic trends and do not require estimation of the fractional differencing parameter. Results show that the series are all nonstationary, with increments that might be stationary for those variables affecting sun, and anti-persistent for those affecting air temperatures.

    Journal of Geophysical Research vol. 107, no.0 2002

    On nonstationarity and antipersistency in global temperature series.
    O. Kärner
    Tartu Obserfvatory, Törarevere, Estonia

    abstract: Statistical analysis is vcarried out for satellite-based global daily tropospheric and stratospheric temperature anomaly and solar irradiance data sets. Behavior of the series apperas to be nonstatinary with stationary daily increments. Estimating long-range dependence between the two series reveals a remarkable difference between the two temperature series. The global average tropospheric anomaly behaves similarly to thye solar irradiance anomaly. Their daily increments show antipersistency for scales longer thanb 2 months. This property points at a cumulative negative feedback in the Earth climate system governing the tropospheric variability during the last 22 years……..The observed global warming in the surface air temperature series(Jones et al. 1999) is more likely produced due to over nonstationary variability of the Earth climate system under anti-persistent solar forcing.

  520. Hank Roberts:

    > mechanism?

    A Darwinian mechanism for biogenic ocean mixing

    Kakani Katija
    (Bioengineering, California Institute of Technology)
    John Dabiri
    (Bioengineering and Aeronautics, California Institute of Technology)

    Recent observations of biogenic turbulence in the ocean have led to conflicting ideas regarding the contribution of animal swimming to ocean mixing. Previous measurements indicate elevated turbulent dissipation in the vicinity of large populations of planktonic animals swimming in concert. However, elevated turbulent dissipation is by itself insufficient proof of substantial biogenic mixing. We conducted field measurements of mixing efficiency by individual _Mastigias_ sp. (a Palauan jellyfish) using a self-contained underwater velocimetry apparatus. These measurements revealed another mechanism that contributes to animal mixing besides wake turbulence. This mechanism was first described by Sir Charles Galton Darwin and is in fact the dominant mechanism of mixing by swimming animals. The efficiency of Darwin’s mechanism (or drift) is dependent on animal shape rather than fluid length scale and, unlike turbulent wake mixing, is enhanced by the fluid viscosity. Therefore, it provides a means of biogenic mixing that can be equally effective in small plankton and large mammals.

    http://meetings.aps.org/link/BAPS.2009.DFD.BE.5

  521. Hank Roberts:

    Phil C
    — that was for a while a very popular paper in certain circles:
    http://scholar.google.com/scholar?cites=6701307676645840349&hl=en&as_sdt=2001&as_vis=1

  522. Hank Roberts:

    Phil C –
    See also:
    http://www.google.com/search?q=site%3Atamino.wordpress.com+nonstationarity

  523. David B. Benson:

    phil c (519) — Unfortunately your link is broken. Here it is:
    http://www.duke.edu/~rnau/411diff.htm
    Proper use of statistics for geophysical time series is found at
    http://tamino.wordpress.com/
    with clear, concise expositions.

  524. Ray Ladbury:

    Dave Salt, Barton Paul Levenson has supplied references for his list–I think it was on this very post. I’m sure he’ll supply you with the references again if you like. And in any case, you ought to be familiar with most of the items on his list, and they provide pretty strong evidence.

    I think that your dismissal of the constraints on CO2 sensitivity is entirely too cavalier. Yes there are a few of the constraints that are quite broad and do have reasonable probability below 2. Taken together, though, they strongly favor a sensitivity of around 3 degrees per doubling and all but preclude sensitivity below 2.1. What is more, if the best-fit value is wrong, it is far more likely to be to low than to be too high.

    This brings me to yet another cavalier dismissal in your missive–this time of the models. The models actually are among the most effective constraints limiting sensitivity at the high end. If you don’t believe in them, then warming could well be above 4 degrees per doubling, and since the consequences effectively scale exponentially with the warming, that would be grave indeed. If you look at Knutti and Hegerl figure 5, this starts getting us into pretty risky territory even for an CO2 concentration of 450 ppmv, which we will almost surely exceed.

    See, this is the point I don’t understand. You guys are so eager for the models to be wrong–as if you could make the problem go away if you could falsify the models. It doesn’t work that way. There is sufficient evidence to demonstrate a credible threat just from the temperature record and the paleoclimate. Without the models, we have a threat where we can’t bound the risk–and the only appropriate response in those situations is risk avoidance.

    Fortunately, though, I think you are wrong about the models. Your continual emphasis on uncertainties in cloud feedbacks doesn’t take into account that the best evidence indicates that such feedbacks, rather than the strong negative feedback you would require to have any validity to your position. In fact there is simpy no evidence backing your sanguine attitude. The best you can come up with are statements about “structural uncertainties” that do not in fact invalidate the known science.

    It is not enough to say “Climate is too complicated to understand.” That is an unscientific attitude. The fact is that we must understand it. The consensus model we have today really does a pretty good job, and it suggests clear guidance for policy. The fact that there remain some uncertainties in the model certainly does not invalidate its successes, and it most certainly does not sanction doing the exact opposite of what the models indicate we should do.

    In the end, Dave, the choice is between following the guidance of science or going 180 degrees against it–science or anti-science. Pick!

  525. Rattus Norvegicus:

    phil c

    One thing you are forgetting is that climate models are *NOT* statistical models. AFAIK, nobody has tried to make a climate projections in the last couple of decades or so using a statistical model.

    As for the two papers you provide, the first one has not been cited by anyone. Nobody, nada, nothing. The second has been cited 15 times. One is a self cite and most of the others are by the likes of Bob Carter, McKitrick, Veizer: you should get the picture. Some of the other cites were in papers completely unrelated to climate.

  526. Ray Ladbury:

    Timthetool, In heating the oceans, there are several processes that are important. Sunlight is certainly the dominant heating source. However, under normal circumstances, the oceans would remain in equilibrium by radiating away heat at the surface to the atmosphere.
    However, IR radiation produces a skin effect decreasing temperature gradient right at the surface, and this limits heat loss–so yes back radiation contributes to heating the oceans by decreasing energy lost. Because of turbulence, the skin effect is transient. However continual mixing between the sunlight-heated upper portion of the oceans and the portion down to several meters distributes the heat. There’s nothing that controversial here. Did you look at the webpage I provided?

  527. Don Shor:

    Hank: “That’s field work done with a research vessel built to actuall stand itself in a vertical position; was or is called “RV Flip” — don’t know if it’s still in service.”

    Yes, FLIP is still part of the Scripps research fleet.
    http://scripps.ucsd.edu/voyager/flip/

  528. jyyh:

    assuming there are causes and consequences (such as melting of ice in increased heat) statistics maybe useful. however, it cannot predict one-time events in a given system. but then again, it might be useful in predicting the timing of a one-time event not included in the description of the said system (yes, i like tamino’s site).

  529. john byatt:

    the aussies here will have heard of senator steve fielding
    the anti science loony ,
    his forum is a laugh a minute , latest post was linked to , ‘its the scientists stupid” at http://www.rense.com/general89/easta.htm global warming created by evil scientists.

  530. Steve Fish:

    Comment by Dave Salt — 2 January 2010 @ 7:25 PM:

    Dave:

    Having read your questions and the responses to them I think I understand what you are asking. I think you want to know of some simple proof of positive feedback to heating of the earth by the CO2 greenhouse effect. If so, check out the following.

    The cycle of the ice ages, consisting of a regular recurrence of glacial and interglacial periods, are coordinated with different length cycles of orbital distance of the earth from the sun, axial tilt of the earth relative to the sun, and precession of tilt, called Milankovitch cycles. When the separate cycles align to reduce solar input to the northern hemisphere a glacial period ensues. When they align to maximize solar input to the northern hemisphere the ice melts in an interglacial. You can check this out on Wikipedia or search the Real Climate site for articles.

    The actual changes in solar input has been calculated and the forcing is not nearly enough to cause glacial and interglacial periods, so there must be positive forcing that enhances the sun’s warming to cause interglacial periods, and positive forcing to enhance the sun’s cooling to cause glacial periods. A positive feedback enhances a forcing whether it is hotter or cooler.

    There are a lot of different feedback mechanisms, but two big ones are the CO2 greenhouse effect and ice albedo. When insolation decreases a little, snow cover stays longer at lower latitudes and it reflects sunlight to enhance (positive feedback) cooling. Over time the oceans cool a little and this enhances solubility of CO2 in the ocean which, in turn, reduces the greenhouse effect to cause further cooling of the planet (also a positive feedback). Eventually glaciers and snow cover a large portion of the earth.

    Similarly, when the orbital and tilt cycles align to warm the northern hemisphere a little the snow recedes to reduce albedo to warm the earth further (again a positive feedback). After the ocean warms, CO2 outgases from the ocean and warms the earth by the greenhouse effect. CO2 varies with temperature, but the time to warm the ocean explains why there is a lag when it is a feedback mechanism. Eventually the earth warms for an interglacial period.

    The earth appears to be in a delicate balance such that a small change in insolation combined with net positive feedbacks can make major changes in climate. The ice ages would not have been possible without positive feedback, and this is why the anthropogenic increase in CO2 is so potentially disrupting.

    Steve

  531. Hank Roberts:

    Don, thanks for the link!
    http://scripps.ucsd.edu/voyager/flip/
    Folks, if you don’t know about this one, don’t miss it.

  532. TimTheToolMan:

    Tim, if you can, please ask a clear question. Tell us what “mechanism” means to you? Do you mean in a computer model? In actual measured behavior in the ocean? Some kind of machine? Something else?

    Its not the kind of question that can be asked or answered “simply” in the absence of background information but with reference to the RC article “Why greenhouse gases heat the ocean”, I was hoping Gavin would understand fairly quickly.

    As far as the answer in practical terms for the models, I was expecting downward longwave radiation to eventually become some X W/m^2 term that is applied to the ocean for each time step and subsequently mixed down into the ocean.

    Where I’m coming from is that Real Climate did an article some time ago explaining how anthropogenic CO2 might heat the oceans “Why greenhouse gases heat the ocean” found in the index under oceans – and this describes a completely different theory as to how the heating may occur.

    As far as I’m aware the theory described in the RC article has never been followed up and the heating effect described has not been quantified so that proper values may be used in the models.

    From my other reading on the ocean skin, it seems that the Real Climate theory “Why greenhouse gases heat the ocean” is truely needed because warming of the skin by downwelling LW radiation and mixing wont on average warm the ocean, it may simply cool it more or less quickly because on average (Schluessel et al., 1990) the skin temperature is less than the bulk ocean temperature.

    Anyway, if someone has a reference to a paper that verifies that the observed ocean temperature increases can be attributed to anthropogenic effects, I’d like to see it.

  533. Chris Colose:

    Dave Salt (#246, 517)–

    The uncertainties in climate sensitivity are not independent of the uncertainties in cloud feedbacks. So while you are correct that the sensitivity estimate uncertainties are quite large (about +/- 50% from the 3 C central estimate), that is still the uncertainty range, and there’s very little chance that the right answer is outside that range. This is still consistent with my statement that you quoted, “Clouds are the largest source of uncertainty in quantifying the extent of climate feedbacks.”

    Concerning climate models, all models can be shown to be “wrong” in some sense, but being wrong may not take away from their usefulness. For instance, most (all?) models are too conservative in simulating the NH sea ice loss, but there’s many other variables to climate than just sea ice, and not too many sane people will use this fact to say “well models are wrong, there’s nothing to worry about, minus well throw a party.” Similarly, there’s much more to climate than the tropical “hot spot.” Currently, the observational data and signal-to-noise ratio are such that it is difficult to tell with high confidence whether models currently capture expected or real-world behavior very well. There’s no evidence that an obvious discrepancy exists, but if it did, it would have several interesting implications (and scientists like new things!). It would matter quite a bit to the hurricane community. The implications for climate sensitivity would likely be small, but could mean an even stronger sensitivity, since the lapse rate feedback would be less negative with a stronger vertical temperature gradient. These type of issues appear in all fields of science. If all the issues were “settled” then there would be no reason to have researchers in the field or students interested.

  534. edrowland:

    >> Fortran is simple, it works well for these kinds of problems, it complies efficiently on everything from a laptop to massively parallel supercomputer, plus we have 100,000s of lines of code already. If we had to rewrite everything each time there was some new fad in computer science (you know, like ‘C’ or something ;) ), we’d never get anywhere. – gavin]

    No, really. This is unbelievably shocking stuff. This is a coding style that’s almost 40 years out of date, and even then not done to then-current 1960s standards. It violates every single coding principle used by modern programmers, without exception.

    In modern programming languages, 100,000 lines of code isn’t really that much. But 100,000 lines of code in that coding style is 100,000 lines of unsupportable code. Embedded constants all over the place, not so much as a comment as to what the data is, let alone the provenance of the data, or what’s being done with it. No structuring of data. Insane variable names. Global data being set on an all-but-arbitrary basis.

    For something so important, this is not well done, at all.

    [Response: We have a serious refactoring exercise going on to better structure the code, and that will help. But the language will still be Fortran. - gavin]

  535. Rod B:

    re [Response: No. They aren't LW emitters. - gavin]

    333 Watts/m^2 seems like an awful lot to be coming from clouds, water vapor and CO2. Is there any other contributor to the downward LW radiation? Or is it what the GHGases actually emit whether it seems like a lot to me or not?

  536. Ernst K:

    Tim the TM said: “I was expecting downward longwave radiation to eventually become some X W/m^2 term that is applied to the ocean for each time step and subsequently mixed down into the ocean”

    That’s basically what the article is doing, except it’s putting far more attention on the “applied to the ocean” part than you apparently expected and taking it more or less for granted that the reader already understands the “downward longwave radiation to eventually become some X W/m^2 term” part.

    There’s a figure in that article that breaks it all down into 5 steps.

  537. PeteB:

    Dave Salt, here is my understanding

    Dave Salt said : ” The low-level IPCC documents provide a candid and thorough summary of the current status of climate science. They are an honest attempt to tell a complex story where some of the most significant details are still poorly understood.”

    Agreed up to the point of ‘the most significant details’. The areas that are not well understood are significant but not ‘the most significant’

    Two well understood elements that make up the climate sensitivity are the CO2 ‘greenhouse effect’ and the combined water vapour / lapse rate feedback (that I think brings you to around 2.4 Deg C) These are now well understood (see Box 8.1 in http://ipcc-wg1.ucar.edu/wg1/Report/AR4WG1_Print_Ch08.pdf in section 8.6) and confidence has significantly improved since the TAR.(see 8.6.3.1.2)

    The other areas have varying degrees of uncertainty associated with them, with clouds being perhaps the most uncertain. These uncertainties give rise to quite a big range for climate sensitivity (the often quoted 2 – 4.5 Deg C with around 3 Deg C the most likely)

    Remember there are two approaches to this, one is to come up with a climate sensitivity based on understanding and modelling each contributing factor and running the model and seeing what you come up with, the second is to observe overall what effect on temperature an increase/decrease in a known climate forcing has (taking into account error bars in the forcing and the resultant temperature change). From this you can calculate the overall feedback and what the likely amplification of the CO2 ‘greenhouse’ forcing is. This is covered in chapter 9 http://ipcc-wg1.ucar.edu/wg1/Report/AR4WG1_Print_Ch09.pdf

    As mentioned in chapter 9, if you combine the probability distributions from several independent observation events this can improve the estimate of climate sensitivity e.g. http://www.jamstec.go.jp/frcgc/research/d5/jdannan/GRL_sensitivity.pdf

    Point 2) – There are certainly some areas of the model that are not well understood, but there are a lot of areas that are well understood and conform well to the observations (see Gavin’s posts here on models)

    Dave Salt said “3) The controversy that rages over this issue appears to derive from the way that the low-level details are ‘interpreted’ for policy makers. Worst case scenarios seem to be highlighted, while the associated uncertainties appear to lack the necessary emphasis.”

    But these are covered very fairly in the Summary for Policymakers, with each statement having a ‘likelihood’. I think you would have a hard time arguing these are minimising uncertainties or emphasising the ‘worst case’, I would say this is a very conservative (small c) document.

    http://ipcc-wg1.ucar.edu/wg1/Report/AR4WG1_Print_SPM.pdf

    http://ipcc-wg1.ucar.edu/wg1/Report/AR4_UncertaintyGuidanceNote.pdf

  538. FurryCatHerder:

    I’m going to finish reading the 4 pages of comments I’ve not read yet, but I can no longer restrain myself in regards to the carbon tax proposals.

    The critical fact that bears keeping in mind is that 100% of what we “buy” goes all the way back to “energy”. If you say “but raw materials don’t!”, wrong — raw materials require energy to extract from wherever they are hiding. “Services” — people use energy to show up for their service sector job. And so on. It’s all energy, which is why renewable energy is such a fantastically wonderful idea.

    In short, a “carbon tax” is a flat tax scheme, and as such is regressive. No one is really going to suggest that. A “carbon tax with quotas” — starting to make more sense, but that just gets us to tax brackets as we have them today. And instead of “loopholes”, you’d have the rich buying “offsets”.

    As regards the comment that even Liberal Democrats don’t believe in AGW, I have to agree 100%. If Al Gore actually BELIEVED what he’s saying, no one would have found those 22,000KWh a month electric bills. I used about 3,800KWh last year (yeah, that’s the entire year — it comes out to about 320KWh per month, or about 1/70th of what Al Gore uses) and I’m far from a Liberal Democrat. And I live in Central Texas. And run the A/C. And have a house full of computers that run 24/7.

    When Al Gore cuts his electric consumption by 98.5%, then I think people will look at AGW more seriously. Because if Mr. Power Point can’t actually reduce his actual use of fossil fuels, why should I?

  539. Jacob Mack:

    First of all happy new years to all! Gavin, very clear, accurate and honest piece. I like how straightforward the graphs are, the explanations and admissions of margins of error. The models have greatly improved since the 1980′s and they are continuing to be improved upon.AGW remains a serious issue based upon sound science and mathematical analysis.

  540. Richard Palm:

    You’ve said several times that the models are not fitted to the temperature data. Would it be correct to say that the model outputs are derived solely from calculations based on physical laws?

  541. Rob:

    @226

    What would the output of the GCMs look like if there were no CO2 increase? Any links to a graph? thanks!

    [Response: Assuming you mean no forcings of any kind, then the ensemble mean would be flat, but you'd still see excursions of the same magnitude as the grey bands above. - gavin]

    No, I mean just without an increase in CO2, all others stay the same. Thanks. (Sorry for the delayed follow-up, forgot I asked…)

  542. Ray Ladbury:

    Timthetool:
    I have repeatedly suggested that you go to Minnett’s website:
    http://www.rsmas.miami.edu/personal/pminnett/Complete_List/complete_list.html

    There are several papers there that characterize the skin effect. Once you know the thermal profile of the skin, it is just thermodynamics to calculate heat transfer across the skin layer. Keep in mind that this is a transient effect. The skin is established and breaks on a regular basis. This would make it a sub-grid effect, so you would be average the effect over time and space subject to prevalent conditions within the grid square. This is an educated guess on my part, based on my (very) general knowledge of the models. I’m sure Gavin will correct me if I am wrong. However, we know that oceans are warming and that the models reproduce the effect pretty well. What is more, the physics is pretty well known.

  543. Damien:

    re #534
    “We have a serious refactoring exercise going on to better structure the code, and that will help. But the language will still be Fortran. – gavin”

    Putting aside the legacy code issue, why Fortran? With Fortran 2003, some of the interoperability issues with C have been sorted and it’s going to be very hard to argue that Fortran will run more efficiently than C?

    Just to venture even more off topic, why not profile the code and re-write a small percentage of critical routines in assembly? It’s routine in both games programming and embedded systems and can boost performance over vanilla C by quite a bit.

    Curious, how valuable would it be to cut (say) 10% of the time off a model run?

  544. grumpy software architect:

    edrowland #534 – another hysterical coder… what exactly is awful? Throwing around phrases like “every single coding principle” just displays your lack of connection with modern programming. Unless of course you think that modern programming is defined by VB.Net.

  545. grumpy software architect:

    #543 – skills do not have zero cost. If a team knows how to be productive in a language you will get more bugs and less productivity by switching to something else. Adding assembler to the mix (when I suspect the critical routines are doing arithmetic that Fortran has been VERY good at for some decades) is a recipe for producing garbage.

  546. dhogaza:

    Putting aside the legacy code issue, why Fortran? With Fortran 2003, some of the interoperability issues with C have been sorted and it’s going to be very hard to argue that Fortran will run more efficiently than C?

    Those insisting that C is more readable than FORTRAN may be forgetting that it is C, not FORTRAN, that comes with its own puzzle book …

  547. Hank Roberts:

    For Dave Salt, I wonder if you’re not overly focused on “uncertainty” — which you talk a lot about above and point to in the IPCC references. I don’t know how much science background you have, but it’s important to realize that “uncertainty” in science isn’t a problem or a failure–it’s the whole focus of the enterprise, and it gets narrowed down but not eliminated.

    The uncertainty is talked about all the time, it’s where the excitement and fun and challenge is.

    The very best science can do is say “probably” — probability is what science does. Proof is done in mathematics, not in science.

    Compare: http://imgs.xkcd.com/comics/science_montage.png nails this nicely.

  548. Hank Roberts:

    Oh, I see the problem I think:

    > warming of the skin by downwelling LW radiation and mixing wont on
    > average warm the ocean, it may simply cool it more or less quickly
    > because on average (Schluessel et al., 1990) the skin temperature is
    > less than the bulk ocean temperature.

    That paper published 20 years ago, and I don’t think it means what you think it does. Where are you finding a reference to that? Have you come across something by Gerlich and Tscheuschner that you’re relying on?

    Look at the actual paper and the citing papers, and the author’s extensive subsequent work, and watch out for blogs arguing that the “second law of thermodynamics” proves warming can’t happen. That line of thinking is proposed, debunked, and rebunked quite often.

    If I’ve guessed wrong about where your questions arise, my apology, but I’m still trying hard to figure out what assumptions you’re basing your whole line of questioning on. This seems the most likely recent guess.

  549. Hank Roberts:

    For example, you might been confused by something like this–it appears to be the first in a series of articles claiming to disprove global warming; also featuring references to Niels Corbyn and other familiar names:
    http://juxte.files.wordpress.com/2009/11/climate-change-series-for-reservoir-magazine-jan-may-2009-dr-a-neil-hutton.pdf

  550. Ken W:

    FurryCatHerder (538):

    The “Al Gore is XYZ, therefore AGW is false” argument doesn’t sway anyone with even the slightest understanding of global warming. Al Gore could be a cannibalistic pedophile that’s burning coal in his basement and that wouldn’t have the slightest effect on the scientific evidence for AGW.

    FYI:
    http://www.snopes.com/politics/business/gorehome.asp

  551. Completely Fed Up:

    Damien states: “it’s going to be very hard to argue that Fortran will run more efficiently than C?”

    Uh two problems: the speed of compiled code depends on the capability of the compiler.

    Do you think FORmula TRANslation would be better targeted to compiling formulae in a computer than generic C?

    Secondly, (and really related to the earlier), vector processors used to be written with fortran compilers. The IBM 3090 was a supercomputer ONLY if you used FORTRAN and turned on the vector processing. 30-100x faster.

  552. Completely Fed Up:

    Rob: “No, I mean just without an increase in CO2, all others stay the same.”

    Yes, it would be flat (in the same way as the Midwest American Plains are flat).

  553. Completely Fed Up:

    “If you say “but raw materials don’t!”, wrong — raw materials require energy to extract from wherever they are hiding”

    Wrong. Unless you’re talking of the very trivial.

    I can grow potatoes.

    I can farm a goat (milk is better than cows milk for humans adults and babies).

    Power requirements: nil.

  554. Completely Fed Up:

    Matthew dissembles

    “210, Martin Vermeer: We know too much, not too little.

    If that were true, the models would be exact over all time scales.”

    Incorrect. That would require we know everything, which isn’t the same as “too much”.

    Remember: A little knowledge is a dangerous thing

    So knowing a little is not knowing everything, but it’s worse than knowing nothing.

    Just pointing out that you are (likely deliberately) messing up the meaning to get the desired conclusion.

  555. lgp:

    Regarding the graph ” IPCC AR4 models plotted against the surface temperature records from the HadCRUT3v and GISTEMP products (it really doesn’t matter which). ”

    If it really doesn’t matter which, then why not plot IPCC AR4 models vs UAH and RSS, which do cover the same time period and aren’t as subject to anthropogenic errors?

    Regarding “the comparison of the ocean heat content (OHC) changes in the models compared to the latest data from NODC. Unfortunately, I don’t have the post-2003 model output handy”

    Your comment Ignores the step at 2001 due, perhaps, to a major instrumentation change? This step can hardly be physical, as no such step is shown in the prior data. And 2003 is over half a decade past … why the reluctance to plot the models since, do you know if they are having difficulty matching the 2001 step change? The linear extrapolation to 2010 is pretty lame (starting point fallacy). A linear extrapolation starting in 1965 would be more appropriate and show the models in 2010 are out of line with the observations.

  556. JCH:

    “… and this describes a completely different theory as to how the heating may occur. …” – TtTM

    I think this is the source of his confusion. The article is a response to Fred Singer, who raised an objection to the existent notions of how GHGs warm the ocean. By my reading, the author was not proposing a completely different theory. He’s was merely trying to get the Singers of the world up to speed. I would think the models, since they predicted increased OHC and that has been confirmed by observations, already effectively included the physics the article explains.

  557. John P. Reisman (OSS Foundation):

    #547 Hank Roberts

    This is an important point.

    To understand basically what is going on, focus on what is now virtually or reasonably certain. This gives one a good overall picture of the problem.

    Once that is understood the uncertainties come into focus as to relevance to future potentials.

    Science in a conservative endeavor by all reasoned accounts. In other words, I can reasonably expect that the uncertainties are worse, not better, than we would like to think based on current indicators.

  558. Tilo Reber:

    Gavin:
    “As you can see, now that we have come out of the recent La Niña-induced slump, temperatures are back in the middle of the model estimates. If the current El Niño event continues into the spring, we can expect 2010 to be warmer still.”

    Apparently you consider “La Nina-induced slumps” as an aberration and El Nino induced rises as just getting back to normal. Why is that? Why not produce another ENSO corrected data set, and let’s see what has actually happened since 1998. If you don’t want to do it, then give the algorithm to me and I will do it. And I’ll let you know the results.

  559. SecularAnimist:

    FurryCatHerder wrote: “When Al Gore cuts his electric consumption by 98.5%, then I think people will look at AGW more seriously.”

    No, they won’t. Because the people who think that Al Gore’s electric consumption has anything to do with the scientific reality of anthropogenic global warming, are by definition incapable of looking at anything “seriously”.

    If Al Gore reduced his electric consumption to zero and lived in a cave eating nuts and berries and wearing homespun hemp, Rush Limbaugh would just tell those folks that this was proof that Gore’s secret plan to get rich from wind turbines, while simultaneously destroying liberty and capitalism and imposing World Liberal Government with himself as dictator for life, was even more insidious than they had thought. And his listeners, being “skeptics”, would of course unquestioningly believe every word.

  560. Doug Bostrom:

    edrowland says: 3 January 2010 at 1:32 AM

    “No, really. This is unbelievably shocking stuff…”

    Once your shock has dissipated, what do you find in the way of actual problems with the output? And are all the models convergently wrong in their gross estimations? You say the code is so poorly readable, so how would the persons constructing the models produce that convergence?

    “I don’t like the code”: Just another desperation argument, same as “all the data is bad” or “the tenure process is broken.” It’s a weak argument lacking necessary explanatory power against all the multiple indicators requiring to be accounted for in any successful effort to dismiss AGW.

    Hank Roberts says: 3 January 2010 at 11:05 AM

    Debunking —> “rebunking.” Wonderful!

  561. flxible:

    Completely Fed Up: “Power requirements: nil”

    wrong … aside from the fact that human food is a “raw material” for your personal energy requirements, even if you grow your taters and goats by human power alone using zero external inputs [the real raw materials], at the very least, someone consumed the energy to clear those carbon sequestering trees from your land, plus without the microbial energy expended in the soil extracting the plant nutrients needed you’ll have no edible tubers – in fact after a couple years of those microbes working away, your crops would have consumed all the nutriative energy available …. and at that level of agriculture how long would you last?

  562. Ernst K:

    Comment by FurryCatHerder — 3 January 2010 @ 2:35 AM:

    “In short, a “carbon tax” is a flat tax scheme, and as such is regressive. No one is really going to suggest that. A “carbon tax with quotas” — starting to make more sense, but that just gets us to tax brackets as we have them today. And instead of “loopholes”, you’d have the rich buying “offsets”.”

    First, you could return the revenue form the carbon tax back to the public on a per capita basis while leaving the current income tax regime in place. If anything, this would make the tax system less regressive if you assume that people with low incomes use less energy than those with high incomes. Also, I don’t see why anyone should get tax credits for offsets, simply because they are so difficult to verify.

    If we’re talking about the “eliminate income tax and replace it with carbon tax” proposal, I don’t think it’s reasonable to assume that carbon tax could fully replace income tax revenue and be set at the appropriate level to meet emissions targets at the same time. If you do the math for the US with 300 million people and emitting 20 tonnes CO2 per capita, in order to generate $1 to 1.5 trillion a year to replace just personal income tax revenue, you’d need a tax rate of $170 to $250 per tonne CO2 (or $600 to $900 per tonne C). From what I’ve seen, even the studies which suggest relatively high C prices (e.g. Ackerman and Finlayson, Climate Policy, 2006, 6, 509-526) don’t reach this kind of a price until the 22nd century. So you’d have to think such a tax rate would reduce consumption by quite a bit, which means the rate would have to be even higher to replace personal income tax revenue.

  563. Tilo Reber:

    Completely Fed Up: #553
    “Yes, it would be flat (in the same way as the Midwest American Plains are flat).”

    Then it would be wrong; since climate has almost never been flat – even when there was little or no change in CO2.

  564. Comletely Fed Up:

    Tilo misses the point by miles (by ducking):
    ““Yes, it would be flat (in the same way as the Midwest American Plains are flat).”

    Then it would be wrong”"

    Nope, the climate would be flat in the same way as the Midwest American Plains are flat.

    Ever stood in them, Tilo?

    Not really flat. You can hide a lot of infantry in that flat country. Same with the Ural plains. Great land for an ambush, despite being “flat”.

    Heck, even a perfectly flat lake isn’t flat if it extends far enough.

    The earth curves. The moon pulls.

  565. Comletely Fed Up:

    “flxible says:
    3 January 2010 at 1:25 PM

    Completely Fed Up: “Power requirements: nil”

    wrong ”

    Right, not wrong.

    Unless you go to that insane place where the answer to “What powers a boat, a train and a human?” is “The Sun!” then link wind power to the sun, fossil fuels to trapped sun and food to the sun.

    No power required.

  566. Ray Ladbury:

    Tilo, Ever been to the Midwest American Plains?

  567. Barton Paul Levenson:

    Mathew: the payback time for nuclear power is much shorter than the payback time for solar.

    BPL: What parallel universe did you say you came from?

    In this one a solar installation can be complete in a couple of years and a nuke takes 7-10 years, and the solar installation can start generating electricity as soon as part of it is up, while the nuke has to wait until the whole thing is finished.

  568. Alfio Puglisi:

    Tilo Reber, #558
    Here you can find a series with volcanic forcing and ENSO removed (“GISS adjusted”, fourth graph in the page.) The result is… interesting :-)

    http://tamino.wordpress.com/2009/12/31/exogenous-factors/

  569. Comletely Fed Up:

    I note that fixable DID go the “The Sun powers all these things” route.

    Tell me, how does nitrogen fixers produce CO2?

    Mind you, you’re deliberately dissembling: the problem isn’t energy, it’s burning fossil fuels for energy.

  570. Barton Paul Levenson:

    CatHerder,

    Al Gore owns a large mansion, which he uses as an office for a number of his enterprises, and which houses his secret service detail as well as his family. Despite that, he has insulated the place thoroughly, installed solar panels, and buys wind power. What more do you want?

    But assume Gore were a profligate hypocrite. If Albert Einstein was cruel to his wife, as recent documents indicate, does that mean that relativity is wrong? If Samuel F.X.B. Morse was a racist political crazy, does that mean the telegraph doesn’t work? If William Shockley babbles about race and IQ, does that mean his work on transistors was valueless?

    In short, do you know what an ad hominem argument is?

  571. Ray Ladbury:

    Tilo Reber@558 asks “Why not produce another ENSO corrected data set, and let’s see what has actually happened since 1998.”

    Be careful what you ask for:

    http://tamino.wordpress.com/2009/12/31/exogenous-factors/

    Result from Tamino: “The interesting thing is that, using the adjusted data, the warmest year on record is 2009!”

  572. CM:

    Dave Salt,

    Your latest post (#517) helps. Unlike a number of pseudo-skeptics coming by here, you are focusing on an important point: cloud feedbacks being uncertain, poorly constrained by observations, and of potentially huge significance. You also read and learn from materials pointed your way, so perhaps you are one of the few genuine global warming *skeptics* to grace these pages.

    My layman’s understanding is that your conclusions (1) and (2) are basically sound. I don’t think anyone here would disagree with you that cloud feedbacks (among others) are not “settled science”. On the other hand, you may be missing some perspective on the independent evidence for a climate sensitivity of around 3 degrees C. And you have not backed up your conclusion (3) with any examples. I think it’s wrong if you are talking e. g. about the IPCC Summary for Policy-Makers. I thought PeteB (#537) made these points well.

    When you complain about lack of any testing against “real-world evidence”, I wonder why you are dismissing all that is said e.g. in ch. 8 of the IPCC report (which you have read) about how the models are tested against observations of various cloud properties and found wanting — which is why their cloud-feedback projections remain uncertain.

    ‘Uncertain’ rather than ‘falsified’ — is that what bothers you? From what you wrote earlier (#246) I gather that by ‘prediction’ you mean something that enables falsifying a theory, and your gold standard of such a prediction is the tropical troposphere ‘hot spot’. So let me ask: What do you think the hot spot means, what is it that you think will be falsified if the hot spot fails to turn up? This is not a digression — I want to understand what ‘predictions’ you want, and I think you may have been misled about this one.

  573. Hank Roberts:

    Tilo, you’ve misunderstood 553– you can’t have ever walked across any significant part of the Great Plains. He’s saying the model output without the change in CO2 would be “flat” resembling the last 10,000 years of climate, I think, plenty of wiggles in that.

    You know the uncertainty goes up over longer time spans. I hope you’re not just intentionally misunderstanding the conversation there. The question was about the actual current models being discussed and what they do if CO2 is left at a fixed level. We’d see something like the Holocene, eh?

  574. Hank Roberts:

    Here, for Tilo:
    http://2.bp.blogspot.com/_3c5RQ0PubuY/St_ySuiyKqI/AAAAAAAAHXI/aOrgYMsUwTU/s400/entire+track.jpg (map route, including crossing the Great Plains)
    http://1.bp.blogspot.com/_3c5RQ0PubuY/St_yFYlWYaI/AAAAAAAAHXA/AEk6nGxLW5Q/s400/entire+profile.jpg (profile; note the resemblance to the Holocene)

  575. Hank Roberts:

    > rebunked, rebunking
    From a “team effort” (heh) based on an original word by Rob Dekker
    http://www.google.com/search?q=site%3Arealclimate.org+rebunking

  576. Tilo Reber:

    Secular Anamist: #559
    “Rush Limbaugh would just tell those folks that this was proof that Gore’s secret plan to get rich from wind turbines,”. . . “And his listeners, being “skeptics”, would of course unquestioningly believe every word.”

    Can you identify a single person who claims to be a skeptic because of Rush Limbaugh? Or is that just a stereotype you like to use because if fits the warped notions that you love to delude yourself with.

  577. Brennan:

    I love this discussion. I have been reading it from the binning, got tired around post #139, which is the thread I was watching the most.

    The problem with the issue is, I think, is not whether or not global warming proponents or skeptics are right. I am a skeptic, but I must say, I might be wrong. I am also an “environmtalist”, in the sense that I join efforts to protect the soil and the air from on-going distrous damage. So, I am really, really tempted to jump on the band-wagon, since I can imagine all sorts of side benefits to reducing CO2 emmissions for the environment.

    The problem I see it is the scale of action that is being proposed by global warming proponents.

    In order for me to intellectually jump on the bandwagon of the scale of actions recommended, something frankly only someone who pays a lot of taxes can appreciate the difficulty of, I would have to have near certainty on 4 or 5 things, since the overall certainty is the combination of those things. Those things are:

    1. Global Warming is “happening” in the sense that is being suggested.

    I could give this maybe a 90%. Everyone is being too rude to one another for me to fully trust them. Sadly, the East Anglia emails show those guys to be just the sort people I wouldn’t personally trust with something important.

    2. Global Warming is happening quickly, inexorably, and with catastrophic effect, such that the current generation needs to do something big. I’m pretty iffy on this one. Maybe 50%.

    When models have to go back so far to show the trends, and 10 years of recent data that challenge the model is too “short-term” to draw a firm conclusion on the model’s accuracy (I think Gavin said the data show that the model “could be right”), I’m not feeling a real urgency on this one. Granted, if it takes 100 years to do something, and there are only 90 left, then we are late. I understand that. Not convinced.

    3. Man is causing global warming to a significant degree, such that if we stopped doing whatever is that is causing it, it would stop or signifcantly slow. I am at about 40% on this.

    I’ve been reading here, including the helpful links, for about 4 hours now (after many more than that over the years of course), and I am amazed at how badly the media reports the real case for global warming, and how reluctant the GW proponents are to discuss them. This link is fantastic: http://www.skepticalscience.com/How-do-we-know-CO2-is-causing-warming.html . And yet . . . the CO2/water-vapor link is being discussed like a salesman discusses a creaky ball-bearing, rather than like a teacher or scientist would. It seems the “amplification” affect needs quite a bit more study. It is a big weak link, let’s discuss it.

    4. CO2 emmissions are the overriding means by which man is causing global warming. I am at about 10% on this one.

    I am just not convinced of this by anything I have read. I see that there is SOME effect, but it could be extremely tiny based on what I have read. The CFC paper from Waterloo, as credible on the surface as anything else I have read today, seems so slow to make it into discussions. What gives?

    5. Stopping CO2 emmissions will fix the problem. I am 95% on this on.

    The problem is, there are so many other good environmental benefits to using less fossil fuel, it is tempting to try and fit this whole discussion into that box. This issue presupposed all the previous issues are truw of course.

    6. We are near a tipping point, such that at any moment, we may pass a point of no return. I am at maybe 1% or 2% on this one.

    If someone wants to point me to THAT link, I would love to see it. I might be more inclined to join the asteroid deflection crowd based on the probablities there.

    The net is, I am at about 45% that one day we should do SOMETHING; at about 18% that it is necessary in my lifetime; at 1.8% that we ought to do what is being prescribed; and .018% that we ought to do it NOW.

  578. flxible:

    I note that FedUp went to that “insane place” where vegetables and animals are raised without recourse to the use of fossil fuels for energy – for clearing the land, for fertilizers, for making the tools to do the farming, for getting the crops to the consumer, for building the storage facilities …. of course the sun powers all things, especially growing food, which has nothing to do with the original posters statement that energy extraction requires energy – your assertion of energy-less potato culture is the trivialization

    the “problem” actually isn’t even using fossil fuels for energy, it’s overuse driven by overpopulation

  579. Hank Roberts:

    Brennan, you’ve missed this: human activity matches past asteroids in impact.

    Early draft of a paper now paywalled, I think; you can find more like this:
    http://www.agci.org/dB/PDFs/03S2_KCaldeira_OceanPh.pdf

    “… unabated CO2 emissions over the next several hundred years may produce changes in ocean pH greater in magnitude than any experienced in the past 300 myr, with the possible exception of rare catastrophic events in Earth history 7,11
    ——–
    7. Caldeira, K. & Rampino, M. R. Aftermath of the end-Cretaceous mass extinction – possible biogeochemical stabilization of the carbon cycle and climate. Paleoceanography 8, 515–525 (1993).
    11. Beerling, D. J. & Berner, R. A. Biogeochemical constraints on the Triassic-Jurassic boundary carbon cycle event. Global Biogeochem. Cycles 16, 101–113 (2002).

    So as you’re worried about the consequences of an asteroid impact, and understand what they were — read up.

    http://scholar.google.com/scholar?hl=en&q=ocean+pH+change

    Yes, for some reason people are more upset about what some outside force does than what we do to ourselves — how many people die on highways every year from drunk drivers? how many die from terrorist attacks? Which worries us enough to make fundamental changes in how we live?

    Look at the extreme rapid change in the oceans, the foundation of the food chain, where most of the food and oxygen are produced by plankton. If it were an asteroid impact, would you work to stop it from happening?

    Knowing we’re doing it to ourselves, will you work to stop it?

    If some enemy were doing to the planet what we’re doing, we’d be at war.

  580. Doug Bostrom:

    Brennan says: 3 January 2010 at 7:07 PM

    Taking at face value what you say about your commitment to caring for the environment and your belief in the value of reducing fossil fuel usage, why do you even -care- whether you need to “jump on the bandwagon”? I suspect maybe something to do with fear of financial loss, given your remark about taxation.

    Mysterious.

  581. Tilo Reber:

    Alfio #568
    “Here you can find a series with volcanic forcing and ENSO removed”

    Thanks Alfio. But there are two problems. First, I don’t use GISS. I consider it an outlier. But I will take UAH, RSS or HadCrut3. Second, I want to plot it myself and put a trend line through it. I don’t need a hundred year chart to show the last 12 years. It only obscures what I’m trying to find out. Last year Gavin produced an ENSO corrected set of HadCrut3 data. I plotted the data against the regular adjusted HadCrut3 data here:

    http://1.bp.blogspot.com/__VkzVMn3cHA/SHLOM1k5XJI/AAAAAAAAADE/u7AlyoBk0EU/s1600-h/ENSO+Adjusted+HadCrut3v+Data.bmp

    As you can see, both trend lines are close to flat. I would like to see what the same ENSO adjusted trend line looks like with the 2009 El Nino year added. I expect that the HadCrut3 adjusted line will now be slightly up instead of slightly down. But I would expect that the ENSO adjusted line would be very similar. Meaning that 90% of the IPCC expected warming of .22C would still not be there. It would be nice if Gavin produced the same data, but updated. On the other hand, it might be even better if I had the algorithm and could update it myself whenever I want. Obviously I can’t be certain what the results will be. But I would like to know.

    Ray: #571
    “The interesting thing is that, using the adjusted data, the warmest year on record is 2009!”

    Fine by me Ray, if it comes from satellite data or a HadCrut3 data. My interest is in the slope of the line and how close to the .2C per decade IPCC prediction it is.

  582. Brian Dodge:

    “If you just look at the changes since 2000 say, the spread is wider but there is no obvious discrepancy either (you can draw in the 2009 values if you like). – gavin]”
    Done – http://www.imagenerd.com/uploads/ipccgistemp-a47CE.jpg – with an OLS trend from 1998 drawn in, and which is only slightly less than the trend from 1995, statistically significant per http://tamino.wordpress.com/2009/12/15/how-long/

    “A new international task-force set-up, charged with the responsibility of establising an officially recognised database for ‘Global temeprature’ to support all future policy planning.”
    “There are however other measures that have less noise – stratospheric temperatures, or Arctic sea ice – the signals are stronger there. – gavin]”
    Hoe about http://www.woodfortrees.org/plot/nsidc-seaice-n/from:2006.6/trend/plot/nsidc-seaice-n/from:2002.6/trend/plot/nsidc-seaice-n/from:2000.6/trend/plot/nsidc-seaice-n/from:1998.6/trend/plot/nsidc-seaice-n/from:1990.6/trend for “trends” upon which to base policy, with the understanding that as long as the ice is decreasing, it’s too hot, and policy to reduce GHG’s (carbon tax rates, whatever) must be set proportional to the decline. And when the Arctic Ice gets below half its historic levels. the rate of decline will level off(since negative values of area/extent are physically impossible), so we will have to start using another metric such as glacier volume, or Greenland Ice sheet mass loss. The advantage of using these metrics is that we already have historic data, so we don’t have to delay action for another data set to be implemented. and they are relatively low variability.

    “…without the microbial energy expended in the soil extracting the plant nutrients needed you’ll have no edible tubers – in fact after a couple years of those microbes working away, your crops would have consumed all the nutriative energy available…”
    The energy is continually being renewed by sunlight, stored using water and CO2. Fixed Nitrogen also only requires sunlight and air to be regenerated. The P, K, and mineral micronutrients can be badly redistributed by human activities (landfilling, “disposal” of sewage in streams, rivers, and ultimately the ocean), but it’s not really thrown away. see http://nssdc.gsfc.nasa.gov/image/planetary/earth/apollo17_earth.jpg “Probably the most requested picture of the Earth, this picture was taken by the Apollo 17 astronauts…”

  583. John P. Reisman (OSS Foundation):

    #577 Brennen

    I invite you to contact me directly. I would be happy to give you a call and discuss these points. It is a lot easier to examine through interactive discussion on these points that to write out all the contexts.

    You are reading, so your knowledge and understanding will improve.

    http://www.ossfoundation.us/contact-info

    It’s all about context. For example, you say that you are 95% confident that stopping Co2 emissions will fix the problem but only 10% on mans Co2 emissions are a problem. These things need context to be better understood.

    For some light reading try these:

    1. http://www.ossfoundation.us/projects/environment/global-warming/natural-cycle

    2. http://www.ossfoundation.us/projects/environment/global-warming/forcing-levels

    3. http://www.ossfoundation.us/projects/environment/global-warming/human-caused

    4. http://www.ossfoundation.us/projects/environment/global-warming/greenhouse-gases

    5. http://www.ossfoundation.us/projects/environment/global-warming/security

    http://www.ossfoundation.us/projects/environment/global-warming/summary-docs/leading-edge/2009-may-leading-edge

    6. http://www.ossfoundation.us/projects/environment/global-warming/feedbacks

  584. TimTheToolMan:

    Regarding : “That’s basically what the article is doing, except it’s putting far more attention on the “applied to the ocean” part than you apparently expected and taking it more or less for granted that the reader already understands the “downward longwave radiation to eventually become some X W/m^2 term” part.”

    But there is potentially a world of difference between a heating component added to the ocean and then mixed down versus heat that never got out in the first place. Especially when it comes to implimentations in a model.

  585. TimTheToolMan:

    Regarding : That paper published 20 years ago, and I don’t think it means what you think it does.

    Well I think it stated “Northern Atlantic” so had a limitation on the area the skin temperature is on average lower than the ocean bulk temperature, but other than that what do you think it means?

  586. Ray Ladbury:

    Brennan@577. Let’s look at the evidence wrt your criteria:

    1. Global Warming is “happening” in the sense that is being suggested
    OK, if you don’t like HADCRUT, the is GISTEMP (terrestrial), and UAH and RSS (Satellite), all of which show about the same trend as HADCRUT. In addition, we have a lot of other data (trillions of tons of ice lost, earlier springs, later first frosts…) that also support the notion of a warming world. There is zero evidence that suggests a cooling or constant temperature world.

    2. Global Warming is happening quickly, inexorably, and with catastrophic effect, such that the current generation needs to do something big. I’m pretty iffy on this one. Maybe 50%.
    The pace of warming over the past 30 years is the fastest pace in any comparable period over the period for which we have reconstructed temperatures. We also know (from ice core data) that the effects of CO2 persist for centuries, and that it can take decades for temperatures to stabilize even after CO2 stabilizes. At the current rate of growth we will easily reach 450 ppmv within 20 years. This equates to between 2 and 3 degrees of warming, where we could start seeing very significant effects due to climate change. Read this paper:
    http://www.iac.ethz.ch/people/knuttir/papers/knutti08natgeo.pdf

    3. Man is causing global warming to a significant degree, such that if we stopped doing whatever is that is causing it, it would stop or signifcantly slow. I am at about 40% on this.
    The current warming carries the signature of a greenhouse mechanism–including such aspects as simultaneous tropospheric warming and stratospheric cooling, polar amplification. What is more, we know with 100% certainty that CO2 is an important greenhouse gas. The fact that increased CO2 would cause warming was predicted in 1896. So the fact that we are causing warming is not a surprise–it’s what we expect from the physics.

    4. CO2 emmissions are the overriding means by which man is causing global warming. I am at about 10% on this one.
    See above. Also, Lu’s CFC chemistry is interesting, but his climatology is utter crap. Look at Uncle Eli’s sight among others for a critique.
    http://rabett.blogspot.com/2009/12/if-you-got-hammer.html

    5. Stopping CO2 emmissions will fix the problem. I am 95% on this on.
    No. Stopping CO2 emissions will sotp making things worse.

    6. We are near a tipping point, such that at any moment, we may pass a point of no return. I am at maybe 1% or 2% on this one.
    Consider what this means. When the biosphere and oceans and melting permafrost become a carbon source rather than a carbon sink, then there is probably nothing at all we can do to bring things back. We are on the rollercoaster, and the only planet we know that is hospitable to life will have just become a 4th grade science experiment.

    Look at the evidence, Brennan. Look at all of it. This is important.

  587. TimTheToolMan:

    JCH says: …I would think the models, since they predicted increased OHC and that has been confirmed by observations, already effectively included the physics the article explains.

    And I would think that because there is no followup paper that quantifies the effect (that I’ve found anyway) there can be no way the models can include the physics because its not formalised.

    The fact the models have confirmed the historical observations comes more from their finely tuned assumptions that the observed ocean heating that isn’t accounted for by “anything else” is accounted for by anthropogenic effects.

    Pity it all goes wrong when the oceans do something unexpected…like start to cool. Then the predicted global temperatures begin to go pear shaped when compared to reality as well.

  588. FurryCatHerder:

    Ken W @ 550:

    Wait, I didn’t say that AGW is or isn’t real. I’m very on the record here as saying that I don’t think it matters, because the problem that WILL affect us far sooner — dwindling fossil fuels — has the same solution as AGW.

    Do I personally believe in man-made global warming? Sure. I also believe that the giant ball of fire in the sky has more of an impact than most of the scientists here will accept simply because they’ve not found something other than “Hey, SC24 is a fizzle, and the temperature isn’t going up, but Tamino says that’s okay, too!” So I’m skeptical on the ratio of “solar influence” to “CO2″. But I’m 100% in agreement that if we burn every bit of carbon fuel we can get our fat fingers on, we’re in for hot weather and no energy to do much about it, to say nothing about changing the face of the planet not for the best.

    But that’s besides the point. The point is that ACTIONS speak far louder than words. And based on that Snopes article, Al Gore still uses more power in a month than I use in a year. Based on that, I stand by what I said — Al Gore does not believe in global warming. It makes him some money, maybe helps if he wants to run for president again some day, but believe in it? No.

  589. Brian Dodge:

    Can you identify a single person who claims to be a skeptic because of Rush Limbaugh? Or is that just a stereotype you like to use because if fits the warped notions that you love to delude yourself with.
    Tilo Reber — 3 January 2010 @ 5:55 PM

    http://www.nationalcenter.org/2008_06_01_BlogArchive.html
    ‘I believe Rush Limbaugh is America’s #1 asset on global warming education. He takes the time to understand the science and the economics, and has the talent to explain it understandably and entertainingly. I shudder to think we’re we’d be without Rush.”

  590. Tilo Reber:

    Hank #573
    “Tilo, you’ve misunderstood 553– you can’t have ever walked across any significant part of the Great Plains.”

    Hi Hank. I live in Colorado – a few miles down the road from Trennberth and Pielke. I’ve been to Iowa, North Dakota, Nebraska, Kansas and Oklahoma. And I prefer cycling to walking. I took the first part of his statement literally. “Yes, it would be flat”. I assumed that he just added the second part for color. But you do bring up an interesting point when you say:

    Hank: #574
    “profile; note the resemblance to the Holocene”

    So are you saying that a model with no CO2 forcing could produce the same kinds of effects that we had in the Holocene, particularly the period 6 to 8 thousand years ago, including a century or more long warming period that produced temperatures higher than today? And what elements of natural variation would the models be modelling when they did that? It reminds me of this statement by Briffa:

    “… and I contend that there is strong evidence for major changes in climate over the Holocene (not Milankovich) that require explanation and that could represent part of the current or future background variability of our climate.”

    So are you saying that the models are modeling the variability that Briffa is talking about? And what is that variability if it is not CO2 and it is not Milankovich?

  591. Sou:

    Being a first time poster here, I’ll say thanks and congrats to realclimate and all its contributors.

    #577 Brennan says: “I am at about 45% that one day we should do SOMETHING; at about 18% that it is necessary in my lifetime; at 1.8% that we ought to do what is being prescribed; and .018% that we ought to do it NOW.”

    May I suggest you keep reading. From reading I have become even more aware of how the climate is sensitive and of its immense complexity.

    Out of curiosity I wonder if you have considered how you reached your views on other matters which are not nearly as complex. For example, do you support:

    1 the wearing of seatbelts in cars and/or crash helmets with bikes
    2 action to limit CFC emissions to help restore the ozone layer
    3 programs to discourage smoking cigarettes.

    If so, why? Was it mainly because you understood and accepted the science, or because of weight of public opinion, or because it seemed intuitive or that governments made laws about them or other reason? Conversely, if not, why not?

    I suspect that now that 190 (more or less) governments from all political persuasions and types of rule have accepted the risk of global warming, more people will come to accept it as well. It is very rare for so many dissimilar nations to cooperate in this fashion and most heartening.

    Although I strongly doubt there will be a universal satisfactory agreement on a common means of tackling the problem (at least in the short term), this may turn out to be less important than the already achieved agreement that there is an urgent problem.

  592. FurryCatHerder:

    Tilo @ 576:

    Can you identify a single person who claims to be a skeptic because of Rush Limbaugh? Or is that just a stereotype you like to use because if fits the warped notions that you love to delude yourself with.

    The amount of influence Rush Limbaugh has should not be underestimated. While I can’t NAME a person, I do know quite a few people who quote Rush Limbaugh and are full-blown denialists.

    The worst thing about Limbaugh and the environment is that he’s a flat out liar on the key points, and he knows it. His mantra is that Mankind is too puny to damage the planet (though lately he’s appealing to G-d being too smart to create a planet we could destroy — he’s really hammering on the G-d thing these days). And yet he’s known of, seen, talked about, etc. places that we have done a very thorough job of trashing.

    But it gets him ratings and makes him money. So …

  593. David Miller:

    Tilo, #576:

    I know half a dozen people whose understanding of global warming is based on what they hear on “conservative media”.

    They were at my house on Christmas day discussing what a hoax global warming is along with other ‘conservative’ topics. They’re all family – I know what their information sources are.

    Given that ‘conservative media’ would include Rush, Glenn, Sean, Neal, Laura, Fox News in general, and a few more, and that they all use the same playbook, I suppose it’s hard to blame Rush all by himself. But that’s not really what you were asking, is it?

  594. JasonB:

    538, FurryCatHerder:

    “In short, a “carbon tax” is a flat tax scheme, and as such is regressive.”

    That doesn’t make it wrong.

    The whole point of a carbon tax is to somehow price in negative externalities, which, by definition, are real costs that are currently not borne either by the producers or the consumers:

    http://en.wikipedia.org/wiki/Externalities

    This distorts the market because it will lead to greater production/consumption of products with greater externalities rather than products with lower overall costs.

    In the case of fossil fuels, a carbon tax seems like the most straightforward way to price in those externalities and allow the free market to operate correctly.

    I would argue that the price placed on the carbon should be, in the first instance, based on the best scientific estimate of the true cost of that carbon without regard for any policy goals. This would basically remove the distortion that currently exists, and would naturally increase or decrease in response to changes in the climate’s status (i.e. the true cost of the carbon would go up as the earth warmed, while it could potentially drop down to zero if we ever managed to get CO2 concentrations low enough — in fact, in the face of an imminent ice-age at some point in the future, the true cost could even be negative and the carbon tax turned into a carbon subsidy!).

    Note that I am not proposing a formula for carbon price based on the earth’s temperature or anything silly like that — it would have to be based on the best estimate of the true cost of emitting that carbon at that point in time.

    Yes, it would be a “regressive tax”, but then the price of a litre of milk is also “regressive” in that sense, and in the above scenario, all we’re trying to do is make the price of the product accurate.

    You’ll note that I deliberately left out policy considerations in the above carbon price calculation. By that I mean questions like “We want to advance the nuclear/solar/wind power industry, what carbon price do we need to impose to make them competitive with coal?”. Those policy considerations — which would re-introduce distortions into the market to advance some goal — are a separate issue that governments could think about adding on top of the “correct” carbon tax, and elections could be fought on that basis if they wish. But those issues can’t be discussed clearly until carbon is priced “correctly” and all distortions in the current system are removed. An implication of this is that the base carbon tax rate itself should be determined independently of the government of the day, similar to the way reserve banks determine interest rates in response to measures of inflation, and, ideally, the same base rate would be used worldwide (since the cost shouldn’t really depend on location). Countries should be free to impose tax “corrections” on imports from countries that have set their tax rate below the international standard; this would encourage recalcitrant countries to impose the correct tax themselves so that at least they get to keep the money rather than the country they are exporting to.

    NB: I am under no illusions about how hard it would be to price carbon “correctly”. Some externalities would be really hard to account for — for example, how much of the cost of things like the Gulf Wars should be added to the cost of the carbon in oil? No doubt it is non-zero, but getting a single number that everyone agrees on would be impossible. Likewise, it is almost impossible to estimate the future possible financial impact of emitting one tonne of CO2 right now given the uncertainties not only in climate forecasting but also in how we will respond in future. Nevertheless, I think we need to try, and make the best guess we can at each point in time, with some inertia in the price to avoid changing the market too much from year-to-year and making investment decisions completely impossible. Heck, calculating the correct carbon price could be the remit of the IPCC as part of its reporting process[*], with that price fixed until the next IPCC report.

    [*] You can tell I’m not afraid of the bizarre “world government” scaremongering that some people seem to think is relevant to this discussion, especially given the obvious inability for countries to put aside their own self-interest as evidenced by the Copenhagen outcome. I’m also not afraid of governments using carbon as an excuse to raise taxes — in my experience governments the world over have been able to raise and lower taxes as required for as long as civilisation has existed without needing any help from climate “scares”. Nevertheless, making the carbon tax revenue neutral (i.e. by returning all revenue collected in some way) would help increase the palatability of it for some. (In reality, governments always acquire the money they need for their spending programs one way or another — and taxing is better than borrowing in the longer term — so it’s all swings and roundabouts anyway, regardless of whether the carbon tax is officially revenue neutral or not.)

  595. Brian Dodge:

    “6. We are near a tipping point, such that at any moment, we may pass a point of no return. I am at maybe 1% or 2% on this one.”
    Brennan — 3 January 2010 @ 7:07 PM

    http://eprints.soton.ac.uk/64607/01/2009gl039191%2Baux.pdf
    “More than 250 plumes of gas bubbles have been discovered emanating from the seabed of the West Spitsbergen continental margin… If this process becomes widespread along Arctic continental margins, tens of Teragrams of methane per year could be released into the ocean.”

    http://www.nature.com/climate/2009/0904/pdf/climate.pdf
    “The Siberian Shelf alone harbours an estimated 1,400 billion tonnes of methane in gas hydrates, about twice as much carbon as is contained in all the trees, grasses and flowers on the planet. If just one per cent of this escaped into the atmosphere within a few decades, it would be enough to cause abrupt climate change, says Shakhova. “When hydrates are destabilized, gas is released under very high pressure,” she says. “So emissions could be massive and nongradual.” Shakhova and her colleague Igor Semiletov of the University of Alaska, Fairbanks, believe the plumes they’ve observed confirm previous reports that the permafrost cap is beginning to destabilize, allowing methane to escape from the frozen hydrates below. “Subsea permafrost is like a rock,” explains Semiletov. “It works like a lid to prevent escape of any gas. We believe that the subsea permafrost is failing to seal the ancient carbon pool.”

    http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/ARCHIVE/20080726.jpg
    Note the hole and the thin area in the arctic ice North/NE of the New Siberian Islands; I believe this is being caused by methane fountains (like those described in the first reference above) from the seabed bringing up warmer, saltier plumes of water which have melted the ice from beneath.

    “If someone wants to point me to THAT link, I would love to see it.” Be careful what you wish for.

  596. jl:

    Ray Ladbury could this paper be relevant to TRY’s question??
    thanks jl
    http://www.eumetsat.eu/HOME/Main/AboutEUMETSAT/Publications/ConferenceandWorkshopProceedings/2007/groups/cps/documents/document/pdf_conf_p50_s9_01_harries_v.pdf

  597. Hank Roberts:

    For Tilo:

    “… there’s another class of skeptics who get their climate science from talk radio. They don’t really understand any of the science …”
    http://www.npr.org/templates/story/story.php?storyId=121139996

  598. Philippe Chantreau:

    Tilo Reber, you’re full of it. I have personally run into “skeptics” who believe Limbaugh’s “volcanoes put out more CO2 than people” idiocy many times. Happened in person and on blogs, including John Cook’s Skeptical Science. Why do they believe it? Because Rush says so, as moronic as it may be. There is plenty of these people, everywhere. It’s not a stereotype and makes up a sizeable portion, if not the bulk, of the “skeptics” in the general population. And they don’t even know about McIntyre’s existence (not that they loose much, really).

  599. Matthew:

    570, Barton Paul Levenson: But assume Gore were a profligate hypocrite. If Albert Einstein was cruel to his wife, as recent documents indicate, does that mean that relativity is wrong? If Samuel F.X.B. Morse was a racist political crazy, does that mean the telegraph doesn’t work? If William Shockley babbles about race and IQ, does that mean his work on transistors was valueless?

    Fair enough, but ad hominem arguiments are used against “denialists” as well.

    567, Barton Paul Levenson: In this one a solar installation can be complete in a couple of years and a nuke takes 7-10 years, and the solar installation can start generating electricity as soon as part of it is up, while the nuke has to wait until the whole thing is finished.

    Nuclear power plants pay back the energy that is invested in making them much faster than PV panels do. However, the difference is diminishing (comparing the current generation of PV panels to the kind of PWRs that America uses.)

  600. Kevin McKinney:

    Brennan, (#577, currently) reactions to your points:

    1) The “climategate” emails involve a tiny fraction of the climatologists actively working on the question today. You may not like the picture painted, but that doesn’t change the data.

    2) “Quickly, inexorably, and with catastrophic effect” is a pretty high bar. Why does it need to be BOTH quick and inexorable to merit action? (And technically, aren’t we all hoping like hell it isn’t really “inexorable?”)

    The catastrophic effect part certainly seems well-supported, if also admittedly rife with uncertainties. Generally, I think you’re not asking the right questions here.

    3) Keep reading. There’s lots on this.

    4) Paleo work seems to constrain climate sensitivity to CO2 usefully. The human problem with CO2 is of course that combustion is just so darned convenient. But CFCs should certainly be seriously looked at as well.

    5) Don’t see how you can be 95% on this one if you’re 10% on number 4. The two propositions are more nearly equivalent than independent.

    6) I think you’re backwards on this one. The greater the uncertainty, the more motivation we should logically have to err on the side of caution, and (in the words of another RC post) “hit the brakes hard” on our CO2 emissions.

    And you don’t need this worry to justify action anyway–any two of the criteria you give in point #2 ought, in my view, to suffice. (Eg., a quickly-approaching catastrophe sans “tipping points.”)

    Your “net:” curious numbers, to say the least. . . they seem highly arbitrary, to this reader at any rate. Sorry you’re so unconvinced, but I have to say that your reasoning seems much more consistent on an emotional than a logical basis. Ie., you don’t like the “prescribed action” very much, despite your protestations to the contrary in point 5 and elsewhere.

  601. steven mosher:

    Gavin,

    Can’t wait to hear about winnowing the models. Look forward to it. I guess thats reason enough to come back and start reading here again.

  602. Barton Paul Levenson:

    And for the heck of it, here’s some Stefan-Boltzmann Law logic in Fortran and C, respectively:

    Fortran:

    write (*, *) ‘Please enter the temperature (K):’
    read (*, *) T
    F = sigma * T ** 4
    write (*, *) ‘The flux density is ‘, F, ‘ W m^-2.’

    C:

    printf (“Please enter the temperature (K):\n”);
    scanf (“%d”, &T);
    F = sigma * pow(T, 4.0);
    printf (“The absolute magnitude is: %d\n”, F);

    Which is more readable? Which equation is easier to figure out?

  603. Barton Paul Levenson:

    Tilo: Can you identify a single person who claims to be a skeptic because of Rush Limbaugh?

    BPL: My own brother is a denialist because of Glenn Beck. It happens, Tilo. Propaganda matters. The fact that every right-wing talk show host is claiming AGW theory is a fraud matters. Lying matters. God prohibited bearing false witness for a reason.

  604. Completely Fed Up:

    “The problem I see it is the scale of action that is being proposed by global warming proponents.”

    What “scale”?

    1 trillion over 10 years is (for 7 billion people) is $14 a year, or about 4p a day.

    The scale of Business As Usual would be an economic loss of 10x that value. Excluding (IIRC) any removal of the financial centers if Greenland and West Antarctica melt.

    And your figures are hugely off because you’re ignoring the compound interest. Delaying 10 years could multiply the costs 10-fold. I’ll repeat the canard of 50% of your final pension comes from the money you saved in your first 10 years of working.

    Compounded interest.

  605. Pekka Kostamo:

    577 Brennan: Probably nobody here believes you are a “sceptic”. From your preamble one concludes that you are a “denier” and a waste of time. You just copy common boilerplate used by such impostors, trying to generate some credibility.

  606. Barton Paul Levenson:

    Brennan: CO2 is rising (Keeling et al. 1958, etc.). The new CO2 is undeniably almost all from burning fossil fuels and from deforestation–we know by the radioisotope signature (Suess 1955, Revelle and Suess 1957). As for catastrophic effects — in 1970, 12% of the Earth’s land surface was “severely dry” by the PDSI (Palmer Drought Severity Index). By 2002 that figure was 30% and still rising (Dai et al. 2004). How far do you think it can go before human agriculture collapses completely? (Hint: Ask the Australians, or the people in Darfur.) Then there are the billion or so people in Asia and Latin America who will be without fresh water when the glaciers that supply their rivers evaporate away. India and Pakistan have ALREADY exchanged fire and had troops killed over which side owns a glacier.

    How much evidence do you want? What would convince you?

    References:

    Dai, A., K.E. Trenberth, and T. Qian 2004. “A Global Dataset of Palmer Drought Severity Index for 1870–2002: Relationship with Soil Moisture and Effects of Surface Warming.” J. Hydrometeorol. 1, 1117-1130.

    Keeling, C.D. 1958. “The Concentration and Isotopic Abundances of Atmospheric Carbon Dioxide in Rural Areas.” Geochimica et Cosmochimica Acta, 13, 322-334.

    Keeling, C.D. 1960. “The Concentration and Isotopic Abundances of Carbon Dioxide in the Atmosphere.” Tellus 12, 200-203.

    Revelle, R. and H.E. Suess 1957. “Carbon Dioxide Exchange between Atmosphere and Ocean and the Question of an Increase of Atmospheric CO2 During the Past Decades.” Tellus 9, 18-27.

    Suess, H.E. 1955. “Radiocarbon Concentration in Modern Wood.” Sci. 122, 415-417.

  607. Completely Fed Up:

    “Can you identify a single person who claims to be a skeptic because of Rush Limbaugh?”

    Despite the “Al Gore is fat” arguments, you’ve never identified a single person who claims to accept AGW because of him.

    Anyway, all you have to do is listen in on Rush’s show and you’ll hear plenty of callers saying “you’re so right, you explain it so well”.

    Plus there’s the whole tactical routine denialists go through which are all influenced heavily by Rush, Bill O’Reilly and Glenn Beck. Tactics the few scientists on the denialist side do not propound. So where do you get your inspiration from?

    A rhetorical question.

  608. Completely Fed Up:

    And Dave’s ideas on cloud feedbacks are also igoring that they are both positive and negative.

    If he’s going to go “well the uncertainty means we could be fine, so why bother”, he’s going to have to argue “but the uncertainty means we could be extra-boned, so let’s get cracking”.

    That he propounds uncertainty as DEFINITELY being in the direction of “A-OK” rather than “OHSHIT”, he’s not being skeptical, he’s being disingenuous. Falsely reporting by missing out half the picture. Actually, in this case, two-thirds: there’s

    1) It’s going to be hugely negative (which you have countered as unlikely)
    2) It’s going to have no large effect either way (so AGW isn’t changed which he ignores)
    3) It’s going to be hugely positive (which he’s also ignored)

    Hardly openminded when you close your mind to two out of three outcomes, is it.

  609. Alfio Puglisi:

    Tilo #581,
    rejecting GISS just because you don’t like it is not enough, you need some very good reason. And using only 12 years, with monthly data, leaves your analysis at the mercy of noise and obscures trends. Think about it: to contain all the data, your graph needs a vertical scale equal to one century’s worth of warming, just to show the last 12 years. That means that most of what you are plotting is noise, with respect to the trend.

    Meaning that 90% of the IPCC expected warming of .22C would

    The IPCC does not expect any specific amount of warming for just 12 years. I suggest you double-check your sources.

    Alfio

  610. Ray Ladbury:

    jl@596,
    That’s pretty good, and I think it is mainly what TRY was looking for. It does show changes over time. As I said, though, it is merely a snapshot. pr rather a series. To have a definitive demonstration, you’d also need to know insolation, etc..

    Thanks for this. It’s definitely getting bookmarked.

  611. Jeffrey Davis:

    There’s nothing wrong with coding in FORTRAN. I can’t imagine why you’d switch.

  612. John P. Reisman (OSS Foundation):

    #587 TimTheToolMan

    When did the oceans start to cool?

    http://www.ossfoundation.us/projects/environment/global-warming/myths/ocean-cooling

    http://www.realclimate.org/index.php/archives/2007/04/ocean-cooling-not/

    http://www.ossfoundation.us/projects/environment/global-warming/myths/ocean-cooling

    http://www.realclimate.org/index.php/archives/2008/06/ocean-heat-content-revisions/

    http://www.realclimate.org/index.php/archives/2005/02/why-looking-for-global-warming-in-the-oceans-is-a-good-idea/

  613. Timothy Chase:

    jl wrote in 596:

    Ray Ladbury could this paper be relevant to TRY’s question??
    thanks jl

    http…

    Ray Ladbury wrote in 610:

    l@596,
    That’s pretty good, and I think it is mainly what TRY was looking for. It does show changes over time. As I said, though, it is merely a snapshot. pr rather a series. To have a definitive demonstration, you’d also need to know insolation, etc..

    Thanks for this. It’s definitely getting bookmarked.

    jl, actually that paper is mentioned in:

    This result has been confirmed by subsequent papers using more recent satellite data. The 1970 and 1997 spectra were compared with additional satellite data from the NASA AIRS satellite launched in 2003 (Griggs 2004). This analysis was extended to 2006 using data from the AURA satellite launched in 2004 (Chen 2007). Both papers found the observed differences in CO2 bands matching the expected changes from rising carbon dioxide levels. Thus we have empirical evidence that increased CO2 is preventing longwave radiation from escaping out to space.

    How do we know CO2 is causing warming?
    Thursday, 8 October, 2009
    http://www.skepticalscience.com/How-do-we-know-CO2-is-causing-warming.html

    … where I gave a link to the skepticalscience webpage in 110.

    His “response” to the webpage that I linked to was a few lines in his response to Geoff in TRY’s 163:

    Geoff #117
    Believe it or not, I’m genuinely interested in actual answers. If you look at my postings, I’ve responded in every case! People certainly have great confidence in their answers, but unfortunately they all disagree!
    Q: Can we measure global radiation signature over time? here are some of the answers I’ve gotten:
    ….
    4) Yes, it’s already been done, here’s the link: (pointer to 2001 study comparing 1997 to 1970 – but study was site specific and clear skies only, not really a global assessment – then a more recent study comparing 2003 to 1997 shows no changes)
    5) Yes, it’s already been done, here’s the link: (pointer to downward radiation – interesting, but it seems like they used a model to get final results)

    Should I give all of these answers equal weight?

    Same kind of a study as the 1970 to 1997 and the 1970-2003 that he referred to as 1997-2003 — which extended the results of the earlier study.

    However, I see another problem: the piece mentions the use of models. From the second page:

    Spectra were simulated using the line-by-line radiative transfer model (LBLRTM) [Clough, et al., 2005], version 10.3, at a spectral resolution of 0.1 cm-1. LBLRTM was run with user-defined profiles constructed using monthly mean HadGEM1 output fields of specific humidity, temperature, and sea surface temperature from the global circulation model for April, May, and June of 1970 to simulate IRIS spectra.

    … and as he made clear in (5) of his response 163, “(pointer to downward radiation interesting, but it seems like they use a model to get final results),” he wasn’t much into the use of models in attribution.

    And it was in relation to his point (5) that I stated in 272:

    … it would seem that one of your gambits is to dismiss anything that is the least bit tainted by being partly dependent upon models or theories. But anything that isn’t the direct reporting of sensory data may be regarded as theory-laden.

    TRY was looking for reasons not to accept anything we might have to offer.

    Barton Paul Levenson concluded as much in 475:

    TRY: maybe IR output signature is a predictable, testable item. Maybe not.

    BPL: Already tested. Against time. AGW confirmed. But you just keep refusing to acknowledge it.

    TRY had a way with moving goal posts.

  614. Tilo Reber:

    dhogaza:
    “Those insisting that C is more readable than FORTRAN may be forgetting that it is C, not FORTRAN, that comes with its own puzzle book …”

    I agree that the speed is dependent on the compiler. And I agree that readability is probably more dependent on the programmer than the language. Well, at least between those two. But I think that C is more powerful and the fact that C++ supports object oriented programming can be important for those that know how to do object oriented programming.

  615. Tilo Reber:

    Hank: #597

    It’s nice that Judith Curry has an opinion, Hank. But I would much rather get your response to #590 – especially with regards to your remark on the holocene.

  616. JasonB:

    581, Tilo Reber:

    “First, I don’t use GISS. I consider it an outlier. But I will take UAH, RSS or HadCrut3.”

    Eh? I thought climategate had “proven” anything from UEA cannot be trusted and they manipulate their results while refusing to release their data or source code. Surely you should be using GISS, which makes public both its source code and data, making it beyond reproach?

    (FWIW, I’ve always favoured GISS over HadCrut because their treatment of the Arctic makes more sense to me; what’s your rational and logical choice for choosing the opposite? I hope it’s not simply because you like the result better.)

    “Second, I want to plot it myself and put a trend line through it. I don’t need a hundred year chart to show the last 12 years. It only obscures what I’m trying to find out.”

    It’s now just after midnight here; I’m planning to plot the last 12 hours and put a tend line through it. I suspect it’s going to show something very alarming and showing more than 12 hours would only obscure that.

  617. dhogaza:

    But I think that C is more powerful

    True! You can build pointers that point anywhere, monkeywrenching compiler optimization efforts!

    and the fact that C++ supports object oriented programming can be important for those that know how to do object oriented programming.

    OOP is not a panacea. It is a programming paradigm that works well in some problem domains.

    Actually, FORTRAN 2003 has some primitive support for OOPS as well (though I’m afraid to look to see what that support consists of, I can support the use of FORTRAN in scientific programming without actually becoming more up-to-date than 1960s-era FORTRAN, the last time I programmed in it).

  618. Tilo Reber:

    JasonB: #616
    “(FWIW, I’ve always favoured GISS over HadCrut because their treatment of the Arctic makes more sense to me; what’s your rational and logical choice for choosing the opposite? I hope it’s not simply because you like the result better.)”

    First of all, we cannot assume that the difference between the other sources and GISS is due to the poles alone. It’s possible that if the poles were removed it would still be divergent. Until someone runs that experiment we won’t know. Also, if I remember right, the poles are mainly computed, not measured. This means that the results could be what someone expects should be happening rather than what is happening.

    But let’s assume that the rest of the globe is the same. That means that the entirety of the divergence is due to the poles. There would have to be a lot of change at the poles at a time when the rest of the planet isn’t changing at all. Why should polar temperature be changing drastically at a time when the rest of the planet isn’t changing at all. That doesn’t make sense to me.

  619. Hank Roberts:

    > 590
    No, Tilo, I’m not saying anything you’ve made up there.
    That’s the point–you take a remark and make far more of it than was said.

    As to your other questions, they amount to asking this:

    Do we know why the Holocene was relatively stable compared to other post-ice-age time spans?

    I pasted that into Google, which I recommend.

    Here: http://www.esd.ornl.gov/projects/qen/nerc130k.html

    “The time span of the last 130,000 years has seen the global climate system switch from warm interglacial to cold glacial conditions, and back again. This broad interglacial-glacial-interglacial climate oscillation has been recurring on a similar periodicity for about the last 900,000 years, though each individual cycle has had its own idiosyncrasies in terms of the timing and magnitude of changes. As is usually the case with the study of the past, data are in short supply, and only a few sketchy outlines are known for the earliest cycles (Winograd et al. 1997). Even for the most recent oscillation beginning around 130,000 years ago there is still too much ambiguity in terms of the errors in geological dating techniques, in the gaps in the record, and in the slowness of responses by indicator species, to know precisely when certain events occurred and whether the climate changes were truly synchronous between different regions….”

    No surprise there. The climate models being discussed here are looking at far shorter time spans, about which more is known, and the comparisons that can be made are.

  620. Ray Ladbury:

    Gee, Tilo, I don’t see that the GLOBAL AVERAGE temperature was higher 6-8000 years ago than it is today.
    http://www.globalwarmingart.com/wiki/File:Holocene_Temperature_Variations_Rev_png

    You seem to have a habit of glancing at data without really understanding it.

  621. FurryCatHerder:

    @ 614:

    I agree that the speed is dependent on the compiler. And I agree that readability is probably more dependent on the programmer than the language. Well, at least between those two. But I think that C is more powerful and the fact that C++ supports object oriented programming can be important for those that know how to do object oriented programming.

    Personally, I can’t understand why “My programming language can beat up your programming language” posts are being allowed. I have every expectation that mine will be, even though it shouldn’t! And perhaps only experienced and professional programmers should be allowed to respond so we can all say “Use FORTRAN”.

    I’ve not coded in FORTRAN since the early 1980′s — Marine and Mechanical engineering numerical integration, for the most part. Since then, I’ve written in C for about 25 years, much of that doing operating systems work (former IBM kernel programmer), and the past 5 or so mostly in Java (management code for renewable energy systems of late). Before that, Pascal, BASIC, Assembly, etc. That’s 31 years getting paid to write software. I’ve not checked what operating system realclimate.com is hosted on, but there’s a good possibility some of my code is exercised on the way out the door somewhere. I’m prolific. My code gets around.

    That’s the CV.

    Were I writing all the GCMs I keep hearing about, it would be FORTRAN. It’s a math problem, not a “how many widgets do I need to manipulate?” (handy in Java or C++) or “how many bits do I need to manipulate?” (handy in C) or “ZOMG! MUST B R1LY F4ST L33T CODE!” (Assembly).

    I love C. I think C is great. I hate Java. I think Java is the Spawn of Satan. And I’ve been writing about 20KLOC of Java a year for 5 years running (I type fast) because Java is a great language for manipulating lots of widgets and thingies with similar sorts of properties and actions which can be applied to them. Java is HORRIBLE for writing an operating system. As is FORTRAN.

    As an aside, I recently had to write a piece of numerical integration code in Java and it was a miserable experience. Java? Yipes! C? Double yipes! FORTRAN? Very simple DO loop.

  622. FurryCatHerder:

    Tilo @ 618:

    Yeah, I’m very suspicious (in a scientifically curious sort of way) about the divergence between different temperature sets.

    Perhaps that’s a topic for an entire thread?

  623. dhogaza:

    First of all, we cannot assume that the difference between the other sources and GISS is due to the poles alone. It’s possible that if the poles were removed it would still be divergent.

    Not exactly what Tilo’s asking for, but gives you an idea of how the extrapolation into the Arctic kicks GISTEMP upwards.

    And that if you remove the arctic what’s left of GISTEMP matches HadCRUT reasonably well.

    That was just a quick google hit, I’m sure there’s some real numerical analysis lying around out there in webland if one wants to dig more deeply.

  624. Tilo Reber:

    Ray: #620
    “Gee, Tilo, I don’t see that the GLOBAL AVERAGE temperature was higher 6-8000 years ago than it is today.”

    Thanks Ray. I’ve seen that chart. Let’s compare apples to apples shall we. Proxy in that time period was warmer than proxy today – even using your chart. Tacking on a high instrument record is not meaningful. Who knows what thermometers would have read then. Also, the smoothing reduces many of those peaks. Your surface number doesn’t have the same smoothing. And then there is the evidence that the artic ice may have been melted completely in the summers 6000 years ago.

    http://www.ngu.no/en-gb/Aktuelt/2008/Less-ice-in-the-Arctic-Ocean-6000-7000-years-ago/

  625. TimTheToolMan:

    Re : 612, When did the oceans start to cool?

    You quote opinion pieces and I’ll simply quote a paper that analysed the data and shows measured cooling…

    http://www.ncasi.org/publications/Detail.aspx?id=3152

    You do have to wonder why showing warming is so important that “science” and I use the term loosely resorts to sea level measurements and arguments over OHC to find warming when the purpose built Argo buoys measured cooling.

    They cant both be right (assuming the heat isn’t hiding in the VERY deep ocean which apparently takes a very long time to get there) …so which is more likely to be in error do you think?

    [Response: Easy. The person who is publishing in un-peer reviewed journals. The data for OHC are in the figure above - if you have a problem with them I suggest you take it up with NOAA. Putting this stuff together is non-trivial - you need to account of spatial sampling biases, seasonal biases, possible instrumental biases etc. If I need to choose between professionals who do this all the time, or someone who downloads the data and does a patent 'analysis' on it and publishes in E&E, I'm going to go with the professionals. But even if Loehle did it right , there is plenty of short term variability in these things and yet the long term trends are clear. - gavin]

  626. John P. Reisman (OSS Foundation):

    #624 Tilo Reber

    Unfortunately, your argument is a non sequitur.

    To understand this you need only consider the effects of a longer term exposure to a relatively steady state climate forcing slightly above thermal equilibrium. In other words, when we came out of the last ice age, we spent what looks to be about a thousand years or more in a state conducive to continued albeit slight warming which may of course then allowed for more ice to melt thus allowing for a raised sea level. Then passage back into a state near or slightly below equilibrium would have allowed for more moisture to be transferred back into the ice sheets and glaciers around the world.

    The difference is that we have increased the radiative forcing only recently and the overall system has not had time to catch up due to the thermal inertia of the oceans.

    I realize it’s a bit complex, makes my head spin sometimes too, but the argument you have presented is not evidence that it was warmer then, only a strong indicator that a prolonged exposure to a positive forcing can melt more ice.

    http://www.ossfoundation.us/the-leading-edge/projects/environment/global-warming/natural-cycle

    http://www.ossfoundation.us/projects/environment/global-warming/temperature

    It’s important to keep things in context, the sea level is related to the forcing and time spent at a particular forcing combined with it’s associated climate feedbacks.

    A good experiment to illustrate the relativity factor might be this:

    Light a candle. Now pass your hand quickly over the flame allowing it to touch you. You will notice that you do not get burned as long as you pass your hand quickly enough.

    Now, though I don’t recommend the next part… if you hold your hand directly over the flame for say 60 seconds, you will notice a completely different experience indicated by the rapidly increasing pain in your hand cause by the proximity to the heat source.

    Think about it.

  627. John P. Reisman (OSS Foundation):

    #625 TimTheToolMan

    “opinion pieces”?

    NASA? JPL?

    How can you simply blow it off as opinion pieces unless…

    ohhhhhh… you didn’t read the material or click on the ref links…

    That explains it.

    http://earthobservatory.nasa.gov/Features/OceanCooling/

    And your quoting Loehle in E&E??? They are more policy than science.

    http://www.ossfoundation.us/projects/environment/global-warming/myths/loehle-temperature-reconstruction

  628. Tilo Reber:

    John: #626
    “I realize it’s a bit complex,”

    No John, it’s actually very simple. In fact your argument represents my argument in favor of Cosmic Rays. In other words, why the globe continued to warm for fifty years after GCRs flattened out. But I digress. You are right, it wasn’t necessarily warmer because the Arctic melted in the summer during the Holocene. However, my argument was made in conjunction with the proxy charts which shows that it was warmer in the summer.

    But beyond that, your argument leaves me unconvinced. For example, if we are as warm now as we were in the Holocene then we should be able to melt the Arctic without any further warming. As you state, it’s just a matter of exposing the ice long enough. But the recent stabilization of the Arctic and Antartic sea ice area makes me think that we may be right on the border of how much melt we are going to get – at least at this temperature. I think we’ll need a few more years to be sure. But we may well be maxed out or at least close to maxed out for melting of the Arctic until we get warmer. If that is the case, and if the Holocene was able to melt all of the Arctic in the summer, then it was warmer.

    I think another problem with your argument is that we are not that far away, temperature wise, from the LIA. And the glaciers were advancing in the LIA. So I don’t believe that we are at some hugely elevated level that will keep things melting right from where we are.

  629. TimTheToolMan:

    [Response: Easy. The person who is publishing in un-peer reviewed journals. The data for OHC are in the figure above - if you have a problem with them I suggest you take it up with NOAA. Putting this stuff together is non-trivial - you need to account of spatial sampling biases, seasonal biases, possible instrumental biases etc. If I need to choose between professionals who do this all the time, or someone who downloads the data and does a patent 'analysis' on it and publishes in E&E, I'm going to go with the professionals. But even if Loehle did it right , there is plenty of short term variability in these things and yet the long term trends are clear. - gavin]

    Do you suspect Loehle stuffed it up? This is important stuff with implications for AGW. Are you seriously suggesting that after Willis’ data corrections nobody bothered to redo the work to see if there was still cooling?

    You see, the cynic in me believes that work WAS done and because it wasn’t in agreement with the agenda, it was shelved in the hope that the cooling would eventually disappear.

    [Response: Huh? The NOAA data are continually updated using all the corrections that we know about - just go to the link and download it. I have no idea why Loehle gets a different answer - maybe you should ask him. - gavin]

  630. Tilo Reber:

    dhogaza: #623

    “Not exactly what Tilo’s asking for, but gives you an idea of how the extrapolation into the Arctic kicks GISTEMP upwards.”

    Yes, dhogaza, that shows that GISS will get some warming from the Artic beyond what HadCrut3 and the Satellites get. But I’m not quite following you when you say:

    “And that if you remove the arctic what’s left of GISTEMP matches HadCRUT reasonably well.”

    Can you explain how you reach that conclusion?

    But let’s go back to the comment that you quoted me from. I’m not insisting that GISS diverges outside the poles. I’m just saying that we don’t have enough information to state with certainty that it is only the poles that cause the divergence.

    Again, let’s assume for the sake of argument that it only diverges at the poles. This means that all of the divergence is caused by a relatively small area. There would have to be a lot of warming at the poles to do that. The thing that I find hard to believe is that we are getting a lot of warming at the poles at a time when the temperature across the rest of the globe is flat. And since that warming is not strictly a measured warming, I doubt it further.

    The other thing that bothers me is that the divergence of GISS seems to be mostly in the last dozen or so years. Why wouldn’t the reason for the current divergence also apply to the 70s, 80s and 90s.

    [Response: Duh... because the Arctic has been warming faster than the global mean this decade perhaps? - gavin]

  631. Rattus Norvegicus:

    Well, since Lohele got his temp reconstruction wrong, I would tend to believe that he got this wrong too.

    The one thing that I notice is that he only shows plots for the smoothed data, and no plot for the raw data. It is entirely possible that the result is due to his choice of a smoothing algorithm (oh noes!! Al Gore!). The rest of the analysis is too straightforward for him to really blown it.

  632. JasonB:

    614, Tilo Reber:

    “I agree that the speed is dependent on the compiler.”

    Actually, in the first instance, speed is dependent on the algorithms and implementation chosen by the programmer. About a year ago we improved one of our algorithms that scaled poorly on large problems so that execution time dropped from 12 hours to 20 minutes. My best effort so far is a 1000 times speedup. Same compiler, same computer, better algorithm.

    In comparison, Visual C++ 2008 generates code that ranges from 0-20% faster than the ten-years-older Visual C++ 6.0. As long as the compiler is not pessimising (opposite of optimising) the code, there really isn’t much difference between compilers (even between different languages) on a modern out-of-order CPU.

    “And I agree that readability is probably more dependent on the programmer than the language. Well, at least between those two. But I think that C is more powerful and the fact that C++ supports object oriented programming can be important for those that know how to do object oriented programming.”

    With 15 years’ experience writing commercial software in C++ I often find myself going against the tide when advocating its merits. People rightly criticise its complexity, but in the hands of a skilled practitioner it’s a far more powerful and capable tool than most others, allowing truly beautiful code to be crafted.

    However, in this particular instance, I would not advocate its use. Fortran is a domain-specific language and this is its domain. C doesn’t compete well with Fortran when it comes to numeric code, and even C++ needs all sorts of advanced tricks (my favourite being expression templates — absolutely brilliant) to come out on top. Naive C and C++ code certainly won’t perform as well.

    And that’s the point. Most scientists aren’t professional programmers. To be really good at the craft generally requires a relevant degree (not absolutely required, but very useful for the background theory) and quite a lot of experience. These scientists simply need some mathematical model implemented, and for many of them, Fortran is a language that allows them to do that with little effort.

    That’s not to say that they shouldn’t consider hiring professionals going forward, as the models get more complex. Once you’re into the “hundreds of thousands of LOC” range you’re no longer talking throwaway prototypes, you’re talking about serious investment in software development, and it’s not the most cost-effective use of resources to have highly-specialized (US spelling to avoid spam filter :) researchers spending their time tackling the complexities of large-scale software development. There are programmers with very strong science backgrounds capable of implementing algorithms directly from research publications (and some of us even write papers in the field that our software operates in) so this can be a very good investment.

  633. John P. Reisman (OSS Foundation):

    #628 Tilo Reber

    Your argument would make sense if the Arctic and Antarctic ice were stable. The problem is they are not.

    The ice extent in the Arctic grows back every year because it gets real cold in the winter in the north. But the ice volume is the indicator in the Arctic and it’s anything but stable, currently losing about 10% volume per year:

    http://www.ossfoundation.us/projects/environment/global-warming/myths/images/arctic/20070822_oldice.gif/image_view_fullscreen

    http://www.ossfoundation.us/projects/environment/global-warming/myths/images/arctic

    In Antarctica, it was modeled about 30 years ago that we might expect more ice accumulation down there… I don’t know all the physics of it, and someone might want to comment on that, but it’s a really big chunk of ice and we are adding more moisture to the atmosphere, thus more precipitation in the form of rain and snow. Since the southern hemisphere is mostly water, it does not experience the norther amplification effect. Again in the SH winter, it’s real cold, so of course the moisture precipitates and accumulates.

    http://www.ossfoundation.us/projects/environment/global-warming/arctic-polar-amplification-effect

    As to your assertion that “we should be able to melt the Arctic without any further warming.” This is a great point. But context is key as always. We are already above thermal equilibrium so if the warming could stop right where it is, the the Arctic would in fact melt away.

    Unfortunately we are not at equilibrium with the forcing in the system which is largely outside of the natural cycle, so unfortunately we will continue warming.

    http://www.ossfoundation.us/projects/environment/global-warming/forcing-levels

    I also understand your LIA argument. I think it is a bit off because being a little bit away form LIA temps is a relative assessment and does not account for the amount of energy involved. Since we are talking about W/m2, the “not that far away” assertion hides the reality of the actual amount of energy. You add up all the meters on the surface of the planet and you begin to see how many Watts of energy are involved. We are retaining heat energy because we have increased GHG’s.

    In this case little bits mean a lot when you extrapolate the numbers across the surface of the planet.

  634. Tilo Reber:

    John: #627
    “And your quoting Loehle in E&E??? They are more policy than science.”

    Thanks for the link, John. I read it. I must say that you found a lot of ways to repeat the idea that you don’t like Loehle and that you don’t trust Loehle. But really, when it comes to showing that his work is wrong, it’s just a bunch of hand waving. You quoted Gavin four times. Only one of those quotes actually addressed any problems. You didn’t quote anyone else. So your conclusion is that we can trust Gavin but not Loehle. Fine, you can have that conclusion.

    [edit - leave out the random group smears]

    [Response: I'm not telling you to trust me over Loehle. I didn't do any of the OHC analyses so it's kind of irrelevant to make it personal towards me. I used NOAA's data, and so if you have a problem with it, read their papers and take it up with them. You asked me who I trusted more and I told you. - gavin]

  635. Rattus Norvegicus:

    I see how he blew it: he only analyzed data from 2004 to 2008 rather than the entire series. The x-axis legends on his graphs are rather hard to read.

    Just as a WAG, I would guess that this isn’t enough data to get a statistically significant trend. The smoothing probably increases his confidence intervals.

    The question is why didn’t he just slap a linear trend on it and analyze the noise characteristics to so that he could generate more realistic confidence intervals. This is the sort of straightforward analysis which probably wouldn’t have given him the answer he was looking for, the correct answer: there is no statistically significant trend.

  636. Tilo Reber:

    John: #633
    “The ice extent in the Arctic grows back every year because it gets real cold in the winter in the north.”

    Supposedly not as cold. So it shouldn’t grow back as far. Using your previous example, once the melt has happened, it shouldn’t freeze back. At least not as far out.

    “But the ice volume is the indicator in the Arctic and it’s anything but stable, currently losing about 10% volume per year:”

    I have a hard time believing that we are loosing substantial ice volume without loosing ice area as well. It seems to me that the two would have to go together. Near the edges the ice should be thinnest. And any thinning there should also result in area loss.

    John:
    “I don’t know all the physics of it, and someone might want to comment on that, but it’s a really big chunk of ice and we are adding more moisture to the atmosphere, thus more precipitation in the form of rain and snow.”

    That would explain a thickening of the land ice. It would not explain the extent of the sea ice.

    John:
    “We are already above thermal equilibrium so if the warming could stop right where it is, the the Arctic would in fact melt away. ”

    I’m not quite understanding what you mean by thermal equilibrium here. It seems to me that the .8C of warming that we have had in the past 150 years could push the termal equilibrium further north. But I don’t see why it would push it all the way to the pole.

    John:
    “I think it is a bit off because being a little bit away form LIA temps is a relative assessment and does not account for the amount of energy involved.”

    Well, I have to agree with you that I can’t adequately quantize the argument to stand on it.

  637. John P. Reisman (OSS Foundation):

    #634 Tilo Reber

    I’ve read a lot of different material. I trust Gavin more than Loehle.

    http://www.realclimate.org/index.php/archives/2007/12/past-reconstructions/

    Read the article and go through the comments. See if you really think Loehle is standing on solid ground?

    You can write Loehle and ask him your questions and how he got his results. Maybe ask him to show his code.

    I found his email address on this page:

    http://www.eoearth.org/contributor/Craig.loehle

  638. Bradley McKinley:

    Gavin-

    Am I reading your first graph wrong? It looks to me like what you are saying is that it is perfectly possible to have a trivial amount of warming (~0.06 C / per decade) and still be within the 95% confidence interval. Is that correct?

    [Response: You need to be more specific - what time period? - gavin]

  639. Doug Bostrom:

    TimTheToolMan says: 4 January 2010 at 9:47 PM

    “You see, the cynic in me believes that work WAS done and because it wasn’t in agreement with the agenda, it was shelved in the hope that the cooling would eventually disappear.”

    Translation: “As a contrarian, I always have a joker card (“data is bad”, “scientists are corrupt”, “tenure process is flawed”, ad nauseaum) in my hand so I’m playing it because otherwise I’m bankrupt, bereft of any defense for my assertions.”

  640. Tilo Reber:

    Gavin:
    “[edit - leave out the random group smears]

    [Response: I'm not telling you to trust me over Loehle. I didn't do any of the OHC analyses so it's kind of irrelevant to make it personal towards me. I used NOAA's data, and so if you have a problem with it, read their papers and take it up with them. You asked me who I trusted more and I told you. - gavin]”

    Okay, Gavin, I understand that you have to defend certain people. But my point was to show that all reconstructions have problems, including the ones that John seems to trust. Saying who has the worst problems may well be a matter of opinion. I have no doubt that Loehle’s reconstructions have problems. But are they a strong indicator that the reconstructions are wrong? Regarding your use of NOAA data, can you point me to the NOAA data that make Loehle’s reconstructions wrong.

    [Response: You are confusing two different issues. Loehle is very versitile - he does paleo reconstructions (which we discussed here and which was also published in E&E) as well as calculating trends in the ocean heat content data. One perhaps might judge the credibility of the latter, from the credibility of the former. The OHC data I used come from NOAA NODC (linked above) but I doubt they will shed any light on to temperature patterns in previous centuries. - gavin]

    Gavin:
    “… because the Arctic has been warming faster than the global mean this decade perhaps? – gavin]”

    Yes, but why wouldn’t it have been warming faster than the global mean in the 70s, 80s, and 90s.

    [Response: Why? I have no idea, but it doesn't appear to have. - gavin]

  641. FurryCatHerder:

    Jason B @ 632:

    With 15 years’ experience writing commercial software in C++ I often find myself going against the tide when advocating its merits. People rightly criticise its complexity, but in the hands of a skilled practitioner it’s a far more powerful and capable tool than most others, allowing truly beautiful code to be crafted.

    Within its domain. The point of choosing the correct language for the problem set is that when you do that, the code really does fall out a lot easier, without being kludgy.

    I’m very skilled at bit-banging in C, and can write some truly beautiful code — if bit-banging is required. But slicing and dicing machine words into bits just to prove one’s a L33T programmer is just vanity and the person needs to be fired. Dittos for turning everything into an object.

    The largest programming staff I’ve ever had under me was 12 people and the programmers I trust the least are ones who have one favorite language that they insist on fitting to every problem they encounter.

  642. Tilo Reber:

    Gavin:

    By the way, we are talking at cross purposes a bit here. John’s comment that I was responding to was this one:

    “And your quoting Loehle in E&E??? They are more policy than science.”

    John followed that comment with this link:

    http://www.ossfoundation.us/projects/environment/global-warming/myths/loehle-temperature-reconstruction

    That is the link that I was commenting on, not the Loehle OHC paper. It talks about Loehle’s global temperature reconstruction. I haven’t read Loehle’s OHC paper, so I have no comment on it.

  643. JasonB:

    618, Tilo Reber:

    “[JasonB:] “(FWIW, I’ve always favoured GISS over HadCrut because their treatment of the Arctic makes more sense to me; what’s your rational and logical choice for choosing the opposite? I hope it’s not simply because you like the result better.)”

    First of all, we cannot assume that the difference between the other sources and GISS is due to the poles alone. It’s possible that if the poles were removed it would still be divergent. Until someone runs that experiment we won’t know.”

    The source code and data are available — why not simply do it yourself? No need to assume anything.

    Also, note that I never said anything about assuming the difference was due to the poles alone. I said that GISS’s attempts to model the temperature of the Arctic made more sense to me. This is an a-priori logical reason for preferring GISS without considering what impact that might have one way or the other. If it turned out that GISS showed a lower trend than HadCrut, for example, then I would have more faith in that lower trend simply because the way it was arrived at seems more logical. This is the point I was getting at.

    The fact that the GISS source code and data are available for anyone to find flaws with and I haven’t seen anyone find any flaws that materially affect the result is an even stronger reason to favour their results, don’t you agree?

    “Also, if I remember right, the poles are mainly computed, not measured. This means that the results could be what someone expects should be happening rather than what is happening.”

    The source code and data are available — why not check to see how the poles are handled to make sure rather than speculating?

    As for “computed” vs “measured” — are you aware of how the satellite temperature reconstruction is derived?

    “But let’s assume that the rest of the globe is the same. That means that the entirety of the divergence is due to the poles. There would have to be a lot of change at the poles at a time when the rest of the planet isn’t changing at all. Why should polar temperature be changing drastically at a time when the rest of the planet isn’t changing at all. That doesn’t make sense to me.”

    Perhaps because you aren’t aware that one of the key fingerprints of AGW that distinguishes it from other potential sources of warming is stronger polar warming? That fact alone suggests to me that rigorous attempts to model polar temperature are required.

    Anyway, I don’t see how you can deduce that “the rest of the planet isn’t changing at all”. Here in Australia we’ve just experienced our second-hottest year on record. HadCrut certainly doesn’t show the planet isn’t changing at all, so there is a logical disconnect between your statement “the entirety of the divergence [between GISS and HadCrut] is due to the poles” and your conclusion “the rest of the planet isn’t changing at all”. Looking at the first graph on this page shows very little difference between the two series and that difference could easily be explained by polar warming.

    So far I see a lot of assumptions and decisions based on the results rather than a logical and rational choice based on the way the results are derived. If you think there’s a flaw in the analysis go ahead and “audit” it — isn’t that a large part of what the climategate kerfuffle was all about?

  644. John P. Reisman (OSS Foundation):

    #638 Tilo Reber

    I trust various things with various degrees of confidence.

    I trust the comparisons of the Milankovitch forcing, now past peak, thus heading into cooler times, in contrast to melting ice all around the world to the extent that glacial ice mass balance and expectations regarding polar amplification are knocking down the Arctic Ice as expected and also at an alarming rate, compared to what might be expected had there been no added GHG’s in the atmosphere due to anthropogenic cause.

    NCAR did some neat work on modeling with and without industrial GHG’s to give us a reasonable contrast by illustration

    http://www.ossfoundation.us/projects/environment/global-warming/natural-variability

    The modeled, measured AGW forcing in contrast to the expected forcing from Milankovith is a solid lead. The isotopic signature and the solid knowledge that long wave IR is trapped by GHG seal the deal in so many ways. The culprit is anthropogenic CO2, CH4 N2O and fluorine’s. The temps are rising not cooling as they should be.

    I like to go rock climbing whenever I can. You would have me believe that as I climb up a rock face, I am really climbing down?

    I am having a hard time following your generally inferred logic in the context of the evidence.

  645. JasonB:

    641, FurryCatHerder:

    “Within its domain. The point of choosing the correct language for the problem set is that when you do that, the code really does fall out a lot easier, without being kludgy.”

    Precisely. This is why I would not recommend C++ for scientists writing their own code despite a long history of evangelising it in other areas. It’s a complex language that rewards effort but does take a lot of effort to master, probably more effort than someone for whom programming is not their primary goal can afford to invest.

    “Dittos for turning everything into an object.”

    One of the many things I don’t like about Java. :-)

    “The largest programming staff I’ve ever had under me was 12 people and the programmers I trust the least are ones who have one favorite language that they insist on fitting to every problem they encounter.”

    Actually, the programmers I trust the least are the ones who insist they can’t debug their own code in response to a lecture after the nth time they checked in code with stupid bugs in it (yes, I’ve had one of those). Being able to critically examine your own work and effectively attempt to falsify it is just as useful for a programmer as it is for any scientist.

    Only being proficient in one language is relatively minor in comparison, and of little import if that particular language happens to be the only one in use at that particular shop.

    Anyway, this has gone pretty far off-topic. Sorry Gavin. :-)

  646. John P. Reisman (OSS Foundation):

    #642 Tilo Reber

    Media such as E&E have rather obvious bias. The gist of material on E&E has shown that they favor the controversy that favors a likely preconceived bias for whatever reasons.

    They do not seem to put much out that has much to do with well reasoned science. That’s my opinion and based on the publication record seems reasonably justified.

  647. Doug Bostrom:

    Tilo Reber says: 4 January 2010 at 11:08 PM

    “I have a hard time believing that we are loosing substantial ice volume without loosing ice area as well…”

    Is “I have a hard time believing” supposed to substitute for a coherent argument?

    What you personally believe is one thing, data is another. For instance:

    “November 2009 had the third-lowest average extent for the month since the beginning of satellite records. The linear rate of decline for the month is now 4.5 percent per decade.”

    http://nsidc.org/arcticseaicenews/

  648. dhogaza:

    JasonB:

    However, in this particular instance, I would not advocate its use. Fortran is a domain-specific language and this is its domain. C doesn’t compete well with Fortran when it comes to numeric code, and even C++ needs all sorts of advanced tricks (my favourite being expression templates — absolutely brilliant)

    Of course the whole point of being a compiler writer – which I was for about twenty years – is that the “absolutely brilliant” comments should be the domain of compiler optimization. If you need expression templates to make C++ code using MS’s compiler technology compete with a good FORTRAN compiler (I’m old-fashioned, FORTRAN is the FORmula TRANslator and therefore properly written in CAPS), then that’s not “absolutely brilliant”, it’s an absolutely messed-up compiler (or given C and C++ semantics, an unfortunate consequence of the language).

    Claiming that a language is superior because “absolutely brilliant tricks can make it be as efficiently compiled as straightforward programming techniques in another language” is … not even weak.

  649. dhogaza:

    And that’s the point. Most scientists aren’t professional programmers. To be really good at the craft generally requires a relevant degree (not absolutely required, but very useful for the background theory) and quite a lot of experience. These scientists simply need some mathematical model implemented, and for many of them, Fortran is a language that allows them to do that with little effort.

    And why would someone suggest using a language that you apparently believe would require more effort?

    Hint: the whole point of programming language design is to reduce effort.

    I’d agree with you if you understand the design goals of C++ to be different … but, then again, Strastroup knew (and knows) nothing of language design …

  650. dhogaza:

    FurryCatHerder has it right…

    Within its domain. The point of choosing the correct language for the problem set is that when you do that, the code really does fall out a lot easier, without being kludgy.

    I’m very skilled at bit-banging in C, and can write some truly beautiful code — if bit-banging is required. But slicing and dicing machine words into bits just to prove one’s a L33T programmer is just vanity and the person needs to be fired. Dittos for turning everything into an object.

    Except that kludge leads to kludgey, not kludgy … :)

  651. Tilo Reber:

    Doug:
    “November 2009 had the third-lowest average extent for the month since the beginning of satellite records. The linear rate of decline for the month is now 4.5 percent per decade.”

    I’m not sure what your attachmet to November is Doug, but I think that this chart is more informative.

    http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/global.daily.ice.area.withtrend.jpg

    It shows very low levels of sea ice for most of 2007 and some degree of recovery since. As I said above, I don’t know if that indicates stabilization is taking place due to the fact that the surface temperature hasn’t continued to warm – but it may. We need a few more years to tell.

    Doug:
    Is “I have a hard time believing” supposed to substitute for a coherent argument?

    Well, Doug, I do the best I can, but if you have a coherent argument for why the ice can get thinner without the surface area getting smaller I would like to hear it.

    My argument is this: The ice is generally thicker at the poles than away from them. And the water is generally warmer away from the poles than at the poles. So, for example, if you remove one meter of sea ice at the pole, then removing that same meter or more at the edges would reduce the thickness to zero. When it is zero, the sea ice area is shrunken.

    Do you want to argue that you can remove ice thickness from the pole without also removing it from the edges?

    I think that there has to be a very close correlation between thickness and area. But if you don’t, then please give me your coherent argument.

  652. Doug Bostrom:

    Tilo Reber says:5 January 2010 at 1:54 AM

    I’ll stick with November, but you can pick any month you like.

    Can you show me the “recovery” in this?

    http://nsidc.org/images/arcticseaicenews/20091207_Figure3.png

    Where is the recovery, Tilo?

    Your stage business about thickness versus extent is potentially distracting, but first you have to explain the “recovery” bit.

  653. Tilo Reber:

    JasonB #643
    “Anyway, I don’t see how you can deduce that “the rest of the planet isn’t changing at all”. Here in Australia we’ve just experienced our second-hottest year on record.”

    I’m not sure how Australia is relevant, Jason. I’m deducing that the rest of the planet isn’t changing at all from this:

    http://4.bp.blogspot.com/__VkzVMn3cHA/SQkAxK2k6CI/AAAAAAAAADs/F4NlhqTzFgM/s1600-h/U+11+Year+Temp+Data.bmp

    It tells me two things. The trend since 1998 has been relatively flat – at least through 2008. The divergence by GISS is about .1C per decade. Slightly more from the satellites. This is half of the predicted IPCC decadal warming due to CO2. I consider that significant. In any case, that chart is now a year out of date and we have had a warm 2009. But I don’t think that the divergence has changed. The place where I started into this discussion was about getting and ENSO updated version of HadCrut3. The one that went through last year showed this:

    http://1.bp.blogspot.com/__VkzVMn3cHA/SHLOM1k5XJI/AAAAAAAAADE/u7AlyoBk0EU/s1600-h/ENSO+Adjusted+HadCrut3v+Data.bmp

    My expectation is that when we include 2009 and ENSO adjust it we will still be relatively flat. Hopefully that explains why I think that the rest of the planet isn’t changing at all.

    “Perhaps because you aren’t aware that one of the key fingerprints of AGW that distinguishes it from other potential sources of warming is stronger polar warming?”

    Actually, I am aware of that. But if it’s stronger than the warming across the rest of the globe, what do we get when we multiply zero. And in regards to that effect causing divergence, why wasn’t it causing it in the 70s, 80s, and 90s?

    JasonB:
    “This is an a-priori logical reason for preferring GISS”

    And I agree that it is a good reason. But when other sources diverge, you need to look at the sensibility of the divergence. Saying that it all comes from the small areas at the pole is not sensible to me for the reasons that I gave above.

  654. JasonB:

    I wrote: “However, in this particular instance, I would not advocate its use. Fortran is a domain-specific language and this is its domain. C doesn’t compete well with Fortran when it comes to numeric code, and even C++ needs all sorts of advanced tricks (my favourite being expression templates — absolutely brilliant)”

    648, dhogaza:

    “Of course the whole point of being a compiler writer – which I was for about twenty years – is that the “absolutely brilliant” comments should be the domain of compiler optimization. If you need expression templates to make C++ code using MS’s compiler technology compete with a good FORTRAN compiler (I’m old-fashioned, FORTRAN is the FORmula TRANslator and therefore properly written in CAPS), then that’s not “absolutely brilliant”, it’s an absolutely messed-up compiler (or given C and C++ semantics, an unfortunate consequence of the language).”

    dhogaza, the “absolutely brilliant” thing about using the expression template idiom to implement matrix and vector classes is that you can write C++ code like this:

    v = M*x + b;

    and have the compiler turn it into code like this:

    v[0] = M[0][0]*x[0] + M[0][1]*x[1] + … + b[0];
    v[1] = M[1][0]*x[0] + M[1][1]*x[1] + … + b[1];

    (and some compilers can, in turn, automatically vectorise those statements)

    IOW, you get the performance of hand-crafted statements while still being able to use a nice syntax, and this holds for arbitrarily complex expressions. A naive implementation of those same classes would introduce one temporary vector to hold the result of M*x, a second temporary vector to hold the result of adding the first temporary vector to b, and then finally copy the second temporary vector into v (although the final copy should be elided by a good compiler using Return Value Optimisation).

    The reason this is not a “compiler” thing in the case of C++ is that matrix and vector classes are not included in the language and so must be implemented within the language. The reason they are not included in the language is that C++ is intended to operate in a wide range of domains and there is no one-size-fits-all implementation that suits everybody. Besides, the language is powerful enough that the programmer can implement them within the language and still get the performance they could expect from a “native” implementation if they do it right.

    Note that this is not a limitation of “MS’s compiler technology”.

    “Claiming that a language is superior because “absolutely brilliant tricks can make it be as efficiently compiled as straightforward programming techniques in another language” is … not even weak.”

    I agree, that would be a strange reason to claim a language is superior. Who said that? I was advocating Fortran (NB: http://en.wikipedia.org/wiki/Fortran#cite_note-0) precisely because “all sorts of advanced tricks” would be required to compete with Fortran on its home turf and I didn’t think climate scientists should be investing the effort required to attain that degree of proficiency.

    I wrote: “And that’s the point. Most scientists aren’t professional programmers. To be really good at the craft generally requires a relevant degree (not absolutely required, but very useful for the background theory) and quite a lot of experience. These scientists simply need some mathematical model implemented, and for many of them, Fortran is a language that allows them to do that with little effort.”

    649, dhogaza:

    “And why would someone suggest using a language that you apparently believe would require more effort?”

    Since I clearly wasn’t advocating C++ in this particular case, I presume you mean for normal software development? In that case, simply because once you are proficient, it requires less effort. As a perfect example, the second code snippet above is valid C code; it requires less effort to learn C than C++, and if you learn C then you could happily write code like that all day long. To write the necessary classes in C++ that would allow you to write expressions like the first snippet that will execute as efficiently as the second takes much more work and expertise, but once you have done that, it is clearly easier to write expressions like the first one (and easier to verify their correctness on visual inspection, because they look like the original mathematical formulae) than it is to write expressions like the second one.

    So if you are going to be writing and supporting large scale software products then the investment in mastering a language like C++ can pay off in the long run. But if you’re just putting together little test programs as a sideline to your main task then you’re unlikely to write enough code to pay back the effort required to master the language.

    “Hint: the whole point of programming language design is to reduce effort.”

    Precisely. But it’s not just reducing effort in learning the language, it’s reducing the effort overall. A language might take more effort to learn but if that makes constructing solutions easier then the total effort can be less if you spend enough time constructing solutions. (Ironically, one of the things that makes C++ more complex to learn is that it is a multi-paradigm language. The reason it is multi-paradigm is because sometimes it takes less effort to solve something one way rather than another.)

    Think of it like learning to ride a bicycle or drive a car. If you don’t need to move around much, then not bothering to learn and instead just walking everywhere is a win. But at a certain point, the effort invested in learning pays off in the reduction in effort required to travel. Of course, for short trips (like collecting the mail from the mailbox), walking is still the better option; likewise, for simple, one-off programs, Python (for example) may be a better choice than C++.

    “I’d agree with you if you understand the design goals of C++ to be different … but, then again, Strastroup knew (and knows) nothing of language design …”

    I disagree very strongly with that, but I don’t think this is the time or place to embark on a pointless language war, especially since I was using the point that I normally advocate C++ to lend weight to my observation that in this case I think Fortran is the right option for the reasons I gave. You did realise that, right?

  655. John P. Reisman (OSS Foundation):

    #651 Tilo Reber

    Ah the famous global ice extent graph that shows nothing has changed… unless of course you look closely and put it in context.

    First the graph shows an extent decline. Denialists love the graph though because at first glance it looks like nothing has changed.

    However, as I already pointed out and you apparently did not pay attention to, the ice extent in the Antarctic has increased as expected with global warming and the Arctic has decreased, so in fact the wonderful graph you are showing us confirms the GCM’s are doing their job and global warming is human caused. Thanks for showing that to everyone.

    As I said, and you apparently did not pay attention to what I said (#633), ice volume in the Arctic is telling the story…

    Try to pay attention Tilo, you would not want the nice people here to think you are ignorant, as in ignoring the context and information, would you?

  656. Completely Fed Up:

    “It shows very low levels of sea ice for most of 2007 and some degree of recovery since.”

    And why did Tilo pick 2007?

    Because it was a catastrophic year for ice retreat.

    And why is he concentrating on ice extent rather than ice volume? We have the technology to measure it now. It’s because he wants to lie about what’s happening but cannot outright lie.

    So he picks and chooses what to say.

    There’s a reason why we swear to tell “the whole truth” in court…

  657. Completely Fed Up:

    John P: “Media such as E&E have rather obvious bias. ”

    Is that the one where they have explicitly stated their bias?

  658. Completely Fed Up:

    Tilo revels in his ignorance, reifying it:

    “There would have to be a lot of change at the poles at a time when the rest of the planet isn’t changing at all. Why should polar temperature be changing drastically at a time when the rest of the planet isn’t changing at all. That doesn’t make sense to me.”

    Yup, one of the fingerprints of AGW is that the poles heat more than the equator.

    And please show that the rest of the planet isn’t changing.

    But the proudest statement is the last one.

    Why must your inability to understand prove your thesis?

  659. Completely Fed Up:

    Tilo also assumes he knows all: “Supposedly not as cold. So it shouldn’t grow back as far. ”

    Shouldn’t? Done the maths?

    Or did you pull that from the nether regions, Tilo? And polish it up to present as conclusive because you like the look of it?

    It shouldn’t grow back AS THICK.

    And guess what? We can see that. Sea ice isn’t growing back as thick.

    Mind you, he still doesn’t get the measurement of sea ice extent isn’t “solid ice” but “how far out is there still quite a bit of ice”, therefore the extent can be far more affected by breakup of ice drifting away (which breakup is easier if you have thinner ice) than by how cold it is.

  660. Steve Bloom:

    Tilo, it’s amusing to see you trying to argue about Arctic sea ice from first principles, but it turns out there are, you know, actual observations that contradict your hopes. See here. But it’s even worse than that, it turns out. See here.

    Also, as you can also see from the first link, the thick ice is never centered on the pole (due to prevailing currents in the Arctic Ocean). Note that recently the area of thick ice hasn’t even included the pole.

    I found all of this in less than a minute with teh google. Why not you, next time?

    Oh, and regarding your argument from personal incredulity about polar amplification, see this new paper. Figure 5 in particular is illuminating. Note that the paper regards a planet nearly identical to the one we live on, although with a slightly lower CO2 level (and sufficient time for the climate to have come into equilibrium with it).

  661. Ray Ladbury:

    Tilo Reber says of ice growing back in the cold winter:
    “Supposedly not as cold. So it shouldn’t grow back as far. Using your previous example, once the melt has happened, it shouldn’t freeze back. At least not as far out.”

    Tilo, now you are just making sh*t up! Dude, have you ever watched ice freeze on a pond or stream? Once you have even a thin skin of ice, you have no more evaporation (remember, you are about at the triple point) and much less heat exchange. If it is sufficiently cold it will freeze. The question is whether it will melt in the summer so that you don’t get thick multi-year ice forming. Tilo, you can look this stuff up rather than making it up.

    Given your rather tenuous understanding of the physics, it is not surprising that you are confused. My solution to that would be to try and learn the physics rather than rejecting all the science, but, hey, maybe that’s just me.

  662. Ray Ladbury:

    Tilo, your own graph shows that we’ve lost between 2-3 million sq. km of ice at minimum extent and bit over a million at maximum extent! How can you claim that supports your argument?

  663. Kevin McKinney:

    Tilo, perhaps you should try replacing the assumption of some linear relationship between latitude and ice thickness with actual data. It’s not hard to find.

    http://www.nasa.gov/images/content/365869main_earth2-20090707-full.jpg
    http://www.nasa.gov/topics/earth/features/icesat-20090707.html

    In fact, the thickest ice is clearly just north of the Canadian archipelago. And you have essentially flat distributions stretching for hundreds of kilometers.

  664. Barton Paul Levenson:

    That line in the C output statement should have read “flux density” rather than “absolute magnitude,” of course. Sorry about that. That’ll teach me to cut and paste code.

  665. John P. Reisman (OSS Foundation):

    #653 Tilo Reber

    As has been discussed ad infinitum on this site. Weather is not climate and the climate signal is generally understood as 30+ years with attribution in order to identify the signal above the noise

    http://www.nasa.gov/mission_pages/noaa-n/climate/climate_weather.html

    You’re inferring that you trust short term data over long which translates to you trust weather over climate, which translates to you trust the chaos in the noise more that the signal

    Therefore your argument simply does not stand to well reasoned logic.

    What is interesting to note is that you agree with charts such as global ice extent that when in context show that you agree with AGW since it strongly supports the case when understood in context with the models and predictions. This of course makes me wonder why you have a problem with AGW since it looks like you agree with the evidence, including the norther amplification effect.

    Generally, you are a bit confused on the edge v. thickness argument. Edges can even remain relatively the same and still lose thickness in the middle. The really thick stuff in the Arctic is not in the middle (at the north pole, it is more bunched up near Greenland and the Canadian archipelago, and the edges are not stable as you seem to think.

    http://nsidc.org/arcticseaicenews/2009/040609.html

    http://nsidc.org/images/arcticseaicenews/20091207_Figure3.png

  666. Tilo Reber:

    Doug: #652
    “Can you show me the “recovery” in this?”

    Go back and see what I said Doug. Then look at your chart. Not the trend line. The data. The trend line carries the past into the present.

    “I’ll stick with November, but you can pick any month you like.”

    I don’t want a month, I want all months. And you might want to account for the fact that the earth has 2 poles like my chart does.

    “Your stage business about thickness versus extent is potentially distracting, but first you have to explain the “recovery” bit.”

    John claimed that ice was thinning at a rate of 10% a year. That would require a lot more area shrinkage than we are seeing. And we are not seeing any since 2007.

    Before you go off on the shortness of the period, remember that I also said this in 628. “But the recent stabilization of the Arctic and Antartic sea ice area makes me think that we may be right on the border of how much melt we are going to get – at least at this temperature. I think we’ll need a few more years to be sure. ”

    And remember that this is said in context of melting all of the Arctic sea ice in the summers without further elevation of temperature. Keep the context.

  667. Tilo Reber:

    John: #655
    However, as I already pointed out and you apparently did not pay attention to, the ice extent in the Antarctic has increased as expected with global warming.

    No John, as I previously pointed out, your explanation of the effect of global warming on the Antarctic is false. Your explanation works for explaining the increase in the thickness of the land based ice sheet. It has nothing to do at all with sea based ice extent. Sea based ice doesn’t need more snow or more moisture in the air. The sea has all the raw material necessary to produce ice. Adding more does nothing to increase the ice extent.

    “and the Arctic has decreased”

    Yes, the area decreased until 2007. It recovered after that. As I already said, we need more time to see if that is a stabilization.

  668. Completely Fed Up:

    Tilo
    “However, as I already pointed out and you apparently did not pay attention to, the ice extent in the Antarctic has increased as expected with global warming.”

    So you agree that antarctic ice extension is a model consequence of global warming by AGW and therefore constitutes a proof of the validity of those models. Especially since such a change is counter-intuitive.

    “Yes, the area decreased until 2007. It recovered after that.”

    Nope, there is no evidence the ice has recovered.

    Is the extent back to the same levels?

    No.

    Recovered?

    No.

  669. Completely Fed Up:

    “I don’t want a month, I want all months.”

    On the scale of climate, there’s no difference between 1 month and 12 consecutive months.

    You want all you like, but wanting insufficient data to make a conclusion doesn’t let you make a conclusion with insufficient data.

  670. JasonB:

    653, Tilo Reber:

    “I’m deducing that the rest of the planet isn’t changing at all from this:

    http://4.bp.blogspot.com/__VkzVMn3cHA/SQkAxK2k6CI/AAAAAAAAADs/F4NlhqTzFgM/s1600-h/U+11+Year+Temp+Data.bmp

    It tells me two things. The trend since 1998 has been relatively flat – at least through 2008.”

    Seriously?

    Please, don’t insult my intelligence. I can’t believe you have honestly failed to notice all of the excellent articles around explaining what is wrong with the above statement. Assuming that I’m not aware of them is just rude.

    You may want to consider Pat Michael’s advice: http://www.youtube.com/user/greenman3610#p/u/9/QwnrpwctIh4

    You may also want to think about what happens if you start a year earlier or a year later: http://www.woodfortrees.org/plot/hadcrut3vgl/from:1997/plot/hadcrut3vgl/from:1997/trend/plot/hadcrut3vgl/from:1998/trend/plot/hadcrut3vgl/from:1999/trend

    “This is half of the predicted IPCC decadal warming due to CO2. I consider that significant.”

    Sadly, merely “considering” it significant doesn’t make it so:

    http://tamino.wordpress.com/2009/12/15/how-long/

    You really should look at this as well:

    http://tamino.wordpress.com/2009/12/07/riddle-me-this/

    “But if it’s stronger than the warming across the rest of the globe, what do we get when we multiply zero.”

    Why would anybody be multiplying anything by zero? That doesn’t even begin to make sense.

    “And I agree that it is a good reason. But when other sources diverge, you need to look at the sensibility of the divergence. Saying that it all comes from the small areas at the pole is not sensible to me for the reasons that I gave above.”

    OK, if you want another explanation for why HadCrut underestimates the warming trend, try this:

    http://www.metoffice.gov.uk/corporate/pressoffice/2009/pr20091218b.html

    Since the poles aren’t the only places that HadCrut has no data for, and those “missing” places just happen to also be warming more than average, it’s not surprising that there’s a difference in trend.

    Explain to me again a logical reason for choosing HadCrut over GISS.

  671. Completely Fed Up:

    “John claimed that ice was thinning at a rate of 10% a year. That would require a lot more area shrinkage than we are seeing. And we are not seeing any since 2007.”

    Nope, that would not necessarily require ANY area shrinkage.

    Think of a block of processed cheese, 10 slices deep.

    Eat the top one.

    You have now reduced the thickness by 10% yet reduced the coverage not at all.

    And there HAS been shrinkage, you even concede it. So you have to prove that this shrinkage is insufficient.

    Don’t just state it.

    Prove it.

  672. John P. Reisman (OSS Foundation):

    #657 Completely Fed Up

    Yes.

  673. Tilo Reber:

    Completely: #659
    “Mind you, he still doesn’t get the measurement of sea ice extent isn’t “solid ice” but “how far out is there still quite a bit of ice”, therefore the extent can be far more affected by breakup of ice drifting away (which breakup is easier if you have thinner ice) than by how cold it is.”

    Bad logic. First of all, when you drop beyond a certain density of broken up sea ice it’s no longer included in the sea ice area. Second of all, when you have more solid ice towards the center, you still have thinner, broken up ice at the perimeter, and you have a bigger perimeter, so the resulting sea ice area remains larger.

    The argument remains. If the ice is getting significantly thinner (10% per year), then the area should be getting significantly smaller as well.

  674. Hank Roberts:

    Sorry, Tilo, you’re wrong in your claim of certainty about how the increased sea ice forms, maximally wrong one might say — you’re making a flat statement as though you had some fact, waving your hands and asserting what you want.

    (What became of monicker anyhow, do you trade off?)

    You know how to look this stuff up. You could do so, but you don’t.

    For any new reader,
    http://scholar.google.com/scholar?hl=en&q=-arctic+%2Bantarctic+%2B%22sea+ice%22+AR4&btnG=Search&as_sdt=2001&as_ylo=2007&as_vis=1

    Likely contributors: more warm ocean currents reaching the Antarctic ice along the seashore; that makes for more fresh water melted off the fixed ice; fresh water floating on top of the salt water freezes faster.

    I’d speculate that one possible approach would be to test the isotope ratios of the seasonal sea ice along the Antarctic edge to see if the water in it came from old water that spent a long time as glacial and fixed ice, then melted, then refroze.

    (Anyone working in the area know if that’s been looked at or if samples are available that could be looked at? Plenty to be looked into)

    For example: http://www.agu.org/journals/gl/gl0722/2007GL031648/

  675. John P. Reisman (OSS Foundation):

    #666 Tilo Reber

    As to ice extent ‘months’. If you want to see the trend use more that 12 months. weather is not climate Yo say you want all months then what does this chart tell you about ice extent?

    http://nsidc.org/images/arcticseaicenews/20091207_Figure3.png

    The current ice volume loss does not require ice extent loss. Ice extent loss is occurring also though. Ever been ice skating on a lake, the size of the lake does not determine if the ice is thick enough to skate on and the size of the lake does not change, your argument does not stand.

    http://www.ossfoundation.us/projects/environment/global-warming/myths/images/arctic

    http://www.ossfoundation.us/projects/environment/global-warming/myths/images/arctic/365871main_earth3-20090707-full.jpg/view

    http://www.ossfoundation.us/projects/environment/global-warming/myths/images/arctic/365869main_earth2-20090707-full.jpg/view

    http://www.ossfoundation.us/projects/environment/global-warming/myths/images/arctic/20090406_Figure5.png/view

    http://www.ossfoundation.us/projects/environment/global-warming/myths/images/arctic/20090406_animation.gif/view

    http://www.ossfoundation.us/projects/environment/global-warming/myths/images/arctic/20080924_Figure3.jpg/view

    http://www.ossfoundation.us/projects/environment/global-warming/myths/images/arctic/20080924_Figure3.jpg/view

    Your argument that we need “a few more years to be sure” has no credibility based on the evidence.

  676. Tilo Reber:

    Completely:
    “Eat the top one.

    You have now reduced the thickness by 10% yet reduced the coverage not at all.”

    Again, bad logic. The sea ice is not like a block of cheese. Think of it as being more like a discus with a flat top. It’s thick in the middle and thin at the edges. Then when you remove a certain thickness across the whole thing, you also shrink the surface area.

  677. Doug Bostrom:

    Tilo Reber says: 5 January 2010 at 11:20 AM

    “Go back and see what I said Doug. Then look at your chart. Not the trend line. The data. The trend line carries the past into the present.”

    Yes, the data forces the trend line to slope downward toward the right. In other words, the data says the ice extent is decreasing. Pick any month you want, all of ‘em, you’ll see the same thing.

    I refuse to believe you’re psychotic.

  678. Completely Fed Up:

    “Explain to me again a logical reason for choosing HadCrut over GISS.”

    I can, though it’s not one he’d admit to: it says what he likes to hear.

    This is called cherry picking.

    It’s the same reason he picks 2007 for sea ice extent and even the choosing of sea ice extent as a proxy for temperatures.

    Because not picking them ruins his argument.

  679. John P. Reisman (OSS Foundation):

    #667 Tilo Reber

    As to Antarctic sea ice extent:

    http://www.skepticalscience.com/Why-is-Antarctic-sea-ice-increasing.html
    http://psc.apl.washington.edu/zhang/Pubs/Zhang_Antarctic_20-11-2515.pdf

    Your Arctic recovery meme is based on short term natural variability and has less to do with climate that you would like to believe.

    Climate is generally understood to be 30+ years This web site is about climate, and you keep bringing up the weather???

    You need to understand what you are looking at, and apparently you don’t. You need to realize that your lack of understanding does not change the relevant context of the evidence or the scientific understanding. In other words your opinion does not overturn science.

  680. Steve Bloom:

    Tilo, teh google would have also quickly led you to things like this regarding the Antarctic sea ice. Interestingly, while there’s been a small expanding trend, it’s been geographically very uneven. I don’t recall seeing you explain or even mention that.

  681. dhogaza:

    Completely Fed Up:

    Tilo
    “However, as I already pointed out and you apparently did not pay attention to, the ice extent in the Antarctic has increased as expected with global warming.”

    Actually, you've misattributed the statement, Tilo was quoting John. Tilo then went on to disagree with John.

    So you agree that antarctic ice extension is a model consequence of global warming by AGW and therefore constitutes a proof of the validity of those models. Especially since such a change is counter-intuitive.

    So, no, he doesn’t.

    Anyway, Tilo rejects observational data that doesn’t conform to his world view, such as the fact that arctic sea ice volume has steadily decreased, the fact that we’re at essentially the same record minimum as in 2007 at the moment doesn’t show “recovery from 2007″, etc.

    Tilo’s been spinning the same tired tales for years, now.

  682. Tilo Reber:

    Ray: #661
    “If it is sufficiently cold it will freeze.”

    Right. Point being that if we are warming it will not be sufficiently cold as far north as it was when we were colder.

  683. Bradley McKinley:

    [Response: You need to be more specific - what time period? - gavin]

    I was just looking at the first graph, and referring to the period 1980-2009. It looked to me like you could still be inside the gray if the observed record started around -0.12 and ended at +0.06, for a total change of only 0.18 over the ~30 year period. That is what I was referring to as a “trivial” amount of warming. I think I see where you are going though, and that is that the model’s forecast curves upwards in the post-2000 period, meaning that you still couldn’t be within the 95% interval with only 0.06 rise per decade for very long. What is the minimum amount of warming you could see through 2100 and still be inside 95% of the model runs? Is it 1.7 for A1B?

    [Response: For the model runs, the 95% lowest bound on trends from 1980-2009 is 0.07 deg C/dec (mean is exactly 0.2 degC/dec) - actual trends were 0.16 deg C/dec. From 2010 to 2100, the range for the A1B scenarios is [0.15,0.38] (mean 0.26) degC/dec (that’s a rise of between 1.7 and 3.6 deg C from now to 2100). – gavin]

  684. Completely Fed Up:

    “Point being that if we are warming it will not be sufficiently cold as far north as it was when we were colder.”

    No.

    That isn’t the point.

    It doesn’t even fall out of any sensible thinking on it.

    Sea ice extends where some “pixel” is at least 15% ice. Therefore the sea ice extent is highly dependent on breakup.

    And if it is -1C and warms by 1C, it’s gotten warmer but hasn’t gotten any less frozen.

    Plus, what do you have surrounding the North Pole (as opposed to the South one)?

    Land.

    You’re waving your arms around like Magnus Pike and making as much sense as Snow’s “swingometer”.

  685. Completely Fed Up:

    “Again, bad logic. The sea ice is not like a block of cheese. Think of it as being more like a discus with a flat top.”

    Again, bad logic. The sea ice is not like a discus with a flat top. The flat top has already once been brought to your attention but you ignore it (“I see no ships!”). But it;’s more like a slush puppy poured out in to a large bowl.

    Sea ice extends to where there is about 5x more “not ice” than ice.

    So how can sea ice extent be an absolute reading of sea ice extend without seawater?

  686. Completely Fed Up:

    For all those complaining about the short shrift some dumb questions get, link to Tilo’s posts and his refusal to read anything he doesn’t like.

  687. Tilo Reber:

    Kevin: #663
    “Tilo, perhaps you should try replacing the assumption of some linear relationship between latitude and ice thickness with actual data. It’s not hard to find.”

    Kevin, my argument doesn’t depend on a linear relationship. And it doesn’t depend on the thickest ice being at exactly the north pole. Do you get a lot of ice at the poles and is it cold at the poles? Yes. Do your get a lot of ice at the equator and is it cold at the equator? No. In general, does ice get thinner as you get away from the poles? Yes.

    It doesn’t matter if the shape is not perfect or if the center of the thickest ice isn’t exactly at the pole. The idea that thinner ice should mean less ice area still applies.

  688. John P. Reisman (OSS Foundation):

    #676 Tilo Reber

    Well, there certainly is a thickness problem here ;)

    Tilo, try thinking of it this way. You have a block of ice, you carve off half of it from the bottom, does the surface area change? No. It’s a simple illustration. the real world is more dynamic but your logic is completely screwed up on this.

    Now run along and tell your friends how mean I am that I was so abusive as to insult your logic.

  689. Completely Fed Up:

    Tilo: “And it doesn’t depend on the thickest ice being at exactly the north pole.”

    Really? May I remind you:

    “Think of it as being more like a discus with a flat top.”

  690. John P. Reisman (OSS Foundation):

    #686 Tilo Reber

    I admit that in your view, you are correct. Unfortunately your view is not in line with the world of evidence and observation called reality.

    To paraphrase Newton, ‘if you have seen so little, it is because you remain stooped to limit your view’.

  691. dhogaza:

    Among other things, Tilo’s ignoring the effects of currents and wind …

    Tilo, there’s not sea ice at the equator, but you can find penguins off the west coast of Ecuador and the water there is much colder than the more northern Pacific coast of Costa Rica (I’ve swum in both). Why do you think that is?

  692. Barton Paul Levenson:

    Tilo: I consider that significant.

    BPL: Forgive me if this sounds hostile, but nobody cares what YOU consider significant. In science, “significant” refers to the statistical significance of a measurement, and is something that can be objectively measured. Google “significance testing,” or better yet, take a first-year statistics course.

  693. Ray Ladbury:

    Tilo, Global warming does not mean it won’t be below freezing in December north of 50 deg. N. Good lord, I knew I should have bought up some straw. All the straw men you are constructing there won’t be any left.

    Dude, what is happening in the North is 1)Ice is melting in the summer further North than at any time in recorded history. 2)The ocean refreezes in the Winter. 3)It melts in the Summer again.

    It takes several years to build up thick ice. A yearly freeze-thaw cycle precludes thickening. Go learn some science. PLEASE!

  694. Tilo Reber:

    JasonB: #670
    “You may want to consider Pat Michael’s advice:”

    Jason, it’s almost as though you haven’t paid attention to anything that we have talked about. Take Michaels objection to starting with an El Nino year and ending with a La Nina year. Why do you think that we have been talking about ENSO corrected data all of this time?

    Take Michaels point about not making the assertion that global warming has stopped. I’ve never made that statement. My statement is that there hasn’t been any since 1998. Those are two completely different things.

    JasonB:
    “You may also want to think about what happens if you start a year earlier or a year later:”

    Same point. That’s why we want to use ENSO corrected data.

    Now, let’s seperate what we are debating about into two different parts. The first concerns what has happened since 1998. The second is if that is significant or not.

    The skeptics statement is that the climate has been essentially flat since 1998. I think that ENSO corrected HadCrut3 and ENSO corrected UAH and ENSO corrected RSS will all show this. If you want to use the outlier, then be my guest. But even your outlier has less warming than predicted by the IPCC.

    Now, regarding the element of significance, I don’t accept Tamino’s arguments. Tamino censors everyone with significant disagreements. I don’t consider any of his posts as being resolved issues since he doesn’t give the opposition a chance to speak. Besides, what happened to your demand for only considering peer reviewed papers as authoritative when it comes to quoting your favorite web site.

    I also find Tamino’s approach as unconvincing because it is not adequately related to physical processes. The idea that you have to filter out elements of natural variability to see a trend is a good one. The problem is when you identify a trend that is shorter than natural cycles of variability. The thirty year rule will not cover all cycles. For example, one side of a PDO cycle can be that long – so you can end up identifying a trend that is nothing more than one phase of a PDO cycle. Apparently, Tamino has now come up with a number that says 15 years is significant. That would be even more subject to identifying a false trend due to natural variability. I think that the better approach is to identify the natural elements of variability and remove them. Then you should be able to identify a trend in a shorter time period. In this case, when we remove the elements that we know about since 1998, we are still flat. This means that if CO2 is forcing at the level that is claimed, then we don’t know enough about the natural elements of variation. Or if we do know enough about it, then the CO2 forcing is not as large as claimed.

    And here is a paper from Science that places a lot of significance on just ten years worth of data.

    http://www.sciencemag.org/cgi/content/abstract/1110252

    From the abstract:
    “This imbalance is confirmed by precise measurements of increasing ocean heat content over the past 10 years.”

    JasonB:
    “Since the poles aren’t the only places that HadCrut has no data for, and those “missing” places just happen to also be warming more than average, it’s not surprising that there’s a difference in trend.”

    The satellites are not missing those other areas, and their trend is slightly lower, even, than HadCrut3.

  695. Tilo Reber:

    John: #688

    “Tilo, try thinking of it this way. You have a block of ice, you carve off half of it from the bottom, does the surface area change? No. It’s a simple illustration. the real world is more dynamic but your logic is completely screwed up on this.”

    Been there John. See #676.

  696. Doug Bostrom:

    Tilo, I’m still waiting for your explanation of the recovery of Arctic sea ice.

  697. Tilo Reber:

    dhogaza: #691

    “Among other things, Tilo’s ignoring the effects of currents and wind …”

    That is true, dhogaza, I am. Can you explain how that plays into the idea that thinning ice should also have shrinking ice area?

    You may all be curious to know that the UAH December anomaly is 0.28C. I know, I know – it’s only weather. I was a little suprised. I thought it would be warmer since the El Nino is still at full strength and since there is a very hot spot in the southern pacific that is the size of the US.

    [Response: Much as the subject appears to fascinate others, we are not interested in a month by month or week by week accounting of the weather. Take it elsewhere. - gavin]

  698. David B. Benson:

    Tilo Reber (694) — Tamino’s Open Mind is a “stupid-free” zone for those interested in discovering how statistics is applied to aspects of climatology. I find it most informative; reading there has induced me to start studying

    Jianqing Fan & Qiwei Yao
    Nonlinear Time Series: Nonparametric and parametric methods
    Springer Verlag, 2003.

    At this point I Know have some sort of grip of the linear ARMA models.

    Next, there are very, very few “cycles” in climatological data. There are “oscillations”, meaning just variability and most of this variability is just pink or red-pink noise:
    http://en.wikipedia.org/wiki/Pink_noise
    TO some extent there are quasi-periodic oscillations (QPO) such as the quasi-biannual oscillation (QBO); such can be modeled by ARMA processes but not by old-fashioned periodic functions.

    You should check, but it is highly likely the satellities are missing both polar regions. In addition, I believe you are incorrecvt about RSS.

  699. Hank Roberts:

    > here is a paper from Science that places a lot of
    > significance on just ten years worth of data.

    Tilo won’t respond except with more red herring, but for any youngster reading along, some herring detection here:

    What does “a lot of significance” mean to Tilo?
    What does significance mean to a statistician?
    Why are these different?

    Compare noise versus signal and years to detect a trend:
    – annual global measurements (ONE data point each year)
    – sea temperature measurements (how many data points?)

    See also the citing papers, including
    http://www.pnas.org/content/106/38/16120.abstract

    and http://www.arctic.noaa.gov/reportcard/seaice.html

  700. John P. Reisman (OSS Foundation):

    #694 Tilo Reber

    Short terms can work if you can identify the attribution and relative forcing amounts. Ocean cycles are good in this respect. Science certainly does not know everything about ocean cycles but that does not mean science knows nothing.

    Have you considered politics, your are quite the spinner of reality, or quite likely you simply don’t know enough about the science to understand the context and relevance of what you are looking at, as you have repeatedly shown in your posts.

    My guess is that you are either paid to obfuscate, or you are doing this of your own accord. I hope it is the former because if it is the latter, then you have more serious problems.

  701. Tilo Reber:

    Completely: #689
    “Really? May I remind you:
    “Think of it as being more like a discus with a flat top.””

    LOL. Okay, Completely, now think of it as being a lopsided discus. It still has areas of thin ice and thick ice. Peel away some thickness of ice and some of the thin ice disappers and becomes a smaller ice area.

  702. Deech56:

    RE Tilo Reber

    And here is a paper from Science that places a lot of significance on just ten years worth of data.

    http://www.sciencemag.org/cgi/content/abstract/1110252

    What is the noise in that data set? Significance is a function of the trend and the error, so measurements that show a strong trend and are damped (er, show less variability), like ocean heat content, may be significant at shorter time periods.

  703. Completely Fed Up:

    Tilo: “LOL. Okay, Completely, now think of it as being a lopsided discus.”

    Nope, not that either.

    A discus isn’t 15% wood and 85% air and still counted “discus”.

    “Peel away some thickness of ice and some of the thin ice disappers and becomes a smaller ice area.”

    But unless it peels away to less than 15% of the original ice area, you can still get “100%” ice coverage and therefore “read” more ice than there is.

  704. Hank Roberts:

    See also:
    http://www.google.com/search?q=site%3Atamino.wordpress.com+tsonis

  705. Hank Roberts:

    Tilo, you’re making this stuff up without any source.

    Kids, you can easily check this kind of claim. Just paste his words into Google, using them as search terms, and read the results. You’ll find out what’s actually known.

    Here, for example:

    http://www.arctic.noaa.gov/reportcard/seaice.html

    Read the whole page, it’s not that long, to understand what’s going on.

    Excerpt follows:

    Recent estimates of Arctic Ocean sea ice thickness from satellite altimetry show a remarkable overall thinning of ~0.6 m in ice thickness between 2004 and 2008 (Figure. S4a). In contrast, the average thickness of the thinner first-year ice in mid-winter (~2 m), did not exhibit a downward trend. ….

    The total multiyear ice volume in the winter experienced a net loss of more than 40% in the four years since 2005 while the first year ice cover gained volume due to increased overall coverage of the Arctic Ocean. The declines in total volume and average thickness (black line in Figure S4a) are explained almost entirely by thinning and loss of multiyear sea ice due to melting and ice export. These changes have resulted in seasonal ice becoming the dominant Arctic sea ice type, both in terms of area coverage and of volume….

  706. Hank Roberts:

    PS, the above link tells you the observations, which contradict the PR talking points being repeated above:
    the thin (mixed and first year) ice is near the pole and the thicker (multiyear) ice is nearer the edge, where it gets pushed during the melt season and stacks up.

    See the illustration:
    http://www.arctic.noaa.gov/reportcard/figures/s3.jpg
    Figure S3. Arctic sea ice distribution in March of 2007, 2008, and 2009. Multiyear ice is in white, mixed ice aqua, first-year ice teal, and ice with melting surface red. Dark blue is for open water and brown for land….

  707. John P. Reisman (OSS Foundation):

    #695 Tilo Reber

    I did read your #676 and you were responded to in #685

    Your logic does not make any sense. In the context of this argument sea ice is like a block of cheese. In fact it is easy to imagine a reduction of ice thickness and even an expansion of ice extent. I simply don’t understand why your brain seems incapable of understanding this?

    El Nino is at full strength?

    http://www.esr.org/pdo_index.html

    How do you figure?

  708. John P. Reisman (OSS Foundation):

    #701 Tilo Reber

    Okay, now think about reality. Or can you prove that Atlas is swimming around in the Arctic and maybe with Poseidon is holding up the Arctic ice sheet and tipping it?

    Wow, Tilo has created a new Pseudo-science: Greek mythology mixed with fanciful storytelling…

    It’s called ‘Mythcience’

    Just wait till the universities start writing new textbooks. Tilo is going to be rich beyond the dreams of Avarice.

  709. Steve Bloom:

    Tilo: “Peel away some thickness of ice and some of the thin ice disappers and becomes a smaller ice area.”

    Up in 660 I provided you with two links to observations disproving this too-simple idea of yours and here you are continuing to repeat it. Do you have a reading comprehension problem? Do periodic arthritic seizures prevent you from clicking? As a child were you bitten by Ayn Rand? Does telling porkies fire off the pleasure center in your brain? You tell me.

  710. John P. Reisman (OSS Foundation):

    #697 Tilo Reber

    Sorry, I sent you PDO to show the PDO phase in contrast to 1997/8

    http://www.cpc.noaa.gov/products/analysis_monitoring/enso_advisory/ensodisc.html

    El Nino “at full strength” is a relative term. Do you mean in comparison to the 97/98 event, or just for it’s current phase? There is a difference in “strength” you know.

  711. dhogaza:

    the thin (mixed and first year) ice is near the pole and the thicker (multiyear) ice is nearer the edge, where it gets pushed during the melt season and stacks up.

    Yes, as I said above (and Tilo more or less laughed at), Tilo is ignoring currents and winds.

    The ice isn’t sitting there like a discus. Or frisbee. Or a loaf of bread.

    It’s being pushed around, and when thick chunks get floated out through the ummm Fram(?) Straight into warmer waters they just *melt*.

    BTW, look how wiggly this years refreeze ice extent line is compared to the 2007-2008 one.

    Thinner ice moving apart, closer together, above the 15% coverage threshold, then below, etc? Just a guess but it’s interesting to see how different this year’s refreeze is (oh, yeah, it’s refreezing at a slower rate, too, tied with 2007-2008 at the moment despite the summer minimum being significantly higher).

    “recovery” my a** …

  712. flxible:

    not sure why some of you persist in encouraging Tilo’s foolishness, but I think his persistance may have something to do with his view of RC

  713. John P. Reisman (OSS Foundation):

    #712 flxible

    I appreciate his foolishness. Just take a look at RC”s site stats. They are getting 6 to 10k visitors per day lately. The more Tilo posts here, the more we can help those thousands of visitors understand just how silly his points are.

    C’mon Tilo… post some more… I and others here are ready to correct your silliness for those who actually care about learning about ‘Real Climate’.

  714. Tilo Reber:

    Deech56 #702
    What is the noise in that data set? Significance is a function of the trend and the error, so measurements that show a strong trend and are damped (er, show less variability), like ocean heat content, may be significant at shorter time periods.

    Okay, I buy that in concept. But what if we remove variability for the surface temperature record. For example, by using ENSO corrected data. Then wouldn’t that also allow you to have a shorter period that was significant.

  715. Tilo Reber:

    Completely:
    “A discus isn’t 15% wood and 85% air and still counted “discus”.”

    Okay, I admit, that went right over my head. Help me out.

    “But unless it peels away to less than 15% of the original ice area, you can still get “100%” ice coverage and therefore “read” more ice than there is.”

    At the perimeter much of the ice that is counted as part of the ice area is already close the 15% range. And much of it is thin ice. Take away a meter of thickness, like you are doing in the thickest part, and pieces of that ice disappear completely. That then removes the area from the map.

  716. Steve Bloom:

    Thanks for the link, flxible. In particular, I liked this from Tilo: “The attempt by the scientists at the Hadley Climate Research Unit to illicitly control the debate about global warming by using their influence with publishers and the IPCC will come as no surprise to the thousands of skeptics that have had their legitimate questions censored at Real Climate.” (For those without a scorecard, the Hadley Center and the Climate Research Unit are entirely distinct institutions, aside from both being located in Blighty.) As Ronald Reagan once said, facts are stupid things.

    I liked the headline on the next item, too: “More Fraudulent Censorhip at Real Climate.” Earth to Tilo: In the English as she is spoken, “fraudulent” plus “censorship” does not equal “fraudulent censorship.” One of the things I’ve noticed about scientists is that they tend to express themselves with, if anything, an excess of precision, usually to the benefit of clarity (big exception for Mike Hulme in this latter regard). You’re kind of the opposite. I don’t expect you to ever change the essential dishonesty of your views, but if you want to get better at expressing them I suggest you make a study of how RP Jr. goes about it.

  717. Tilo Reber:

    Completely: #685
    “But it;’s more like a slush puppy poured out in to a large bowl.
    Sea ice extends to where there is about 5x more “not ice” than ice.”

    Kind of hard to measure ice thickness on a slush puppy, isn’t it? But okay, I’ll take the slush puppy model if it makes you happy. As long as you don’t claim that it’s like a block of cheese.

    In a slush puppy some of the ice is still thick and some is still thin. Some chuncks are large and some are small – if you like. Again, this means that removing a certain thickness of ice will mean that some of the surface ice will disappear. At the perimeter where there is already just 15% coverage, that ice will drop below 15% and the area will no longer be counted.

  718. Hank Roberts:

    “… and who knows, in time, maybe he’ll learn to cite …”

    [Response: nice ref - gavin]

  719. Tilo Reber:

    John: #710
    “Do you mean in comparison to the 97/98 event, or just for it’s current phase?”

    I’m talking about the current phase. Here:

    http://www.cpc.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdf

    See page 5 of 37. The charts on the right look like we may be maxed out in all but Nino 1+2. The next month should tell us for sure.

  720. Steve Bloom:

    Re #710: John, just so we’re clear, there’s no particular reason to think that the PDO drives much of anything. Tilo and friends don’t understand what it is, so for them it’s become kind of a climate hope chest to drop all their fears into (sorry, Tilo’s rhetorical excesses are inspiring me). Plus of course “Pacific Decadal Oscillation” sounds important.

    Anyway, the PDO involves looking at North Pacific SSTs and seeing if they’re very slightly warmer or cooler than the global signal. We can do the same thing with any region of the ocean and absent anything else going on it wouldn’t mean bupkes, but in the case of the North Pacific it was noticed that certain fish species that people like to eat are rather sensitive to those slight changes. In other words, the PDO is of economic but not (much) climatological importance. I say not much as opposed to no importance since the PDO does indeed describe real differences from the overall temperature trend and so can be linked to climate in its region, but is very much not a significant driver. This recent review is worth a read if you want more detail.

  721. Tilo Reber:

    dhogaza:
    “Yes, as I said above (and Tilo more or less laughed at), Tilo is ignoring currents and winds.”

    No laughing dhogaza. I believe that the ice moves around to some extent. But I still need an explanation for why that means the thin ice wouldn’t melt completely and as a result why thinning wouldn’t also reduce area. Take a look at a chart like this:

    http://igloo.atmos.uiuc.edu/cgi-bin/test/print.sh

    See the green ice. It is around the edges. See the darker red ice, it’s generally closer to the center. As you watch the change through the year the ice on the outside will grow last and disappear first. The stuff around the edges will melt before the stuff in the center. Again, it’s not perfect, but it does follow that pattern. The currents can also change this to an extent. But the pattern is still similar.

  722. Greg C.:

    To chip in my own two cents on programming languages:

    When I am prototyping, I usually use Python + numpy since it’s quick and dirty, is reasonably fast, and the strong and dynamic typing makes it hard for me to write code that will result in a segmentation fault so I don’t have to be as paranoid while coding.

    When I write non-prototype scientific code where I really care about performance, I first write the main number-crunching kernels in Fortran because it is both *fast* and *expressive* for brute-force number crunching on multi-dimensional arrays. Then I write the code for the algorithm itself using a higher-level language that has stronger typing and better support for expressing complex control flow, and have it call the Fortran kernels in order to do the heavy lifting.

    My personal favorite algorithm language of late is Haskell because not only is it very expressive, but its type system gives you a lot of power to ensure that particular kinds of objects can only be used in very specific ways, which lets you prevent yourself from making whole classes of mistakes. However, in the past I have also used Python as the “glue” language to tie Fortran kernels together, and I would be open to using C++ for this role as well. (Incidentally, I know that many people disagree with me on this, but C++ templates rock since they let you be able to write algorithms in a very general way without losing performance for special fast cases; there have been times when this has *really* helped me a lot, since it prevented me from having to write two versions of the same code just to have both a flexible and a restricted but fast version.)

    So in short, my philosophy is that one should be open minded about the possibility of using multiple languages in a project so that each part of it can be written in the language that is optimized for solving that particular problem. There is a strong downside to this approach, though, which is that it assumes that other people are willing and able to learn more than one language in order to work on your project.

  723. Timothy Chase:

    John P. Reismann wrote in 707:

    El Nino is at full strength?

    http://www.esr.org/pdo_index.html

    How do you figure?

    John, that is a link to a page on the Pacific Decadal Oscillation. It is somewhat similar to the El Nino Southern Oscillation but not the same.

    You can see the difference in patterns here:

    The Pacific Decadal Oscillation
    http://jisao.washington.edu/pdo/

    Additionally, El Nino is quasi-periodic (~2-7 years) whereas PDO is often regarded as closer to pink noise.

    As for ENSO, it is strongly positive. Full strength? Hard to say, but certainly not comparable to the super El Nino of 1998.

    Please see:

    ENSO cycle as indicated by 1st EOF
    of surface current and SST anomalies
    http://www.esr.org/enso_index.html

    ENSO Update
    17 December 2009
    http://iri.columbia.edu/climate/ENSO/currentinfo/QuickLook.html

    Regardless, global temperature typically lags ENSO 4-6 months. If ENSO continues through the spring and the sun continues to become more active…

    Disappearing sunspots may signal end to global warming
    Examiner.com – ‎Dec 16, 2009‎
    http://www.examiner.com/x-32936-Seminole-County-Environmental-News-Examiner~y2009m12d16-Disappearing-sunspots-may-signal-end-to-global-warming

    Oops! I mean:

    2009′s Sleepy Sun Finally Woke Up in December
    By Alexis Madrigal
    December 31, 2009
    http://www.wired.com/wiredscience/2009/12/the-year-in-sunspot

    … we might have an interesting year.

  724. Timothy Chase:

    PS

    John, sorry, I see you already made the correction. However, hopefully my above comment will contain some useful or at least interesting information for some.

  725. CTG:

    Dictionary definition of recovery:
    re·cov·er·y (r-kv-r)
    n. pl. re·cov·er·ies

    2. A return to a normal condition.

    The only possible way that you can characterize 2009 Arctic ice conditions as a “recovery” is “2009 has recovered to the long-term downward trend”, as though it is perfectly normal for Arctic ice to be declining year-on-year.

    I’m guessing by your name, Tilo, that English may not be your first language, so you can be forgiven for not understanding what “recovery” means. But now that it has been pointed out to you, I trust you won’t continue to say that Arctice sea ice has “recovered”, will you?

  726. Timothy Chase:

    Arctic ice isn’t what it used to be, or so it would seem, what it appears to be…

    Please see:

    David Barber, Canada Research Chair in Arctic System Science at the University of Manitoba, says satellite images used to track the overall extent of Arctic ice don’t adequately perceive how weak and “rotten” the region’s older, thicker, multi-year ice cover has become.

    Arctic ice meltdown remains severe: report
    Randy Boswell,
    Published: Friday, November 27, 2009
    http://www.nationalpost.com/story.html?id=2276659

    … and:

    “We are almost out of multiyear sea ice in the northern hemisphere,” he said in a presentation in Parliament. The little that remains is jammed up against Canada’s Arctic archipelago, far from potential shipping routes.

    Scientists link higher Arctic temperatures and melting sea ice to the greenhouse gas emissions blamed for global warming.

    Barber spoke shortly after returning from an expedition that sought — and largely failed to find — a huge multiyear ice pack that should have been in the Beaufort Sea off the Canadian coastal town of Tuktoyaktuk.

    Multiyear Arctic ice is effectively gone: expert
    David Ljunggren, Reuters, OTTAWA
    Thu Oct 29, 2009
    http://www.reuters.com/article/idUSTRE59S3LT20091029?sp=true

    Barber et al. (2009), Perennial pack ice in the southern Beaufort Sea was not as it appeared in the summer of 2009, Geophys. Res. Lett., 36, L24501

  727. John P. Reisman (OSS Foundation):

    #719 Tilo Reber

    Thanks. Let’s see how it plays out. But the effects seem to be less. The 97/8 event was like a good El Nino surfing a wave on the north shore.

    #720 Steve Bloom
    Right, I don’t know if it’s a driver, but I still kinda look at it as a wave of temperature that can feed something else. I don’t know enough about it to understand what the mechanisms are but it looks to me like El Nino is the surfer and PDO is the wave and the bigger the wave, the more rad the ride.

    #723 Timothy Chase

    My bad. I tried to correct in #710

    #724

    An awesome post Timothy! Nice to know my screw ups can inspire something good once in a while :)

  728. Didactylos:

    Tilo’s arguments confused the heck out of me, since while exhibiting complete ignorance of ice dynamics, they also didn’t seem to help his larger anti-warming argument. So I dug back and found his original weird claim, and it became clear where he went wrong.

    Tilo, forget about the ice thickness, please. It seems to confuse you. Instead, consider ice age for a moment. Single year ice forms every year, and most of it will melt again. Some of it will survive and become thicker second year ice. Once, there was a very high proportion of very thick, very old ice in the Arctic. Now, all the ice is young – mostly very young. Young means thin.

    Now, due to thermodynamics that are beyond my power to explain, it does not follow that a warm Arctic means thinner than normal single year ice. For ice to form, below freezing is all it takes. In fact, counter-intuitively, warmer temperatures may cause faster and thicker ice formation. In the Arctic, “warmer” just means “not so impossibly mind-numbingly cold”.

    The take-home point is that massive melting and low sea ice extent minima year after year reduces the average age of the ice, and consequently reduces the average thickness of the ice.

    When it comes to long-term measurements of actual multi-year ice thickness, data is very, very sparse. There have been a few studies, but I wouldn’t place too much weight on them. My point is that we don’t need these studies to make the claim that ice is getting thinner (although the studies agree with this conclusion). We don’t need to worry about definitions of extent, melting mechanisms, or any of the weird similes that have been proposed. Ice, like any natural phenomenon, can be studied in incredible detail, and while it might be fun to hammer out all the minutia, we risk losing sight of the main point: it’s melting.

    Claiming that ice extent is “recovering” is as daft as claiming that global temperature is “cooling”. Why do people expect global records every single year?

  729. Steve Bloom:

    Re #727: John, that’s entirely reversed as to the PDO. I also think the wave analogy isn’t very good, although it’s a bit less so if applied to El Nino (which would in turn make the PDO and other smaller-scale climate phenomena the riders). The review I linked to describes attempts to establish whether the PDO significantly drives or even significantly affects the adjacent components of the climate system, the short answer being that it mostly doesn’t. That’s in sharp contrast to ENSO, which affects things at great distances and directly influences the global temperature trend. ENSO is as powerful as it is because it’s driven by heat accumulation and loss from the West Pacific warm pool, which is one hell of a driver.

  730. Didactylos:

    See page 5 of 37. The charts on the right look like we may be maxed out in all but Nino 1+2. The next month should tell us for sure.

    It’s the same error deniers make when reading any graph! The first derivative doesn’t tell us anything about whether a time-series has peaked. It has no predictive powers at all! Following this screwy logic, we would have concluded that it had “peaked” in September-October, too. November would have been a huge shock! It’s the “cooling since 1998″ fallacy all over again.

    Has it peaked? I have no idea. The forecasts say El Niño will continue throughout spring, but I understand prediction beyond that is very uncertain.

  731. JasonB:

    694, Tilo Reber:

    “Jason, it’s almost as though you haven’t paid attention to anything that we have talked about.”

    Oh, the irony!

    “Take Michaels objection to starting with an El Nino year and ending with a La Nina year. Why do you think that we have been talking about ENSO corrected data all of this time?”

    And you’ve missed the point — unless you think ENSO is the only thing that affects variability?

    The forcings are small relative to the variability — IOW, the signal-to-noise ratio is very poor. Therefore, a lot of data is required to tease out the signal. Removing the effect of ENSO does improve the signal-to-noise ratio and thereby can allow trends to be detected with shorter time periods, but why do you assume something magical about starting in 1998?

    Given your refusal to accept direct observational evidence when it comes to Arctic sea ice, I also have to wonder — why are you so willing to accept the mathematics involved in removing that ENSO effect? If somebody was to bother doing it for you (since you have made absolutely no effort to do it yourself) and it showed a positive trend on your favourite data, would you still treat it as gospel or would you throw it into the same bin that you throw everything else that doesn’t agree with your preconceptions?

    “Take Michaels point about not making the assertion that global warming has stopped. I’ve never made that statement. My statement is that there hasn’t been any since 1998. Those are two completely different things.”

    If you say so; your statement is still obviously wrong.

    “Same point. That’s why we want to use ENSO corrected data.”

    No, you want to use ENSO corrected data because you believe it will show a flat trend on your favourite data set. (You know, the data set from “the climate scientists involved in the CRU e-mail scandal”, to use your words.) I actually doubt it will, but knock yourself out — just do it already!

    “The skeptics statement is that the climate has been essentially flat since 1998. I think that ENSO corrected HadCrut3 and ENSO corrected UAH and ENSO corrected RSS will all show this.”

    Why all this thinking? Why not doing? Just eyeballing the curves I have a really had time believing that UAH or RSS will show what you think they will.

    “If you want to use the outlier, then be my guest. But even your outlier has less warming than predicted by the IPCC.”

    Are you trying for some record in the number of obviously erroneous claims per sentence? You did read the article that these comments are in response to, did you not?

    Are your posts an example of those that you say “are allowed because they carry no weight on the actual debate”? Hmm… You might be on to something there. Gavin is obviously censoring all of your “more difficult” posts and just letting the vacuous ones through.

    “Now, regarding the element of significance, I don’t accept Tamino’s arguments. Tamino censors everyone with significant disagreements. I don’t consider any of his posts as being resolved issues since he doesn’t give the opposition a chance to speak.”

    Ah, yes, I guess I should dismiss the theory of evolution as well if talkorigins.org doesn’t given the Creationists a chance to speak. That’s obviously the best way to determine the accuracy of the science.

    “Besides, what happened to your demand for only considering peer reviewed papers as authoritative when it comes to quoting your favorite web site.”

    Where did I demand that?

    “I also find Tamino’s approach as unconvincing because it is not adequately related to physical processes.”

    Just how do you think Tamino created the ENSO-corrected data that you’re so desparate for?

    What you seem to be saying is that if Tamino or someone else did what you are clearly unwilling to do yourself and produced an ENSO-corrected HadCrut data set, you would dismiss it immediately if it didn’t show what you wanted it to show on the basis that the approach is “unconvincing because it is not adequately related to physical processes”. But if it did show what you’re hoping for (i.e. a flat trend from the cherry-picked start date of 1998) then it would suddenly be gospel.

    Don’t you see the problem with this?

    The only reason you are cherry-picking a start date of 1998 and a temperature series from “the climate scientists involved in the CRU e-mail scandal” — you know, the ones who refused to release all their source code and data, and who demonstrably omit areas shown to be warming faster than average — and then use an approach that is “unconvincing because it is not adequately related to physical processes” to filter the effects of ENSO from that data is because you think it will support your claim that “the climate has been essentially flat since 1998″.

    If it doesn’t, you have so many built-in excuses for ignoring the result that I have to wonder why you think anybody would bother doing it for you?

    Tell me again, without looking at any data — what is your logical reason for favouring a temperature series that omits the Arctic and many other areas with stronger warming than average, produced by people who have refused to release their source code or data? What is your logical reason for thinking that ENSO is the only source of variability in the weather that allows you to arbitrarily choose the start date once it is removed without any regard for signal:noise ratios?

    “Apparently, Tamino has now come up with a number that says 15 years is significant.”

    I think you read too much into it — what he’s saying is that given that data, less than 15 years is not significant. It’s setting a lower bound on that particular set of data.

    JasonB:
    “Since the poles aren’t the only places that HadCrut has no data for, and those “missing” places just happen to also be warming more than average, it’s not surprising that there’s a difference in trend.”

    “The satellites are not missing those other areas, and their trend is slightly lower, even, than HadCrut3.”

    Yes, but the satellites aren’t measuring the same thing — they’re reconstructing the temperature of a signficant body of air rather than just the temperature of the air near the ground, and longer-term, the difference in trend between them is not that great — the 2000s were 0.1932 degrees hotter than the 1990s according to GISS, 0.1551 degrees hotter according to RSS, and 0.1632 degrees hotter according to UAH. Doesn’t seem like a huge disconnect to me. Not only that, but adding in the past decade of temperatures to the UAH data actually increases the trend:

    http://www.woodfortrees.org/plot/uah/plot/uah/trend/plot/uah/to:1999/trend

    Yes, that’s right — the trend for UAH is higher if the last decade is included; how does that square with the notion that there hasn’t been any warming since 1998? More importantly, the satellite records respond much more strongly to ENSO than the surface temperatures do, and I’ve cherry-picked the dates above to include 1998 in the shorter trend and the recent La Nina-affected years in the longer trend — why you expect removing the effect of ENSO would support your argument is beyond me.

  732. John P. Reisman (OSS Foundation):

    #729 Steve Bloom

    Thanks. I’m always trying to find good analogies. I’m going to have to go deeper on the PDO ENSO connections.

  733. Doug Bostrom:

    Tilo might want to read this:

    “If you’re looking for some button-down traditionalist who relies on so-called induction, conventional logic, and verification to arrive at what the scientific community calls ‘proof,’ then I’m afraid you’ve got the wrong guy,” said the intrepid 44-year-old rebel, who last month unveiled a revolutionary new model of atomic structure that contradicted 300 years of precedent. “But if you want your results fast and with some flair, then come with me and I’ll prove that the boiling point of water is actually 547 degrees Fahrenheit.

    What my hopelessly pedantic colleagues fail to realize is that their scientific method is just that—their method,” said Hapner, whose self-published 2004 thesis argued that matter exists in four states: solid, liquid, gas, and powder. “After all, would a chemist who closely observes a phenomenon, formulates a hypothesis, predicts a likely outcome, and then tests the hypothesis be capable of proving that photons, far from being subatomic particles, are actually the size of a child’s fist?”

    It’s true that I’ve been condemned and ridiculed by the world’s most prominent chemists, as well as by a good number of amateur hobbyists,” Hapner said as he rubbed a balloon on his head to demonstrate a basic principle of hydrodynamics. “But then, wasn’t Einstein ridiculed when he unveiled his theory of relativity, or Copernicus when he posited that the Earth revolved around the sun? True, I have since proved them both wrong, but at least they took risks.”

    http://www.theonion.com/content/node/49180

  734. Timothy Chase:

    I had written above in 723:

    Regardless, global temperature typically lags ENSO 4-6 months.

    … but I wanted to check this as it had been a while since I had read this — and also wanted to prive a reference.

    The figure appears to be 6 months:

    Following an El Niño the global surface air temperature typically warms up by perhaps 0.1°C with a lag of ~6 months [Newell and Weare, 1976; Pan and Oort, 1983; Jones, 1989; Wigley, 2000]. In an exceptional event such as the 1997–1998 El Niño the amount exceeds 0.2°C. Christy and McNider [1994] and Angell [2000] show that the entire troposphere warms up with an overall lag of 5–6 months, but the lag is slightly less in the tropics and is greater at higher latitudes. Consequently, the empirical evidence suggests a strong diabatic component to El Niño–Southern Oscillation (ENSO).

    Kevin E. Trenberth etl al. (24 April 2002) Evolution of El Niño–Southern Oscillation and global atmospheric surface temperatures, Journal of Geophysical Research, Vol. 107, No. D8, 10.1029
    http://www.cgd.ucar.edu/cas/papers/jgr2001b/jgr2.html
    http://www.cgd.ucar.edu/cas/papers/2000JD000298.pdf

    However, there is the suggestion that a rise in temperature actually drives ENSO with a lag time of about 5 months:

    Figure 2a shows the cross-correlation between SOI and the ΔT/Δt function (for Δt = 1 month) for positive lags (SOI leads ΔT) and for negative lags (ΔT leads SOI). Two important points come out of this analysis. First, there is a peak at about lag = -5 months with positive correlations and a peak at about lag = +11 months with negative correlations.

    Tsonis, A. A., J. B. Elsner, A. G. Hunt, and T. H. Jagger (2005), Unfolding the relation between global temperature and ENSO, Geophys. Res. Lett., 32, L09701

    … but this is refering to a smaller “fluctuation”:

    Second, the positive correlations in Figure 2a when ΔT leads SOI indicate that positive (negative) temperature fluctuations precede El Niño (La Niña) development. At the same time, the negative correlations when SOI leads ΔT indicate that El Niño (La Niña) relate to future negative (positive) temperature tendencies. This suggests that a positive (negative) global temperature tendency triggers an El Niño (La Niña), which ultimately reverses the tendency.

    ibid.

    …Where it is the release of the heat to and spread of the heat over the ocean surface which further heats the troposphere:

    True enough (as we show in Figure 1) once an El Niño is initiated and warm water spreads over a significant portion of the planet, the global mean temperature will increase (also as mentioned above other mechanisms contribute to this warming). Thus, initially the role of El Niño is to support the positive tendency.

    ibid.

  735. Hank Roberts:

    http://arctic.atmos.uiuc.edu/cryosphere/multiyear.ice.quikscat.mov
    2007
    “… Multiyear sea ice is older and generally thicker ice – sea ice that has survived at least one melt season (shown in brighter white).”

    Not thicker at the middle.

  736. Phil. Felton:

    Tilo Reber says:
    5 January 2010 at 8:18 PM
    dhogaza:
    “Yes, as I said above (and Tilo more or less laughed at), Tilo is ignoring currents and winds.”

    No laughing dhogaza. I believe that the ice moves around to some extent. But I still need an explanation for why that means the thin ice wouldn’t melt completely and as a result why thinning wouldn’t also reduce area. Take a look at a chart like this:

    http://igloo.atmos.uiuc.edu/cgi-bin/test/print.sh

    See the green ice. It is around the edges. See the darker red ice, it’s generally closer to the center. As you watch the change through the year the ice on the outside will grow last and disappear first. The stuff around the edges will melt before the stuff in the center. Again, it’s not perfect, but it does follow that pattern. The currents can also change this to an extent. But the pattern is still similar.

    But why show us 30yr old data, here’s the current data: http://arctic.atmos.uiuc.edu/cryosphere/NEWIMAGES/arctic.seaice.color.000.png

    Here’s the moving ice: http://i302.photobucket.com/albums/nn107/Sprintstar400/Drift.png

  737. Timothy Chase:

    Steve Bloom wrote in 720:

    … there’s no particular reason to think that the PDO drives much of anything. Tilo and friends don’t understand what it is, so for them it’s become kind of a climate hope chest to drop all their fears into (sorry, Tilo’s rhetorical excesses are inspiring me). Plus of course “Pacific Decadal Oscillation” sounds important.

    Actually the Pacific Decadal Oscillation is fairly important in the North Pacific. But during the warm phase of the Pacific Decadal Oscillation the North Pacific is predominantly cold. We call it the “warm phase” of the Pacific Decadal Oscillation because there is a warm sliver of water along the US Pacific Northwest — but what’s in a name?

    Please see:

    Is Pacific Decadal Oscillation the Smoking Gun?
    Saturday, 3 May, 2008
    http://www.skepticalscience.com/Is-Pacific-Decadal-Oscillation-the-Smoking-Gun.html

    So “skeptics” get fooled twice when they assume that the oscillation must be important since it has the words “Pacific” and “Decadal” in its name — and then they get fooled again when they try to argue that it is the “warm phase” of the oscillation that is driving global warming.
    *
    Steve Bloom wrote in 729:

    The review I linked to describes attempts to establish whether the PDO significantly drives or even significantly affects the adjacent components of the climate system, the short answer being that it mostly doesn’t. That’s in sharp contrast to ENSO, which affects things at great distances and directly influences the global temperature trend. ENSO is as powerful as it is because it’s driven by heat accumulation and loss from the West Pacific warm pool, which is one hell of a driver.

    As for ENSO driving PDO, you might also want to check:

    Matthew Newman et al. (1 Dec 2003) ENSO-Forced Variability of the Pacific Decadal Oscillation, Journal of Climate, Vol. 16, No. 23 (here)

    Just curious… would the importance of ENSO contrasted to PDO in climate variability be partly due to water vapor partial pressure being an exponential function of temperature? A difference of one degree Celsius in the tropics will mean a great deal more water vapor than a difference of one degree in the cold North Pacific — although it might be a little hard to see this living in the Pacific Northwest, warmed by the Japanese current.

  738. Barton Paul Levenson:

    TR: Take Michaels point about not making the assertion that global warming has stopped. I’ve never made that statement. My statement is that there hasn’t been any since 1998.

    BPL: Your statement is wrong. Not a different point of view, not a clever new take on things, not a brilliant contrarian idea. Just flat-out dunce-cap wrong. As has been pointed out to you over and over and over and over and over again on many climate blogs over the past several years.

    Stop it with the Big Lie technique, okay?

  739. Barton Paul Levenson:

    1870 13.37 University of Illinois Sea Ice Dataset
    1871 13.44 million square km
    1872 13.40
    1873 13.56
    1874 13.50
    1875 13.46
    1876 13.44
    1877 13.57
    1878 13.47
    1879 13.44
    1880 13.52
    1881 13.79
    1882 13.73
    1883 13.53
    1884 13.60
    1885 13.47
    1886 13.39
    1887 13.25
    1888 13.54
    1889 13.48
    1890 13.50
    1891 13.62
    1892 13.59
    1893 13.48
    1894 13.45
    1895 13.58
    1896 13.47
    1897 13.35
    1898 13.25
    1899 13.42
    1900 13.46
    1901 13.39
    1902 13.47
    1903 13.24
    1904 13.20
    1905 13.21
    1906 13.34
    1907 13.23
    1908 13.30
    1909 13.35
    1910 13.53
    1911 13.62
    1912 13.60
    1913 13.62
    1914 13.47
    1915 13.39
    1916 13.61
    1917 13.82
    1918 13.73
    1919 13.49
    1920 13.37
    1921 13.42
    1922 13.34
    1923 13.20
    1924 13.37
    1925 13.12
    1926 13.43
    1927 13.49
    1928 13.47
    1929 13.49
    1930 13.20
    1931 13.17
    1932 13.36
    1933 13.12
    1934 13.79
    1935 13.67
    1936 13.40
    1937 13.51
    1938 13.24
    1939 13.45
    1940 12.99
    1941 13.60
    1942 13.61
    1943 13.56
    1944 13.53
    1945 13.48
    1946 13.79
    1947 13.60
    1948 13.76
    1949 13.94
    1950 13.78
    1951 13.85
    1952 13.90
    1953 13.30
    1954 13.32
    1955 13.33
    1956 13.47
    1957 13.20
    1958 13.10
    1959 13.46
    1960 12.91
    1961 13.08
    1962 13.16
    1963 13.50
    1964 13.35
    1965 13.39
    1966 13.29
    1967 13.03
    1968 13.28
    1969 13.51
    1970 13.28
    1971 13.17
    1972 13.39
    1973 12.93
    1974 12.88
    1975 12.95
    1976 13.15
    1977 13.00
    1978 13.05
    1979 12.45
    1980 12.54
    1981 12.42
    1982 12.80
    1983 12.61
    1984 12.28
    1985 12.44
    1986 12.45
    1987 12.65
    1988 12.56
    1989 12.45
    1990 12.11
    1991 12.20
    1992 12.45
    1993 12.26
    1994 12.37
    1995 11.89
    1996 12.07
    1997 12.07
    1998 12.41
    1999 12.40
    2000 12.14
    2001 12.34
    2002 12.13
    2003 12.14
    2004 11.90
    2005 11.65
    2006 11.49
    2007 10.33

    Going up or going down, Tilo? Or staying the same?

  740. Bryan S:

    Gavin,

    I have taken a little time this morning to refresh myself on the ocean heat content data that you show. Obviously, there are still some unresolved issues remaining with the correction of the XBT warm bias. Consider the Dominguez et al (2008) reconstruction. Near the end of their series in 2001, they showed a heat content of approximately 9X10^22 Joules. This compares to the Levitus (2009) curve which shows only 5.8X10^22 Joules.

    [Response: These are anomalies to possibly different baselines. They are not commensurate. - gavin]

    Now, if I splice the Argo data since 2005 onto the end of the Dominguez reconstruction, and compare to the GISS model E ensemble mean (extrapolation) from your posted diagram, it is quite evident that the rate of heat uptake in the GISS-ER ensemble mean far exceeds the rate of heat uptake inferred from the observed ocean heat content trend time series since around 1995. If the Dominguez data set is accurate, then the net radiative imbalance implied by GISS-ER over the time period since 1995 is too high. There is also something I don’t understand which is going on between what you show as the GISS-ER ensemble mean, and the GISS-ER runs shown in the Dominguez paper. Although the radiative imbalance looks about the same over the time period since 1995, the heat content in your latest post is shifted downward relative to the data posted in Dominguez, and yours better matches the Levitus data set. Can you describe what the reason for the difference between your latest post and GISS-ER data shown in the Dominguez paper? I suspect that the importance is not the absolute values of OHC, but rather the rate of change over time (TOA radiative imbalance).

    Now, if we look at the larger AR-4 spread shown in Dominguez (2008), things look even more curious, when we splice onto the tail of Dominguez’s plot the recent OHC data since 2005 (as shown in Levitus, 2009). In this plot, it becomes quite obvious that over the last 15 year period, the ocean is accumulating heat far below the rate implied by the multi-model ensemble mean. (Incidentally, I estimate that over the last 15 years, the rate of heat uptake by GISS-ER is about the same as the larger AR-4 multi-model ensemble mean.)

    Although the match with the Levitus data that you show looks good now, with the net radiative imbalance implied by extrapolating the GISS-ER into the future, a very large delta will quickly develop between the model ensemble mean and observations, unless there are some very large upward step changes in the observed ocean heat content in the next several years. Time will tell.

  741. Tilo Reber:

    Steve Bloom:
    “Do you have a reading comprehension problem?”

    No, but you seem to have a topic comprehension problem. I never claimed that there were not assertions in the literature that ice thinning was happening; so why bother me with links to information that I’m already aware of. My argument is that the thinning claims are difficult to believe without a corresponding shrinkage of sea ice area. Now if you can provide me with a link that can explain the physical process of having the ice thin without the area shrinking then give it to me. Also tell me that is what it is, because I have no interest in reading a lot of irrelevant links.

  742. Tilo Reber:

    Timothy Chase:
    “Regardless, global temperature typically lags ENSO 4-6 months. If ENSO continues through the spring and the sun continues to become more active…”

    Gavin:
    “If the current El Niño event continues into the spring, we can expect 2010 to be warmer still.”

    I always find it interesting that people who are warning us of temperature rise at the same time seem to be praying for that temperature rise.

    [Response: Don't be stupid. My statement is purely factual (and correct) and my desire not to have significant climate change far outweighs my desire to be proven correct in forecasting it. - gavin]

    Anyway Timothy, the lag time is closer to 3-4 months. At least that is what I found from looking at the data. Comparing this table:

    http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ensostuff/ensoyears.shtml

    with the temperature record. Hansen states 3 months. Tamino is using 4 for his ENSO correction.

    If we are in fact peaked out on this El Nino, then between the wind down and the lag we will probably get noticable effects through mid summer. I don’t know if that will be enough to make 2010 special for the AGW people. We will have to see.

  743. Tilo Reber:

    Didactylos: #728
    “Instead, consider ice age for a moment.”

    Why would I consider ice age. If we take one cubic meter of ice that is at a certain temperature and is one year old and if we take another cubic meter of ice that is at the same temperature but is 2 years old, then are you saying that one will take more heat to melt than another. If that is not what you are saying, then I don’t care what the age is. If your only point is that older ice is thicker, then I still don’t care how old it is because the only thing that is still relevant is the thickness.

    “Now, due to thermodynamics that are beyond my power to explain, it does not follow that a warm Arctic means thinner than normal single year ice.”

    If you are saying that ice formation is independent of temperature, then why doesn’t it extend further south. Especially if all of the Arctic is “so mind numingly cold”. Too bad it’s beyond your power to explain. Because without an explanation I’m not going to believe it.

    Didactylos:
    “Claiming that ice extent is “recovering” is as daft as claiming that global temperature is “cooling”.”

    Let’s be clear on the claim here. I’m claiming that there was a slight recovery in the sea ice area since 2007. If you want to argue that point, then we can. Let’s not pretend that the argument is about something that I didn’t say. It’s very easy to beat your own strawmen. I’m not making claims beyond 2009. What I am saying is that the temperature has flattened. I don’t know if it will continue to be flat, but IF it does, then what I am saying is that what has happened in the last two years may be an indicator of a stabilization starting in the sea ice. And I have said that we will need more time to be able to tell. Charts that show sea ice decline up to 2007 are pointless since I am not questioning them. The only question that I have in that regard is the shortness of the satellite record. I don’t think that we can say from that record what normal variability is.

  744. Tilo Reber:

    Barton:
    Going up or going down, Tilo? Or staying the same?

    That’s a lot of wasted space, Barton; epecially considering that I only said that the ice has recovered slightly since 2007 and since you stop at 2007. See my response to Didactylos to see what I am claiming. I know that everyone here is extremely excited about ice are shrikage up to 2007. But unfortunately you cannot transfer your excitement to the debate, since I am not doubting it.

  745. Rob:

    Gavin,
    could you please attend to 541? Thanks.

    Here’s a copy for convenience:

    What would the output of the GCMs look like if there were no CO2 increase? Any links to a graph? thanks!

    [Response: Assuming you mean no forcings of any kind, then the ensemble mean would be flat, but you'd still see excursions of the same magnitude as the grey bands above. - gavin]

    No, I mean just without an increase in CO2, all others stay the same. Thanks. (Sorry for the delayed follow-up, forgot I asked…)

    [Response: For the period shown in the graphs? You'd see a slight decline over time in the mean. See figure 9.5b in IPCC. - gavin]

  746. Tilo Reber:

    JasonB:
    “And you’ve missed the point — unless you think ENSO is the only thing that affects variability?”

    No, you’ve missed the point. The debate around the slope of the trend since 2008 is mostly centered around ENSO. The 98 El Nino and the 2008 La Nina. So let’s get that removed. There hasn’t been much volcanic activity, so we don’t need to worry about that. Then we will have a trend line that we can talk to. If that trend line is still relatively flat, then we need an explanation about what other elements of variation are suppressing the supposed signal. If it is relatively flat and we cannot identify the natural elements of variation that are responsible, then the IPCC climate sensitivity number is in big trouble.

    JasonB:
    “but why do you assume something magical about starting in 1998?”

    I’m not sure why you have trouble understanding that. I want to know, what is the period of time during which we have not followed IPCC predictions. That is something that you don’t want to know apparently. I could use dates before then, but I’m not arguing the fact that the temperature was rising before then – so why should I. I could use dates after then, but that would not answer the question that I want to ask.

    “No, you want to use ENSO corrected data because you believe it will show a flat trend on your favourite data set.”

    No, having a favorite data set is your problem and Tamino’s problem. I’m willing to accept one of three ENSO corrected data sets.

    “Just how do you think Tamino created the ENSO-corrected data that you’re so desparate for?”

    We were talking about his claim for significant time periods, not his ENSO charts. I believe that his ENSO chart for GISS is probably about right. If you read the rest of what I said that should have been obvious.

    “Doesn’t seem like a huge disconnect to me.”

    It’s not relevant to the discussion. I was talking about the divergence since 1998. My charts back that up. I was not talking about comparisons between the 90s and the 00s.

    JasonB:
    “What you seem to be saying is that if Tamino or someone else did what you are clearly unwilling to do yourself and produced an ENSO-corrected HadCrut data set, you would dismiss it immediately if it didn’t show what you wanted it to show”

    I’m really not interested in your speculation about my motives. If you go back and look you will see that I asked Gavin to update his ENSO corrected HadCrut3 and failing that to give me the algorithm so that I could do it myself. And I offered to share the results, regardless of what they were.

  747. Steve Bloom:

    Re #737: Thanks for the additional PDO info, Timothy. This post from Atmoz (found via your Skeptical Science link) is also informative. The upshot:

    “(T)he mode of variability known as the PDO has the same spatial and temporal characteristics as the mean global surface temperature anomaly. PDO doesn’t cause global warming, the PDO is global warming. (Insert all the caveats of PCA; statistical relationship not causal, linear, etc.) One reason that the time series of the PDO may look so noisy compared to the time series of the mean surface temperature anomaly is simply because it has less area, and therefore less data.”

    This is non-expert handwaving, but I think the answer to your question is that ENSO and the PDO are qualitiatively very different. El Ninos push up global temperatures in the short term by taking a bunch of hot West Pacific warm pool water and distributing it out across the ocean surface where it is relatively quickly lost to space, thus the very real impact on gloabl climate. The PDO does nothing of the sort.

  748. Steve Bloom:

    Re #741: As you would know if you actually paid attention to the nice observations, Tilo, older (and thus thicker) ice accumulates in a gyre, the contents of which have been preferentially flushed out through the Fram Strait in recent years.

  749. Tilo Reber:

    Phil:
    “But why show us 30yr old data, here’s the current data:”

    Just lazy I guess. It’s the first thing you get when you go to the page. But thanks for the update.

  750. Ray Ladbury:

    Tilo, the satellite data are particularly susceptible to ENSO, so it is unlikely that the MEI would adequately compensate for the effect. I would say that in a period where El Nino is important, it is probably important NOT TO USE UAH or RSS.

  751. Completely Fed Up:

    “744
    Tilo Reber says:
    6 January 2010 at 12:36 PM

    Barton:
    Going up or going down, Tilo? Or staying the same?

    That’s a lot of wasted space, Barton;”

    Which is called “dodging the question”.

    Note: there is no actual space on the internet. So it isn’t wasted.

    “See my response to Didactylos to see what I am claiming.”

    He didn’t ask what you were claiming. He asked “up, down or steady”.

    Which is it?

  752. Doug Bostrom:

    “If you go back and look you will see that I asked Gavin to update his ENSO corrected HadCrut3 and failing that to give me the algorithm so that I could do it myself. And I offered to share the results, regardless of what they were.”

    How’s that going? Assuming Gavin is not going to do the work for you, that is?

  753. Doug Bostrom:

    “My argument is that the thinning claims are difficult to believe without a corresponding shrinkage of sea ice area.”

    Why not go to “the thinning claims” and identify how they’re wrong?

    In any case, unless you’re completely blind or just plain obdurate, you can see that ice extent has been shrinking, so your fundamental premise appears pretty stupid. You’re arguing for something that is plainly not in evidence.

    Meanwhile, since you’re so demanding, here’s a demand in turn: you speculate that the multi-decade decline in extent may have arrested itself. How? Why?

    What a waste of disk space this has become.

  754. Susan:

    Barton Paul,
    I’m not Tilo, but from other charts I’ve seen, 2009 sea ice coverage looked a lot like 2004-2005. Given the uncertainties in deriving the numbers you’ve provided by the university of illinois( the university certainly wasn’t collecting data on sea ice extent in 1870 or the earlier 1900′s was it, and to the same precision as satellite data?) Isn’t it safest scientifically speaking to say “Staying the same”?

  755. FurryCatHerder:

    Tilo @ 666:

    Before you go off on the shortness of the period, remember that I also said this in 628. “But the recent stabilization of the Arctic and Antartic sea ice area makes me think that we may be right on the border of how much melt we are going to get – at least at this temperature. I think we’ll need a few more years to be sure. ”

    I’d suggest you plot peaks-to-peaks and troughs-to-troughs and see what that tells you. What it should tell you is that we’re losing ice extent on a trending-downwards cycle. Part of why I’m confident that 2010 will see an increase in minimum extend (more ice at the bottom, not more non-ice) this year is because there’s a solid track record of a multi-year recovery to a near-term high after a record low, followed by a return to the decline, a fresh record low, not-quite-complete-recovery, new low, etc.

    So … 2010 will have some “recovery”, but at some point in the future, 2010 will be above any other year’s recovery. Unless we quit it with all this CO2 stuff.

    Also, get all excited about increases in Antarctic ice really doesn’t bode well. The north and south poles are not equivalent. Yes, they are cold, but one is LAND and the other is SEA.

  756. davidmhoffer:

    Since the original topic was revisiting models I did just that. I was looking at Aono/Amoto 1994 temperature reconstruction for Kyoto which was one of the first hockey stick graphs. It has a very accidental… but huge… error that totaly skews the graph. I would love to get in touch with Aono to discuss. In the meantime I’ve posted an analysis and corrected reconstruction here http://knowledgedrift.wordpress.com/category/knowledge-drift-and-the-climate-debate-how-ancient-calendars-caused-global-warming/

    [Response: Interesting, but unfortunately you are almost certainly wrong. The Gregorian calendar didn't reach Japan until 1873 and previously they would have used there own luni-solar dates based on old Chinese calendars. The authors must therefore have had to have conversant in the translations between calanders and your supposition that they weren't is not supportable without some actual evidence. - gavin]

  757. Doug Bostrom:

    FurryCatHerder says: 6 January 2010 at 3:31 PM

    “So … 2010 will have some “recovery”, but at some point in the future, 2010 will be above any other year’s recovery.”

    That’s it, in a nutshell, as brief scrutiny of data reveals.

    “Also, get all excited about increases in Antarctic ice really doesn’t bode well.”

    Hah! Another isolated “weather” observation, but they just found Mawson’s ill-fated aircraft in Antarctica. Left on the ice in 1914, still on the ice in 1931, still there in 1975, now just discovered at low tide where it was sitting on the bottom having apparently been dropped by the ice at some point. Moment of discovery:

    “Tony Stewart, the [Australian expedition] field leader, said: “The carpenter just ambled in and said, ‘I think I might have found the air tractor,’ like he’d just picked up a newspaper at the local store. You haven’t seen us move so quickly in a long time.”

    “It was part of the fuselage of the historic plane, exposed by a blue moon (the second full moon in a calendar month), the lowest tide ever recorded at that site and an unprecedented melting of ice.”

    Is it weather, or climate? Interesting story, in any case:

    http://www.independent.co.uk/news/world/australasia/antarctics-first-plane-found-in-ice-1856789.html

  758. Didactylos:

    I’m claiming that there was a slight recovery in the sea ice area since 2007.

    And that’s your problem. You don’t understand why this is ludicrous, in the same way you don’t understand why your other complaints don’t compute. There are countless explanations of why you are wrong, from me and many others. I’m not sure you bothered to read them all, but it is painfully clear that you don’t understand any of it.

    Should we continue to waste our time? You are clearly out of your depth. This isn’t your fault, but it would help if you could recognise the fact and stop trying to swim unaided.

    Ask for help. It is the only way to make progress.

    I want to say more, but I honestly don’t think you will pay any attention.

  759. Hank Roberts:

    > Isn’t it safest scientifically speaking to say
    > “Staying the same”?

    Nope. If it were they would, but as it isn’t, they aren’t.

    You don’t need “brick moon” satellites from the 1800s or deep time to figure out when a polar sea was ice-covered; the animals and plants that live under ice make very different sediment layers than the animals and plants that live in open water, and sediment layers are well studied.

    http://www.google.com/search?q=sediment+core+ice+open+water

  760. dhogaza:

    Stabilization of Arctic sea ice?

    Right on the 3% annual decline for extent…

  761. Didactylos:

    Susan said:

    2009 sea ice coverage looked a lot like 2004-2005.

    It’s good that rational questions can come out of even the most pointless of discussions. Susan, with ice, just as with temperature, we need to look at a longer period than 5 years to see the trend. With just 5 data points, you will only see noise. They could be any value at all, and you would still be able to infer nothing from them.

    Fortunately, we have a lot more than 5 years. http://maps.grida.no/go/graphic/minimum-arctic-summer-sea-ice-extent

    So, Tilo wants to pretend there has been a “recovery” since 2007. That’s nonsense. After an extreme value like 2007, it is completely unsurprising that following values are closer to the trend line. If we called it a recovery after every minimum, then we would have a lot of recoveries!

  762. Matthew:

    722, Greg C. Thank you for the programming tip. It confims my recent decision to start using Python. For I have Numerical
    Recipes in both Fortran and C.

  763. Hank Roberts:

    PS for Susan, from the search I suggested above, these may be helpful. If you have been reading something that contradicts what you find here, please say where you read it.

    http://beyondpenguins.nsdl.org/issue/column.php?date=May2009&departmentid=field&columnid=field!researcher

    Mentions the author of the sea ice section of this report:
    http://www.climatescience.gov/Library/sap/sap1-2/final-report/

    There’s much more at that Google search and you can certainly improve on it; pick appropriate key words to add, and of course try Scholar

  764. Completely Fed Up:

    Susan, have a look here:

    http://www.youtube.com/watch?v=2nruCRcbnY0

  765. davidmhoffer:

    [Response: Interesting, but unfortunately you are almost certainly wrong. The Gregorian calendar didn't reach Japan until 1873 and previously they would have used there own luni-solar dates based on old Chinese calendars

    PRECISELY! As the Gregorian calendar had been in use in Japan since before Aono/Amoto were born, they would not have been familiar with its history. Conversion from luni-solar dates would have relied on counting the number of days from the winter solstice, a methodology they would have developed in their initial research. As they worked backward in time using that method, they would not have known that the winter solstice that had occured on Dec 22 for the first 400 years of their data suddenly jumped to Dec 12 in 1582AD. They would have continued to use the same off set from the winter solstice that they had always used.

    If someone has a way to get in touch with the researchers (I have been trying) I would be eager to discuss with them. In the meantime, the corrected graph oscillates in tandem with the European MWA and LIA, suggesting that my correction is valid.

    [Response: This makes no logical sense. The conversion of the Japanese calendar to Gregorian has no relationship to the Julian calendar at all. Nothing special happens in 1583 and so your fix is meaningless. - gavin]

  766. davidmhoffer:

    The point is that there WAS no Gregorian calendar to convert TO! It didnt START until Oct 15, 1582. The day before that was Oct 4, 1582. [edit]

    [Response: Now you are being ridiculous. The bloom date is being presented in the Gregorian calender consistently throughout the paper. You can convert any date from old-style or Japanese-style to a Gregorian calender date regardless of whether you are before or after 1583, or whether anyone in the world used that calendar at the time. - gavin]

  767. Hank Roberts:

    Davidmhoffer: Google Scholar.

    http://scholar.google.com/scholar?sourceid=Mozilla-search&q=climatic+reconstruction+Japan+calendar

    finds, for instance:

    http://www.cfa.harvard.edu/~wsoon/MiyaharaHiroko08-d/AonoKazui07-Aug23-KyotoSpring.pdf

    [PDF] … of cherry tree flowering in Kyoto, Japan, and its application to reconstruction … Y Aono, K Kazui – International Journal of Climatology, 2008 – cfa.harvard.edu
    … Phenological data from the instrumental period were calibrated using springtime temperature observations, and then data from the historical period were used to reconstruct climate changes. … In this study, the dates, according to the Japanese lunar calendar, on which …

    Cited by 13:
    http://scholar.google.com/scholar?cites=3858062092740034921&hl=en&as_sdt=2000

  768. Doug Bostrom:

    davidmhoffer says: 6 January 2010 at 7:30 PM

    Another eureka moment bites the dust. Still, it was an innovation and you should be proud of at least thinking of it.

  769. Bryan S:

    Gavin,

    OK. The baselines are indeed slightly different in these two series.

    Let me go at this in a more precise way. The extrapolation of the GISS-ER ensemble mean shows an average estimated heat uptake of around 0.7X10^22 Joules per year from 1995 to present. However, when I use the Dominguez data up to 2003, then splice the Argo data since 2003 (adjusted for the baseline*) onto the end of the series, the rate of warming is only around 0.4X10^22 Joules per year (about the same as their long term increase since the 1960’s).

    [Response: I don't think that is valid. There is considerable overlap in the period 2001 to 2005 as the Argo program ramped up and having that data assimilated consistently is important. You can't simply graft on the anomaly from one analysis on to the other. I think we will just have to wait for the Domingues group to do that properly. - gavin]

    This rate of heat uptake is *considerably less* than the extrapolation of the GISS-ER ensemble mean, or an extrapolation of the AR-4 ensemble. In the interest of education, it would be great if you include the GISS model output after 2003 plotted to the same baseline as the Dominguez series (updated with the adjusted Argo data after 2003) and show this. I constructed a cursory plot of this myself, and the results are quite interesting. It looks like the models suggest an average radiative imbalance over the last 15 years that is significantly higher than indicated by the updated Dominguez series (please check). Regardless whether we look at Levitus or Dominguez though, the point remains that the next 5-10 years will be very telling on whether the models are accurately representing the net TOA radiative imbalance, especially since is becoming more clear that the decadal variablity is not as high as previously believed. Going forward, nearly all the individual realizations that I see never produce a single year without a significant gain of heat, short of a major volcanic eruption. I’m just hoping we don’t have another big eruption, since this would surely introduce some ambiguity into the picture.

    All who are interested, please look at figure 2 in Dominguez et al (2008) for more background. This is the plot that I have tried to update.

  770. Hank Roberts:

    > davidmhoffer says: 6 January 2010 at 7:30 PM
    > … Oct 15, 1582. The day before that was Oct 4, 1582.

    “… September 2, 1752 was followed by September 14, 1752. The English people were furious at the change “give us back our 11 days” was the popular cry at the time.”
    http://www.the-kingdom.ie/news/story/?trs=cwaumh

  771. Kevin McKinney:

    My, Tilo, you are a prolific poster, to be sure.

    Perhaps you can explain to me why you persist in arguing from first principles in the teeth of observations?

    Had you looked at some of the links given, you’d see that there is clear observational evidence that, indeed, multiyear (ie, thick) ice can decline quasi-independently of extent. So what’s the point of arguing it “can’t” happen? It can, and it has.

    More helpful–I mean, helpful to you–would be the question of where your logic fails. Certainly you’ve had a lot of folks trying to help you out. . .

  772. JCH:

    Just curious. It appears to me the arctic has a lot of ice limiting shoreline. Hasn’t the ice extent record has been constrained versus the temperature record?

  773. Hank Roberts:

    > the arctic has a lot of ice limiting shoreline.
    > Hasn’t the ice extent record has been constrained …

    Well, the Antarctic does too, in reverse, eh?

    Sea ice, fixed ice, grounded ice, icebergs, cap ice, thickness, age, density, composition — and I’m sure a real scientist can list far more things to watch.

  774. dhogaza:

    Just curious. It appears to me the arctic has a lot of ice limiting shoreline. Hasn’t the ice extent record has been constrained versus the temperature record?

    It certainly limits the maximum winter extent. If you look at current maps, such as this one, you’ll see that the landlocked portions of the arctic sea are already frozen up to land.

  775. RaymondT:

    Gavin, In the WCC3 presentation by Mojib Latif in Geneva last September he showed that hurricane activity and Sahel rain can be tracked to variations in Atlantic sea surface temperature. He then asked: how much of the decadal NAO variability is forced by changes in boundary conditions ? Since one of those boundary conditions is the radiative forcing due to an increase in CO2 my question is then how much influence does global warming due to CO2 increase have on NAO variability ?

    [Response: Do you mean NAO (North Atlantic Oscillation - defined as the pressure difference between Iceland and the Azores) or the AMO (Atlantic Multidecadal Oscillation - defined from the detrended Atlantic sea surface temperatue)? Depending on the answer, the response is different - there is some evidence that the NAO will move into a more positive phase (on average) in a higher CO2 world, for instance, The AMO is trickier since any departure from linearity in the response to all forcings will affect the AMO 'index' simply because of how it is derived. - gavin]

  776. RaymondT:

    Gavin, Thanks for your reply. You mentionned that “there is some evidence that the North Atlantic Oscillation NAO will move to a more positive phase (on average) in a higher CO2 world”. Where could I find this evidence ? Thanks to your excellent web site I have been more and more convinced that the radiative forcing due to CO2 explains best SO FAR the trend in increasing global temperatures. I am less convinced however of the effect of the gentle ALTHOUGH PERSISTENT increase in global temperatures due to AGW on the occurence of extreme climate events. What is the link between the radiative forcing due to CO2 and the number and intensity of el-nino or la-nina events for example ?

  777. David B. Benson:

    RaymondT (776) — Two papers in “Ocean Circulation and El Nino: new research” assert that global warming is likely to lead to more frequent El Nino events.

  778. Ernst K:

    Monthly SOI index data:

    http://www.cgd.ucar.edu/cas/catalog/climind/SOI.signal.ascii

    It shows a weak, far from statistically significant, downward trend (El Nino events occur when the SOI is low).

    If you plot a 20 year+ moving average you’ll see that there was no trend at all until about the 1960s.

    CO2 radiative forcing, obviously, has a very strong statistically significant positive trend.

    Certainly interesting, but I wouldn’t hazard to anything stronger given all the noise in the SOI data.

  779. Barton Paul Levenson:

    TR,

    Who the hell cares what it’s done since 2007? It’s 2010, TR, 3 years later. Go CHART the numbers I gave you and tell me whether it’s done anything similar before–and how many times. It jogs up and down. The TREND is still down.

  780. Barton Paul Levenson:

    TR: The debate around the slope of the trend since 2008…

    BPL: Repeat after me:

    You need 30 years to find a climate TREND.
    You need 30 years to find a climate TREND.
    You need 30 years to find a climate TREND.

    Repeat it until it starts to sink in.

  781. Barton Paul Levenson:

    Susan: Given the uncertainties in deriving the numbers you’ve provided by the university of illinois( the university certainly wasn’t collecting data on sea ice extent in 1870 or the earlier 1900’s was it, and to the same precision as satellite data?) Isn’t it safest scientifically speaking to say “Staying the same”?

    BPL: No. The “safest” thing to do scientifically is to go with the data. And whether the University of Illinois was collecting data on ice extent in 1870 or not, locals on land and sailors at sea certainly were. Do you think UI just pulled those numbers out of its blogs?

  782. Hank Roberts:

    Googled:
    http://www.google.com/search?q=North+Atlantic+Oscillation+NAO+will+move+to+a+more+positive+phase+(on+average)+in+a+higher+CO2+world

    Found, among others, in the first page of results:

    http://insciences.org/article.php?article_id=1384
    (Appears to be a press release, or written from one)

    Illustration from Woods Hole:
    http://www.whoi.edu/page.do?pid=7545&tid=441&cid=85378&ct=61&article=54686

    “The research team found the variability of the NAO decade-to-decade (multi-decadal scale) has been larger, swinging more wildly, during the late twentieth century than in the early 1800s, suggesting that variability is linked to the mean temperature of the Northern Hemisphere. This confirms variability previously reported in past terrestrial reconstructions.

    “When the Industrial Revolution begins and atmospheric temperature becomes warmer, the NAO takes on a much stronger pattern in longer-term behavior,” said Goodkin. “That was suspected before in the instrumental records, but this is the first time it has been documented in records from both the ocean and the atmosphere.”

  783. RaymondT:

    @777 David B Benson, 778 Ernt K and 782 Hank Roberts, Thanks for your replies. How frequent are El Nino and why ?

  784. Tilo Reber:

    As much fun as it was talking to all of you, I decided to take a break and plot the RSS and UAH data from 1998, since they are now available to the end of 09. This gives us 12 full years. Here are the results.

    http://3.bp.blogspot.com/__VkzVMn3cHA/S0a9K-nTbYI/AAAAAAAAAFw/oWOaPsw2J6k/s1600-h/Twelve+Year+Satellite+Trend.bmp

    When skeptics say that it hasn’t warmed since 1998, this is what they mean. We can argue the significance, but we cannot argue the basis for their claim. By the way, for those of you who claim that it is due to the large El Nino at the start, look at the effect of the 2 year long La Nina that followed only 3 month after that El Nino. The effect on the slope by the two events is that they basically cancel each other out.

  785. CTG:

    As much fun as it is watching you rebunking the “flat since 1998″ myth, Tilo, when will you stop cherry-picking and accept that these short-term trends are meaningless with respect to climate.

    Have a look at this.

    Three trends in the UAH data of exactly the same length, the only difference being the start and end date of each trend.

    Two are positive, one is negative. Which is the one that you claim is significant? Surprise, surprise – the one starting with 1998.

    Do you really think that if you just keep on endlessly repeating “the world has been cooling since 1998″ that it will magically come true?

  786. Barton Paul Levenson:

    Kudos to Hank for the “The Brick Moon” reference!

  787. Barton Paul Levenson:

    And here’s why Tilo’s #784 is wrong, something I’ve pointed out to him ever since he started with this claim long ago on Deltoid:

    http://BartonPaulLevenson.com/Reber.html

  788. Completely Fed Up:

    “When skeptics say that it hasn’t warmed since 1998, this is what they mean.”

    You mean “according to the CRU data which the climategate emails PROVE has been falsified it hasn’t warmed since 1998″.

    According to other data, 2005 was warmer.

    And it’s false that it hasn’t warmed:

    2000 was warmer than 1999.
    mid 2005 warmer than mid 2004.
    early 2007 warmer than early 2006.
    2009 warmer than 2008.

    So its warmed many times since 1998.

  789. skeptic:

    I wonder what that graph would look like with satellite temps (UAH & MSS).

    Just curious.

    [Response: They are different metrics, with different amounts of variability and I don't have the relevant model results at hand. - gavin]

  790. Tilo Reber:

    Barton:
    “And here’s why Tilo’s #784 is wrong, something I’ve pointed out to him ever since he started with this claim long ago on Deltoid:”

    Barton, have you noticed that it’s 2010 now?

  791. Tilo Reber:

    GTC:

    Why would you not use the last available data in your choices?

    “Two are positive, one is negative. Which is the one that you claim is significant? Surprise, surprise – the one starting with 1998.”

    First of all, I’m not making 13 year claims, I’m making 12 year claims. So 97 is irrelevant to the claims that I’m making. I acknowledge that temperatures were rising until 1998.

    Second of all, three month after the 1998 El Nino ended a two year La Nina started. The effect of these two events on the slope was to cancel each other out. Your desire to start in 1999 just puts you at the beginning of the La Nina. And that is the only reason you get the positive slope. Last year the claim that people here made against the no warming scenario also included the fact that we had a La Nina in 2008. Well, that is over and we have added an El Nino year at the end – and still there is no warming.

    But really, the whole argument about choosing a starting point relative to a given ENSO event can be settled by using ENSO corrected data. I did that last year when Gavin produced an ENSO corrected data set. Here is the result:

    http://1.bp.blogspot.com/__VkzVMn3cHA/SHLOM1k5XJI/AAAAAAAAADE/u7AlyoBk0EU/s1600-h/ENSO+Adjusted+HadCrut3v+Data.bmp

    Take a close look at that chart. You can see how much the 98 temperature was reduced due to the ENSO correction. And yet the ENSO corrected trend was still relatively flat. Also, there was only a tiny difference between the ENSO corrected trend and the non corrected trend.

    It’s time to deal with the reality that the IPCC predicted rate of temperature rise should have been .24C over that 12 years and it is simply missing. And we don’t know why, since the level of CO2 has continued to rise as quickly as ever.

    One more thing GTC, positive and negative are not in themselves the issue. The issue is “where is the .24C positive?”

  792. Jim Eager:

    Tilo Reber @784: I decided to take a break and plot the RSS and UAH data from 1998…

    Dense as a rock set in concrete.

    We know how septics get their “cooling since 1998″ meme, Tilo.

    We also know how wrong that meme is.

    [Response: More to the point it is extremely boring. Please no more on this. - gavin]

  793. Completely Fed Up:

    Tilo: “It’s time to deal with the reality that the IPCC predicted rate of temperature rise should have been .24C over that 12 years and it is simply missing.”

    Please show where the IPCC reported that 12 years will see 0.24C warming.

  794. Hank Roberts:

    RaymondT, you typed your question in the wrong little box.
    See the upper right corner of your web page? Where it says Search?

    Put your question there, and do it twice, once for searching the Site and once for searching the Web; it will look like this after you hit Enter:
    http://www.google.com/search?q=How+frequent+are+El+Nino+and+why

  795. Don Shor:

    Completely Fed Up: Please show where the IPCC reported that 12 years will see 0.24C warming.
    From the 4th Assessment via Wikipedia: “A temperature rise of about 0.2 °C per decade is projected for the next two decades for all SRES scenarios.”
    I realize that is 2007.

    [Response: Before everyone else makes the same point, you do realise these are very different statements? - gavin]

  796. Steve Bloom:

    Re #785 (CTG): I like “rebunking” very much and will use it. Re Tilo, I’ll predict that starting next year he’ll a) do a linear comparison of 1998 and 2010 to show that the temp increase isn’t statistically significant, and b) keep complaining that all the observations must be fraudulent and/or unreliable. If it’s a hot year to the point that a) doesn’t work, he’ll stick with b). Just sayin’.

  797. Completely Fed Up:

    Hey, at least Tilo thinks that the CRU data is right: it has 98 as the hottest single year.

    So he hasn’t bought in to the CRU conspiracy “Climategate”.

  798. CTG:

    Tilo asks “where is the .24C positive?”

    Here are the decadal average anomalies from GISTEMP:
    1880s -0.17
    1890s -0.3
    1900s -0.25
    1910s -0.21
    1920s -0.1
    1930s 0.01
    1940s 0.06
    1950s -0.02
    1960s -0.04
    1970s 0.02
    1980s 0.26
    1990s 0.39
    2000s 0.62

    So the 2000s are 0.23°C warmer than the 1990s.

    Does that answer your question, Tilo?

  799. Don Shor:

    [Response: Before everyone else makes the same point, you do realise these are very different statements? - gavin]

    Statement one: the IPCC predicted rate of temperature rise should have been .24C over that 12 years
    IPCC report: A temperature rise of about 0.2 °C per decade is projected for the next two decades for all SRES scenarios.

    Yes, I realize they are not the same. “…should have been” is not a reasonable statement. I am assuming that the IPCC report was the source of the .2/decade estimate.
    I don’t think anyone has ever predicted that the temperature change will be linear. Is it accurate to say that the global temperature trend has been running at the lower end of the IPCC-reported SRES scenarios?

    [edit]

  800. Don Shor:

    Anyone looking for a more detailed article about variations in temperature trend over decades may be interested in eduardo’s recent post at Van Storch’s web site: http://klimazwiebel.blogspot.com/2010/01/ten-years-of-solitude.html
    “Climate simulations show that decades of near zero or even negative global annual trends are not particularly unusual.”

  801. Doug Bostrom:

    Completely Fed Up says: 8 January 2010 at 2:18 PM

    “Hey, at least Tilo thinks that the CRU data is right: it has 98 as the hottest single year.”

    That’s one (the only?) of the amusing aspects of the CRU thing. A lot of contrarian theorizing depends on these records, often referring to variations rather minute compared to the more gross effects preoccupying mainstream scientists.

    There’s a lot that going around. On the one hand you’ve got the conspiracy nuts complaining about “science for tenure” and “grant gobbling” rackets. On the other you’ve got people using various weird integrations of the same supposedly corrupt data, relying on minutia to explain away obviously more powerful and less noise-sensitive conclusions.

    Coherence was never their strength. I don’t know if one could find actual cases of mutual exclusivity as legs propping up the teetering stool of doubt but at least in terms of unlikely coincidences and juxatapositions we’re not looking at stable furniture.

  802. Tilo Reber:

    Completely:
    “Hey, at least Tilo thinks that the CRU data is right: it has 98 as the hottest single year.

    So he hasn’t bought in to the CRU conspiracy “Climategate”.”

    Completely, the best thing to do if you want to know what I think is to ask me.

    First, regarding the CRU data, it was the proxy data that was manipulated. I don’t see evidence of the surface temp being manipulated. There are complaints in the code about the slopiness and inconsistency of the data. But I don’t remember seeing anything that would make the surface temp data flat out wrong. Doesn’t mean that there isn’t – but I don’t know of any evidence at this point.

    In any case, my reason for trusting HadCrut3 is that it agrees reasonably well with the satellite data. If it didn’t, I wouldn’t trust it.

    Regarding the .2C per decade, I’m sure that you can do the math to get .24C in 12 years. And Don Shor gave you the quote. Yes, yes, I know that it does not mean that every decade will show the same rise. But in the absence of any known elements of natural variation that can keep it from getting that .24C, I expect to see the .24C. If it isn’t there, we should be able to explain why. Isn’t that exactly the point that Trenberth makes in one of his recent papers.

    GTC: #798

    I’m not comparing decades. Do you understand the difference? I know that temperatures were rising in the 90s. See #784.

    Don:
    “Climate simulations show that decades of near zero or even negative global annual trends are not particularly unusual.”

    Is that as a result of simulating elements of natural variability or is it as a result of injecting noise that is thought to be like natural variability. If it is simulating elements of natural variability, then what natural variability are the models simulating. And since the decade is already in the books, did we observe those elements of natural variability operating?

  803. Barton Paul Levenson:

    Gavin, didn’t you say that should be the last post on this subject? Would it be unnecessarily hostile of me to recommend that TR be kicked the heck off RealClimate until he agrees to talk about something else? This is wasting dozens of posts, edging up toward the hundreds, simply because he refuses to admit reality.

  804. Hank Roberts:

    TR is still confusing noise and forcings, eh?
    Tilo Reber has a thread of his own at Deltoid.

    “Since Tilo Reber’s comments always seem to take discussion off topic, all further comments from Tilo should be posted to …
    http://scienceblogs.com/deltoid/2008/05/the_tilo_reber_thread.php

  805. Completely Fed Up:

    Don says: “I don’t think anyone has ever predicted that the temperature change will be linear.”

    But what dittos denying AGW ***have*** claimed is that the IPCC predicted continuous linear increasing temperatures. Then when this doesn’t turn up, say that the IPCC prediction of same (which they didn’t) shows they’re wrong.

  806. John P. Reisman (OSS Foundation):

    #802 Tilo Reber

    Your assertions continue to be out of context. Although there are the typical array of flaws in this post of yours, my favorite is this:

    But in the absence of any known elements of natural variation that can keep it from getting that .24C, I expect to see the .24C.

    So now natural variation is no longer occurring? What are you smoking these days?

    Willful ignorance has no value. While it is important to refute silliness and stupidity, the repeated spinning and ignorance of Tilo proving to the planet that he is incapable of learning is more boring than educational for RC readers.

    Maybe he is pushing people so he can get the RC badge of dishonor and say we are mean and rude? Though I can’t think of anything more rude than a petulant child that refuses learn out of spite or willful foolishness, or is compensated in some form for being the class clown.

  807. Laurie:

    “Unfortunately, I don’t have the post-2003 model output handy…”
    Why not?

  808. John P. Reisman (OSS Foundation):

    #807 Laurie

    Do you have copes of all your grocery shopping lists handy from 2003. I would very much like to do a stochastic analysis and compare that to HADCRUT3 data to see if any discernible patterns appear in your spending and grocery choices that I can use to prove that human caused global warming is not occurring.

    If you don’t have that list (data) ‘handy’…, “Why not?”

    I mean, you must have all the time in the world to go fetch any request I have, right?

    I mean, you don’t have any other responsibilities or duties, right?

    I mean, you are at my beckon call to go get or spend the next three weeks retrieving any piece or pieces of data I request from you personally, right?

    I mean, you don’t have a job or family responsibilities, right? No interests in having a life, going to the movies, seeing friends, watching the news, taking a few minutes out to rest your mind, eating a meal, going to the store, talking to friends…

    Another, lame question… how inappropriate. No wonder these phantoms don’t post their last names.

  809. Tenney Naumer:

    re: 808

    Goodness, John!

    And I remember a time when you thought I was too hard on some people. LOL

  810. wazzamad:

    Well if Hanson’s “scenario B” was supposed to be ‘plausible’then the rest of his predictions are not worth betting on.There is a .3 degree celcius difference between ‘B’ and observations as of the latest data.With that kind of discrepancy for 25 years,that means 1.2 degrees celcius error in ‘B’ per century! The only conclusion one can draw is that the model has poor predictive value.

    [Response: The only conclusion one can draw is that you aren't paying much attention. - gavin]

  811. John P. Reisman (OSS Foundation):

    #809 Tenney Naumer

    No worries Tenney. I think it is apropos to attack the argument and the method and even the mentality and premise from which it derives. Sometimes, when a pattern is sufficiently proven even the integrity or degree, or lack thereof, of honor displayed in such naive nuanced tones and hues.

    I do fight fire with fire but to quote an old movie with Sean Connery, “leave it to a wop to bring a knife to a gunfight”. I’m half Italian actually and 1/4 Irish with a mix of Russian, but to paraphrase, I tend toward the Powell doctrine. In other words. If someone tosses hot coals out as straw-man arguments, red herrings or non sequiturs, or even mere sparks to appear subtle, I will come back with a flame thrower if I have one and it is the right tool in such instance.

    If I recall properly, I did come down on you a bit, but with respect, because I know you are well intended and as concerned as the rest of us. I was merely concerned that you were coming down a bit hard on the scientists. As I said then, I understand your frustration, many of us share it, but I can’t attack the source of the profoundly important work of the scientists that understand the connections and contexts. My experience is they are all hard working and dedicated to laying the foundation of science that we have the right material to combat the denial of well understood and founded science.

    And as I said then, please don’t get me wrong, because I do appreciate the spirit and the fight you have within you for this most important cause.

  812. Completely Fed Up:

    Don says: “I don’t think anyone has ever predicted that the temperature change will be linear.”

    Maybe he ought to read Tilo’s posts.

  813. Ray Ladbury:

    TR, not satisfied with posting stupidity now tries outright lies:

    “First, regarding the CRU data, it was the proxy data that was manipulated. ”

    Evidence?

    And now back to the stupidity:

    “But in the absence of any known elements of natural variation that can keep it from getting that .24C, I expect to see the .24C.”

    And exactly when do you expect natural variation to cease so we can conduct such an analysis? Ah, but lookie here:

    http://tamino.wordpress.com/2009/12/31/exogenous-factors/

    If you correct only for volcanic forcing and ENSO, we go from an anomaly of about 0 in 1975 to about 0.6 in the latter half of this decade. I make that pretty close to 0.2 degrees per decade. Now I know you won’t like this Tilo, because it’s GISTEMP, but HADCRUT will likely be fairly close to 0.2 as well.

    And Tilo, rather than having Don go do your work for you, why don’t you read Gavin’s tutorial FAQ on models–or are you afraid you might learn something?

  814. Icarus:

    Did anyone predict, decades ago, the degree of ice melt we’re seeing from glaciers, ice sheets, ice caps etc. all over the world from the relatively small amount of global warming we’ve seen to date? We always seem to be reading that effects are exceeding expectations in ice melt and other climate responses and it would be interesting to know if any climate scientists were unusually prescient about such effects.

  815. John P. Reisman (OSS Foundation):

    #814 Icarus

    http://www.ossfoundation.us/projects/environment/global-warming/frank-capra

  816. Don Shor:

    802 Tilo Reber Yes, yes, I know that it does not mean that every decade will show the same rise. But in the absence of any known elements of natural variation that can keep it from getting that .24C, I expect to see the .24C.
    It seems to me that your first sentence cancels out your second sentence.

    812 Completely Fed Up Don says: “I don’t think anyone has ever predicted that the temperature change will be linear.”
    Maybe he ought to read Tilo’s posts.

    Evidently. So, Tilo, do you agree that
    (1) the change in global temperature since 1998 is positive; i.e., increasing?
    (2) the rise in global temperature since 1998 is within the range of model outcomes cited in IPCC 2007?

  817. Rod B:

    Don Shor (816), This is a fool’s errand, none-the-less I’ll try Tilo’s answer: the change in global temperature since 1998 is negative, not positive.

    If you would have started in, say, 1980 or even 1997 or any year in between (years after 1998 are a mixed bag) your statement would have been accurate — positive.

  818. Completely Fed Up:

    Rod B “I’ll try Tilo’s answer: the change in global temperature since 1998 is negative, not positive. ”

    However, that’s not a trend, Rod.

  819. Rob:

    Gavin@745
    [Response: For the period shown in the graphs? You'd see a slight decline over time in the mean. See figure 9.5b in IPCC. - gavin]

    What is the context for figure 9.5b, couldn’t find it in the AR4 Synthesis Report or elsewhere at the IPCC site. Maybe I wasn’t looking good enough…

  820. Rod B:

    Completely Fed Up, but that wasn’t the question.

  821. Hank Roberts:

    http://pbfcomics.com/archive_b/PBF216-Thwack_Ye_Mole.jpg

  822. Hank Roberts:

    > figure 9.5b
    http://www.google.com/search?q=IPCC+figure+9.5b+%2BAR4

  823. tharanga:

    How hard would it be for somebody to just dig up Hansen’s old model and run it again, using the actual observed forcings? I understand that Scenario B is quite close to the actual forcings, but using the actual forcings should remove the question of which scenario was most relevant.

    Also I always wondered why that paper didn’t give an ensemble mean with an envelope, as is now common. Without the envelope, it’s hard to judge the model results. What am I missing?

    I’m late to this one, so sorry if the question was already asked amid the 800 previous comments.

  824. Tristan:

    Maybe this has already been covered before, but please do respond.

    I am in no way, what you would call a denier. I just think I see something here that might need correcting. Therefore, I have some questions about about the Hansen (1988) predictions: Sure, they are old and some would argue irrelevant. Still, I think it’s an interesting narrative to re look at the older predictions (seems to me the older the prediction the more likely any errors are to reveal themselves. Newer models, yes, are likely to be better – but have not had the time so see how good they are).

    Anyway, you say that senario B is running a little hot. As I understood it the senarios were based on CO2 emission levels. From the orig. paper, shown below, it say that Senario A was with the same continued rate of C02 emissions (1.5% annually). Senario B was with decrease growth rates, and senario C with ‘drastically’ decreasing growth.
    Paper
    http://pubs.giss.nasa.gov/docs/1988/1988_Hansen_etal.pdf
    Your previous analysis
    http://www.realclimate.org/index.php/archives/2007/05/hansens-1988-projections/
    Chart:
    http://en.wikipedia.org/wiki/File:Hansen_2006_temperature_comparison.jpg

    As I understand it, globally, we actually went over that 1.5% significantly. I couldn’t find the global emission percentage growth but I assume that the rate has actually increased (correct me if I am wrong).

    Therefore, to compare predictive power of the model don’t you need to go back to the model, plug in the emissions, get the output number and then compare this to observations? Alternative to being able to do this, are you not forced to choose the senario that is, at least, most similar (being senario A?).

    So my question is, how do you justify choosing senario B for the comparison?

    (I’d be happy to be given a link to a post elsewhere. Maybe this chart http://www.realclimate.org/images/Hansen88_forc.jpg does this mean your saying that Senario B is actually the best match for emissions?)

  825. Completely Fed Up:

    Then what was the question, Rod B?

    When you’re talking about cooling in a climate website, you don’t mean “it is colder now than some other point” because that’s nothing to do with climate.

    If you want to talk weather, you can go to your national met service and see if they have info on the weather for you.

  826. Ray Ladbury:

    Tristan, Hansen’s model assumes a significantly higher CO2 sensitivity than do current models. That alone probably is sufficient to explain why it is running hot.

  827. Rod B:

    Completely Fed Up, wasn’t my question; go clarify with the questioner. I was just answering the question that was asked. You must be answering an imaginary question.

  828. Sordnay:

    There is any oficial site where this proyections of the IPCC AR4 models, as in the first figure, are accesible? I had not success locating this metetada (and the envelope). I think they can be used to show anyone wheter this simulations holds with measured temperatures or not. can anyone help?

    [Response: Data is available from here (in particular, Climate Explorer). - gavin]

  829. Tilo Reber:

    Sorry about not answering these questions guys. I had to run off and do other things for a while. It seems that natural variation is the issue. I accept that natural variation could override the CO2 forcing signal for 12 years. But you have to be able to identify what the natural elements of variation are. Let me quote Trenberth:

    “why is the temperature not continuing to go up? The stock answer is that natural variability plays a key role [1] and there was a major La Niña event early in 2008 that led to the month of January having the lowest anomaly in global temperature since 2000. While this is true, it is an incomplete explanation. In particular, what are the physical processes? From an energy standpoint, there should be an explanation that accounts for where the radiative forcing has gone.”

    Two guys named David Easterling of NOAA and Michael Wehner of the Lawrence Berkeley National Laboratory have written a paper that they submitted to Geophysical Research Letters. They basically make all of the points that you made above. I addressed those points in detail here:

    http://reallyrealclimate.blogspot.com/2010/01/another-inconvient-truth-for-agw.html

  830. Completely Fed Up:

    “Also I always wondered why that paper didn’t give an ensemble mean with an envelope, as is now common. Without the envelope, it’s hard to judge the model results. What am I missing?”

    Maybe the same thing as I’d miss if I asked “Why didn’t cars in the early 1900′s use seatbelts as is now common?”.

    Computing power has gone up a lot. Ensembles are a new thing because you need a lot of computing for it. And you still don’t show three different scenarios with an ensemble unless you triple up all the model calculations and the graphing data.

  831. Kevin McKinney:

    Somehow, I’d prefer to go straight to Easterling & Webner.

  832. Hank Roberts:

    > submitted
    Long ago; it’s been published, and discussed he