2008 temperature summaries and spin

Una traduzione in italiano è disponibile qui.

393 comments on this post.
  1. Todd Albert:

    Defining climate merely as average surface temperature is far too simplistic. What would be interesting to look at, rather than mean annual temperatures is the variability of temperature and precipitation patterns throughout the year. A predicted consequence of anthropogenic warming is a more varied climate, more severe ups and downs. Are we seeing that? When Alaska is having record warmth and Florida is seeing record cold, these two tend to cancel each other out when looking at average temperature, but taken together are more indicative of what is actually happening. Are any of these agencies producing variability data sets?

    [Response: I'm not quite sure where the idea that AGW implies more "varied" climate comes from. It certainly isn't a general rule, and I'm not really sure that I know it to be a fact even in specific cases. There is certainly no indication from the models that variability (about the trend) in global mean temperature should change. - gavin]

  2. William:

    Gavin
    You stated “The impacts of the solar cycle on the surface temperature record are somewhat disputed, but it might be as large as 0.1ºC from solar min to solar max, with a lag of a year or two”

    What solar cycle are you referring to and aren’t there more than one? How far back in years
    has there been any reliable measurement of the energy fluctuations in the sun, perhaps
    from something like a satellite? Is it possible there are Solar cycles that have not yet
    been determined that could have greater than the .1C impact you describe above?

    Thanks
    Ed

  3. Timo Hämeranta:

    “North Atlantic SST and European and North American surface temperatures will cool slightly, whereas tropical Pacific SST will remain almost unchanged. Our results suggest that global surface temperature may not increase over the next decade, as natural climate variations in the North Atlantic and tropical Pacific temporarily offset the projected anthropogenic warming.”

    Ref: Keenlyside, N.S., M. Latif, J. Jungclaus, L. Kornblueh, and E. Roeckner, 2008. Advancing decadal-scale climate prediction in the North Atlantic sector. Nature Vol. 453, No 7191, pp. 84-88, May 1, 2008

    Further, in April 2008, scientists at NASA’s Jet Propulsion Laboratory announced that while the La Niña was weakening, the Pacific Decadal Oscillation – a larger-scale, slower-cycling ocean pattern-had shifted to its cool phase.

    Here is a short history of PDO phase shifts:

    In 1905, PDO switched to a warm phase.
    In 1946, PDO switched to a cool phase.
    In 1977, PDO switched to a warm phase.

    Well, it remains to be seen how global climate will evolve in decades to come.

    Well, it remains to be seen.

  4. Richard Pauli:

    Gavin, et al,

    Re #1 You, more that anyone – might define the standard assemblage of data sets that best describe global climate change.

    It might include
    - Surface temperature records (as above)
    - Atmospheric data: temp, GHG levels, etc
    - Ice coverage and ice depth
    - Ocean measurements temperature, acidity, sea level, currents
    - etc..

    Or has anyone defined such a set?

  5. Jim Bullis:

    Re gavin response to #1:
    Didn’t the Al Gore movie tell us that weather would be more extreme due to global warming? When Todd Albert talks about varied climate, is he not referring to weather according to your terminology?

    [Response: No. Extremes of climate cover a wide range of issues - but don't necessarily mean that variance is significantly higher. And each effect should be considered separately - controls on ice storms or tornadoes or heat waves are not the same. Some extremes will likely increase (number of days above 90 F, intense rain, possibly droughts etc.). Some will decrease (extreme cold spells in European winter), some we have no real idea about (ENSO events). But blanket statements - 'extremes will increase' or 'variance will increase' - make very little sense. - gavin]

  6. pete best:

    Ah Gavin, you are spoling the long winters nigths with your high calibre science. What else are we all going to argue about if you scientsits profess to have been telling the truth for 30 years. Damm all of you for your rational scientific research, measurements and good scientific theories.

    MERRY CHRISTMAS – always been an awesome site for us lot.

    Happy New Year to.

  7. jcbmack:

    Todd, there is varied weather,and some climate variations, but not quite how you mean it. The averaging of the trend does indicate warming globally, and the earth is still warming now. What does happen in a giben month, year and sometimes decades is faster or slower warming for the given time period, but this does not reverse the warming trend or do anything to refute the dangers to health that GHG’s present with. You would have to have a 30 year period (or even more) where the magnitude of localized warming and cooling were shown to summate equally where no net warming occured whatsoever, but that is not what is shown. GHG continue to increase in amounts in the atmosphere and as such, over time more warming inevitably continues though there may be breaks for short periods, and some cooling, as already discussed at great length regarding aerosols.

  8. jcbmack:

    Gavin, good presentation as always, but this one in particular shows why global warming is still happening and why it will not just go away.

  9. Hank Roberts:

    > variability

    Usually I see reference to more _local_ variability.

    Example: “… water storage capacity in a region, taking into account that the supply of the resource, the flow into the reserve, is uncertain, that a measure of the uncertainty, the variance, is likely to increase with climate change …

    Journal of Environmental Economics and Management
    Volume 34, Issue 3, November 1997, Pages 207-227
    doi:10.1006/jeem.1997.1011

    Picked arbitrarily among results from
    Scholar: climate warming “increased variability”

    Lots of results talking about agriculture and variability concerns.
    ________________________
    “cowboys injured”

  10. Geoff Wexler:

    A variation of previous question.
    Part 1.
    Even if increased AGW does not imply a more varied climate, would it be of any value to know what the models have say? Or is this old hat? Given that the “wiggles” have a random phase, can’t you estimate (from computer experiments with different initial conditions) some of the higher moments used by the statisticians? First with no forcing and then with a simulated increase of CO2?

    [Response: Sure. I haven't done so, but it could be done. - gavin]

    Part 2.
    As for the suggestion of increased variability there is Figure 6.6 on page 129 of John Houghton’s book “Global Warming” (3rd.Edition) , which is a sketch graph of probability vs temperature (without numbers). One graph is shifted to the right (warmer) and broadened (more variability). Is the link just a speculation?

  11. Alastair McDonald:

    Gavin

    “The 21st century is the current century of the Christian Era or Common Era in accordance with the Gregorian calendar. It began on January 1, 2001 and will end December 31, 2100.”
    http://en.wikipedia.org/wiki/21st_century

    Thus the coldest year of this century is, according to GISTEMP 2008, not 2000 as you assert. 2000 was part of the 20th Century!

    Mistakes like that, whether caused by a desire to counter sceptical propaganda or just due to ignorance, do reinforce my doubts that professional scientists should be entirely believed :-(

    Cheers, Alastair.

    [Response: When did you celebrate the new millennium? ;) - gavin]

  12. Hank Roberts:

    Gavin’s inline response to #5

    > each effect should be considered separately

    makes clear what I was vaguely groping toward in #9.

  13. Todd Friesen:

    I’ve been running some 30 year linear regression models based on GISS, Hadley, RSS, and UAH, inputting variables for volcanic (GISS), solar forcing (Satellite), ENSO (NOAA), and Net Anthropogenic forcing (GISS data).

    I found that with the 30 year time period, the solar trend is only a slight negative, ENSO is also sloped with a slight negative trend. I think volcanic forcing is on a warming trend, because volcanic activity is weighted towards the beginning of the 30 year period. So, I think my regression shows that Anthropogenci warming contributes to about 0.13C/decade out of the total 0.16C/decade (about 0.04C due to volcanic, and -0.01 due to solar and ENSO combined). Hadley had virtually the same results. RSS had just under 0.11C, and UAH had about 0.08C due to anthropogenic forcing. I also noticed that RSS and UAH had greater sensitivity to ENSO and volcanic forcings (I think it was about 50% larger sensitivity).

    Anyway, Gavin, I’m wondering if these findings are similar to the ones you have in understanding the last 30 years, regarding the relative forcing contributors to the 30 year temperature record. You mentioned 0.2C per decade, but I’m not sure if this was a forecast or a current trend.

    Thanks Gavin for your hard work and helping the public understand the issues.

  14. Jonas B:

    So now you have shown that the last 10 years flattish trend is not significantly different from models, because models have great variability. Fair enough!

    Since models have this variability, why is it that measured trends are calculated for only 30 years? By doing this, you always include the exceptional warming roughly between 1978 to 1998.

    Isn’t it more fair to include even more years, for example the last 100 years? If so, the trend would be some 0.7 deg C.

    [Response: The longer the period, the less important the annual variability. So the 100 year trend is a useful guide, though you have to be careful since the expected change over 100 years isn't perfectly linear. Over the last 30 odd years it is much closer to linear, and so linear trend analysis is a little more appropriate. - gavin]

  15. Jim Cross:

    #14 Gavin’s response

    Why is the linear trend more appropriate since the models show anything but a linear trend?

    [Response: Because the forced response (look at the ensemble mean) is close to linear - gavin]

  16. Lynn Vincentnathan:

    The chart, with 2000 as the base year at 0.0, looks like one the denialists might use, tho they’d probably pick 2002 to more clearly prove their point that GW is a hoax, and global cooling was happening.

    Might be good to also include a 100 year chart, or at least a 30 year chart. Then we’d see we were talking about some mole hill atop a mountain.

  17. S. Molnar:

    Gavin, the near-term ENSO predictions are tilting ever so slightly towards another La Niña: http://www.bom.gov.au/climate/enso/.

  18. RichardC:

    Solar variability on human timescales is the 9-14 year (nominally 11) cycle. The SORCE satellite is the current best measurement of solar output (It’s been dropping ever since launch in 2003 – down almost 1 watt/m2) http://lasp.colorado.edu/sorce/total_solar_irradiance_plots/images/tim_level3_tsi_24hour_640x480.png

    Weather variability? Yes, global warming increases absolute humidity so more extreme weather incidents are expected – as in more downpours and fewer drizzles.

  19. John Finn:

    GISTEMP 1984-2008 0.19+/-0.05 (LO-index)

    1. So the 1984-2008 is not significantly different to the trends of a number of pre-1945 25 year periods (e.g. 1916-40, 1917-41)
    2. 1984 does appear to be a GISS local minimum – why was this year chosen.

    [Response: That's when the Hansen et al runs were started (and where the forcing was a projection, rather than known already). - gavin]

    3. Temp trends which which begin before 1993/94 and after ~1981 are affected by the Pinatubo cooling (admittedly less so in the early 1980s than later). If the Pinatubo effect was removed, trends that begin in the post-1980s period would be remarkably similar to thosethat begin in the pre-1920 period.

    There’s clearly something else going on here. CO2 levels were completely different; Leif Svalgaard maintains there is very little solar effect – so, as Timo in #3 says, ocean circulation must be a big player.

  20. Jim Cross:

    #15 Gavin response

    Is the ensemble mean the black line?

    [Response: yes. - gavin]

    Okay. I know this post is all about how the models show variation from year to year. Shouldn’t they also show variation from decade to decade? Or on even longer time scales?

    [Response: They do. It's smaller than the recent trend though. - gavin]

    I haven’t seen yet anything definitive on the correct time frame to be looking at all of this. It is clear that one or two years is way too small a time frame. Is thirty years too short too? We have projections going to 2100 and, on this site, we have seen a rotating globe comparing two 5 year time frames.

  21. Alder Fuller:

    Well done here. Continued thanks.

    I’ll add my vote for & interest in hearing more about construction of an “index variable” that captures the variability of multiple components.

    “Anyone who expresses shock at this is either naive or … well, you know.”

    Sad thing is, those voices seem to be getting more shrill. Intellectual death throes? One can hope …

    A~

  22. jae:

    c’mon, gavin, you’re not being fair. Why don’t you show AR4 model ensemble, al la Santer vs. actual temperatures.

    [Response: Those are the models, and that is the actual temperature. What more do you want? - gavin]

  23. Todd Friesen:

    John #19,

    Volcanic activity is indicated by Stratospheric Aerosol forcing in the link below.
    http://data.giss.nasa.gov/modelforce/RadF.txt

    There’s more than just Pinatubo to consider in the 30 year trend. There was sigificant strato-volcanic forcing data in 1982 and 1983. This partly explains why 1984 was a local minimum. (My model suggests a lag between volcanic forcing and temperature change of 1 or 2 years). This has more of an effect on the 30 year trend than Pinatubo because the effects of Pinatubo are around the middle of the time period. With a 1984 starting point, Pinatubo will have some effect, though maybe not substantial. I quantified the volcanic bias to account for about 0.04C/decade of the 0.16C/decade trend (global GISS land+ocean starting 1979). ENSO and solar have a slight negative slope.

    I think it is clear that ocean oscillation is a significant factor, and helps explain some of the anomalies along the way. It may even help explain (in part) some 30 year trends. The last 30 years, though, it seems to have had a slight negative effect.

    If you are looking at a 100 year trend, looking at the PDO data, I don’t think it contributes much to the slope, and if it does, I can’t tell which direction. A 60 year trend, maybe a little upward movement. It’s pretty much certain that the long term trend isn’t explained all that much by ocean oscillations.

    I think a large majority of the long-term trend (i.e. 100 years) is explained by anthropogenic warming. Whenever I try to model 30 year or 130 year trends, the fit is quite horrible without including anthropogenic forcings. With Anthropogenic forcings, it’s quite amazing how well the temperature series fits. Maybe it’s just correlation. I think when you couple sound physical science theory with supporting statistial correlation, you have a fairly credible theory.

  24. Pat Neuman:

    I disagree with climate projections in #3. I feel too much weight is being given to historical data trends. Abrupt climate change can not be ruled out.

  25. Hank Roberts:

    > SORCE
    http://lasp.colorado.edu/sorce/data/tsi_data.htm#apps

    “… Present absolute accuracy is estimated to be 0.48 W/m^2 (350 ppm), largely determined by the agreement between all four TIM radiometers. There remains an unresolved 4.5 W/m^2 difference between the TIM and other space-borne radiometers, and this difference is being studied by the TSI and radiometry communities.”

  26. Ray Ladbury:

    Alastair, the fact that you feel that failing to observe a convention established by a religious decree compromises the science is one of the most nonsensical contentions I’ve run across of late–and given the recent events in the news, that says a lot.

  27. Ray Ladbury:

    Well, there you have it. It’s obvious that warming stopped in 1983… and again in 1991… and again in 1999. Geez, guys, how many times does it have to stop before we can all go back to driving hummers? ;-)

  28. Eli Rabett:

    Eli thinks you need go have a word with Roger. He is patting himself on the back again. For better or worse, that is a carrot free zone.

  29. Philip Machanick:

    Gavin asks Alistair (#11): “When did you celebrate the new millennium?” If he had any sense, twice :) .

    Something else I’ve been wondering about. Since Arctic ice is disappearing faster than expected, how does that appear affect the temperature trend? Aside from the positive feedback effect of lowering albedo, won’t taking latent heat of melting out of the equation — if the ice disappears early enough to make a difference — mean that temperatures go up faster for the same net energy change (even allowing that much of the missing ice used to be on land)?

  30. Hank Roberts:

    http://newsimg.bbc.co.uk/media/images/45146000/gif/_45146192_ice_extent_466.gif

    http://news.bbc.co.uk/2/hi/science/nature/7786910.stm

  31. Edward Greisch:

    Thanks Gavin, for another great article. I’m keeping the URL only this time to save space. IF you convince the denialists of the 0.2 degrees centigrade per decade, the next thing they will say is “who cares?” I have found other places that say things like: “The rain moves a lot of miles for a small temperature change and agriculture fails soon;” and “6 degrees more and we go extinct when H2S is made in large amounts by ocean bacteria.” 0.2 degrees centigrade per decade requires 300 years to reach 6 degrees centigrade, so they aren’t interested. You noticed a non-linearity, but records don’t go back far enough to find a curve. Denialists will also claim that corn will grow well on thawed-out tundra, an idea I think most farmers would find silly. Thawed tundra just isn’t the same as Iowa top soil. I don’t know of a web site that publishes equally good articles as often on the horrific consequences for humans. There are several that sometimes post great articles on the consequences, but none that I know of that match RealClimate day after day. Do you know of one?

    0.2 degrees centigrade per decade seems huge to me and you but small to denialists. I think it is a frame of reference thing, an education problem, an IQ problem and possibly an overdose of testosterone problem.

  32. wayne davidson:

    #29 and 30

    It affects Arctic temperature like this:

    64-90 N Temperature anomalies (NASA GISS)

    2001 102
    2002 126
    2003 122
    2004 77
    2005 223
    2006 191
    2007 211

    That is an average of 1.5 C with a definite upward trend

    Contrarians eager to use temperature trends to earn no respect, love the 40′s or 30′s explaining away a mysterious cycle:

    1943 132
    1944 115
    1945 61
    1946 4
    1947 111
    1948 23
    1949 34

    average temperature anomaly of +0.69 C. 33-39 is +0.74 anomaly

    so the cycle misses a doubling of sorts.

    I am a rabid proponent for worldwide DWT charts, they will come one day… Just a fan of the surface temperature trend because there is nothing else as frequently used. Past November was warm:

    http://data.giss.nasa.gov/cgi-bin/gistemp/do_nmap.py?year_last=2008&month_last=11&sat=4&sst=0&type=anoms&mean_gen=11&year1=2008&year2=2008&base1=1951&base2=1980&radius=1200&pol=reg

    Not much “blue” in the Arctic (not with urban heat islands or heavy industries) with a mean zonal anomaly of +4 C near the Pole. Along with that
    the ice is substantially thinner due to clouds, and 2008 will have the same extent of 2007 likely soon. Its another December when it gets -40 C well south of the warmer Arctic as well.

  33. Julius St Swithin:

    Reading this and other related sites it is clear to me that English needs a new word. We have “weather”, which is what happens over a period less than a week or so; we have “climate”, which is what happens over periods longer than several decades. What we don’t have is a word for what happens over periods from a few weeks to few decades. Combinations such a “clither” or “weamate” don’t sound appealing. So, before the festive season get in full swing, does any one have a good idea for a new word. For example, it would be useful if we could say “Despite the claims of the deniers, the *insert_new_word_here* of the last few years does not contradict the claims that the climate is changing and temperatures are increasing by 0.2 C/decade.”

  34. Alan:

    Just a nitpick. Common sense would dictate otherwise but I belive the 21st century started 1st of Jan 2001 – at least that’s how I recall it from a couple of years working out Y2K bugs, so assuming “this” decade is the first of the new century is not unreasonable compared to the rest of the spin.
    The problem is that a decade is literally “ten years in a row”, any starting point will do, the phrase “this past decade” makes sense, “this decade” is ambigious.

  35. pete best:

    Re #29, the Arctic losing it s ice faster than models predict might be down to natural variability as much as increased feedbacks due to global warming I have read.

  36. Alastair McDonald:

    Re #29 where Philip Machanic wrote:

    Gavin asks Alistair (#11): “When did you celebrate the new millennium?” If he had any sense, twice .

    Being Scottish I did celebrate New Year in 2001 as well as 2000! And I will celebrate it on 1st January again this year.

    But Gavin is starting his meteorological new year on the 1st December. What he is doing is using cherry picked dates to suit his arguments. The official start of the meteorological New Year is 1st December, and the official start of this century was not the day on which the Millennium was celebrated. It is the 1st Jan 2001.

    Why is this important? Because it makes it look as if Gavin can only answer the problem of why global warming seems to have stalled by fiddling the statistics. So he is giving heart to the sceptics, not defeating them.

    But it is also symptomatic of a much bigger problem. The upper troposphere is not warming in the way the models predict, but rather than listen to criticisms of the models he has been a contributing author to a series of papers which use dubious statistics to “prove” that the models are correct.

    In the latest of these Figure 6″ clearly shows little correlarion between any of the MSU and radiosonde data and the multi-model average (thick black line.) Only by adding a new set of MSU data RABCORE, which itself does not lie within the standard deviation in the upper troposphere, is the data made to look as if it averages out to meet the models. It is a case of two wrongs matches: radiosonde data and RAOBCORE calculations, being made to look like a the required match: multi-model average :-(. But it is only the radiosonde date that is correct. That is what is measured. If the models do not agree then they are wrong!

    Cheers, Alastair.

  37. Johnno:

    I should point out that in the popular media that claims of global cooling have been very strident. Verbal attacks on mainstream climate science are perhaps louder than they have ever been. So what? I half expect someone in the Australian media to declare that we should burn more coal to ward off an impending Ice Age. If 2009 is another cool year everything could be turned around. Mitigation programs and research could be abandoned by governments. AGW as a popular idea could itself be in crisis with consecutive cool years.

  38. pascal:

    Hi Gavin

    A good article, thanks !

    But it is’nt sure that Niña passed.

    please, look at this link.
    http://www.climat-evolution.com/article-25794509.html

  39. Pierre Allemand:

    Just to try to summarize what you say in your post, we can say: “according to the most recent observations (say last 10 years) one can declare that global warming is going on its way without any explainable change”.
    My question is : what should be the observations which should allow to say: “one can declare that global warming seems to have ceased”.

    Now, if after deep thought, it appears difficult to decide what should be different in the observations (to be allowed to declare the second) can we finally add to the first: “but nobody can say, for sure, that global warming has not actually ceased”.

  40. Georg Hoffmann:

    Hi Gavin
    I plotted for example the decadal trends for the ECHAM5/MPI IPCC model. Dont read the german text (though it would be easy for you, I know)

    [Response: ;) - gavin]

    just jump to figure 4. Even in scenario A2 the models produce still slightly negative or near zero decadal trends until 2040 or so.
    http://www.scienceblogs.de/primaklima/2008/07/die-mar-von-der-beendeten-erwarmung-und-den-modellen-die-etwas-vorhersagen.php

    As often the observed and modelled variability is pointed out it doesn stop stupid remarks such as this citation stemming apparently from David Whitehouse.

    If the predicted cooling by la Nina had not occurred then 2008 would probably have been the same temperature (given the uncertainties) as every year since 2001 and that in itself would require explanation.I am broadly in favour of the global warming­CO2 hypothesis but I know it is just that, a hypothesis – and that needs testing against real observations in the physical world. If it isn’t, then it’s not science.

    Here:http://www.timothybirdnow.com/?p=1447

  41. Kevin McKinney:

    Johnno in #37 says:

    “I should point out that in the popular media that claims of global cooling have been very strident.”

    Maybe, but that doesn’t mean that it is data driven; 2008 was by no means a cool year in historical terms. As Gavin’s post has it:

    “This puts 2008 at #9 (or #8) in the yearly rankings, but given the uncertainty in the estimates, the real ranking could be anywhere between #6 or #15. More robustly, the most recent 5-year averages are all significantly higher than any in the last century. The last decade is by far the warmest decade globally in the record.”

    These facts need to be emphasized very clearly in popular media.

  42. John Finn:

    [Response: That’s when the Hansen et al runs were started (and where the forcing was a projection, rather than known already). - gavin]

    Ok fair enough, thanks. I did vaguely remember something about this but it came to me after I’d posted the message. But , as Todd in #23 points out, 1984 could have been affected by the El Chichon eruption which means that the early part of the 1984-2008 period was affected by 2 volcanic eruptions which must influence the trend.

    Re: #23

    Todd

    I’m not sure how you are including the PDO in your model, but Spencer (and others) has shown that PDO can be significant and may explain much of the 20th century warming.

    In your post, you write


    If you are looking at a 100 year trend, looking at the PDO data, I don’t think it contributes much to the slope, and if it does, I can’t tell which direction. A 60 year trend, maybe a little upward movement. It’s pretty much certain that the long term trend isn’t explained all that much by ocean oscillations.

    A couple of things to say here:

    1. The 100 year trend is only 0.07 deg/decade anyway so I wouldn’t expect the PDO long term trend to contribute much. It’s surely the periods where the trend is amplified which are of interest…..
    2. We appear to have had 3 PDO shifts in the past 100 years, i.e. 2 cool->warm and one warm->cool which coincided exactly with the 2 strong warming periods and the mid-20th century cooling (or non-warming) period.

    Note the term PDO is used above as a generic term for ocean oscillation.

    Re: #32

    Wayne Davidson

    I don’t think anyone is suggesting that there isn’t an AGW signal – just that it’s nowhere near as large as generally claimed.

  43. John Lang:

    The timeline starts with a La Nina and ends with a La Nina but there are a number of El Ninos in the middle.

    There was La Nina in 1999 and 2000.

    El Ninos from 2002 into 2003, 2005 and 2006 into 2007.

    Then it ends with a La Nina starting mid-way in 2007 extending into 2008.

    If you pull the +/- 0.1C impact from these Ninos (they were not big enough to get to the 0.2C impact) – you have a pretty flat line throughout the period.

    http://img241.imageshack.us/img241/374/1999nino34rj7.png

  44. Florifulgurator:

    Variability, variance – volatility ?! (as in financial maths …)
    Which reminds me Kiyoshi Ito has died recently, famous for the “Ito lemma” in financial maths. Rarely one hears of Ito calculus in climate science… wink wink …

  45. tamino:

    I stole the title of your post for one of my own. I hope you don’t mind.

  46. ccpo:

    “I don’t think anyone is suggesting that there isn’t an AGW signal – just that it’s nowhere near as large as generally claimed.”

    Oh, I don’t know:

    “This puts 2008 at #9 (or #8) in the yearly rankings, but given the uncertainty in the estimates, the real ranking could be anywhere between #6 or #15. More robustly, the most recent 5-year averages are all significantly higher than any in the last century. The last decade is by far the warmest decade globally in the record.”

    Deniers, critics, skeptics… all rely on focusing on pieces of data. I have literally never seen one even attempt to deal with the totality of evidence.

    So, when 9 of the top ten warmest years have all been in the last 10 or 11 years, that’s a very large signal, particularly since it sits at the end of a very long upward trend.

    Cheers

  47. Bob Deering:

    Not to derail this topic, but I’m getting bombarded by denialists sending me links to Inhofe’s latest claim of 650 scientists disputing that CO2 is causing global warming, etc etc. Here’s the congressional link: http://epw.senate.gov/public/index.cfm?FuseAction=Minority.Blogs&ContentRecord_id=2158072e-802a-23ad-45f0-274616db87e6

    Could you please consider addressing this on Gavin?

    Thank you.

    [Response: It's not science and so it doesn't really belong here. However, others have dealt with this (and the previous version) quite well. See these links (or here or here). Bottom line, if it's a scientist they've likely been misquoted and misrepresented, but many (most?) are not scientists at all - and though there are a few climate scientists (the usual suspects), no list of cut-and-pasted quotes culled from the world's press and blogs comes anywhere close to the level of peer-reviewed science on this topic. However, in the same spirit of McCarthy's 57 (or 83 or 209) names on his list of communists in the State Department, the point is not to have anyone be convinced that this is meaningful, but simply to have something to wave in the air and froth about. - gavin]

  48. wayne davidson:

    #42, John Fnn, I doubt that surface temps are doing a good job at measuring temp anomalies, because of stable weather from unusual planetary wave placements which sometimes give a rather large temperature anomaly noise signal. It is the weighted temperature of the the entire troposphere which matters. That calculation varies a whole lot less. Yet precluding DWT’s, AGW signal is still present with enormous implications for the Arctic first, as models capably suggested. Now, for any run of the mill contrarian to claim that the models are at best good for only one day forecasts is belligerence against the science they claim to understand. I’ve seen infamous Hall on CBC a while back, making a claim that current Arctic warming is nothing, has happened before, the man does not know the Arctic, has incredible ego, making himself the repository of climate science despite all other climatic red flags flashing in front of his eyes, he may be a retired U professor, with some support amongst a handful of yahoos who enjoy making a fuss. The very frozen sea scape has changed for thousands, if not millions of square kilometers, is like waking up one morning in a NYC without any cars. A TV starved for attention contrarian would gleefully say the buildings are still there, no change!

    The world wide temp anomaly is sometimes deceiving when interpreted by lobbyists, any normal climatologist would focus on the areas of the world where feedbacks are strongest to confirm without a doubt that AGW is present. And the temperature signal, if analyzed properly, is a whole lot steadier in favor of a slow but non stopping warming trend.

  49. RichardC:

    46 ccpo says, “So, when 9 of the top ten warmest years have all been in the last 10 or 11 years, that’s a very large signal, particularly since it sits at the end of a very long upward trend.”

    The skeptics’ point is simple: The alarmists’ admit that the first half of the 20th century can be largely explained by natural variability – solar, etc. So plot a sin curve over the last 50 years. It sure looks like we’re simply at the peak of a natural curve, doesn’t it?

    There will be no consensus amongst the general population until the above argument is destroyed – not with scientific “mumbo-jumbo”, but actual disastrous data. The arctic sea ice will ~finish melting and then everyone will agree. Two to four years should be long enough. Then we’ll start brimstoning the atmosphere and merrily keep tossing CO2 as the problem will be “solved”.

  50. Todd Friesen:

    #42

    For my 30 year model, I tried adding PDO data, but it didn’t improve the fit at all. That’s not to say there isn’t a correlation. Rather, ENSO data provides a better fit to the temperature data points. When I took out ENSO, and threw in PDO, then there was improvement in fit, of about 1/3 to 1/2 the effectiveness of ENSO, over not having any ocean variables. NOAA had some data that proxies ENSO going back before 1950, so I used that in my longer term models. (After re-reading your comment, I see that you are using PDO more generically to include the effects of ENSO).

    Regarding the 100 year 0.07C/decade trend. The first 50 years had little or no net anthropogenic influence (there were forcings to be sure, but mostly offsetting). The first 50 years (my longer term model was based on GISS land station data) had something like a 0.15C upward trend due to increased solar activity, compared to a ~0.10C anthropogenic contribution. In the last 50 years, solar forcings were relatively flat, and anthropogenic contributions contributed about 0.6C. ENSO was up slightly, but by only about 0.03C in total.

    I don’t have the model in front of me, just a few graphs that resulted from my model where I’m eyeballing the increase.

  51. John Finn:

    Re: #47

    Wayne

    The GISS trend at the Arctic was about the same for the 1910-35 period as it was for the 1978-2007 period. Admittedly the starting point in 1978 was higher than it was in 1910 so the final temperatures (as you pointed out) ends up higher in 2007 than in 1935. But the Arctic warmed at pretty much the same rate. Unfortunately, the long-term surface records are the only comparisons we can make because there were no satellites in 1910, so we have no way of knowing what the Arctic troposphere temperatures were back then.
    I’m not sure if this addresses any of your points, since you seem to be attributing comments to me which I never made.

    Between 1935 and 2007, the Arctic appears to have warmed about half a degree which, in the absence of any other proven cause, I’ve assumed is due to increased GHGs. Though I wouldn’t be surprised if there’s a solar signal in there as well. After all, the 3 strongest solar cycles ever recorded all occurred in the second half of the 20th century. Whether, its GHGs or solar, I’m not convinced a ~0.5 deg increase in 70 years is particularly alarming.

  52. Peter McGrath:

    @33…

    Julius it could be the ‘swithin’. Weather lore says that the weather for St Swithin’s day sets the pattern for the next 40 days. Weather, a week. Climate, and whole bunch of trends over years. Anything in between, the swithin.

  53. Earl Killian:

    In the graphs, it appears that the GCMs have higher variability than reality. Is this supported by statistics, or is the eye just picking out the outlying GCMs?

    [Response: Some do, some don't - however ten years is a little too short to define what the base standard deviation is, so the relative smoothness of the obs over this period is not necessarily representative of the true variance. - gavin]

  54. Slioch:

    Gavin (or someone): could you say a few words about the effects of an El Nino or La Nina episode on the heat balance of the Earth.

    Suppose, for example, an El Nino raised the average global temperature by 0.2C above what it would otherwise be for a number of months.

    A number of positive (and possibly negative) feedbacks seem likely:

    Increase water vapour in the atmosphere => increased GH effect.
    Change in cloud cover => changed albedo/night heat loss.
    Decreased CO2 uptake to oceans => increased GH effect.
    Changes in vegetation => changes in albedo/CO2 levels.
    Melting ice/snow => decrease in albedo.

    Has anyone tried to quantify these, or are the effects just too small/short-lived or unknown?

    I assume the overall effect would be a positive feedback. That is, although an El Nino episode is primarily concerned with re-distributing (but not changing the total amount of) heat in the ocean/atmosphere system, the combined feedbacks would tend to increase the heat in that system. (And for a La Nina the feedbacks would tend to decrease the total heat in the system.)

  55. tamino:

    Re: #51 (John Finn)

    Between 1935 and 2007, the Arctic appears to have warmed about half a degree…

    Looks to me like it’s closer to a full degree. The 5-year average centered on 1935 is 0.518, the 5-year average centered on 2005 (the most recent available) is 1.636 — a difference of 1.118 deg.C.

    Even if you take the highest 5-yr average from the first half of the 20th century (centered on 1945), it’s still only 0.808, fully 0.828 deg.C less than the most recent 5-yr average.

    The net warming of the arctic over the entire time span of GISSTEMP data is OVER 2.5 deg.C.

    You’ve lived up to your usual habit by fulfilling the prophecy of this post’s title: spin.

  56. Lynn Vincentnathan:

    I’m wondering about el nino & la nina. Is there some absolute temps that determine whether we are in one of these, or are they relative temps. (Or are these just particular configurations of temperatures, with the average temp of the entire oceans remaining the same?)

    It seems to me with the ocean warming, there would be more el nino years as GW progresses, and less la nina….unless it’s based on relatively greater or lesser temps year to year.

  57. Kevin McKinney:

    Is it just me, or does attempting to “explain” warming trends in terms of cycles really just tacitly abdicate explanation?

    More specifically, how does a cycle such as PDO affect the planet’s energy budget? If it can’t, then it isn’t really a “cause” of warming or cooling, though it may be part of a larger mechanism, I suppose.

    Aren’t such cycles just emergent distributional patterns within the various energy fluxes, all of which are driven by solar input and modified by the effective rate of radiational output at TOA?

  58. Lynn Vincentnathan:

    RE #29 & “won’t taking latent heat of melting out of the equation — if the ice disappears early enough to make a difference — mean that temperatures go up faster for the same net energy change..”

    A physics teacher I know wondered the same thing, and spoke of how a glass of water with ice cubes stays fairly cool until the last cube completely melts, then the water warms fairly quickly to room temp. I think he said that the reason the water didn’t warm linearly as the ice melted, is because energy was going into the melting process, rather than the warming process; but once there was no more ice the energy went directly into the warming.

    Seems this might hold for larger scale events, such as the arctic ice melting (i.e., there would be more warming in the arctic ocean in our current times, except some of the “warming” energy is going into the melting process rather than warming).

  59. mauri pelto:

    Back online after five days without power thanks to bizarre ice storm in northeast. Every other ice storm I have experienced is light freezing rain that goes on and on. This was a major downpour that still managed to freeze. Good post, I wonder what the next substantial el nino will bring given that la nina could not remove 2008 from the top ten?

  60. Maya:

    #51: 0.5 degrees in 70 years might not be (to you – it will be to my grandchildren!), but 0.5 degrees in 20 years (see figure 1: http://earthobservatory.nasa.gov/Features/ArcticIce/arctic_ice3.php) is considerably more alarming. The problem is the ice, or rather the lack thereof. As this quote (from here: http://earthobservatory.nasa.gov/Features/ArcticIce/arctic_ice4.php) explains rather succinctly:

    “…as sea ice melts, Arctic waters warm, greatly altering ocean processes, which in turn have an effect on Arctic and global climate, says Michael Steele, senior oceanographer at the University of Washington, Seattle. As the oceans warm and ice thins, more solar energy gets absorbed by the water, creating a positive feedback that leads to further melting and warming.”

  61. John Finn:

    Re: #55

    You’ve lived up to your usual habit by fulfilling the prophecy of this post’s title: spin.

    I don’t do spin,Tamino . I did a quick and hurried least squares fit on 1935-2007 (GISS 64N-90N) then multiplied the annual rise by 72 (number of years). I might have made an error. I did it in my head and the GISS values are in 0.01 deg, so it’s more than possible. I haven’t got access now but I’ll check it again later and if I’ve made a mistake I’m quite preapred to admit it.

    More specifically, how does a cycle such as PDO affect the planet’s energy budget? If it can’t, then it isn’t really a “cause” of warming or cooling, though it may be part of a larger mechanism, I suppose.

    It doesn’t but it can allow more heat from the oceans into the atmosphere. This is where our measurements have been taken over the past 100 years. As I said to Wayne, above, these are the only comparisons we have.

  62. Red Etin:

    #49 Richard

    “The arctic sea ice will ~finish melting and then everyone will agree. Two to four years should be long enough.”

    If you can guarantee an ice-free Arctic, you might want to advise those who are currently building Arctic rigs and ice-breakers. I’m sure they’ll pay you a bunch. Then come and see me, I’ve got a bridge for sale.

    Looks at the facts of sea ice cover, not the waving and frothing of alarmists:

    http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.area.jpg

  63. Pat Neuman:

    Re 3, 24,

    ref: Abrupt Climate Change: Will It Happen this Century?

    http://www.climatescience.gov/Library/sap/sap3-4/final-report/sap3-4-press-release.pdf

  64. tamino:

    Re: #61 (John Finn)

    The arctic trend from 1935 to 2007 is demonstrably nonlinear — a linear trend can easily be shown to underestimate the warming. Severely. In fact, the arctic trend from 1975 to the present is also demonstrably nonlinear, and a linear trend again underestimates the warming. This is in sharp contrast to the global trend from 1975 to the present, which is statistically indistinguishable from a linear trend plus stochastic (random) noise.

  65. dhogaza:

    If you can guarantee an ice-free Arctic, you might want to advise those who are currently building Arctic rigs and ice-breakers. I’m sure they’ll pay you a bunch.

    An ice-free arctic in the summer won’t get rid of the need for ice-breakers in fall, winter, and spring. Nice little strawman you’ve got there.

  66. colin Aldridge:

    I have seen a couple of papers, admittedly only in the blogosphere, which try and model the bit between climate change and weather based on AMO ENSO and CO2. These attempts give much better fits than ENSO plus C02 alone and suggest the CO2 component is nearer 0.7c for a doubling which is below the low end of IPCC by quite a lot.

    Do you have a view on this Gavin. The obvious criticism is that given enough variables you can get anything to fit anything but its clear there are “natural variations at work” which are more than noise and CO2 signal

    [Response: The main issue is that in the real world many things trended up in the 20th Century - sulphate aerosols, CO2, black carbon, maybe even solar for the earlier part at least. Therefore any correlation analysis will conflate these things and so you can get any one of them you like to explain all the trend. None of these correlation methods of climate attribution are robust especially if they use just the global mean surface temperature - which is why physics-based methods are generally preferred. There are some analyses that are worse than others though - for instance using a trend+AMO to match the N. Hemisphere temperatures is simply correlating the temperature with itself. Not much predictability there. Similarly, correlating T against CO2 and expecting the coefficient to give the equilibrium response is just foolish. - gavin]

  67. RichardC:

    57 Kevin, you’re right that it’s primarily just a masking of the underlying trend. Technically, I think the common knowledge is actually backwards! An El Nino warms the surface of the planet, so more heat will escape to space. La Nina cools the surface, so less heat escapes. On a first-order level, El Nino cools the total ocean/atmosphere system while La Nina warms it. As you said, the oceans count and atmospheric heat content is negligible compared to OHC.

    62 Red, note the ~ in front of “finish”. It means approximately. Also note that the ice is thinning more rapidly than the extent is declining. The extent figure is extremely misleading. The only reason it is used is that it used to be impossible to measure volume. When I asked them a few months ago, the NSIDC said that within a year or two volume measurements will be up and running.

    Dr Maslowski made an estimate in 2007 which used data through 2004 and came up with 2013 as the first year with a total meltdown of arctic sea ice. Add in 2007 and 2008 data, and that prediction seems pretty solid. http://news.bbc.co.uk/2/hi/science/nature/7139797.stm

    As for icebreakers, that most of the ice will clear in September doesn’t negate the need for November-July. With more utilization of the Arctic Ocean, I’d guess icebreakers will be as busy as ever.

    Why do deniers ask for a guarantee when parsing statements which are caveated with “~” and “should”? If I was gonna give a guarantee, I’d a done it. The caveats were carefully inserted and the phrase was in the context of convincing people. I stand by my statement that essentially everyone will be probably be convinced within 4 years.

  68. John Finn:

    Re: #61 (John Finn)

    The arctic trend from 1935 to 2007 is demonstrably nonlinear — a linear trend can easily be shown to underestimate the warming. Severely. In fact, the arctic trend from 1975 to the present is also demonstrably nonlinear, and a linear trend again underestimates the warming. This is in sharp contrast to the global trend from 1975 to the present, which is statistically indistinguishable from a linear trend plus stochastic (random) noise.

    Ok – I’ll give you that. Though, the non-linearity essentially results from the ocean cycles.
    The fact remains that the rate of warming in the early 20th century is comparable to that in the late 20th century whether you look at the Arctic in isolation or the globe as a whole and since CO2 levels were markedly different in the 2 periods there must be another significant factor. Incidentally you appear to have written something which contradicts itself but I think I understand your meaning.

  69. John Finn:

    Re: #67

    57 Kevin, you’re right that it’s primarily just a masking of the underlying trend.

    Surely a strong El Nino phase amplifies the trend while a La Nina phase masks the trend. The underlyimng trend, therefore, probably lies somewhere between the 1945-75 trend and 1976-2008 trend.

  70. David B. Benson:

    John Finn (68) — A good approximation formula for the CO2 is logarithmic in the concentration, as found here:

    http://forecast.uchicago.edu/samples.html

    but the emissions have increased approximately exponentially:

    http://cdiac.ornl.gov/trends/emis/tre_glob.html

    and the combination, leaving all other factors aside, gives (nearly) a linear trend line. Which, given I’ve left everything else out is about what you’ll eyeball using the decadal averages from the HadCRUTv3 global surface temperature product:

    http://tamino.files.wordpress.com/2008/04/10yave.jpg

  71. tamino:

    Re: #68 (John Finn)

    All you have to do is look at the linear fit compared to the data, to see how obviously bad that model is. So either you looked and went with that model anyway, or you didn’t even look.

    And now I’m supposed to believe you when you say “the non-linearity essentially results from the ocean cycles,” and “there must be another significant factor”?

  72. John Millett:

    Deviations from trend also provide useful information. Define weather as annual temperature observations and climate as n-year average weather. The maximum deviation from (linear) trend in the Hadcrut2 (winter) data 1850-2007 occurred in 2006 for n=25 and in 1884 for n=35. The recent warming, despite the accompanying unambiguously higher emissions, is not unambiguously exceptional.

    [Response: .. in terms of variability. However, you have to factor in a larger uncertainty in the earlier data... - gavin]

  73. wayne davidson:

    #68 John Finn.

    “The fact remains that the rate of warming in the early 20th century is comparable to that in the late 20th century whether you look at the Arctic in isolation or the globe as a whole and since CO2 levels were markedly different”

    warming not comparable to recent days, especially with Arctic ice, I am not aware of any historical descriptions comparable to ice conditions now a days, from 1900 to 1950, or from 1985 backwards…

    #62 Red Etin, “Looks at the facts of sea ice cover, not the waving and frothing of alarmists:”

    Good idea, wrong adjective:

    http://www.natice.noaa.gov/pub/West_Arctic/Canadian_Arctic_West/2008/canwcurrentcolor.pdf

    http://www.natice.noaa.gov/pub/West_Arctic/Canadian_Arctic_West/1996/canw961203.gif

    Even with Polar ice completely melted during the summer in the future, Arctic ice extent will
    be quite high during the long night till mid March. Its volume which matters. If you understand the links above, volume is wholesale a lot less compared to 1996, along with open water, with very little multi year ice in the archipelago. We are mostly talking about Climate Change, which is happening, not” Climate Armageddon”… Never read once, not once, Gavin and peers trying to frighten the willies out of anybody.

  74. John Lang:

    Some have asked about the El Nino and La Nina trends over time (and the AMO index as well).

    The Raw data shows there is slight warming trend in both of these indices going back to 1871 and 1856 respectively. There is an increase of 0.035C per decade in the Raw Nino 3.4 region data and a 0.023C per decade trend in the Raw AMO data. Yes, the oceans are warming but these trends are 10% to 20% of the predicted surface warming trend of about 0.2C per decade.

    If you pull the trend out of the ocean indices, as you should do, you can get something like a natural climate variable. The ENSO can affect temperatures by as much as +/-0.2C. The AMO has a bigger impact at as much as +/-0.3C impact.

    Here is the detrended Nino 3.4 anomaly back to 1871 – lots of rapid ups and downs. 80% of the peaks (up and down) occur around December.

    http://img218.imageshack.us/img218/6444/nino34anomalyft6.png

    Here is the detrended AMO index which has much longer cycles of 25 years or so but shows much less overall variability than the ENSO has (+/-0.6C versus the ENSO at +/- 3.0C). Note that it does seem to match some of the bigger climate cycle swings such as the downswing from 1900 to 1919, the upswing from 1920 to 1945, the downswing from 1946 to 1975 and the upswing from 1975 to 2006.

    http://img234.imageshack.us/img234/2853/amoanomalyrc3.png

    For comparison purposes, here the untrended Raw AMO index which shows an definitive increase over time but the scale and the lower magnitude of the AMO variability makes it look bigger than it really is.

    http://img357.imageshack.us/img357/900/trendedamoindexkq9.png

  75. Hank Roberts:

    John Lang, pointer please to the source of those images and the data used; if the images are your own work, where did you get the data?

  76. Peter Brunson:

    Always enjoy the posts on this site.

  77. Ark:

    On #72: Gavin, isn’t the real point that the magnitude of individual year deviations from the (rising) trend says nothing about the “exceptionality of recent warming”?

  78. Mark:

    Hank, 75, you may want to hold back on the “links links LINKS!!!” mantra.

    Try saying what you think is going on and then asking what shows your version to be wrong and theirs right. If you think they are right then ask and say it is so you can see whether it’s a “gut feeling” or whether there’s real information backing it up.

    I mean, if you don’t know what else it should be, why do you think it could be wrong? That’s a denialism.

  79. colin Aldridge:

    NCAR publishes NAO data going back to 1860. You can find it here. http://www.cgd.ucar.edu/cas/jhurrell/indices.html

    This does show an upward trend but it is pretty small as John Lang suggests
    An analysis of the NAO by Hurrell can be found on the same website. His paper, some years ago, was agnostic on whether AGW drives/forces/influences the NAO.

  80. X:

    Re: #70 David B. Benson

    If the increase in CO2 over the last century is exponential, the resulting forcing wouldn’t be linear with time, due to the pre-existing CO2 concentration.

    log(A + B*exp(k*t)) is not close to linear in t unless B*exp(k*t) >> A, which is not currently (and hopefully ever) the case.

    [Response: You haven't got it quite right. Exponential growth in this context is related to a fixed time for doubling or a constant percentage growth. This can be written as C=C0 * (1+a)^t or C=C0 * exp(kt). Forcing is ~log(C/C0) = t*log(1+a) or k*t and thus is linear in time. - gavin]

  81. Ray Ladbury:

    Philip and Lynne, On the question of whether all the melting ice could be slowing warming, the headline today saying we’ve lost 2 trillion tonnes of ice since 2003. A very rough back of the envelope calculation suggest that energy required to melt that ice is equivalent to 1-2% of the additional energy due to greenhouse warming over the same period. Not insubstantial, but not all that significant.

  82. Todd Friesen:

    74,

    Linear detrending doesn’t make a lot of sense, particularly when you are trying to control for anthropogenic forcings, which has certainly not been linear over the 1856-2008 period. It’s just a local temperature proxy to estimate global temperatures. Just about any local temperature proxy (covering the same amount of area) will fit as well as AMO. ENSO variability helps explain global temperatures, as it combines statistical correlation with physical science. the fact that AMO has low variability suggests you have to be especially careful in attributing cause to a correlation. It probably trends the global temperature anoamlies well, becuase, well, global temperature changes are causing unadjusted AMO variability.

    For kicks, I tried incorporating AMO in my 30 year model, and it improved the fit somewhat. The problem is that the shape of AMO doesn’t differ significantly from anthropogenic forcings, and so one can be substituted for the other. One way to interpret this is that anthropogenic forcings are a significant cause of AMO variability (in addition to solar, ENSO, volcanic and anything else that affects climate).

  83. Hank Roberts:

    Todd, you’re claiming the AMO — the “O” stands for “oscillation” — matches the result from increasing CO2.

    Wha-a-a-at?

  84. Rando:

    More back-of-the-napkin trivia – two trillion tons of ice over 5 years is roughly equivalent to the total discharge of the Mackenzie River, which flows directly into the Arctic basin, over a 6 year period (annual mean of ~10,000 cms).

  85. X:

    Re: #80, Gavin’s response

    C = C0 * exp(k*t) is of course pure exponential growth, but an equation of that form doesn’t well represent the historical atmospheric CO2 concentration during industrialization, which was the original context (See #70). An added constant, A ~= 280, corresponding to pre-existing CO2 improves it greatly, but removes the linearity of the final expression. Gavin, I assume it’s uncontroversial that the CO2 forcing has increased at an increasing rate over that period.

    [Response: No-one is claiming that the entire history of CO2 change has been exponential - that wouldn't be a good fit at all. The issue is how it is increasing now. (By the way, your expression has the concentration at t=0 (pre-industrial) C0=A+B (not A)). But in any case, do an expansion about today (t1) and you will see that the forcing increase is linear in time i.e. F ~ F(t1) + k*(t-t1)*B*exp(k*t1)/C(t1) (minor correction made) - gavin]

  86. keith:

    Aren’t there 4 different global temperture sets? Why don’t you include the satellite data from UAH MSU?

    [Response: The satellite data measure something different. They are not equivalent to the surface temperatures and comparisons with the models would need to be with those diagnostics specifically. I would also point out that there are multiple versions of those data products as well, and so any comparison should be with all of them (RSS, UAH, UMD (not up to date unfortunately), not just one that you might prefer for some reason. I'll put up a post on the differences at some point, but the description here is a useful start. - gavin]

  87. William:

    Gavin, instead of selecting 1999 or 1998 as the reference year could you show us what the graph would look like if you pick the baseline used by the IPCC in the AR4?
    Thanks

    [Response: There are lots of different baselines used in IPCC for different reasons and there is no objective way to prefer one over another. But the figures using 1979 or 1990 are linked above already. The basic picture is the same - 2008 is a cool anomaly on the back of a warming trend and is very analogous to similar cool anomalies that occur in the models at random intervals. If you want something more specific let me know. - gavin]

  88. Todd Friesen:

    83,

    I don’t think there’s as much oscillation going on there as indicated by the linear detrended data. The linear detrending was intended to control for GHGs, but since net anthropogenic forcings are not linear, the untrended data is suspect.

    There’s some discussion on this issue here: http://en.wikipedia.org/wiki/Atlantic_Multidecadal_Oscillation.

    The question I have is how much of the current AMO warming period is due to a faster local effect of Anthropogenic Global Warming? How would the shape differ if the detrending was done with Net Climate Forcing data, rather than just linear detrending over a 152 year period of time?

    Since I’m not an expert, I will defer to those who are. I’m just giving reasons why I think the theory is suspect.

    Perhaps Gavin can comment on this?

    [Response: I commented on this very issue in an earlier comment thread a few months back: "In control simulations with GCMs such as used in Delworth and Mann (2000) and Knight et al (2005), there is no need to separate the internal multidecadal variability from the forced long-term trend, because there is no change in radiative forcing, and thus no forced (including anthropogenic) large-scale trend to contaminate the estimate of internal multidecadal variability. No such luck in the real world, where both are present. In that case, one needs to use some technique for separating the multidecadal variability from the long-term trend. In many papers, this is simply done by subtracting off a linear trend and defining the residual as e.g. the "AMO". I don't particularly like that approach, because the radiatively forced temperature trend is extremely unlikely to be linear in time [this is an issue we discussed in Mann and Emanuel (2006)]. I prefer frequency-domain signal detection techniques such as the “MTM-SVD” technique (for obvious reasons) which was employed by both Delworth and Mann (2000) and Knight et al (2005).” -mike]

  89. Anon:

    As scientific men we should set up a common set of parameters for verification. What kind of temperatures in the next ten years would match the data and what would not?

  90. X:

    Re: #85, Gavin’s response

    … No-one is claiming that the entire history of CO2 change has been exponential …

    Sorry to go on about this minor point. Post #70 was suggesting that CO2 emissions followed an exponential course over a long period, and that therefore the corresponding forcing was linear over the same period (at least since the early 20th century, as this was a response to #68). I was just pointing out that this does not follow, as the forcing goes with the log of total concentration, not the increase (leaving aside how the increase in concentration relates to emissions). Of course the CO2 forcing can be represented as locally linear, but that wasn’t the issue.

    [Response: Well, it's worth pointing out then that the history of CO2 forcing has not been perfectly exponential in the past. However, it is close to exponential now, and the forcing is increasing roughly linearly in time. - gavin]

  91. JW:

    “There will undoubtedly also be a number of claims made that aren’t true; 2008 is not the coolest year this decade (that was 2000), global warming hasn’t ‘stopped’…”

    However, 2008 was the second coolest year of this decade (using your graph), so that statement would be correct.

    [Response: A decade is 10 years. The statement is wrong. - gavin]

    If global warming hasn’t “stopped”, then why isn’t it getting warmer? Your 1999 figure shows 2008 almost returning to 1999 levels. Do we see any reason to expect an upturn in 2009?

    [Response: Yes. Based on our understanding of climate physics, I think the likelihood of a warmer 2009 is very high. - gavin]

  92. Ray Ladbury:

    Anon, Ya just don’t get it, do you? You can’t tell much of anything from looking at a decade–any decade. Climate is noisy. Period. It is only on multi-decade timescales that long-term trends emerge from the noise.

    X, what matters is the change in concentration and the change in forcing–and that is pretty close to linear.

  93. snorbert zangox:

    Gavin,

    When I look at the comparisons of temperature change vs. model prediction that you showed us, I see something different from what I think that you see.

    The first thing that I see is a fallacy of the faggot. You have plotted the output of what looks like a couple of dozen different model simulations. None of them does a particularly good job of tracing the actual temperature changes, but in aggregate, the eyeball average of all of them appears to fall at approximately the ending temperature for the 10-year graph. Even if the aggregate of the models falls close to the 20- and 30-year graphs, the aggregate of a couple of dozen weak arguments is not a strong argument for model accuracy, just as a faggot, a bundle of sticks, is not as strong as a log of equal diameter.

    Secondly, the eyeball average of the model outputs does not fall particularly close to the endpoint of the temperature record. It falls somewhat above the ending temperature of the 20-year graph and it falls far above the ending temperature of the 30-year graph.

    Finally, I see that the eyeball line of best fit through the model outputs on the 30-year graph implies a trend of approximately 1.5 C degrees per century. If this trend continues, I cannot see the need for panic. That would mean that the temperature change during the next century would be just a bit larger than we have seen in the past century; a change that has caused no obvious harm. Or, perhaps you consider a 30-year trend to be a short-term change that probably does not predict the long-term accurately. Which brings me to ask, what length of change can we assume will predict long-term changes? Is the 130 or so year time that humans have been measuring temperature adequate?

    One more thing. All of these comparisons use temperatures between 1980 and the present. Why did you not include the satellite data in your comparisons?

    [Response: see above. Satellite data are a different diagnostic of the climate - related, but not commensurate. - gavin]

  94. JW:

    “There will undoubtedly also be a number of claims made that aren’t true; 2008 is not the coolest year this decade (that was 2000), global warming hasn’t ’stopped’…”

    However, 2008 was the second coolest year of this decade (using your graph), so that statement would be correct.

    [Response: A decade is 10 years. The statement is wrong. - gavin]

    (JW response – OK, if you are including 1999, your “base” year, than 2008 is the third coolest this decade. My point is that calling 2008 the third coolest (rather than the second coolest) this decade is just as accurate as calling it the “…the coolest year this century (starting from 2001)..” (a correct statement) )

    [Response: That wasn't the statement in question. Your point? - gavin]

    If global warming hasn’t “stopped”, then why isn’t it getting warmer? Your 1999 figure shows 2008 almost returning to 1999 levels. Do we see any reason to expect an upturn in 2009?

    [Response: Yes. Based on our understanding of climate physics, I think the likelihood of a warmer 2009 is very high. - gavin]

    (JW response – In that same manner, were you at this time last year predicting that 2008 would be cooler or warmer than the 6 or 7 previous years?)

    [Response: There was a substantial La Nina brewing this time last year and 2007 was (or very close to) the warmest year on record. Thus I would have predicted 2008 to be a cooler year than 2007 - Now, I don't recall actually making such a prediction (though possibly I did somewhere in the comments?) - but the GISTEMP authors did. Their statements seem to have been vindicated. - gavin]

  95. Kevin McKinney:

    “Even if the aggregate of the models falls close to the 20- and 30-year graphs, the aggregate of a couple of dozen weak arguments is not a strong argument for model accuracy, just as a faggot, a bundle of sticks, is not as strong as a log of equal diameter.”

    Incorrect analogy. Model realizations will (and should) differ; their clustering *does* tell us something.

    “Secondly, the eyeball average of the model outputs does not fall particularly close to the endpoint of the temperature record.”

    Who cares? The endpoint is not a privileged datum.

    “That would mean that the temperature change during the next century would be just a bit larger than we have seen in the past century; a change that has caused no obvious harm.”

    Perhaps you should go back and have another look at AR4.

  96. Maya:

    “a change that has caused no obvious harm”

    Tell that to the polar bears.

  97. David B. Benson:

    snorbert zangox (93) — I’ll not attempt here to list all the harms which global warming has already caused to those living on some edge of the cryosphere, i.e., below glaciers or near the sea of the wwest coast of Alaska. Nor will I attempt to relate droughts and floods to global warming, others have already done that.

    Instead I just encourage you to read Mark Lynas’s “Six Degrees”.

  98. snorbert zangox:

    JW, Gavin,

    The year 2000 was the last year of the 20th century. Think of it as 199ten. The first year of the 21st century was 2001.

  99. Chris Colose:

    JW,

    The problem is this whole ranking of individual years, which is not a good way to think about climate. What’s more, the uncertanties over an individual year may be greater than the differences between the nth greatest, nth-1, nth-2, etc years on record. Gavin’s statement about next year being warmer than this probably reflects the La Nina at the beginning of the year rather than the extra years worth of CO2, which is very small. IF you’re addicted to which year comes in 1st and second and third, etc like the media seems to be, then ENSO variations play a large part in that, but it is very small compared to the longer term (~0.7-0.8C) trend.

  100. snorbert zangox:

    Gavin,

    What is not commensurate about the satellite temperature data?

    [Response: They measure something different (MSU-TLT is a weighted average of temperatures reaching from the surface to 10km, peaking at around ~4km and with significant influence from surface type depending on elevation and polar latitude). Therefore comparing them with surface temperature anomalies from the models is not comparing like with like i.e. they are incommensurate. There are ways to create synthetic MSU data from the models, and I'll discuss this in another post. - gavin]

  101. JW:

    Gavin – thanks for your responses to me, above. In an article cautioning about “spin”, I can see it would be difficult for you not to engage in a little spin of your own.

    Quote from your article: “Thus we are sure that you will soon read that 2008 was warmer than any year in the 20th Century (with the exception of 1998), that is was the coolest year this century (starting from 2001), and that 7 or 8 of the 9 warmest years have occurred since 2000. There will undoubtedly also be a number of claims made that aren’t true; 2008 is not the coolest year this decade (that was 2000),…”

    So, the phrase “was the coolest year this century” is correct, but the phrase “2008 is not the coolest year this decade” is not correct? If “This century” is from 2001 on, then in order to be consistent, “this decade” should also be from 2001 on. If 2008 was the coolest year this century, then it is also the coolest this decade. Or, they both should be relating to the last 100 years or last 10 years, respectively. It’s your site, it’s your spin.

    I understand your reluctance last year to have predicted 2008 would be cooler than 2007.

    Regards,
    JW

    [Response: With all due respect, this is kind of tedious. A decade is ten years. 2008 is not the coldest year this decade. Enough already. - gavin]

  102. Kevin McKinney:

    #98–”The problem is this whole ranking of individual years, which is not a good way to think about climate.”

    Well, it’s not the most sophisticated. But it is a useful way to get at trends when talking with folks without a statistical background. For a lot of people, the statement that “every year from 2001 forward falls in the list of the 10 warmest years of all time,” is a powerful corrective to the “it’s been cooling since 1998″ meme. Many people have trouble seeing why you shouldn’t just make that obvious point-to-point comparison.

  103. jorge kafkazar:

    # jcbmack Says:
    16 December 2008 at 3:55 PM

    “Gavin, good presentation as always, but this one in particular shows why global warming is still happening and why it will not just go away.”

    I agree. The graphs themselves are particularly impressive examples of intermodel concurrency. Although the scatter may appear at first glance seem quite extensive, it’s readily obvious to the eye that, despite broad swings of the various models, the actual data record trendlines stays well within the +/- 1 sigma envelope, very similar to the way it would have if random numbers had been used instead of the GC models. Perhaps not profound, but very interesting and very illustrative nonetheless.

  104. S2:

    If global warming hasn’t “stopped”, then why isn’t it getting warmer? Your 1999 figure shows 2008 almost returning to 1999 levels. Do we see any reason to expect an upturn in 2009?

    If 2009 turns out to be cooler than 2008, then that would probably put it below the warmest ten years seen to date.

    It’s not impossible, but this hasn’t happened since 1992.

    I would bet money on 2009 being warmer than 2008.

  105. John Millett:

    Gavin’s response to #72 warned of the greater uncertainty of 19th century data. Statistical analysis reveals in the more recent 1959 – 2005 period, that when emissions increased relative to trend, temperatures fell relative to trend; and vice versa. The science says that emissions are linked to temperature via atmospheric concentration of CO2. During this period, when emissions increased relative to trend, concentration fell relative to trend; and vice versa. The corollaries of this counter-intuitive finding are: atmospheric CO2 concentration must be responding to something other than emissions; controlling emissions won’t control concentration; and if, as protagonists claim, concentration controls temperature, policies to control emissions would fail to achieve their objective.

    Over the period 1959-2007 direct correlation between concentration and temperature implies that changes in the former explain about half the changes in the latter. However, correlation does not necessarily denote causation; concentration and temperature could both be responding independently to a third climate agent, as two features of the climate system suggest is likely. Given that the atmosphere does not mix across the equator and that most emissions of CO2 are generated in the northern hemisphere, how do they become uniformly distributed in the atmosphere? And how does uniformly distributed CO2 concentration cause the northern hemisphere to warm faster than the southern one? While the atmosphere keeps to its side of the equator, ocean currents, with which the atmosphere exchanges CO2, range across it. There is here a strong suggestion that the oceans, not emissions, are feeding the atmosphere with CO2. Not only do the oceans range more widely than the atmosphere but they constitute an infinitely greater heat sink with commensurately greater potential to affect surface temperatures around the globe. Oceans could be the third climate agent affecting both concentration and temperature, rendering spurious the observed correlation between them. Add the inverse correlation between emissions and concentration and severe doubt emerges about man’s ability to control temperature by controlling emissions.

  106. steve:

    I have to admit I’m a bit confused on why a changing current does not effect the energy budget when they are known to effect the temperature. Wouldn’t the albedo of the earth change depending on how severe winters were and the location where most storm fronts occurred. Could anyone point me to a paper on this I hate to waste everyone’s time answering someone out of their field. thanks

  107. Aaron Rury:

    One of the major policy pushes in reference to AGW is to systematically reduce the amount of carbon that is emitted into the atmosphere. Since we are exactly sure what the impact of carbon emitted into the atmosphere, besides its effect on overall absorption of light, is it too naive to think that just reducing the amount of carbon emitted into the atmosphere will reduce the temperature? Is there a way to a priori determine whether or not the atmosphere with exhibit a hysteresis between CO2 concentration and temperature as we reduce carbon emission? I have tried to find some publication that research this idea, but have not found anything on the topic. Any directions would be much appreciated. Thanks.

  108. David B. Benson:

    John Millett (105) — I disagree with central points in your analysis, but I’ll just mention that CO2 is well-mixed in the atmosphere with a mixing time of about 2 years; air does cross the ITCZ.

    And of course the southern hemisphere, being mostly ocean, warms more slowly than the northern hemisphere.

    Oh yes. You might also care to look at the great changes in atmospherin methane over the interval of interest to you.

  109. David B. Benson:

    Aaron Rury (107) — Even if human-caused emission ceased today, the world would continue to warm for centuries as the oceans slowly respond to the extra warmth. There are many papers, but I suggest you read David Archer’s “The Long Thaw” as a place to begin.

  110. Jim Eager:

    Re Red Etin @62: “Looks at the facts of sea ice cover, not the waving and frothing of alarmists:
    http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.area.jpg

    Which tells us only that the Arctic still refreezes each winter but tells us nothing about the age or volume of that ice.

    What was that you were saying about waving and frothing?

  111. Ray Ladbury:

    John Millett, Great. Now go design a climate model that explains everything in terms of your idea, figure out exactly by what mysterious mechanism ocean currents are controlling everything and you can get famous and go on Oprah! Go ahead. We’ll wait.

  112. S. Molnar:

    OT: I have grown to expect RC to cover the Fall AGU meeting. Is a post planned? Even if we can’t have the incomparable liveblogging of raypierre this year, a quick summary of potentially interesting developments would be welcome.

  113. Ike Solem:

    RE#33

    Quote: “What we don’t have is a word for what happens over periods from a few weeks to few decades.”

    That’s likely mostly ocean variability, plus random events like large volcanic explosions. Pinatubo, for example. Here’s a worthwhile post with comments from 2006 on that, interesting in hindsight (since the 2005 estimates of cooling ocean surface waters were based on flawed data):

    http://www.realclimate.org/index.php/archives/2006/08/ocean-heat-content-latest-numbers/

    For the published report, see Robock:
    http://climate.envsci.rutgers.edu/pdf/VEAChapter1_Robocknew.pdf

    The ocean is where many of the greatest uncertainties lie, but those are mostly of the week-to-decade variety, as far as long-term temperature trends due to atmospheric CO2 forcing go…. Spreading ocean hypoxia might be a bigger concern than ocean acidification, actually – but with such limited data, it’s hard to tell. We do know that large hypoxic zones are now a regular part of the seasonal regime of many ocean areas, from the Pacific NW to the Gulf of Mexico. We don’t really seem to have a good idea of how major ocean circulation patterns will change as the planet warms, either. The El Nino/Southern Oscillation is an example of internal variability, but it’s also an example of changes in the heat/water vapor exchange between ocean and atmosphere brought on by atmospheric and oceanic circulation changes, and all that will itself be influenced by warming waters and land bodies.

    As far as abrupt climate change, the first examples might be transitions to permanent drought regimes, with global warming-induced changes in atmospheric circulation over the oceans playing a role. “Abrupt” here means over a 30-year period or so, as in sub-Saharan Africa.

    1. http://www.newscientist.com/article/dn9229-global-warming-stretches-subtropical-boundaries.html

    2. Model Projections of an Imminent Transition to a More Arid Climate in Southwestern North America, Seager et. al 2007

    3. Widening of the tropical belt in a changing climate, Siedel et. al 2008

  114. Hank Roberts:

    Anon, ocean currents:
    http://scholar.google.com/scholar?q=%22ocean+currents%22+Panama+climate

    Aaron Rury:
    http://www.nature.com/climate/2008/0812/images/climate.2008.122-f1.jpg

    _____________
    “actors realism”

  115. Ron Durda:

    Gavin,
    Re: your response to JW in post 101 (Dec. 18, 5pm).

    With all due respect there seems to be two plausible interpretations to your statement that, “A decade is ten years. 2008 is not the coldest year this decade”.

    Webster’s New World Dictionary, Third College Edition, provides two definitions that are germane to this issue. A-“a group of ten“, and B “ …officially, a ten year period beginning with the year 1, as 1921-1930…etc. [and in] common usage, a ten year period beginning with a year 0, as 1920-1929…etc.”

    Thinking of def. “A”, your claim about the coldness of 2008 could be paraphrased 2008 is not the coldest year IN THE PAST TEN YEARS, while with def. “B”, the paraphrasing would be that 2008 is not the coldest year SO FAR this decade (either officially or in common usage).

    This ambiguity could be resolved if you would give an actual starting date for your decade…or did I miss it?

    Thank You,
    Ron.

  116. Dave Werth:

    Gavin, in #100 you said “…temperatures reaching from the surface to 10km, …”. Is that 10km above the surface regardless of the elevation of 10km above sea level?

    [Response: Actually it varies as a function of surface type. Closer to 10km above the surface than above sea-level though. - gavin]

  117. Philip Machanick:

    #62 Red Etin says:

    Looks at the facts of sea ice cover, not the waving and frothing of alarmists:

    http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.area.jpg

    I looked at that, thank you. With neither waving nor frothing, I observed that the minimum summer sea ice extent dropped from 5.5Mkm2 to 3Mkm2 over the period graphed, a decrease of 45%. Is that what you wanted us to pay attention to? Or were you hoping that sneering would frighten us off from checking the facts?

    We have a recent prediction from a large study that the Arctic will be ice free by 2015, a big advance on the previous surprise prediction of 2030.

    Purely looking at ice extent misses another important variable, ice thickness. As ice becomes thinner because more of it is fresh since last summer (here’s a reference with a more complete analysis), sea ice extent can fall of very fast in summer.

  118. rando:

    Re 117: I’m willing to bet you 1 million dollars that the Arctic will not be ice free by 2015.

    [Response: You'd be better off finding someone who predicted that (if anyone) - gavin]

  119. Hank Roberts:

    Rando, the bets so far are about summertime ice, is that what you mean?
    See Stoat for details.

    S.Molnar, re blogging from the ACU, I agree, I’d been hoping to hear more from those attending this year. There are some out there:

    http://www.google.com/search?q=2008+AGU+%22San+Francisco%22+blogging

  120. Philip Machanick:

    Rando (#118): Of course I meant summer ice (#117), not the whole year.

    It’s kind of silly to score points on a narrow nitpick. The world climate does not depend on my (or any one elses) ability to express myself clearly.

  121. Mark:

    re #118. Do you even HAVE a million?

    OK, I bet a bajillion squillion dollars.

  122. Mark:

    Aaron, 107, it will stop getting worse quicker. That’s all that will be certain of happening. Depending on how MUCH we reduce output, the CO2 may start reducing fairly quickly, though the results of this may be unwelcome (acidic waters, for example). The inertia of the system may still continue but the length of time for that change to get noticed depends on how much CO2 is reduced.

    Maybe the reason why you find nothing is because it’s not a question that needs to be answered.

    After all, if your doctor tells you to stop smoking because of the cancer risk, you stop. This may not stop a cancer that has already started growing but if there is one, it is easier to treat.

  123. Andrew:

    Re #106 Steve;

    This paper describes trends in snow cover extent.

    http://www.unep.org/geo/geo_ice/PDF/GEO_C4_LowRes.pdf

    Notice; snow cover extent in the Northern Hemisphere shows a decline except for the months of November and December. Since there is little sun shine during those months, the albedo feedback are minimal.

    In contrast, reduction in snow cover extent is greatest during the spring when albedo feedback is more significant.

    The increased amount of winter snow cover has many people wondering about global warming. However, it is happening because global warming is also leading to increased precipitation, especialy in the winter.

    Re # 115 Rando;

    Could we agree that an ice free arctic corresponds to less than 0.1 Mkm^2 of sea ice and on a definition of a climatically significant volcanic eruption?

  124. Nick Gotts:

    As scientific men we should set up a common set of parameters for verification. – Anon

    All you women, don’t you bother your pretty little heads about climate change any more, you hear?

  125. Ray Ladbury:

    Mark and Rando: In the interest of keeping the bet fair, I volunteer to hold the money while we wait for the outcome. ;-)

  126. ldavidcooke:

    Gavin,

    One quick question, what happens to the trend line if you base it on the mean of the entire population of all the various records, rather then on start year or a specific representative sample year? In short, my thoughts are that comparing data against the entire population values with trend lines for peaks, valleys and averages should provide some interesting fodder for conversation.

    Thanks,
    Dave Cooke

  127. Ike Solem:

    Don’t forget that most of the warming is going into the oceans. That’s the essential reason why the long-term trend is robust – there will be many fluctuations in surface temperature, but the warming signal in the oceans is just as strong.

    Note that ocean temperature changes can be much smaller, yet represent far greater amounts of energy change. If you take a cubic meter of ocean, and a cubic meter of dry air, the difference in the ability to store heat is over 3000-fold (4.186 J/cm^3-K vs. .0013 for air)

    Thus, if the oceans are warming, that will not be erased by any short-term fluctuations in atmospheric temperature. And yes, the oceans are warming:
    http://www.sciencemag.org/cgi/content/abstract/309/5732/284

    Penetration of Human-Induced Warming into the World’s Oceans,
    Tim P. Barnett,1* David W. Pierce,1 Krishna M. AchutaRao,2 Peter J. Gleckler,2 Benjamin D. Santer,2 Jonathan M. Gregory,3 Warren M. Washington4

    Science 8 July 2005:
    Vol. 309. no. 5732, pp. 284 – 287

    A warming signal has penetrated into the world’s oceans over the past 40 years. The signal is complex, with a vertical structure that varies widely by ocean; it cannot be explained by natural internal climate variability or solar and volcanic forcing, but is well simulated by two anthropogenically forced climate models. We conclude that it is of human origin, a conclusion robust to observational sampling and model differences. Changes in advection combine with surface forcing to give the overall warming pattern. The implications of this study suggest that society needs to seriously consider model predictions of future climate change.

    1 Climate Research Division, Scripps Institution of Oceanography, 0224, La Jolla, CA 92037, USA.
    2 Program for Climate Model Diagnoses and Intercomparison/Lawrence Livermore National Laboratory, Post Office Box 808, Livermore, CA 94550, USA.
    3 UK Met Office Hadley Centre and University of Reading, Reading RG6 6BB, UK.
    4 National Center for Atmospheric Research, Post Office Box 3000, Boulder, CO 80307, USA.

    There is no uncertainty about that. Nevertheless, world leaders continue to ignore the reality while making plans to continue with business-as-usual. It’s the Mbeki-Mugabe phenomenon (wrt HIV/AIDS) on a much larger scale – government leaders ignoring science in favor of their own peculiar beliefs – Mbeki appeared to truly believe that HIV did not cause AIDS, and that retroviral drugs were toxic.

    Mbeki ignored the science on HIV, Guardian UK, Dec 17 2008

    “Malicious or not, the former South African president’s Aids policy is responsible for hundreds of thousands of deaths.”

    The same can be said of many other world leaders, whose lack of action today and over the past few decades will also result in hundreds of thousands (if not millions) of deaths over the decades to come.

  128. reenactor:

    Actually, I don’t think anyone with an 8th grade education would describe 2008 as the warmest year of the TWENTIETH century.

  129. William:

    #113 Ike Solem
    You state: “We don’t really seem to have a good idea of how major ocean circulation patterns will change as the planet warms” If that’s the case then the there must not be a good understanding of ocean circulation patterns i.e. the science is not settled.

    You State: “As far as abrupt climate change, the first examples might be transitions to permanent drought regimes” Either it will or will not, when you say something “might” happen it’s uncertain therefore the science on that is unsettled.

    You state: “That’s likely mostly ocean variability, plus random events like large volcanic explosions”. Which is it? Not knowing is uncertainty i.e. the science is not settled.

    It was my understanding that the science was settled on climate change. Anything might happen. If your premise is that the GCM’s are certain about what will happen then there is no need to qualify your statements and predictions. Otherwise let’s all agree to the statement GCM’s might be right or they might be wrong and remove all this reference about the science being settled.
    Thanks
    William

    [Response: Now this is tendentious twaddle. Perhaps you would care to point out anywhere on this site, or in anything any of us have written that declares that 'the science' (whatever that means) 'is settled'? This is simply a false binary distinction (settled/unsettled) foisted on a much more complex situation where there are large gradations in what is understood, done purely to imply that if something is unsettled, we can say nothing. Well, that is BS. (Sorry to be harsh, but really!). - gavin]

  130. Hank Roberts:

    reenactor; you “don’t think anyone … would” — no one has said anything like what you’re mocking. Did you misread the original post?

  131. snorbert zangox:

    Gavin,

    I am not sure that you (in your discussion of incommensurate satellite data) are not merely talking about a different, albeit more complex, physical model needed to get from signal strength to temperature. Every means of measuring temperature requires application of mathematics based on physical theory to convert a signal to a temperature. Liquid in glass thermometers require a different set of physical theory and mathematics than do thermocouples.

    Would you say that data from those two methods are incommensurate?

    [Response: Not unless you had good reasons to suspect that there was a problem there. But why can't you just accept that a weighting of temperature from the ground to 10km, varying as a function of location, is a different quantity than the surface temperature anomaly? Just because something is measured in the same unit, doesn't make it the same. Just for fun, look up what the mean MSU-TLT temperature is globally (not the anomaly, the absolute number), and then come back and tell me it's the same as the surface temperature. They are related, but they are not the same. - gavin]

    Moving on to a slightly different subject. Anthony Watt is at it again. He has plotted the 20th century temperature data as reported by USHCN to the same data as adjusted by GISS for a single station in Santa Rosa NM. (http://wattsupwiththat.com/2008/12/08/how-not-to-measure-temperature-part-79-would-you-could-you-with-a-boat/#more-4455). Mr. Watt demonstrates that 100% of the warming at this station during the 20th century occurred during the adjustment process. The folks over at Climate Skeptic repeated the exercise for the entire 20th century United States temperature record and found a similar result (http://www.climate-skeptic.com/2008/12/global-warming-is-caused-by-computers.html).

    Hmmm.

    To be fair, both sources acknowledge that there are legitimate reasons for making post-measurement adjustments to the raw temperature data, and I agree. I just find it peculiar that the raw temperature record would show little or no warming, but the adjusted data do show warming.

    My musing on all of this led me to an actual question, which is, “What physical data would induce you to reconsider your belief that anthropogenic carbon dioxide is causing the ongoing warming?”

    I know that I am waiting for the GCMs to make some accurate projections of climate conditions before I will reconsider my position. It often seems similar to Waiting for Godot.

    [Response: Well instead of waiting around aimlessly, I suggest you do some reading. Hansen et al 1992 for instance, or even Hansen et al 1988, or Legrande et al, 2006, or IPCC(1990) etc. For what is being claimed in the future, the models have already demonstrated skill. And as for CO2 not causing warming, try redoing the whole of the HITRAN database, showing that Tyndall (1867) and everyone who has followed was wrong, find another reason why the ice ages were as cold as they were, and then invalidate all of radiative transfer theory without undermining all of the existing satellite records. Let me know how that goes. - gavin]

  132. Peter K Miles:

    Baselines:

    With temperature data being reported as anomalies relative to a baseline I am interested in knowing how the ‘standard’ baselines were selected. The most common one appears to be the 1961-1990 period, but I also see 1951-1980. I understand that 30 years appears to be the standard minimum for such climatic comparisons, but why not a longer baseline in a time period that is better compromise between accurate temperature recordings and limited green house gas forcing….say a 90 year period such as 1851 – 1940?

    [Response: You want a period long enough to average over interannual variability, but short enough so that you can see climate change. 30 years is the de-facto standard. - gavin]

  133. Aaron Rury:

    Re: 122

    Mark, I don’t think that you understand my question possibly. In phase space, there are many different trajectories that would give increasing temperature, some with increasing CO2 concentration and some with decreasing CO2 concentrations. This is true of most thermodynamic systems. I was wondering if there were any papers on this issue in the frame of the climate as a thermodynamic system. It seems rather dismissive to claim that this question does not need an answer.

    As for your analogy, if I smoked in the past and stopped before cancer began to grow, I can still get cancer in the future due to my smoking. This is because my cells have a type of “memory” of my smoking. I think our climate system may also have this type of memory when it comes to CO2 or other gas concentrations. Please remember that these systems, like most, are not as simple as we might think.

  134. SecularAnimist:

    Regarding “spin”, the blog at Washington Monthly highlights the following from CNN last night:

    Yesterday, CNN’s Lou Dobbs … told viewers that the weather has been “unbelievable,” because there are “unusual storms and a deep freeze across much of the country tonight.” Dobbs was particularly animated about snowfall in Las Vegas, Malibu, and Payson, Arizona. “So what are those folks talking about global warming?” Dobbs asked incredulously.

    To “discuss” the subject, Dobbs invited CNN meteorologist Chad Myers and Heartland Institute science director Jay Lehr onto the show.

    Not surprisingly, Lehr told Dobbs what he wanted to hear, starting with an anecdote about Lehr’s sky diving hobby.

    LEHR: “I have jumped out of a plane in Ohio every month for 31 years, and I track the weather constantly to find out if I can make it out of a plane. And I can tell you, the weather the last ten years hasn’t been significantly different than the ten years before that or the ten years before that. It has been — it is always changes what the weather is about. And to say that it has to do with global warming is really more of a joke than anything else. Why people are so alarmed about it, I have no clue.”

    DOBBS: “You know, that’s fascinating.”

    Before ending the segment, Lehr added that the sun, “not man,” warms the planet, and that “right now,” we’re “going in to cooling rather than warming.”

    … though Dobbs apparently forgot to mention it, the Heartland Institute is a conservative think tank subsidized by ExxonMobil, not an independent scientific organization, and Jay Lehr’s background is in “groundwater hydrology,” not climate science.

    … the bizarre commentary from CNN’s Chad Myers wasn’t much better. He argued that it’s “arrogant” to think that humans can affect the climate (“Mother nature is so big,” he said) and that people who accept global warming are only looking at “a hundred years worth of data, not millions of years that the world has been around.”

    So this is the message, and these are the messengers, that the American public is hearing from “the most trusted source in news”.

    Suffice it to say that so-called “mainstream” media coverage of anthropogenic global warming and climate change still leaves much to be desired.

    [Response: Very odd. I've been on Dobbs' show twice and he, the reporter and the producer seemed to get it. Let's hope this was just an aberration. - gavin]

    [Response: Indeed, I was on Lou Dobb’s too (once w/ Gavin), and Lou didn’t even want to discuss the science, considering it ’settled’. He wanted to talk ’solutions’. This evident retrenchment is disappointing. I saw the segment yesterday. Chad Meyers appeared a bit stunned by Lou’s ambush, and came across as more dismissive then I believe he is. I think he was trying to say something we all know, that you can’t seen climate change in the day-to-day weather. You have to look at the longer-term trends. But he appeared flustered, and didn’t quite communicate that message. Coupled with CNN’s recent dismissal of Myles OBrien and his entire science and technology team, who had set the broadcast media gold standard for climate change coverage, this is a worrying development at CNN. - mike]

  135. Aaron Rury:

    I actually found this article on this issue, but in a different context.

    http://www.nonlin-processes-geophys.net/15/541/2008/npg-15-541-2008.html

    It shows that going between states of all ice and all water on a global scale for a planet climate in a two-dimensional climate model, the temperature will show a history dependent temperature. They do not speculate why however.

    This is a very simplistic model, but it shows the point I was trying to make. These climate system are complicated enough (much more complicated than a simple two dimensional model) to show hysteresis with respect to many parameter changes. If there is any other work like this that someone knows of, please let me know. Thanks.

  136. Rod B:

    Gavin (129), the gist of your argument is true, but (and this is admittedly a nit over a likely poor choice of words) to say the phrase “the science is settled” or its definitive equivalent has not been posted in RC tells me you’re in overload in managing RC — (and you probably really are and all greatly appreciate it!) Maybe not by folks you necessarily sanction, but it is all over the place.

    [Response: 99.99% of the time it is said it is to make the same lame contrarian point. The other 0.01% of the time it is usually an activist of some sort, and even then it is related purely to the standard consensus (as we defined it years ago). You can search but I challenge you to find one scientist saying any such thing about any of the secondary issues such as ocean circulation, or regional rainfall or hurricanes etc. - gavin]

  137. Steve Horstmeyer:

    Lou Dobb’s show mentioned in #134 made businessandmedia.org here is the link:

    http://businessandmedia.org/printer/2008/20081218205953.aspx

  138. Mark:

    Aaron, 133. There are many phase spaces that have no oxygen around you too. Yet you still fail to suffocate.

    People here know what phase spaces mean.

    Don’t think by using them you’ll flim-flam anyone.

    And you are incorrect about how cancer forms. The cells don’t “remember” squat. The single cancer cell can metastasize and live dormant. If you take treatment the cells die off and if you aren’t adding more by smoking, you won’t be adding cells that are cancerous to new places where they will not be picked up and removed.

  139. Joe Hunkins:

    such variability is indeed predicted by climate models

    This sounds odd to me. Is the point that climate variability has consistently been falling within the ranges we’d expect from current models? Is an alternative even possible given the large number of factors that lead to year to year prediction uncertainties?

  140. Mark:

    And further to the answer to 132, much less than 30 years and you’re looking at decadal patterns being left as signal rather than noise and if you use much more than 30 years, you’re looking at 100 years which means you’re unable to react within a lifetime. 30 years is about a generation of humans. You will personally be able to remember the days of your youth when you’re middle aged and will be able to extrapolate.

    If, on the 10,000 year scale the planet will cool, that doesn’t help us if our destruction is occurring on the century scale, does it.

    So it’s kind of pragmatic: things that take longer may take too long for us to be able to react to and much shorter and we KNOW we’re including things that will reverse.

  141. Mark:

    Ray #125.

    Will you accept a cheque???

    :-P

  142. Falconsword:

    … though Dobbs apparently forgot to mention it, the Heartland Institute is a conservative think tank subsidized by ExxonMobil, not an independent scientific organization, and Jay Lehr’s background is in “groundwater hydrology,” not climate science.
    ——————————————————————————————————-

    Yes, and most of the so called ‘climate scientists’ are being funded by government grants, and those grants are written by liberal politicians hoping to get a bigger piece of the pie from the ‘green energy boondoggle’ that Obama is going to ram through. So both sides show bias. The difference is you refuse to notice your own sides bias, instead you yell ‘debate is over’, or ‘consensus has spoken’. What scientist in his/her right mind uses concensus as a basis for solid scientific theory?! Lunacy!

    [Response: Very odd. I’ve been on Dobbs’ show twice and he, the reporter and the producer seemed to get it. Let’s hope this was just an aberration. - gavin]

    [Response: Indeed, I was on Lou Dobb's too (once w/ Gavin), and Lou didn't even want to discuss the science, considering it 'settled'. He wanted to talk 'solutions'. This evident retrenchment is disappointing. I saw the segment yesterday. Chad Meyers appeared a bit stunned by Lou's ambush, and came across as more dismissive then I believe he is. I think he was trying to say something we all know, that you can't seen climate change in the day-to-day weather. You have to look at the longer-term trends. But he appeared flustered, and didn't quite communicate that message. Coupled with CNN's recent dismissal of Myles OBrien and his entire science and technology team, who had set the broadcast media gold standard for climate change coverage, this is a worrying development at CNN. - mike]

    By “getting it” we must assume slurping the AGW theory. I wonder how many people will die from hypothermia this winter before the average person starts to ‘get it’?

    [Response: So let's get this straight, the existence of winter precludes the possibility of anthropogenic climate change, and you think that NASA, NSF, NOAA, DOE and NIH research grants are allocated by politicians? Hmm. Let us know when you want to start talking about the real world. - gavin]

  143. wayne davidson:

    #134, DWT’s not as measured by MSU…. Are very powerful tool in determining
    how cold this air, big freeze, contrarians are using to prop up their house of cards claims.
    Uptown NY state DWT last week from surface to tropopause: 260.6 Kelvin..
    Surface temperature on 12/12 +13.6 C. THis morning same station DWT to trop.
    256.06 K with a temp this morning of -2.1 C… 15.7 C of surface temperature difference = 4 Kelvin
    drop for the entire troposphere. The true measure of temperature change is found with the entire troposphere, comparable Decembers much show if really there is an incredible cooling, or simply one thing, winter……

  144. Hank Roberts:

    From the AGU meeting:

    http://www.achangeinthewind.com/2008/12/we-have-to-tell-people-something-is-happening-with-the-permafrost.html

    _________________
    “eruption Intime”
    _________________
    Ever wonder if someone were to write software to let ReCaptcha assemble sentences or paragraphs, not just two words at a time, we might really be surprised?

  145. Matt:

    Are you SURE about your ENSO-neutral forecast this winter? As Monty Python would say, “Here comes another one, here it comes again”…

    http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ocean/weeklyenso/heat-last-year.gif

    [Response: It's not my field, but I'm happy to go with the consensus forecast as the best guess. - gavin]

  146. Mark:

    Joe, 139. Is it just possible that within the errors attributed, the models are, y’know, actually RIGHT?

    Or is that impossible?

  147. dhogaza:

    Yes, and most of the so called ‘climate scientists’ are being funded by government grants

    “so called”?

    Prediction – 99% of the people here stopped reading your post at that point, and having skimmed down to read your handle, won’t bother to read anything else you post here again.

  148. Kevin McKinney:

    “Yes, and most of the so called ‘climate scientists’ are being funded by government grants, and those grants are written by liberal politicians hoping to get a bigger piece of the pie from the ‘green energy boondoggle’ that Obama is going to ram through.”

    Are these the same liberal politicians who tried to muzzle Hanson and other NASA personnel on the subject of AGW? Because I don’t think there have been too many ‘liberals’ in control on the federal side between 2000-2006.

    “The difference is you refuse to notice your own sides bias, instead you yell ‘debate is over’, or ‘consensus has spoken’. What scientist in his/her right mind uses concensus as a basis for solid scientific theory?! Lunacy!”

    Well, if punctuation is a guide, you’re the one doing the yelling. At the end of the day, the answer to your ‘concensus’ question is “all scientists.” Science is driven by evidence, but evidence can be accepted or not–as your post so aptly illustrates. Hopefully the valid evidence will be the most persuasive in the long run.

    Certainly the broad acceptance of AGW today is an example of an idea surviving on its merits in the face of decades of skepticism. The idea has thrived because the evidence keeps getting stronger. (If you are not familiar with this history already, see “The Discovery of Global Warming,” by Spencer Weart–it is linked in the sidebar to the right of each RC page. It is a fascinating and enlightening read.)

  149. SecularAnimist:

    Falconsword wrote: “Yes, and most of the so called ‘climate scientists’ are being funded by government grants, and those grants are written by liberal politicians hoping to get a bigger piece of the pie from the ‘green energy boondoggle’ that Obama is going to ram through.”

    I guess that would be “so called climate scientists” as opposed to real climate scientists like Rush Limbaugh?

  150. Matt:

    The mean of that IRI consensus is now -0.5C for DJF, or borderline La Nina. Last year’s subsurface data preceded the surface anomalies, so get ready for a La Nina surprise this winter…

  151. Hank Roberts:

    Reminder — quoting the nonsense, even to refute it, increases both the number of times search engines find it, and the likelihood that the uneduated reader will remember the nonsense.

    Make a specific positive statement that differs — to be remembered — rather than a repetition of the mistake followed by some comment on it.

  152. Ray Ladbury:

    Falconsword says: …well, nothing very interesting.

    Next!

  153. Jim Eager:

    Re Gavin’s in-line @142, that assumes birdtalk can even recognize that there is a real world.

  154. RichardC:

    138 Mark says, “And you are incorrect about how cancer forms. The cells don’t “remember” squat. The single cancer cell can metastasize and live dormant.”

    Whether a cell metastasizes or not isn’t relevant to developing cancer, though it does affect survival rates.

    Cancer often (always?) requires more than one mutation in a cell. So when smoking causes a large number of cells to acquire 1 or 2 of 3 mutations for cancer, then it becomes more likely for the ex-smoker to get cancer. On the other hand, the body does clean itself up, and after a number of years the risks for an ex-smoker drop. Besides, “remember” was in quotes – 2 of 3 mutations, fully mutated yet dormant, or damaged in some way that encourages future mutations (say damage to the cilia which help clear the lungs) – they all fit the term rather well.

    142 Falcon claims, “most of the so called ‘climate scientists’ are being funded by government grants, and those grants are written by liberal politicians”

    I didn’t know Bush and Co were ‘liberal’. James Hansen’s experience is quite different from what you describe. Are you postulating about the future, cuz if you are talking about the past, your comment is fanciful at best.

    143 wayne says, “The true measure of temperature change is found with the entire troposphere”

    I disagree. The true measure is found in the entire ocean/atmosphere system, with perhaps the top meter or three of land surface. Given the relative masses, that means ocean temp is all that really matters. The ‘at the surface’ measurement is used because it’s where we live. Anthro-bias.

  155. Jim Cross:

    Gavin and Matt,

    The actual weekly discussion of ENSO at the same site says:

    “Based on recent trends in the observations and some model forecasts, ENSO-neutral or La Niña conditions are equally likely through early 2009.”

    Something I am sort of hazy about is why La Nina or El Nino would affect world temperatures so dramatically. After all, neither changes the basic solar input to the system. At most, they seem to redistribute the heat and shouldn’t be changing its absolute value.

    Can anyone explain that?

    [Response: They change both the cloud distribution and total water vapour in the system. - gavin]

  156. Les J:

    Gavin: what is your response to the criticism of your graphs, by Lucia at the Blackboard?

    [Response: I have no idea who she thinks she is arguing with. Since she never actually talks to me or asks for clarification, she persists in imagining interpretations of my thoughts that have very little to do with anything I actually think. If you think there are any substantial issues to be addressed, let me know. - gavin]

  157. Jim Cross:

    So, in other words, if we went into a period where La Nina dominated, then we would cool or not warm as fast? And, vice versa, in a period where El Nino dominated, we would warm faster?

    Correct me if I’m wrong, but ENSO isn’t really well understood from a causality standpoint or long term predictability.

  158. Jim Galasyn:

    Global warming causing more tropical storms: NASA

    LOS ANGELES (AFP) – Global warming is increasing the frequency of extremely high clouds in the Earth’s tropics that cause severe storms and rainfall, according to a NASA study released Friday.

    The space agency’s Jet Propulsion Laboratory (JPL) said a study by its scientists “found a strong correlation between the frequency of these clouds and seasonal variations in the average sea surface temperature of the tropical oceans.”

    “For every degree Centigrade (1.8 degrees Fahrenheit) increase in average ocean surface temperature, the team observed a 45-percent increase in the frequency of the very high clouds,” according to the study, recently published in Geophysical Research Letters.

    “At the present rate of global warming of 0.13 degrees Celsius (0.23 degrees Fahrenheit) per decade, the team inferred the frequency of these storms can be expected to increase by six percent per decade.”

  159. Les J:

    That’s not an answer, Gavin.

    from her site:

    That text seems plausible if we compare data to models using Gavin’s cherry picked baseline year of 1999. In contrast, if we use the slightly different (and equally cherry picked) baseline year of 1998, one would show that all but one out of 49 model runs lies above the trend.

    [Response: But what is your point? (there are 55 runs in any case). I'm perfectly well aware that the start date is subjective - I said so above. I also said this was for 'fun' and it wasn't anything 'profound' and that trends are a better thing to look at (but I did that months ago). What would you like me to add that I didn't already acknowledge? I'll also point out that 1998 is extreme cherry picking, 1999 not so much. If her point is to argue that short term comparisons aren't particularly useful, I will gleefully agree. - gavin]

  160. Les J:

    Her point was that with short term comparisons, with arbitrary start dates, you could pretty well get any result you want.

    The chart at the top of this page, then, would also be representative of her point.

    Thanks for agreeing.

    [Response: Bingo! So that goes for starting in 2001 as well I suppose? - gavin]

  161. Les J:

    Her point was that with short term comparisons; with arbitrary start dates, you could pretty well get any result you want.

    The chart at the top of this page, then, would also be representative of her point.

  162. Les J:

    2001, yes. Or 1998. Or 1999, for that matter.

  163. dhogaza:

    Her point was that with short term comparisons, with arbitrary start dates, you could pretty well get any result you want.

    Which, of course, is exactly what she’s done in the past with her “temps from 2001 prove IPCC projections wrong” baloney.

  164. David B. Benson:

    Jim Cross (157) — El Nino indicies exhibit a 3.6 year periodicity (and lots of ‘noise’ as well, of course). Still, this means that there is some slight predictably to ENSO. It is a subtopisc here:

    http://tamino.wordpress.com/2008/11/12/co2-blip/

  165. Les J:

    dhogaza: actually, IRC, she said that from 2001, measured temperatures vs IPCC projections fall outside the 95% confidence limits.

    Which has just as much validity as Gavin’s chart above.

  166. Andrew:

    Actually, the year 1999 was more in line with global temperature trends than 1998 was.

    As a little exercise, take 30 years of annual average global temperature data, put it into Excel and draw a liner trend graph.

    For the years 1968 to 1998, the trend line is below the year 1998.
    On the other hand, for the years 1969 to 1999, the trend line falls almost exactly on the value for 1999, at least using NCDC data.

    Most impartial people should agree that 1998 was an anomoly and it would be wrong to use it as the starting point for future comparisons.

  167. Les J:

    As for trends? Long term linear trends won’t show any rapid changes in a system, especially in long running systems, and especially if you go out to the start of the data.

    If I plot and linear trend UAH data, and insert anomalies of 0.0, it takes until about 2025 until I see a flat trend.

    I haven’t done it with GISS or Hadley data, but I suspect that I would need 100 years, or more, of 0.0 anomalies to get a flat trend, if I start the trend around 1900.

    Do we need to wait 100 years? Nope. If Gavin is right, we will see a continued 0.2 deg/decade of warming, and the temps will come back inside the 95% levels. If Lucia is right, the measured temps will continue to fall outside of 95%.

    I can wait.

  168. Wayne Davidson:

    #154 RichardC: “he true measure is found in the entire ocean/atmosphere system, with perhaps the top meter or three of land surface. Given the relative masses, that means ocean temp is all that really matters. The ‘at the surface’ measurement is used because it’s where we live. Anthro-bias.”

    I am all for it! a planetary ocean/atmosphere temperature index would be nice, but I deal mainly with the atmosphere, which is warmed by the sun and ocean (sometimes cooled by the ocean). Studying just the atmosphere offers a clear focus .

    Anthro-biased surface temperatures are flawed by its spacial randomness. It is not an easy straight world wide average, its taken where ever humans live, from below sea level to 3 to 4 thousand meters above. Its a mistake not to consider better averages. Humans live at the bottom of an ocean of air, global surface temperatures vary too much, and need be taken long term by necessity. A DWT is the best metric for temperature with respect to the atmosphere. The only other thing that comes close is IR down welling.

  169. Rod B:

    Gee, is it time to regurgitate the ‘AGW causing more hurricanes’ again? So soon?

  170. John Finn:

    Re: #127

    Don’t forget that most of the warming is going into the oceans. That’s the essential reason why the long-term trend is robust – there will be many fluctuations in surface temperature, but the warming signal in the oceans is just as strong.

    Can someone explain the exact mechanism for this process. OK I know the oceans are warmed by the sun, but I’m more interested in the amount of additional warming that has resulted from the reported increase of ~1.6 w/m2 due to GHGs since ~1850.

  171. Hank Roberts:

    Rod, you _can_ digest new science. Chew. Ruminate.

    > according to a NASA study released Friday….
    > The space agency’s Jet Propulsion Laboratory (JPL) said
    > a study by its scientists “found a strong correlation ….
    > … released Friday.

    Rod, it’s barely Saturday. You’re regurgitating prematurely.
    Don’t stick your finder down your throat immediately.
    Give your tender digestion time to assimilate the unfamiliar.

    If you fwow up evewy time NASA posts a press release, you’ll never assimilate any actual information.

    Reading the actual paper is sort of minimal competence to demonstrate before decrying the result. Check the work, see if you can find a problem with the correlation.

  172. Ray Ladbury:

    Rod,
    There is a new result that has bearing here:

    http://www.jpl.nasa.gov/news/news.cfm?release=2008-242

  173. Jim Cross:

    #164

    According to the Wikipedia, recent El Niños have occurred in 1986-1987, 1991-1992, 1993, 1994, 1997-1998, 2002-2003, 2004-2005 and 2006-2007.

    I suppose Tamino can look into his tea leaves of statistics and derive a 3.6 year cycle from that but I only see that it is something that happens every couple of years in a chaotic fashion.

    Since ENSO does seem to drive global temperatures to a considerable degree (warm year 1998 was El Nino and this cooler year La Nina), it would be nice if it were understood more.

  174. Bill H:

    Gavin:

    Sorry, try as I may, I remain a sceptic. I am curious, what would have to happen for you to stop believing the models are predictive? Seriously. These models output results so variable that there is hardly an outcome immaginable that does not fall within an acceptable range. If all outcomes are acceptable then in what sense have these models been proven or disproven? I applaude scientists for there efforts here but this simply tells me that climate is: a) a complex system which cannot be accurately predicted or b) climate prediction is still in its infancy and more research is needed. Either way, suggesting that this evidence is absolutely conclusive is just bizaar to me. For many this long ago stopped being science and has morphed into political activism.

    There is a credibility gap a mile wide here [edit]

  175. Ray Ladbury:

    Bill H., Perhaps you would find the science more convincing if you understood it. Weather is noisy. It is chaotic. It cannot be predicted. However, if you look at long-term trends–e.g. 30 years or more–trends emergy. This is climate. One of the most prominent trends is the long-term warming.
    What you are looking at in the graph is what happens when you use climate models to predict weather. You learn little from the spread of the models. Instead, look at the median or mean. That’s where you see the trend, especially in the 1979-2009 plot.

    You ask what it would take to “falsify” the models. The answer: a better model. GCMs explain a broad range of climate phemonena–from long-term paleoclimatic trends to response to short-term perturbations like ENSO and volcanic eruptions. Any new model needs to do at least that well. The fact that all models imply anthropogenic warming means essentially that you can’t explain climate without AGW being a consequence.

  176. Jim Dunlap:

    Wyoming says:

    snorbert zangox Says:
    18 December 2008 at 4:23 PM
    JW, Gavin,

    The year 2000 was the last year of the 20th century. Think of it as 199ten. The first year of the 21st century was 2001.

    Another way to look at it, since this is all religion based. Roughly speaking Christ was born on day zero (I know we use Dec 25 and others point out that it had to be in March some time, but in any case). Then the end of the first year of his life was his 1st birthday. YOur first year of life does not occur in year one, but in year zero. His 100th birthday was ..ta da! year 100. Big surprise. So…his 2000th birthday came after the last day of what year? Sort of seems to be the day after Dec 31st 1999 doesn’t it? So common sense being what it is…most folks think that the new century/millenium start on New Years day 2000. All things being equal I prefer pagan rituals. They are a lot more fun.

  177. Eric Rasmusen:

    Gavin, you replied to someone:

    “(MSU-TLT is a weighted average of temperatures reaching from the surface to 10km, peaking at around ~4km and with significant influence from surface type depending on elevation and polar latitude). Therefore comparing them with surface temperature anomalies from the models is not comparing like with like i.e. they are incommensurate. There are ways to create synthetic MSU data from the models, and I’ll discuss this in another post. – gavin]”

    I look forward to a post on this. Wouldn’t it be more useful to use, instead of MSU-TLT, a measure at a single height?

    [Response: You study climate with the diagnostics you have, not the ones you might want or wish to have at a later time. - gavin]

  178. Hank Roberts:

    > remain a skeptic … stopped being science …

    No, it’s continued to be science, which is informing political activity.

    You’re confused about the outcomes; you misstate the facts then leap to the conclusion that what’s known now can’t be useful.

    Politics is the art of getting moving _while_ trying to understand what’s happening, not just standing still watching trouble coming.

    http://www.google.com/search?num=50&hl=en&newwindow=1&safe=off&hs=77O&q=%22climate+prediction%22+infancy+%22more+research+is+needed%22&btnG=Search

  179. Jim Galasyn:

    Rod reminds me of Homer Simpson: “Eggheads — what do they know?”

  180. Nick Gotts:

    “Sorry, try as I may, I remain a sceptic.” – Bill H.

    The rest of your comment indicates that you’re not trying to understand the science at all.

  181. Phil. Felton:

    Jim Dunlap Says:
    20 December 2008 at 10:51 AM

    Another way to look at it, since this is all religion based. Roughly speaking Christ was born on day zero (I know we use Dec 25 and others point out that it had to be in March some time, but in any case).

    The problem with that argument, which is the source of this whole issue, is that there was no year zero!
    The first year was 1 so jan 1 xxx1 is the first year of the calendar decade, century, millennium. Decade is also used in the more general sense of ’10 years’

  182. Matt:

    To Jim Cross #173: The fascinating factor here is that if NASA is correct and we have indeed crossed the threshold into a negative Pacific Decadal Oscillation, then we can expect more La Nina (cooling influences) vs. El Nino events (warming influences) in the coming few decades. Already, this decade has cool events outpacing warm events (with no strong El Nino events in ten years’ time).

  183. SecularAnimist:

    Phil. Felton wrote: “The problem with that argument, which is the source of this whole issue, is that there was no year zero!”

    Sure there was a year zero — the year before the Big Bang. And since time begins with the Big Bang — or more precisely, the concept of time cannot be applied beyond the Big Bang — the year zero may be regarded as infinitely long, or infinitesimally short, whichever you prefer.

  184. James:

    Of course there is a year zero: the year preceeding year 1. Basic arithmetic, you know? Sure, certain religious “authorities” can’t (or couldn’t) wrap their minds around the concept, but is that reason for the rest of us to forever be enthralled by their mistake?

  185. Brian Klappstein:

    “…This coming winter is predicted to be ENSO neutral…”

    No doubt I’m not the first to comment but the SOI looks anything but neutral these days.

    Regards, BRK

  186. RichardC:

    Jumping on the 0 (no) bandwagon:
    Golly, should this yearly wrangling be on the Mountains and Molehills thread?
    The dominant numbering system goes straight from 1 BC to AD 1, but to be fair, I’ll wish an early Happy New Year to all, regardless of which decade it is, and when it might start!

  187. Rod B:

    Hank, Whew! Good! Thanks! I was just reacting to the headline in, and the post 158.

    But then comes Ray to back it up ;-) … though he was referring to severe storms which at least has a teeny better correlation.

  188. Lynn Vincentnathan:

    RE what year is this, anthropologists use “BCE” before the common era, and “CE” common era (replacing BC & AD) to make it somewhat more universal and secular. There are calendars for many civilizations, and we’d be in very different years on each of them, and the Mayan calendar is much more accurate than ours…which has leap years & even then is a bit inaccurate.

    I’m thinking the big bang might be like absolute zero in temp (kelvin scale), and the different calendars of civilization like Fahrenheit and celsius scales, except that time is nothing like temperature or space, tho we use the space analogy to think about it (a point in time, a length of time…). We have to think of time in re to movements of astronomical bodies, esp the sun & moon. Apparently the Hopi had a better concept of time for physics, one detached from the space metaphor.

    All I can say is we’re very late in seriously taking up the AGW issue, and time is of essence.

  189. dhogaza:

    I was just reacting to the headline in, and the post 158.

    Which is quoting a new paper from JPL, which …

    But then comes Ray to back it up … though he was referring to severe storms which at least has a teeny better correlation.

    Ray kindly pointed you to.

    And they’re claiming a *strong* correlation, not a “teensy better” correlation.

    But, of course, it’s typical for denialists to handwave off research they don’t read.

  190. Hank Roberts:

    Wait, at least let’s read the press release together, shall we?

    The correlation (strong) described is between high clouds and sea surface temperature.

    I think they’ll make the connection between sea surface temperature and storms in the paper.

    It’s a press release. What do we know about press releases?
    (Someone should study them, it’d be a good thesis topic …)

  191. dhogaza:

    I think they’ll make the connection between sea surface temperature and storms in the paper.

    Actually they did it in the quote in the press release, that bit about a 6% decadal increase related to a 1.6C (or something like that, less than 2.0C) decadal increase in global temps.

    Right or wrong, I can’t judge. But that’s how they allowed themselves to be quoted, and I would guess they didn’t say this if their paper contradicts it.

  192. PHE:

    “Swiss glaciers in ‘full retreat’”

    Don’t miss this further proof of the tragedy of AGW:
    http://news.bbc.co.uk/2/hi/science/nature/7770472.stm

  193. Jim Cross:

    #192

    PHE, did you read the article?

    The decline began in 1860 and the glaciers lost mass even faster in the 1940′s.

  194. davidgmills:

    Perhaps the most intriguing part of your post was this:

    “However, we are at a solar minimum. The impacts of the solar cycle on the surface temperature record are somewhat disputed, but it might be as large as 0.1ºC from solar min to solar max, with a lag of a year or two.”

    At least you see seem to concede that increases and decreases in solar magnetic output are capable of changing the average global temperature.

    [Response: No. There is no compelling evidence that magnetic activity noticeably affects climate - gavin]

    Svensmark has said that at solar minimum, cloud cover may increase by 3-4% over solar maximum.

    [Response: He can say what he likes, it doesn't make it true. Continuations of the data he used do not support any such change. - gavin]

    The 20th century had the most magnetic sun of the last 1500 years and possibly the last 8000 years. So if Svensmark is correct (and his CLOUD project at CERN may prove that increased cosmic radiation from low solar magnetism increases cloud cover) then we have to be concerned about the impact that a number of continuous years of low solar magnetism would produce.

    [Response: The long term trend is not certain, and equally convincing reconstructions (Mueschler etc) show similar solar activity in more recent times. Note the CLOUD is not Svensmark's project (AFAIK he is no longer on the science team), and it's impact on our understanding of solar impacts on climate in recent decades is going to be very close to zero (since, as I'm sure you know, there is no long term trend in GCR). - gavin]

    Sunspots are indicative of the strength of solar magnetic output. During the 20th century we had the most sunspots we have had since sunspots were first noted and counted. But beginning in about 2002, the numbers of sunspots began to wane during solar cycle 23, far more so than generally predicted. This solar minimum is a very deep one, with solar cycle 24 yet to kick off and about a year and one half late already. 2008 was the most sunspotless year since 1913 with about 255 spotless days as of December 20. (The sun is spotless today).

    The decrease in solar magnetism is now obvious with the solar wind the lowest since the space age began.

    Also others have noted that decreased solar magnetic output also decreases solar UV which heats up the atmosphere and expands the ionosphere, increasing the ionosphere’s height. Right now, the low magnetic solar output has shrunk the ionosphere to its lowest levels since the beginning of the space age.

    Livingston and Penn in 2005 predicted that based upon the observed decline in solar magnetic output that by 2014 or 2015 the sun’s magnetic output will have dwindled to the point where the sun produces no sunspots. Others have noted that when the sun goes into these magnetic funks, these periods last from between 30-70 years.

    So the question is, what happens to the earth if many successive years of 0.1C degree negative anomalies occur?

    [Response: Think about your question again (the answer is contained within it). - gavin]

    Do you think we get to a point where the earth cools by 1C degree, and if so, how long would it take?

  195. Mike Lawley:

    Gavin, Where can I find a list of the data collection points for the data used to calculate the earth’s surface temperatures? And other information about the gathering of the data?

    [Response: The sources for GISTEMP are described and linked to on their website. Most data comes from GHCN (details at NOAA's website). - gavin]

  196. Hank Roberts:

    Aside for the “we can’t go photograph the satellite so how do we know it’s giving accurate information” question: calibration:

    http://spiedl.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PSISDG00708100000170811B000001&idtype=cvips&gifs=yes

    Absolute radiometric calibration accuracy of the Atmospheric Infrared Sounder (AIRS)
    Proc. SPIE, Vol. 7081, 70811B (2008); DOI:10.1117/12.795445
    Online Publication Date: 20 August 2008

    —-excerpt—-
    … AIRS has demonstrated in-flight NIST traceability and high radiometric accuracy. This accuracy is achieved in orbit by transferring the calibration from a Large Area Blackbody (LABB) to the On-Board Calibrator (OBC) blackbody during preflight testing. The LABB theoretical emissivity is in excess of 0.9999 and temperature uncertainty is less than 30 mK. The LABB emitted radiance is NIST traceable through precision Platinum Resistance Thermometers (PRTs) located on the internal surfaces. The radiometric accuracy predictions for AIRS based on the OBC, LABB, and pre-flight measurements give an accuracy of 0.2K, 3 sigma. AIRS pre-flight calibration coefficients have not changed in flight, preserving the link between observations and pre-flight calibration and characterization. An update is being considered that will improve accuracy and preserve traceability. …
    —-end excerpt—–

  197. jcbmack:

    Well placed reference Hank, there is a lot of recent data from AIRS and some other sources.

  198. thingsbreak:

    @194 [davidgmills]

    “Svensmark has said that at solar minimum, cloud cover may increase by 3-4% over solar maximum.”

    He can “say” whatever he likes, there is virtually no evidence to support the claim, and quite a bit that rejects it.

    (ReCaptcha: “head Tragedy”)

  199. Jim Cross:

    #194 Gavin

    I’ve heard this many times about no long term trends in GCR and more or less accepted. But what about this?

    http://en.wikipedia.org/wiki/File:Solar_Activity_Proxies.png

    The Be10 which is a proxy for GCR clearly looks to have a trend of reduced GCR for more than the last 100 years.

    [Response: It all depends on where you measure it. At Dye3 in Greenland, there is a trend, but there isn't in the data from the South Pole. Trends in recent decades in both cases do not come out of the noise. Plus, you have the problem in knowing how to calibrate a Be10 concentration to solar activity. There is little reason to prefer 10Be over the last 50 years over the continuous measurements from the cosmic ray monitoring instruments (ie. CLIMAX Neutron Monitor) and these show no trend. - gavin]

  200. davidgmills:

    RE: My post at 194 and your responses:

    My post: Svensmark has said that at solar minimum, cloud cover may increase by 3-4% over solar maximum.

    [Your Response: He can say what he likes, it doesn’t make it true. Continuations of the data he used do not support any such change. - gavin]

    First thanks for the response.

    I think there is more than a sufficient basis to conclude that
    Svensmark could be right with his estimations and I am aware of papers that critique his work. I am also aware of papers that support it.

    Most notably I would refer you to Jasper Kirkby’s recent paper on what the CLOUD project is about. (Kirkby is the director of the CLOUD project). If you have read the article already or know about Jasper Kirkby, no condescension is intended.

    Here’s the link:

    http://arxiv.org/PS_cache/arxiv/pdf/0804/0804.1938v1.pdf

    Since it is a pdf, I can not cut and paste so I have handwritten a few quotes from his conclusion which I will quote here:

    “Numerous paleoclimatic observations, covering a wide range of time scales, suggest that galactic cosmic ray variability is associated with climate change…. The satellite data suggest that decreased GCR flux is associated with decreased low altitude clouds, which are known to exert globally a net radiative effect…. The question of whether, and to what extent, the climate is influenced by cosmic ray variability remains central to our understanding of the anthropogenic contribution to present climate change.”

    This is a thirty eight page paper with about 175 footnotes (Svensmark is footnoted four or five times) that describes in detail why Kirkby thinks this project is warranted. He goes into great detail about the correlation between cosmic radiation and climate not only for the last millennium, but for three other time periods dating all the way back to 550 million years ago.

    He also details the ways in which cosmic radiation could effect climate and supports this with his numerous references.

    What concerns me is that climatologists see no need to wait to see if there is any correlation between the magnetic output of the sun and climate change. Kirkby clearly thinks this research is “central to our understanding of the anthropogenic contribution to present climate change.”

    If it is central, why not do the research to see how central? Why not wait for the results? They may be surprising. I think Kirkby expects them to be significant. Why? His review of the cosmic radiation correlation with climate for the last 550 million years.

    I think Kirkby believes the CLOUD project will show, (as Svensmark’s pilot project SKY has already tentatively indicated), that cosmic radiation is able to seed low clouds in quantities sufficient enough to effect significant climate change.

    [Response: It is often the case that a PI for a project thinks it is 'central' to understanding some big problem. I might go as far as to suggest it's almost universal. However, it can't be universally true. The existing data, and the lack of a GCR trend in recent decades already imply that whatever comes out of CLOUD, it's role in attributing recent trends will be negligible, and the impact on future projections negligible. It may improve our understanding of solar cycle effects, or for the impacts of long term solar in the past. But the indications are not good (i.e. no correlations of climate change to the Laschamp excursion or the B-M magnetic reversal etc.). Understanding ionization impacts on aerosols is important, but it is not the game-changing study you (and possibly Kirkby) are anticipating. - gavin]

  201. Mike Lawley:

    Gavin, With respect to comment 47, I have heard the same thing about IPCC. That many of the \scientists\ listed as members of the IPCC are not scientists and that some of the scientists listed have left the IPCC as a result of their disagreement with IPCC findings. The same source goes on to say that there is substantial disagreement among the scientists that remain members over the conclusions of IPCC studies.

    [Response: None of this is true in substance. I am aware of only two people (over 3 working groups and over the last two reports) who left the IPCC chapter they were involved in. That is not overwhelming. There is I think only one person on the IPCC author list who is also on Inhofe's sceptics list (who hasn't been horribly misquoted) (J. Christy). As for 'disagreement' where is it? Thousands of scientists reviewed the reports and were able to make as many critiques as they wanted. The basic fact is that IPCC is the mainstream - go to the AGU website and check the abstracts of last weeks meeting. Out of thousands dealing with climate, you'll find maybe half a dozen that go against the 'consensus' with the vast majority trying to move beyond what's already been found in order to tackle the remaining uncertainties. - gavin]

  202. Hank Roberts:

    Note that Kirby writes

    “… the reported correlation of GCR flux and low cloud amount,
    measured by satellite [13, 14, 15]. Although the observations are both disputed [16, 17, 18, 19, 20, 21] and supported [22, 23, 24] …”

    and (p. 16) he’s talking about events such as crossing the galactic plane, or running into relatively dense interstellar clouds, not about local changes in our Sun over short time spans.

  203. Charles:

    Slightly OT, but I am wondering if there has yet been any reaction to Don Easterbrook’s presentation at the just-finished AGU conference. Here’s a link to his presentation: http://www.agu.org/cgi-bin/SFgate/SFgate?&listenv=table&multiple=1&range=1&directget=1&application=fm08&database=%2Fdata%2Fepubs%2Fwais%2Findexes%2Ffm08%2Ffm08&maxhits=200&=%22GC21A-0725%22

    I’ve read Chris Colose’s response: http://chriscolose.wordpress.com/2008/11/11/easterbrook-and-the-coming-global-cooling/. I’m wondering if there have been any other direct responses. I realize Dr. Easterbrook has been repeating this argument for several years, mostly at conferences. I cannot find any peer-reviewed journal articles of his which outline his ideas (is the lack of a peer-reviewed paper by him on the subject indicative of anything?), nor any other direct responses to his work in the peer-reviewed literature.

  204. davidgmills:

    RE: Post 199

    You say: The existing data, and the lack of a GCR trend in recent decades already imply that whatever comes out of CLOUD, it’s role in attributing recent trends will be negligible, and the impact on future projections negligible.

    Where is this data? I keep hearing about it but I haven’t yet had a good source to see. I would like to take a look at it. Thanks.

  205. davidgmills:

    RE: Post 199

    You say:

    The existing data, and the lack of a GCR trend in recent decades already imply that whatever comes out of CLOUD, it’s role in attributing recent trends will be negligible, and the impact on future projections negligible.

    I keep hearing about such data but I have yet to find a good source. Where is the data of which you speak? And what lack of GCR trend are you referring to?

    Thanks.

  206. davidgmills:

    RE: Post 200

    You say: “The existing data, and the lack of a GCR trend in recent decades already imply that whatever comes out of CLOUD, it’s role in attributing recent trends will be negligible, and the impact on future projections negligible.”

    I keep hearing about this data but have yet to find a good source for it. What is your source? And what do you mean by “the lack of a GCR trend in recent decades?” High solar magnetism, corresponding low cosmic radiation, and corresponding high temperatures seem like a trend to me.

  207. Andrew:

    Re #203:

    Eastabrook claims 23 periods of global warming and cooling over the past 500 years, but erroneously focuses on just one region of the world.

    Maybe some reader don’t realize that average global temperatures for the last decade are likely greater than any decade of the past 100,000 years.

    http://en.wikipedia.org/wiki/File:Holocene_Temperature_Variations.png

    Also, while not necessarily reflective of average global temperatures, consider that glaciers in the Alps have retreated to levels not seen for over the past 6000 years.

    http://news.bbc.co.uk/2/hi/science/nature/7580294.stm

  208. pete best:

    All the deniers and so called skeptics who have posted here many many times and who have been answered in a most patient and scientiic way by Gavin, Erasmus and others should explain the most prophecy (I might have overdone it a bit with that word) of climate change models and theory and hypothosis, namely that of the Arctic.

    http://nsidc.org/data/seaice_index/images/daily_images/N_timeseries.png

    The sea ice is acting totally out of character but not out of climate science theory, just a little faster but it is one of the strongest climate science claims and is truer (natural variability is probably helping summer sea ice melt and behaviour to) than even stated.

    http://www.newscientist.com/article/dn16307-arctic-melt-20-years-ahead-of-climate-models.html

    The NSIDC are calling it right and the ice/water albedo affect is scientifically accurate and telling.

    Come on skeptics, give us your answer to this one and stop filling this site with endless dross that stop GISS from doing even more compelling work to demonstrate that Santa is soon going to be swimming around for most of the summer?

  209. steve:

    re Andrew 123

    Thank you for your response. Sorry it took so long to get back to this but in my defense it is a busy time of the year. The trend of snow isn’t really what my topic was. My question was does a significant oceanic event, such as a La Nina or El Nino, effect the energy budget of the earth. Intuitively it seems it should. I was wondering if there was a study to show that it doesn’t. Perhaps this is a stupid question and everyone already knows it does and that caused the confusion?

  210. Ray Ladbury:

    Davidgmills, There are many strands of scientific evidence indicating no trend in GCR:
    1)Single-event upset rates have not changed dramatically indicating that over the space era (which encompasses the warming epoch), there is no significant change in GCR fluxes
    2)There is no significant trend in ground-based neutron fluxes going back to the ’50s

    In addition, the “mechanism” proposed for amplifying a flux that averages 6 particles per square cm per second into a global climate signal is questionable at best. Moreover, there is the question of how such a mechanism even if operative would account for all of the other massive evidence favoring a greenhouse mechansim. One example: how does it simultaneously warm the troposphere and cool the stratosphere?

  211. Matt:

    A few models like the NOAA CFS are now forecasting STRONG Nina conditions this winter. With subsurface temperatures now in the -4 to -5C range, this may not be far-fetched anymore.

    http://www.cpc.ncep.noaa.gov/products/people/wwang/cfs_fcst/images/nino34SSTMon.gif

  212. Hank Roberts:

    > does a significant oceanic event … [affect] the energy
    > budget of the earth

    Only if you can show it changes either the incoming or outgoing energy.

    Do you find a significant change in the planet’s albedo that follows ocean cycles? Or something?

    Take a pot of ice and water on a hot stove. Measure the temperature at different points inside. Stir. Measure again.

    Did the energy balance of the system change? Significantly?

  213. steve:

    “Do you find a significant change in the planet’s albedo that follows ocean cycles?”

    Hank, this is my question. Asking me the same question is not an answer it is mearly a reiteration of the original question. Apparently neither of us know.

  214. Julius St Swithin:

    #208 Pete

    An alternative spin on the ice figures is that the average area of earth’s ice caps is reducing at 0.07% per annum.

  215. FurryCatHerder:

    “[Response: Yes. Based on our understanding of climate physics, I think the likelihood of a warmer 2009 is very high. - gavin]”

    Warmer than what?

    [Response: 2008. - gavin]

    Other than increasing concentrations of CO2, what leads you to believe 2009 is going to be “warmer”, and “warmer than what?”

    I’m glad we’re having winter where I live for a change. But I’m not seeing winter disappearing magically in 9 more days.

  216. Hank Roberts:

    Steve, I’m just another reader like you; best I can do is suggest how to look for answers while waiting to see if an expert comes along.

    Google finds some likely papers you might want to look at, just pasting in the string (they do surprisingly well with natural language questions):
    http://www.google.com/search?q=change+in+the+planet’s+albedo+that+follows+ocean+cycles%3F

    Seriously, look at a few of the top hits there. Question I think you may want to look into is whether there’s a persistent (ratcheting) kind of change, a “trend” — or a natural variability that would be “noisy” information.
    Scholar doesn’t with that string but does find a lot with a slightly revised string:
    http://scholar.google.com/scholar?sourceid=Mozilla-search&q=albedo+change+ocean+cycles

  217. Ray Ladbury:

    Julius St. Swithin spins ice loss figures: “An alternative spin on the ice figures is that the average area of earth’s ice caps is reducing at 0.07% per annum.”

    That might provide some comfort if ice loss trends were linear. They ain’t. What’s more the physics says that the more ice melts, the faster the rest will go.

  218. FurryCatHerder:

    Gavin,

    I discussed a possible wager with someone earlier in this year that 2009 was not going to be warmer than, I think you’d said either 2005 or 1997. Care for a gentle-peoples wager at this point?

    [Response: No. - gavin]

  219. Hank Roberts:

    Remember, if you’re in the USA, Internet gambling is illegal these days. Else
    http://www.google.com/search?q=climate+wager

  220. Ike Solem:

    For a very good general overview of El Nino:

    http://www.cosmosmagazine.com/features/online/1787/how-el-nino-cycle-works

    If you read that and then go to the Australian BOM page, http://www.bom.gov.au/climate/enso/ , you can see the current conditions, a cold tounge extending west at the equator. The SOI index is explained here: http://www.atmosphere.mpg.de/enid/192.html

    Australia is very interested because of the El Nino effect on drought, which will be increased by a warming atmosphere:

    According to Beard, the widespread decline in Australia’s water reserves over the past five to seven years has involved numerous factors, including the two El Niño events, natural variability and climate change. “It’s impossible to disentangle these down to specific numbers, but the climate change signal will not reverse,” said Beard.

    Neville Nicholls from Monash University, in Melbourne, who is an author on recent U.N. Intergovernmental Panel on Climate Change (IPCC) reports, and a former group leader at BOM’s Climate Forecasting Group, said that predicting the impact of climate on the ENSO is complex and beyond the capabilities of current models.

    “However, all the models and physical reasoning and empirical studies all indicate that future droughts will be warmer even if they are no drier – we have already started to see this happening,” says Nicholls. “The warmer conditions will presumably lead to a greater demand for water.”

    So Australia will have to get used to living with worsening droughts and the unpredictable cycles of wet and dry are here to stay. As the BOM explains: “El Niño is not a freak of climate, it’s not a rogue weather phenomenon, and it isn’t in any way abnormal”.

    Note to William:
    Uncertainty and lack of uncertainty is the issue in the settling of science… which settles like what? It’s an open-ended approach. When cold fusion was refuted by the APS, all they said was that they were 99% sure that cold fusion was just experimental error. Would you go tell someone to invest a few billion in cold fusion, because that 1% chance justified it?

    Another example is the risk involved in living next to a nuclear power plant vs. the risk involved in living downwind to a coal-fired power plant. You will certainly be breathing in a lot of pollutants downwind from a coal plant – mercury, arsenic, sulfur and nitrogen oxides, and particulate matter of widely varying composition. For example, see this 2004 study on the air in Beijing (pdf)

    A nuclear power plant carries a risk of catastrophic failure and/or limited radioactive releases. The limited releases are the greater actual threat to anyone living nearby, and the global safety record is not too bad – it’s just that any catastrophic failure is one too many. However, faced with the certainty of inhaling coal particulates, vs. the uncertainty about radioactive releases, I’d far rather live next to a nuclear power plant.

    Perhaps one could avoid the certainty of inhaling coal emissions if you had your own personal filtered air supply… and they do build such systems, I believe. You’ll want to get one of these: http://www.theyesmen.org/agribusiness/halliburton/

    Those aren’t the only two choices, though. I’d rather live next to solar or wind-powered generators linked to electricity storage systems. That would be the lowest-risk solution.

  221. Andrew:

    Internet gambling is illegal in many areas, but there is no reason why a person can not take a stand and make a prediction of future average global temperatures. For example, I’m confident enough to predict that the average global temperature for 2009 will be among the top decile of the instrumented record using the NCDC database as the measure. In fact, we will all probably witness every year of the foreseeable future being in the top decile. This is based on several factors:

    First, CO2 levels are consistently rising and driving global temperatures higher. There is enough momentum in the system that even a leveling of CO2 level will not result in significant cooling for at least a decade.
    Second, the extent of spring and summer NH snow cover has shown a consistent long term trend downward, thus increasing solar absorption and may have crossed a tipping point threshold.
    Third, Methane levels, stable for the last decade have started to rise and may represent another feedback.
    Third, ENSO is predicted to be neutral for next year. Even if La Nina conditions were to develop, temperatures would likely be no cooler than 2008, which was also a top decile year. That is La Nina conditions are no longer sufficient to drive global temperature out of the top decile.
    Fourth, Solar Irradiance being at a 50 year low, is more likely to rise than to fall any further. That 2008 was a top decile year with irradiance at a 50 year low is proof enough that the sun is not driving the current rise in temperature.
    Sixth, Aerosols are not likely to increase meaningfully. Of course, this could change with a significant eruption and could eventually result in a single year not being among the top decile.

    Curious to see if anybody else is willing to make a prediction for next year before 12/31/2008.

  222. David B. Benson:

    Andrew (221) — The committed warming from additional CO2 continues upward for many, many centruies. It takes a long time to warm the oceans.

  223. Rod B:

    Andrew, interesting analysis. But, how do you account for the level or decreasing 5-10+year periods in the past while CO2 was continuing to rise dramatically? What’s the basis for your solar irradiance prediction? And is 2008 really a top decile? What is “a” or “among the top? Are you looking at the most recent decade?

  224. Ray Ladbury:

    Rod, You already know the answer to your question: weather. All increased CO2 means is that it is warmer than it would be otherwise. And yes, if you look at the data, 2008 is the 9th warmest year. Would you like me to tell you anything else you already know?

  225. David B. Benson:

    Rod B (223) — Link1:

    http://tamino.wordpress.com/2008/12/17/2008-temperature-summaries-and-spin/

    links back to thread with same name here. Link2

    http://climateprogress.org/2008/12/17/nasa-another-brutally-hot-year-for-the-siberian-tundra/

    points out the climatological year 2008 was warmer than any year last century other than 1998.

  226. dhogaza:

    But, how do you account for the level or decreasing 5-10+year periods in the past while CO2 was continuing to rise dramatically?

    If you can’t answer this one yourself, Rod, then the lengthy period of time you’ve spent here have been totally wasted.

  227. tamino:

    Re: #223 (Rod B)

    … the level or decreasing 5-10+year periods in the past while CO2 was continuing to rise dramatically …

    Rod, go read this. Thoroughly. Then please stop bothering us with this ludicrous argument.

  228. davidgmills:

    So Ray and Gavin:

    I want a guarantee. I want to know for certain that if the sun goes spotless for the next thirty, forty or fifty years, we will not have another mini-ice age.

    All this data about GCR and UV may be suspect as far as you are concerned.

    But the public will want to know: Can you guarantee there will not be another mini-ice age if the sun goes spotless for decades?

    How can you make this guarantee? What do you know about the mini-ice age that makes you so certain a weak magnetic sun was not responsible for it?

  229. dhogaza:

    But the public will want to know: Can you guarantee there will not be another mini-ice age if the sun goes spotless for decades?

    Science can’t even guarantee the sun will *exist* tomorrow. You might wake up to find that poof! It’s gone!

    But the public will want to know: Can you guarantee there will not be another mini-ice age if the sun goes spotless for decades?

    I don’t hear the public clamoring for this particular guarantee. I’m sniffing a thought train on your part that’s analogous to arguing that you won’t stop smoking unless your doctor can GUARANTEE that a truck won’t fall on your head.

  230. Ray Ladbury:

    Davidgmills, Oh, that’s what that was. I wondered what that noise I heard earlier was. It must have been the public clambering for a guarantee that we weren’t going to have another mini-ice age!

    David, first, the mini-ice age seems to have had several causes, including increased volcanic activity and decreased solar irradiance. Second, even if we were to have a mini-ice age, it would last at most a few decades, after which CO2 would kick right back in where it left off. This is because the effects of CO2 persist for centuries, while Grand Solar Minima last at most a few decades.
    Second, if you want a guarantee, might I suggest religion rather than science.
    Third, Added forcing from CO2 probably makes a mini-ice age pretty unlikely at this point.
    Fourth, why not learn the real science before going off on some wild goose chase for a mechanism that may or may not be extant.

  231. Andrew:

    Rob B:

    In the past, decreasing global temperature over 5 to 10 year periods were the result of natural variations. Those natural variation of course continue to exist. However, what has changed is that rising CO2 (and CH4) levels are now driving global temperatures higher to such a degree that natural variations (with the exception of large volcanic erruptions) are no longer sufficient to drive any particular year out of being a top decile year.

    The fact that 2008 was a top decile year with both solar forcing and ENSO aligning to lower temperatures is another sign that we are in a new era. Of course, the recent La Nina was not the strongest La Nina there has ever been and it was not lined up to drive all of 2008 towards lower temperature, but then again 2008 was a warm enough year that it was clearly within the top decile.

    Anyhow, I also realize that eventually, we won’t be witnessing every year falling within the top decile, but it is clear enough that that will take a long time.

    So, anybody willing to make an educated guess as to which decile 2009′s global average temperature will fall in?

  232. Hank Roberts:

    > What do you know about the mini-ice age that makes you so
    > certain a weak magnetic sun was not responsible for it?

    I know how to look things up. You can too.

    David Mills, try this kind of search in Google:
    http://www.google.com/search?q=solar+magnetism+proxies+paleo

    You’ll find discussions, for example this one cautioning about how to approach what we know:

    —–excerpt——
    Solar Forcing of Past-Climate Proxies….
    NASA GISS and Columbia University Feb 2008

    Solar signals in paleo-data
    Best efforts use multiple proxies/spatial patterns
    Problems abound:
    –Non-climatic noise in data archives
    –Ubiquity of decadal variability in climate:
    –10-12 year cyclicity does not imply solar response
    –Unclear interpretation of proxies
    Wishful thinking in the literature:
    –too much correlation, not enough causation
    –phase drift often ignored (or described as ‘non-linear’)
    –explained variance often very low (or suspiciously high!)

    —-end———-

    And you’ll find original data contributions at this page:
    http://www.ncdc.noaa.gov/paleo/forcing.html

    Where you can download much, including just for example this paper:

    Radionuclide-based Solar Magnetic Activity, 1,000 Years, Muscheler et al. 2007, Text or Excel

    Tell us what you read.
    Remember the cautions — don’t just go browsing until you find the one paper that fits your preconceptions about The Truth. Think.

    Don’t rely on me, I’m just some guy on a blog, why believe anything I tell you?

    Do for yourself.

  233. Geoff Beacon:

    Are there any month to month estimates of the Earth’s radiation balance similar to GISS Surface Temperature Analysis?

  234. Ray Ladbury:

    Geoff Beacon, Well, there might be some good measurements had the current administration launched Triana instead of mothballing it. Now they’re trying desperately to launch it–after removing ALL the Earth-observing instruments.

  235. William:

    Journal of the Atmospheric Sciences October 1973 in article titled “A parameterization for the Absorption of Solar Radiation in the Earth’s atmosphere” has an illustrative graph that shows that CO2 at most has an effect of 1 watt per square meter per 100A at wavelengths that are also duplicated by H2O. The study states “The principal absorbers in the earth’s atmosphere are water vapor in the troposphere and ozone in the stratosphere.” One of the authors was Mr. Hansen.

    [Response: why do you think this is interesting here? None of the models would work at all if they didn't take into account the absorption of solar by water vapour. I do hope you are not confusing absorption of short-wave solar radiation with the absorption of long wave radiation from the surface, which as I'm sure you know is the famed 'greenhouse effect'. - gavin]

  236. Rod B:

    Ray, David, dhogaza, tamino, Your paranoid defensiveness is showing. I wasn’t asking anything for my understanding. I was asking Andrew for his explanation following his assertion that 2009 will be hotter because of increased CO2, not because of random weather changes. Odd how Andrew’s assertion did not seem to bother anyone. Especially since David, et al are wrong or misleading in reading the GISS references. 2008 is the coolest year since 2001, the 3rd coolest in the past decade, and “between the 7th and 12th warmest” year since 1880(?). I’m not sure what Andrew meant by decile — why I asked — and that of course might change things here. (not that anyone cares about little details of fact, though…)

  237. Rod B:

    Andrew (231), just read your post. If decile means “in the top ten” then your statements make sense. You implied that there was something extraordinary about the CO2 effect in 2008 (which I contended would be incorrect), while I suspect you meant that the factors mitigating temperature rises will be less than in some previous periods. Yes?

  238. Ike Solem:

    Mini Ice Age? Anyone see this:

    http://www.sciencedaily.com/releases/2008/12/081218094551.htm

    The paper in the press release is on the role of pandemics in causing a spike in reforestation across the Americas from the period ~1500-1750, based on sediment studies of carbon isotopes:

    “We looked at ice cores and tropical sponge records, which give us reliable proxies for the carbon isotope composition of atmospheric carbon dioxide. And it jumped out at us right away,” Nevle said. “We saw a conspicuous increase in the isotope ratio of heavy carbon to light carbon. That gave us a sense that maybe we were looking at the right thing, because that is exactly what you would expect from reforestation.”

    During photosynthesis, plants prefer carbon dioxide containing the lighter isotope of carbon. Thus a massive reforestation event would not only decrease the amount of carbon dioxide in the atmosphere, but would also leave carbon dioxide in the atmosphere that was enriched in the heavy carbon isotope.

    The reforestation scheme (photosynthesis drawing down CO2 over a long period) fits the cooling trend better than either solar variability or volcanic eruptions. There can be multiple events involved besides just altering atmospheric CO2 levels – for example, as marshes turn into forests natural methane emissions are reduced, and less agriculture means a reduction in methane emissions as well.

    That was a slow change over many years… and if that can induce a little Ice Age, the much larger changes of today should have a larger effect, and probably for a longer period of time than 250 years.

  239. dhogaza:

    If decile means “in the top ten” then your statements make sense.

    Top tenth, actually …

    And, Andrew’s wording is very clear …

    The fact that 2008 was a top decile year with both solar forcing and ENSO aligning to lower temperatures…

    He didn’t imply there was anything “extraordinary” about the CO2 effect in 2008.

    Nor did he say this:

    I was asking Andrew for his explanation following his assertion that 2009 will be hotter because of increased CO2

    He quite clearly stated that 2009 is predicted to be ENSO-neutral, rather than La Niña/cooling. He quite clearly stated that since 2008 has seen a 50-year solar minimum, his guess is that solar output is more likely to increase or remain constant in 2009, rather than go down further.

    So, all things being equal, one might expect 2009 temps to be higher than 2008. Increasing CO2 makes it more likely, but nowhere does he sat what you claim he says.

    Go read what he said again. I’m sure you can figure it out.

  240. Ray Ladbury:

    Rod, You said, “But, how do you account for the level or decreasing 5-10+year periods in the past while CO2 was continuing to rise dramatically?”

    I answered weather, and that you already knew the answer. How is it paranoid to respond to what you wrote? Precision matters in science.

  241. Pat Neuman:

    Something weird is happening to Arctic sea ice lately. The rate of change in extent has flattened to near zero. The implications are astounding.

    http://nsidc.org/arcticseaicenews/

  242. Hank Roberts:

    Pat, check the ocean temperature outside the Arctic basin. Sea ice about filled up the basin early in December, per the same NSIDC page.

    Pure speculation follows; perhaps this warm water
    http://www.nature.com/ngeo/journal/v1/n10/abs/ngeo316.html
    is delaying formation of sea ice outside the Arctic?

  243. davidgmills:

    Oh, I haven’t been guaranteed that there will be global warming? I must have missed something.

    You guys apparently don’t know a guarantee when you give one:

    “CO2 would kick right back in where it left off.”

    Is this an implied guarantee or an outright express guarantee, because I’m confused.

    But it is just as I suspected, no one here really seems to have a clue about what decades and decades of low solar magnetism would do to climate models.

    And yet we have scientists who are predicting by 2014 or 2015 the magnetism of the sun will be so low as to produce no sunspots.

    http://www.astroengine.com/wp-content/uploads/2008/08/livingston-penn_sunspots2.pdf

    Fess up guys. You don’t know jack about the sun.

    [Response: Neither do the people you are quoting. If instead of warbling on about guarantees (which don't exist), you'd asked simply what is the relationship between the radiative forcing expected from a prolonged solar minimum and the expected forcing from increasing CO2, you would have got a much more productive answer (assuming of course that is what you actually wanted). The forcing from a solar minimum (compared to the mean) is about 0.12 W/m2, the extra forcing from 10 years of CO2 increasing at ~2ppm a year is 0.27 W/m2, 20 years +0.78 W/m2 etc. Therefore, after approximately 5 years, the CO2 change would dominate, even assuming we were in radiative equilibrium to start with (which seems unlikely). Thus there is no evidence that the solar change would dominate even over a decadal period. - gavin]

  244. Hank Roberts:

    PS, Pat, I’d also wonder if that’s not a data glitch, comparing it to the Cryosphere Today image. Has anyone asked NSIDC about it directly?

    http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.365.jpg
    ______________________
    “downfall plant being” says ReCaptcha
    Trouble with plankton?

    [Response: Yes. - gavin]

  245. Jim Cross:

    Gavin and Hank

    Nice weather report! :)

  246. wayne davidson:

    241-242, Pat, Hank… Read the report, is nice, but misses the cloud bit, last year had more open water hence more latent heat from freezing sea water, yet it was a bit colder last year vicinity of the Pole, DWT temperatures quite warm in November. Sea water was warmer last year during the summer super melt, so I doubt that sea water has something to do with this. Tropical Thunder clouds begets more Arctic low clouds, so it seems, fall of 2008 being a busy year for hurricanes, ie tropical cloud activity, it stands to reason that there was more aerosol seeded clouds here, hence more heat, thinner ice, warmer surface air. For the GCR “gives more clouds” gang, explain why I see 5.2 mag stars now, in finally super cold weather (starting from the South), it appears to me that aerosol activity is abating and clear skies are finally starting to expand.

  247. Hank Roberts:

    > 241, 242, 244

    Not a data glitch:

    http://davidappell.blogspot.com/2008/12/serreze-on-arctic-ice_23.html

    “The NSIDC’s Mark Serreze responded to my question about the recent data on Arctic sea ice extent, using their own data:

    ‘We are quite certain that the almost complete lack of increase in ice extent since about December 10 is real. ….Past 10 days has also seen a very unusual atmospheric pattern. It has been very warm over the Arctic Ocean, and wind patterns have favored a compact ice cover. … appears to be weather related versus climate related. It will be interesting to see what happens over the next week.’

  248. Ray Ladbury:

    Davidgmills asks: “Is this an implied guarantee or an outright express guarantee, because I’m confused.”

    Actually, it’s called science. Maybe you want to try it some time. And I will certainly admit I don’t have any idea how you take a flux of 6 particles per square cm per second and amplify it into significant warming event. But then, from what I’ve heard, nobody else can do much with that problem but wave their hands so hard the levitate.
    Now, CO2, that I understand. It’s documented, verified and well understood. But, again, David, that’s science–you know where you explain things in terms of the understood and not in terms of totally speculative mechanisms that seem to be contra-indicated by the evidence.

  249. Rod B:

    Ray, ’cause your answer had no bearing on my question, which was what Andrew knew, not what I knew (or didn’t know).

  250. Andrew:

    When it comes to average global temperature, there are no guarantees since a climatically significant volcanic eruptions randomly occur. However, the physics of CO2 warming is strong enough that the odds are very good for next year to be among the warmest of the instrumental record. This prediction is not limited to 2009 and will likely be true for every year of the foreseeable future until a climatically significant volcanic eruption actually occurs.

    With regards to the sun and its impact on climate, consider that solar cycle was at a minimum in 1986.
    Any guess as to where the years 1987 and 1988 were ranked for average global temperatures?

    Likewise, consider that sunspots in 1996 were at a minimum and solar irradiance was at a lower value than in 1986.
    Any idea as to where the years 1997 and 1998 were ranked for average global temperatures?

    This is not to suggest that 2009 and 2010 will each establish new maximum average global temperatures, but going forward such records can be expected to be broken every few years.

  251. dhogaza:

    And I will certainly admit I don’t have any idea how you take a flux of 6 particles per square cm per second and amplify it into significant warming event.

    I think it’s time to ask him for a guarantee, no? Turnabouts fair …

  252. Hank Roberts:

    Rod had trouble with your earlier assertions, Andrew; can you give sources for them and these? It’s always a kindness to later readers to help by saying how to successfully start to look for the information, when you challenge people as to whether they have ‘any idea’ about something.
    __________________
    “hearings succeed” says ReCaptcha

  253. OLympus Mons:

    Hi all,
    can any of you guys give an idea on what would have to happen/could happen in 2009/10 that would make you start to question the role of Co2 in Global warming? Thanks.

  254. dhogaza:

    can any of you guys give an idea on what would have to happen/could happen in 2009/10 that would make you start to question the role of Co2 in Global warming?

    A revolution in physics that overturns pretty much everything we know, including the fact that the earth’s not flat?

    There’s no question regarding the role of CO2, per se.

  255. Matt:

    The Europeans’ ECMWF model is joining the NOAA CFS model in calling for a La Nina this Dec-Feb now too:
    http://i244.photobucket.com/albums/gg29/mrwx72/3464.gif

  256. wmanny:

    47c “…if it’s a scientist they’ve likely been misquoted and misrepresented.”

    Has Will Happer been misquoted and misreprented this week? This is not a rhetorical question, by the way.

    [Response: Apparently not. But using the Cambrian to imply that anthropogenic CO2 poses no threat is not an argument worthy of a Princeton professor. - gavin]

  257. Andrew:

    The National Climate Data Center has a record of Global Temperatures from 1880 to the present:

    ftp://ftp.ncdc.noaa.gov/pub/data/anomalies/monthly.land_and_ocean.90S.90N.df_1901-2000mean.dat

    Put the above into Excel, construct a graph of yearly averages and then sort. There are 130 years of records and it is obvious that 2008 is among the warmest 10%. In fact, every year since about 1992 has been among the top decile. Mount Pinatubo was the latest climatically significant eruption and it occurred in June 1991.
    So, it is clear that a large volcano can significantly lower average global temperatures.

    Next, look up data on Solar Cycles, such as this:

    http://en.wikipedia.org/wiki/File:Solar-cycle-data.png

    or this:

    http://www.ngdc.noaa.gov/stp/SOLAR/ftpsolarirradiance.html

    Notice how difficult it is to correlate any of the the various peaks and troughs to the global temperature record. The reason is that there is too much noise (weather) within the Earths atmosphere.
    So, take a look at the record of the ENSO index:

    http://www.ncdc.noaa.gov/img/climate/research/2008/aug/enso/mei-200808-pg.gif

    Notice again how that last decade is not particularly remarkable for ENSO even though average global temperatures during the period are the highest of any measured decade.

    Finally, take a look at the Mauna Loa CO2 records:

    ftp://ftp.cmdl.noaa.gov/ccg/co2/trends/co2_mm_mlo.txt

    Put it into Excel. Draw a trend line and the correlation is 0.99 or better. Okay; now do some math and CO2 levels are increasing about 0.37% every year. From physics, we know that greenhouse Gases account for about 18C of warming in the earth atmosphere. First approximation would suggest that if CO2 were the only greenhouse gas, then its rise would amount to about 0.067C. Of course, CO2 is not the only greenhouse gas and actually accounts for between 9 to 26% of the total. This works out to about between 0.006 to 0.017 C/year of warming.

    The 130 year long warming trend is about 0.005C/year. So, on the long term we are observing the lower end of the physical science range and this suggest that there is likely a lot of momentum within the earths climate system.

    On the other hand, the 30 year trend is about 0.016 C/year. This suggest to me that the stable/cooling temperatures of the 1950s to 70s could have been a bow wave of resistance (negative feedbacks) and we are now on a stable warming ramp. Of course, the above ignores CH4 which accounts for some warming too.

  258. Ray Ladbury:

    Olympus Mons,
    What it would take is a new model that explained climate better than the current one and
    a)had a CO2 sensitivity lower than 1 degree per doubling; or
    b)had a large negative feedback that somehow kicked in right at the current terrestrial temperature range; or
    c)had a mechanism whereby CO2 suddenly stopped being a greenhouse gas at 280 ppmv

    Need I add that there is zero evidence favoring any of these hopotheses? Indeed, pretty much all the evidence is against it. I emphasize again: There is no “theory of anthropogenic climate change”. There is merely our current understanding of climate, and warming from adding CO2 is an inevitable consequence of that understanding. And since I know you will now contend that understanding is flawed, I will ask in advance that you show how by producing the model alluded to above.

  259. Hank Roberts:

    ‘lymp –

    IF for you it’s a clever new question, one you made up yourself, and never heard anyone else ask or answer, that’s reasonable to ask.

    From this end, you’re one of the many, many people. All the rest of them most likely just read it somewhere else and came here to copypaste it in — if that fits you too, read more, please.

    Otherwise it’s just recreational typing for you and a waste of time.

    Pasting your question into Google, or clicking ‘Start Here’ at the top of the page, or clicking the first link under Science in the right sidebar — any of those — would get you a sufficient answer.

    Just try it.

  260. Andrew:

    My bad; greenhouse effect on earth is closer to 33C; not 18C

    http://www.atmos.washington.edu/2002Q4/211/notes_greenhouse.html

    So, linear approximation of annual temperature rise from CO2 change alone works out to between 0.01 to 0.03 C/yr. This means that warming trend of 0.016 C/yr over last 30 years is medium expectation.

    [Response: You're bad indeed. - gavin]

  261. Rod B:

    Hank, after Andrew better defined his assertion (or I better comprehended it) I have no major problems with it.

  262. Hank Roberts:

    > Happer

    Don’t buy the spin that he was fired for denying climate change. He was arguing the industry line that the science wasn’t good enough to justify controls on chlorofluorocarbon — in 1993!
    —————–
    … before the House Energy and Water Development Subcommittee on Appropriations. “I think that there probably has been some exaggeration of the dangers of ozone and global climate change,” he said. “One of the problems with ozone is that we don’t understand how the UV-B is changing at ground level, and what fraction of the ultraviolet light really causes cancer.”
    —————–
    You know how to find that.

    See also the Nobel Prize award in 1995, and
    http://books.google.com/books?hl=en&lr=&id=afI_TuHCrkUC&oi=fnd&pg=PA134&dq=ozone+nobel+prize+speech&ots=EBGevUz4_6&sig=5uj82nCsmVB0uBc9OpDoRnXSIWg

  263. wmanny:

    256c

    “But using the Cambrian to imply that anthropogenic CO2 poses no threat is not an argument worthy of a Princeton professor.”

    Fair enough, and it begs another non-rhetorical question: Why should I believe your argument more worthy than the Princeton professor’s? If you feel that is too provocatively phrased, why do you believe the professor would publicly make, in your estimation, such an unintelligent argument?

    [Response: You would have to ask him that. - gavin]

  264. RichardC:

    243 David says, “And yet we have scientists who are predicting by 2014 or 2015 the magnetism of the sun will be so low as to produce no sunspots.”

    No, the theory is that sunspots could fade visually, but not actually. This doesn’t mean that the sun’s output would decline, but that the linkage between output and visual appearance would weaken. By the way, the sun is now in a deep minimum and there is nowhere to go but up from here. The sun’s output will *NOT* decline significantly from where it is now regardless of how the solar cycle behaves, and it is almost certain that its output will increase in the near future.

  265. Hank Roberts:

    Matt, where’s that come from? I found the ecmwf.int but it’s a big site, didn’t find the forecast.

  266. Sarah McIntee:

    Nice article. Could someone specifically address the variability issue with data, if possible. I ask this because, theoretically, given a relatively closed system, with heat energy being added, thermal expansion and contraction of gas and water vapor, more wind speed, more shouldn’t this also mean more extreme weather? Otherwise, where is the extra energy going?

    Thanks and happy holidays, y’all

  267. Jim Cross:

    #243

    We are at solar minimum now (or just beginning to come out of it). This cycle 24 will peak around 2011 or 2012. What David is talking about is the next solar minimum and the next cycle.

    http://science.nasa.gov/headlines/y2006/10may_longrange.htm

    If the prediction comes true, the solar forcing will be less in aggregate in comparison with twentieth century cycles and presumably GCR flux will increase.

    Even though the amount of change might seem small, we can’t really be 100% sure that there is not some mechanism that might amplify even seemingly small changes. And we don’t have really much to compare this to, since, as the link points out, this could be one of the weakest cycles in centuries.

    [Response: .. or not. But either way, that means the actual irradiance difference (or GCR difference or whatever) has to be less than what we see at a true minimum, and thus it is even less likely to be significant in the face of further GHG increases. - gavin]

  268. Jim Cross:

    #267 Gavin

    Yeah, I know that what you say is the best scientific assessment as to how it will be.

    The only real problem I have with it is our lack of experience with this sort of minimum. You seem to think the next cycle will on radiative balance no worse (and probably slightly better) than an 11 year minimum. But what if, in fact, there is something qualitatively different about these cycles – maybe something like the sun needing to reboot itself every 200 years or so – where the radiative output is lower than the minimum.

    [Response: Sure that would change things, but what evidence is there? There are any number of improbable speculations one could make, but in the absence of any actual measurable effect, it's just pointless. What if there's a meteor strike? or a nearby super nova? or huge volcano? In any such eventuality all bets are off. - gavin]

  269. David B. Benson:

    Sarah McIntee (266) — Yes, Hadley Centre has pointed out that more extreme weather is expected. Note, not just more extreme warmer weather.

    Jim Cross (268) — Somewhere I came across a paper showing that variations in solar irradiance proxies, sunspots and Be10, for other than the sunspot pseudoperiodic ‘cycle’, are best explained as random events. There are no detectable cycles in the sun’s behavior at periods longer than about 11 years.

  270. Jim Cross:

    #268

    I agree that what I said was a bunch of what-ifs without evidence?

    However, solar cycle 25 isn’t in the same category as meteor strikes or big volcanoes.

    We have the historic record of the Maunder and Dalton minimum associated with colder temperatures. And, correct me if I am wrong, but much of argument against solar influence in those cases is based on arguments similar to the one you are offering that the radiative forcing can’t be much different than the 20th century solar minimum.

  271. wayne davidson:

    A simple GCR proof would be to study star magnitudes. If GCR generated clouds do exist, they would form constantly, even in air with low RH (60 to 80% for instance), even with air having low mixing ratios. In very cold air the cloud droplet should form, then become an ice crystal, which would in the millions, reduce vertical visibility enough to mask very dim stars. In mid latitudes to the Pole, very cold air above would produce ice crystals constantly, effectively dimming the night sky, and causing a GCR star magnitude threshold. The GCR proponent must prove that there is such a constant, and also, prove that the night sky gets dimmer during solar minima. I have my own evidence through observations, and there is n such thing as a GCR generated dimming, since clear night sky magnitudes vary, and there are times when sky magnitudes are 5.6 or dimmer, even with a substantial RH layer. It is up to the GCR cloud proponent to come up with facts proving , indirectly, by astronomical observations by an astronomer or observatory that there is a constant GCR ice crystal layer. Those who want to prove the non existence of massive GCR ice crystals,
    observe the night sky, look for the dimmest star possible at zenith, and identify its magnitude.
    Beware of the star you choose, red giant light may be dimmed by high ozone in the stratosphere.

  272. Ray Ladbury:

    wmanny asks: “Fair enough, and it begs another non-rhetorical question: Why should I believe your argument more worthy than the Princeton professor’s?”

    You are missing the point. Don’t “believe” anyone’s argument. Go with the preponderence of the data. Go with the overwhelming majority of experts. Go with the theory that is based on established physics. That’s what science tells you. Any one scientist can be wrong about anything. However, when they agree that an idea is indispensable or a fact irrefutable, you can usually take it to the bank.

  273. Hank Roberts:

    This isn’t the paper you remember, I expect, but it’s relevant, at least showing how hard people have been looking:
    http://www3.interscience.wiley.com/journal/82002927/abstract

  274. Ray Ladbury:

    Jim Cross, Have you read Usoskin and Solanki on Grand Solar Minima? They last on the order of decades. The effects of CO2 last centuries. Guess which one will win.
    While the heliodynamo is complex, it will always be more changeable than the geodynamo due to the greater inductance supplied by Earth’s solid inner core. Result: not a lot of structure in the time series of solar activity beyond the very prominent solar cycle. I recommend learning about it. It’s cool physics. It won’t affect the conclusions reached by climate science regarding greenhouse warming.

  275. tamino:

    Re: #269 (Jim Cross)

    I don’t think there are enough temperature records for the Maunder minimum to establish the colder temperature which you claim. But there are records during the Dalton minimum, and they contradict your claim of a notable temperature effect of the solar event. Wagner and Zorita, studying the specific issue, state

    Therefore, it can be concluded that in these simulations, solar and the CO2 variability have not contributed in an important way to the formation of a thermal DM, and that volcanic forcing was largely responsible for reduced temperatures in the DM.

    I posted on the topic.

  276. Phil. Felton:

    Ray Ladbury Says:
    24 décembre 2008 at 10:18 PM
    wmanny asks: “Fair enough, and it begs another non-rhetorical question: Why should I believe your argument more worthy than the Princeton professor’s?”

    Well there are quite a few Princeton professors who hold the opposite view.

  277. wmanny:

    271. Go with the overwhelming majority of experts? Go with the theory that is based on established physics? Darwin didn’t. That does not mean the majority is wrong this time, but it’s something real scientists always keep in mind.

    (Actually, I followed Gavin’s advice. With respect, you should, too, if you want to challenge your own beliefs, by whatever name you wish to call them.)

  278. Jim Cross:

    #274

    Be clear that I am not disputing the effects of CO2 or denying human generated global warming.

    My argument is more along the lines that solar cycle 25 might push the warming towards the lower end of model projections or perhaps even some flat periods before warming picks up.

  279. Ray Ladbury:

    wmanny, I don’t know how to break this to you: You are no Darwin. The way you revolutionize a field is not by barging in with zero understanding of the science and saying, “You’re all wrong. I see with my superior intellect that it must be this way.” You start with a thorough grounding in the science as it exists. Then you look for ways to make it stronger, look for weaknesses and come up with new ideas with greater explanatory power. Darwin was really starting from square one, except for Linnaeus. Climate sciece has a 150 year history. It works. So it’s kind of unlikely somebody who doesn’t understand even the basics is going to contribute much. Learn first.

  280. wayne davidson:

    276 Phil, Princeton is mostly awesome, where freedom of thought (even faulty) is allowed, take a look at Interesting IR downwelling surge in 2005
    http://www.arctic.noaa.gov/np2005/gallery_np_weatherdata.html

    , I’ve seen preceding years and the ice essentially tracked the same way from 2002 to present, early months after station North Pole deployment are therefore comparable. There was a once over impressive heat wave in the spring, I remember it well, sun disks were unbelievably expanded at the same time. It is on my news log on my website.

  281. Andrew:

    #278 Jim Cross:

    With regards to the sun and its impact on climate; consider that solar cycle was at a minimum in 1986, just prior to 1987 and 1988 each establishing new average annual high global temperatures.

    Likewise, consider that sunspots and the solar cycle was at a minimun in 1996 with solar irradiance at a slightly lower value than in 1986. 1997 and 1998 ended up establising new highs average annual global temperatures.

    A few years of CO2 increases are more significant for global warming than the solar cycle.

  282. dhogaza:

    Go with the overwhelming majority of experts? Go with the theory that is based on established physics? Darwin didn’t.

    There was no extant theory of evolution for Darwin to overturn. He was filling what was in essence a vacuum, a set of observations with no theory to tie them together. And of course Darwin’s Theory of Evolution was *built* on observations, he didn’t build his theory by *denying* observed data or *making sh*t up* (like magic powers for galactic rays).

    Climate science is a very different beast than 19th century biology. It’s a mature field with sound theoretical underpinnings. Science in this state is rarely overturned, and when it is, the outcome isn’t necessarily as radical as climate science denialists preach. Sure, the aether doesn’t exist and electromagnetic radiation propagates through vacuum without any problem whatsoever, and the change in understanding helped revolutionize physics. But the radios and antenna built by people to send waves through the ether didn’t stop working as a result of that revolution. Any revolution of a field as mature as climate science isn’t going to replace CO2 as a warming agent with poof fairies. It’s just not going to happen.

  283. wmanny:

    Ray, you are a good guy, obviously and, as it turns out, so am I. I am envious, for example, that you got to “fetid dingo’s kidneys” before I did or ever could. When you are reduced to putting silly words in my mouth, though, it diminishes you.

    Once again, I am not a scientist, much less a Darwin(!), and I read what I can with the time I have. I have slogged through the AGW bible with no superior intellect I am aware of, unless you were referring to Happer’s, and I have grasped what I can given my BSEE background, from which I am decades removed. I am a mere calculus and English teacher, granted an odd mix, and I am fascinated by what I perceive to be a mild case of hubris on the so-called alarmist side of the issue. [Please note the 'so-called'; I don't like the term any more than the other one that... never mind.]

    You would not think much of me if I were to read only RealClimate to get my information and directions to more information. This is a biased site, which for the most part is up front about it, a site that brooks little dissent but which needs to be read by anyone with an interest in determining what is going on.

    When I bring up Prof. Happer, though, to counter the claim that anyone on Inhofe’s list is “likely [to have] been misquoted and misrepresented”, note the reaction, which was, ultimately, “ask him”. Well, I did. What I don’t understand is, why don’t you, and why doesn’t Gavin? Aren’t you curious? When I encounter eminent folks like Happer, and he’s hardly the only one, stepping up to what is arguably an unpopular microphone, I don’t immediately question his motives, and I don’t see what’s so anti-intellectual about asking the question: Why does he need to be dismissed so quickly?

  284. Nick Gotts:

    “I have slogged through the AGW bible” – wmanny

    That expression alone makes your bad faith abundantly clear.

  285. Hank Roberts:

    > dismissed so quickly?
    Not quickly — since 1993. Do some searching.

    The ozone denial — political, PR-based, industry-driven — seems to have been the last time he was in the news about this. IT’s being spun now as a climate change issue.

    But look at the PR material that was out at the time, and that he’s quoted in. Industry was vehemently denying there was any convincing evidence that there could be some problem developing, long after the science was clear.

    http://johnquiggin.com/index.php/archives/2006/10/21/exxon-we-believe-in-global-warming-so-we-shouldnt-be-criticised-for-funding-global-warming-denialists/

    http://nobelprize.org/nobel_prizes/chemistry/laureates/1995/crutzen-lecture.html

    Go to Scholar, find the man’s publications in the journals, follow them forward by reading papers citing them. See if you can find something relevant to global warming. I didn’t. Do the same for ozone papers. You should look for yourself.

    What I found was the standard industry position — no mechanism, no proof of imminent harm to humans, no reason to regulate, more research needed, continue the course, don’t ban chlorofluorocarbons, attack on the poor, condemning millions to starvation, you know.

    Read Crutzen’s speech. Note what he says about a close call.

  286. Hank Roberts:

    A bit more for you. This is the issue where Dr. Happer — a Republican appointee who had been held over in his position by the incoming Democratic administration — opposed the new administration’s policy.

    He was wrong then. He took the industry line, that delay was smarter than prompt action, and that physicists’ models of change in the upper atmosphere weren’t enough reason to be concerned about ozone loss — that there wasn’t proof yet that it would cause harm at ground level to humans, so wait, delay.

    There are people _still_ denying at CFCs and ozone depletion are a problem, remember? You can look it up.

    Here’s a recent update on the real science:
    http://www.ait.ac.th/news-and-events/archive/2003/News.2007-09-12.142216/

    ——-excerpt follows, see link for full story———–

    On Wednesday, December 3, 2003, Prof. Paul Crutzen’s lecture on the subject of ‘The Antarctic Ozone Hole – A Manmade Chemical Instability of the Stratosphere – What should we learn from it?,’ was held at AIT under the auspices of the International Peace Foundation, in partnership with various national organizations, institutions and enterprises in Thailand. It was the second in a series of the Nobel Laureates’ and Eminent Person’s Lectures at AIT following Prof. Jerome Karle’s lecture titled ‘The Role of Science and Technology in Quest for a World at Peace’ on November 26, 2003.

    For those who have missed Prof. Jerome Karle’s lecture, instructions for viewing lectures online, as well as future listings and lecture archives, are at

    http://www.dec.ait.ac.th/main/nobel/nobel.html

    In a summary, Prof. Crutzen noted: ‘The discovery of the spring time stratospheric ozone hole by scientists of the British Antarctic Survey was one of the greatest surprises in the history of the atmospheric sciences. It was not predicted and initially unexplained. After intensive research efforts by many international scientific teams it has been clearly demonstrated that the observed rapid ozone depletions are due to catalytic reactions involving chlorine atoms and chlorine oxide molecules, more than 80% of which are produced by the photochemical breakdown of industrial chlorofluorocarbon (CFC) gases.’

    In the lecture, Prof. Crutzen presented the processes that lead to the ozone depletions. ‘Since 1996, by international agreements, the production of CFC products is forbidden in the industrial world. However, despite this laudable measure, it will take some 50 years before the ozone hole will have closed. Some scientists believe that it might take even longer,’ he said. For those who have attended, anyone would agree that he showed that mankind has been very lucky and that things could have been much worse.’

    ——-end excerpt——–

  287. dhogaza:

    Gotts has it nailed, the “AGW bible” comment sums up wmanny’s bad faith very clearly.

    Wmanny, comparing science to religion isn’t going to win you any friends in the reality-based community.

    You would not think much of me if I were to read only RealClimate to get my information and directions to more information.

    Actually, you’d win our respect, because it would indicate you’re really interested in learning about the SCIENCE. Blathering away with denialist talking points is how you lose respect around here, not by studying science.

  288. Hank Roberts:

    The archive link at AIT isn’t working; I’ve emailed per their error message asking if they can make it available

  289. Phil. Felton:

    Just because someone is eminent in one field does not make him an expert in others. Will’s expertise is in Atomic Physics:
    http://www.physics.princeton.edu/www/jh/research/happer_william.html

    Note that he does not include Princeton’s Atmospheric and Oceanic Sciences Program or the Princeton Environmental Institute among his interests.

  290. Ray Ladbury:

    wmanny, Happer is a condensed matter physicist. Why should I care what he thinks about climate? I see no indication he has given it much deep thought–nor indeed that he has gone out of his way to learn the relevant physics. It’s a bit like asking my plumber for investment advice.

  291. Nick Gotts:

    “Darwin was really starting from square one, except for Linnaeus.” – Ray Ladbury@279

    Not really. There was the geological evidence showing that the Earth was at least millions of years old; the evidence for extinction, and for wholesale changes in the biota over time; the work on biological classification which had advanced greatly since Linnaeus (it wasn’t Darwin who recognised that “Darwin’s finches” were all finches); work on the distribution of organisms across the earth; speculations about evolution going back to Lamarck, and Darwin’s own grandfather Erasmus; Malthus’ work on the implications of the tendency of populations to increase geometrically and hence the pressure on resources. Your main point stands, however: Darwin spent a quarter-century after the Beagle vogage both increasing his expertise in geology and biology, and corresponding with his scientific peers about a vast range of subjects touching on evolution. When he eventually published Origin of Species, he synthesised an enormous body of existing knowledge. As ever, the “lone persecuted genius” picture of scientific progress is a gross caricature.

  292. Ron Taylor:

    davidgmills and wmanny, you remind me of some students I encountered some years ago in a graduate course in theoretical mechanics. They simply did not understand the prerequisite material, and their strategy was to try to bluff their way through on what they did know, intuition, and gall. The latter led them to take an aggressive stance in challenging the professor. It was, to say the least, a pathetic performance. The professor scorched them. Be thankful you are dealing with such tolerant people here.

  293. wmanny:

    OK, Ray, so Happer is dealt with. He’s an ozone apostate [not your point, I know] and a plumber, and of no interest to any readers here but me. I get it.

    Here’s the thing, though: I refuse to make the assumption that Happer has not done his own reading and had his own interactions with folks who know what they are talking about, just as you have, and drawn his own conclusions. See, when you’re down here where I am and unable to make my own a priori determinations, not being in the profession or in any way part of the establishment scientific community, I am interested not only in reading what conclusions Hansen, Schmidt, Holdren, Ladbury and even Mashey have drawn, just to name a few names. I am also interested hearing from Lindzen, Geigengack, Happer, McIntyre and others who are off the reservation. This is how I would characterize my open mind on the issue, though I understand why you believe it should be closed at this point, and I have never doubted your sincerity on that point. But when I am told, repeatedly, that the debate is over, even as it rages, I am not as sanguine as you.

    You will disagree, of course, but I still believe that it would be better tactics in the face of the meaningless but easily exploited decade of temperature flattening, to engage with the skeptics rather than to seek to dismiss out of hand with name-calling and the like. If you believe the truth is on your side, in the form of the preponderance of evidence, what in the world do you have to fear from the Happers of the world?

    [Response: Fear? Nothing. But if you think adding to ignorance and increasing disinformation is a positive benefit to society, or to its ability to make good choices about future directions… well, let’s just say, I don’t. – gavin

  294. jcbmack:

    then there is the erroneous reports of the climatologist Dr. William Gray who blames all the warming on the thermohaline circulation and reports that relative humidity is not near constant and that water vapor therefore is a net negative feedback. He has been in the science for 5o years and yet he still wrong. He specializes in hurricanes and yet cannot see the irony of his statements where hurricanes in many regions decrease in incidence, but do in intensity. He attacks Hansen without evidence and utilizes proxy data after he criticizes middle and upper lay troposphere and his analysis of proxy data for paleoclimate.

  295. dhogaza:

    You will disagree, of course, but I still believe that it would be better tactics in the face of the meaningless but easily exploited decade of temperature flattening, to engage with the skeptics rather than to seek to dismiss out of hand with name-calling and the like

    Which is why YOU, yes, YOU, should be spending all your time arguing with Flat Earth Society people that their position is untenable.

    Engage with the Skeptics! Don’t do anything useful, just engage with the flat earthers! There’s no calling on earth more noble, after all!

  296. Hank Roberts:

    Worth reading, if you’re interested in political science as it studies climate change; mentioning Happer and others:

    http://sciencepolicy.colorado.edu/admin/publication_files/resource-2590-2008.05.pdf

    Global Environmental Change 18 (2008) 204–219
    Experiences of modernity in the greenhouse: A cultural analysis of a
    physicist ‘‘trio’’ supporting the backlash against global warming

    Myanna Lahsen

    Center for Science and Technology Policy Research, University of Colorado and Instituto Nacional de Pesquisas Epaciais (INPE),
    Av. dos Astronautas, 1758, Sa˜o José dos Campos, SP 12227-010 Brazil

    Abstract
    This paper identifies cultural and historical dimensions that structure US climate science politics. It explores why a key subset of
    scientists—the physicist founders and leaders of the influential George C. Marshall Institute—chose to lend their scientific authority to this movement which continues to powerfully shape US climate policy. The paper suggests that these physicists joined the environmental backlash to stem changing tides in science and society, and to defend their preferred understandings of science, modernity, and of themselves as a physicist elite—understandings challenged by on-going transformations encapsulated by the widespread concern about
    human-induced climate change.
    —————————

    Mainly I post this to suggest further discussion, in the absence of actual climatology science papers by any physicist, does belong in the political science category. The list of people who don’t publish but do opine is quite long, from all areas of politics and policy.

    But they all need to cite their sources in the science journals, if they want credibility. Else it’s all opinion.

  297. Ron Taylor:

    wmanny, you said “I am also interested hearing from Lindzen, Geigengack, Happer, McIntyre and others who are off the reservation. This is how I would characterize my open mind on the issue, though I understand why you believe it should be closed at this point, and I have never doubted your sincerity on that point. But when I am told, repeatedly, that the debate is over, even as it rages, I am not as sanguine as you.”

    Where does the debate rage, exactly? Certainly not in the peer reviewed literature. Certainly not in the conclusions of every scientific society in the world. Aha! I got it – the blogsphere. And Fox News. And Senator Inhoff’s office. Come on, even Exxon has tossed in the towel.

    There is nothing wrong with reading the views of the people you cite, as long as you also read the critiques of their positions. You have to do that with an understanding of how science actually works. Otherwise, you will simply buy snake oil.

  298. wayne davidson:

    Insight is gained not necessarily by following a spokesperson, scientist or a lobbyist. Deep meaning into any science field is gained much further by observation, no theory is proven without observations, to really criticize the mainstream you must look for something which contradicts AGW claims. There are none to my knowledge, even so I continue searching, but unlike Eisenbergs Uncertainty principle, further observations narrow down the inescapable truth, AGW theory is rock solid, once removed
    from tactile senses gained by actual science work, it is easy to be confused by a few scientists most of them lobbyists. Then its a matter of believing one chap against the majority, nothing is gained by pitting one view against another, everything earned by effort in observing validates the mainstream , championed by Gavin, Hansen, Tamino, Hank and Pat to name a few…
    Happy holidays to all

  299. jcbmack:

    wmanny,

    global warming is a real issue. To what degree it will affect us and how long the world continues to emit so much CO2 and CH4 remains to be seen and the exact climate sensitivity is more elusive, but the range is well evidenced and global warming is more than just evidenced it is certain. Detracting from name calling it is not wise to engage in ignoring the overwhelming data and what we are seeing in the globe. As a non scientist wmanny, and perhaps, though I would not automatically assume, without the thorough background in the mathematics, it is not really possible to analyze the core of the data collections themselves. As you admit, it is not your area of expertise that deals with the totality of such matters. There may not be a 1 or 2 meter rise in sea level on such and such a date or when there is a 3.2 degree warming as opposed to a 3.0 degree warming, however, the warming itself is not only well grounded in physics and well modeled with the mathematics; even the physical chemistry, but the ecological changes are already enormous, Honey bees, no, they changed migration patterns and were largely killed by pesticides, they are not so sensitive, but have you heard about the lemmings? How about aquatic fish and other life? Global warming may be of some benefit in certain regions for some period of time, however, it will continue as it already is now, bring about more chaotic weather patterns, droughts, famine, floods, crop shortages etc… We are actually witnessing it now. I take a different approach than many of my peers, I look at the counter arguments, plays devil’s advocate and patiently post the explanations and data on my own blog, but wmanny it is not wrong the basic conclusions reached by NASA, NOAA, Princeton AOS, Harvard research, and countless others besides the IPCC report. there are negative feedbacks and they do arise from a combination of phase changes, and the already discussed to death weather events, however, they do not permanently stop or negate the trends based upon the composition and properties of the greenhouse gases and the semi closed (or semi open depending on semantics and perspective, it amounts to the same thing) planetary-atmospheric system. If it were completely open we would freeze if it were entirely closed we would burn up! That atmosphere held by the gravitational filed constant is analogous to a cell membrane, it forms a semipermeable barrier. There is an energy budget and warming as a whole as not occurred all that rapidly, if it did then we would be in far more trouble. The trend is clear at this time without any legitimate refutation. If we lower these emissions by a lot and keep below 400-450 ppm CO2 and watch those methane emissions and melting permafrost we can significantly slow the warming in 60-100 years and reduce the risks in the couple of decades, adjusting for the lag phase. At any rate that lung cancer, skin cancer and those malaria outbreaks are not imaginary or in the realm of some imaginary philosophical ideals of forms and substance. And yes as a Biologist I am well aware that there were malaria outbreaks in cold climates like Russia, but it is the summers that enable greater yields in the dormancy phases and it is the humidity that can create more conducive environments to Anopheles mosquitoes. Just pick up “The Microbial World.” We are not saying warming creates diseases or invents droughts and famines. We are also not saying, the vast majority of us anyways, that the world is just going to end at a 3.8 degree temperature increase. We are saying we had better reduce emissions and prepare for the detriments of warming and other changes as a result of the warming. Global dimming is old as is cooling, aerosol transfer and black carbon reflective effects.

  300. Jim Cross:

    #281

    Andrew, your reasoning is that future solar cycles will be like the ones of the 20th century. That may be, but you might have missed my original post and link:

    http://science.nasa.gov/headlines/y2006/10may_longrange.htm

    You might also look at this link to understand how unusual the sun has been in recent decades and how unlikely it is to be that way in the future:

    http://cc.oulu.fi/~usoskin/personal/nature02995.pdf

  301. Andrew:

    #300 Jim Cross

    I can appreciate that future solar cycles may have significantly less sunspots than recently. However, from top to bottom, a solar cycles only push solar irradiance from about 1365.5 to 1366.5 Watts/m^2.

    When I put those values into a stephan boltzmann equation, with standard values for albedo and emissitivity, I come up with about 0.05C of surface temperature change.

    When I review CO2 levels and how much they change, I calculate that the impact amounts to between 0.01 to 0.03 C/yr of warming. In other words, increases in CO2 are more significant after just a few years.

    Also, I know that ENSO events can push global temperatures up or down 0.2C.

    So, it is good to keep things in perspective.

  302. wmanny:

    #291 The “lone persecuted genius” picture of scientific progress is a gross caricature.

    Agreed. I was merely referring to Darwin’s having to take on the established physics of his day, in this case Thomson-Kelvin’s.

    Darwin to Wallace: “Thomson’s views on the recent age of the world have been for some time one of my sorest troubles.”

    That’s all.

  303. wmanny:

    #293c

    “But if you think adding to ignorance and increasing disinformation is a positive benefit to society.” No, I don’t think so, Gavin, obviously. Nor do I think engaging those with whom you disagree adds to ignorance, and it seems self-evident to me that lambasting rather than querying one’s opponents is the more ignorant approach. – Walter

    [Response: 'lambasting'? I critiqued his quoted argument. That is a long way from 'lambasting' - However, given his long history (see links passim), I'm not going to hold my breath waiting for a dialogue. - gavin]

  304. Nick Gotts, OM:

    wmanny@302,
    OK. But Darwin’s theory of evolution, like modern climate science, made sense of a vast body of observations that had no alternative explanation: there was therefore a clash between disciplines. There is no such clash between modern physics and climate science; rather, AGW sceptics (even those few who may still deserve that title rather than “denialist”) are in the position of Darwin’s opponents in biology and geology – desperately hopping from one will-o’-the-wisp objection to another, without any sign of an overarching theory.

  305. Jim Cross:

    #301

    On what basis do you assume that irradiance in solar cycle 25 will only go as low as a 20th century solar cycle minimum? Is there a reference for that?

    In addition, there are other things to consider that are not completely understood at this time. What are the climatic effects of a diminished solar wind and interplanetary magnetic field?

    I’ve admitted that I am spectulating somewhat but arguing from the experience of recent solar cycles and the last 50-60 years is spectulating somewhat too.

  306. Phil. Felton:

    Re #280
    wayne davidson Says:
    25 December 2008 at 10:45 AM
    “276 Phil, Princeton is mostly awesome, where freedom of thought (even faulty) is allowed, take a look at Interesting IR downwelling surge in 2005″

    You’re right about Princeton, the most notable case being a distinguished professor and Dean of the Engineering School who set up a lab researching into psychic phenomena (much to the chagrin of many faculty members)!
    The IR data is interesting, in particular the consistent 300+ W/m^2 when the SW has hit 0 as also seen in the recent buoy.

  307. Andrew:

    #305 Jim Cross

    Generally, the most recent observation and trends are the best prediction of the immediate future. This is true for most physical phenonimum.

  308. Hank Roberts:

    http://www.grida.no/climate/ipcc_tar/wg1/images/fig12-7s.gif

    Modeled using only natural forcings compared to observations
    Modeled using anthropogenic forcing compared to observations
    Modeled using the combined forcings compared to observations

    One picture, sums it up. Understand it or go on pretending it can’t be understood. It’s easier to understand than not understand by now.

    Below, hat tip to
    http://www.climateshifts.org/?p=899
    Convincing the climate-change skeptics
    By John Bruno • Dec 23rd, 2008

    a brief excerpt from an op-ed published in the Boston Globe
    John Holdren, August 4, 2008

    “Their arguments, such as they are, suffer from two huge deficiencies.

    First, they have not come up with any plausible alternative culprit for the disruption of global climate that is being observed, for example, a culprit other than the greenhouse-gas buildups in the atmosphere that have been measured and tied beyond doubt to human activities. (The argument that variations in the sun’s output might be responsible fails a number of elementary scientific tests.)

    Second, having not succeeded in finding an alternative, they haven’t even tried to do what would be logically necessary if they had one, which is to explain how it can be that everything modern science tells us about the interactions of greenhouse gases with energy flow in the atmosphere is wrong.”

  309. RichardC:

    305 Jim asked, “On what basis do you assume that irradiance in solar cycle 25 will only go as low as a 20th century solar cycle minimum?”

    Totally irrelevant. Andrew’s analysis was based on a potential grand minimum – as in ZERO sunspots for cycle 25. Even in that extreme and absolute case, the sun will only dim enough to counter a few years worth of CO2 increase.

  310. Hank Roberts:

    > what are the climatic effects …..?

    Try plugging your question into Google Scholar, and reading the results (at least limit it to recent papers and read a few dozen).
    I found a variety of useful papers. You’ll find some of the ones from the PR blogs, BUT, you’ll also find others they don’t tell you about. So, just as a typical example, this:

    http://www.springerlink.com/content/g74070035274784x/

    Then look below the Scholar hit and click “Cited by” to read the list of papers that cited the paper you find, for example

    http://scholar.google.com/scholar?num=150&hl=en&lr=&newwindow=1&safe=off&cites=7969411931024483665

    If your purpose is to learn how to learn, you can do that here.

    To the “gaps” notion, so beloved of people who insist there must be some hidden actor or force not yet discovered, isn’t working out very well so far in any area — this will help you see how the “gaps” get smaller and smaller with more scientific work. Shine some light into your areas of dark.

    No hidden actor yet found.

  311. curious:

    Re #299: Paragraphs might help!

  312. David B. Benson:

    wmanny (283) — I’ve been reading and posting on RealClimate for a few years now. I commend the tolerance of the moderators and the patience with which various responses are made. I also commend the patience of the many amateurs here who have to repeated point out to newcomers that they really should go learn the subject of climatology. I suggest starting with W.F. Ruddiman’s books, “Earth’s Climate: Past and Furture” and his popular “Plows, Plagues and Petroleum”. I then suggest David Archer’s “The Long Thaw” before his other book and harder stuff such as Ray Pierrehumbert’s

    http://geosci.uchicago.edu/~rtp1/ClimateBook/ClimateBook.html

    Once you have read several books and a dozen or so papers you’ll be in a position to begin to understand why the fringe community, several members of which you have named, are simply wrong.

  313. Jim Cross:

    #307, 309

    Obviously you guys have never read The Black Swan:

    http://www.fooledbyrandomness.com/

    Solanki and Figge tried to reconstruct the historical solar irradiance. The effort is difficult and inexact. As they point out:

    “Precise measurements of the irradiance have only
    been made since 1978, whereas longer time series are required
    in order to establish a possible relationship with climate.”

    Their reconstruction for the Dalton minimum has the value possibly as low as 1359 Watts/m^2.

    http://www.acrim.com/Reference%20Files/Solanki%20&%20Fligge_A%20reconstruction%20of%20total%20solar%20irradiance%20since%201700_1999GL900370.pdf

    But who is to say that the Dalton minimum is typical of a grand solar minimum? Perhaps the Maunder was even lower? Or perhaps solar cycle 25 may be the start of one lower yet?

    My point isn’t that CO2 isn’t the cause of most of our recent warming. My point is that you can’t extrapolate from a couple of recent decades of solar cycles and assume future solar cycles will be the same.

    This other article describes just how unusual the recent solar cycles have been and how unlikely future ones will be like the recent ones:

    http://cc.oulu.fi/~usoskin/personal/nature02995.pdf

  314. Hank Roberts:

    Jim, have you read the previous threads where that paper has been discussed at length? Search box will help. One of the authors has participated.
    http://www.realclimate.org/?comments_popup=180#comment-3961

    You’ll find much talking about the same work at the adit and greenwash PR sites, but without the scientists.

    There are a lot of people claiming that the interesting science being done about solar activity must somehow prove there’s some connection to the last few decades of climate change. But nobody has shown one.

    Don’t confuse interesting work on solar activity with the wish to believe it has to explain what CO2 explains.
    Try reading the threads at RC, just to save retyping the same stuff.

  315. Hank Roberts:

    PS, Jim — one useful way to distinguish blather from science is to watch for the phrase you coined above:

    “who is to say”

    is pretty consistently not part of a scientific discussion.

    Say it to any reference librarian — they’ll clear that up for you.

  316. Jim Cross:

    Hank,

    Did you read my post? I didn’t say solar activity explained recent global warming. I said the opposite.

    The problem or issue is I see it is that future solar cycle might actually mitigate temporarily global warming.

    In one way, this would be good. It would give us some breathing room to fix the problem or maybe let peak oil or new technology to reduce human CO2 input into the climate system.

    But there would be a downside.

    The deniers could come out saying “I told you so.” The climate scientists would have to explain things that most people aren’t going to grasp about the problem not having gone away. And most reasonable people are going to be confused.

    The IPCC predictions are serious enough without some of the alarmist tendencies to overstate things about runaway greenhouse effect or oceans rising multiple feet. Let me be clear that scientists aren’t making those predictions but some of this site do.

    If the predictions are too alarmist, it will be so much the worse if something – anything, even a big volcano – comes along makes the predictions look ridiculous.

  317. Hank Roberts:

    There are people who will try to make anything the climate scientists say look wrong. Remind them that scenarios include the various possibilities, that’s one way that scenarios differ from “predictions” — you can show them scenarios including volcanic events.

    I don’t off hand know of any climate scenario that includes a change in the sun great enough to alter Earth’s weather for a few years like a big volcanic event can do. It’d have to be comparable to what’s being suggested by the geoengineers.

    Nor do I know of anything like that described in the observations of other stars like our sun, and I know they’re being watched — it’s the only way to get a better idea of the range of variation that may be possible locally in a hurry.

    Come up with a scenario using what’s known. YOu will never be able to argue with the people who say “but something else might happen.”

    Yep, something else might happen. Don’t bet the farm on it.
    ________________________
    Can someone arrange to send a dozen roses to ReCaptcha for me?
    I think I’m in love. Today’s words: “Seitz missioners”

  318. wayne davidson:

    #306 Phil, I still need some perspective, with respect to say at a more Southern location was the down welling. this paper:

    http://ams.confex.com/ams/Madison2006/techprogram/paper_113329.htm

    refers to a calibration and quality control effort, in Switzerland?? Where Downwelling was measured from 190-320 W/m2…. THat is virtually the same as over the North Pole to Fram quadrant, fascinating if so .

  319. Phil. Felton:

    Wayne, I think they make IR downwelling measurements at Barrow, ARM or SIRS perhaps.

  320. Andrew:

    Jim Cross

    I appreciate Solanki and Fligge’s work.
    They stress, however, that determining
    the quantitative long-term variations of the quiet Sun is highly speculative and subject to large uncertainties. Converting sparse sunspot observations from the 1700’s into watts/m^2 is a feat.
    Notice, they observe greatest uncertainty in the area of your concern (1750 to 1825).

    Anyhow, we are currently at an overdue solar minimum and TSI is about 1365.4 watts/m^2. This is just about the same as the minimum in 1996; so no trend. However, in the 1986 minimum, TSI was about 1365.5 watts/m^2.

    0.1 watt over 22 years works out to about 0.005 watt/yr.
    Plug this into Stephan Boltzmann and it works out to 0.001 C/yr.

    Recent global warming from the rise in GHG is about 0.0166 C/yr.
    0.0166 – 0.001 = 0.0156 C/yr.

    Concentrating on Solar Max and again, no trend between 1990 to 2002; but similar size from 1981 to 2002.

    So, while there may be a long term gradual decline in solar irradiance, it is barely significant compared to current rate of warming.

  321. Scott:

    The IPCC predictions are serious enough without some of the alarmist tendencies to overstate things about runaway greenhouse effect or oceans rising multiple feet. Let me be clear that scientists aren’t making those predictions but some of this site do.

    If I read the some of the conclusions in the latest report on Abrupt Climate Change from the US Climate Change Science Program http://www.climatescience.gov/Library/sap/sap3-4/final-report/default.htm, in particular Chapter 2, it would seem possible to come up with multiple feet of sea level rise due to the understanding of ice dynamics.

  322. Andrew:

    It almost funny.

    Claim 4 feet of sea level rise and you’re an alarmist.
    Claim 1.3 mm/yr and many people relax since they don’t know the differance.

    Or better yet, how about -480 Gt a^-1?

  323. Alan Millar:

    “It almost funny.

    Claim 4 feet of sea level rise and you’re an alarmist.
    Claim 1.3 mm/yr and many people relax since they don’t know the differance. Andrew”

    Well it is funny isn’t it!

    It would take nearly 1000 years to get a four foot sea level rise at 1.3 mm per year.

    Why are you not relaxed?

    Alan

  324. Hank Roberts:

    Lose the trailing comma to make that link work:
    http://www.climatescience.gov/Library/sap/sap3-4/final-report/default.htm

    There are two differences between “feet” and “millimeters per year” — change vs. rate of change is the important one.

    Nobody’s promising a millenium of tranquility followed by a rapid event.

  325. Paul D:

    With regard to “alarmism”, have any climate scientists made a worst-case maximum credible prediction? Have they done any kind of probabilistic analysis – like seismologists and meteorologists do when developing design parameters for buildings and dams? In general, when loss of human life is involved the public demands that structures handle uncertainty by being designed for events with a rather remote probability of occurrence.

    For example, building codes have provisions for design to resist earthquake shaking that have a remote (usually one in 2000 years or so) probability of occurring. Critical facilities like nuclear power plants must be designed for a site-specific “maximum credible earthquake” as their safe-shutdown event. Dams that could result in loss of life must be designed to safely pass a “probable maximum precipitation” – a theoretically derived storm event with a very remote possibility of occurrence.

    Please correct me if I’m wrong, but the IPCC seems to be focusing on a “best prediction” – an event with a 50% probability of exceedence. But I could never consider design anything based on these predictions – it would have a 50% chance of failure.

    So we design for loadings and events with a remote chance of occurring – but we civil engineers never get accused of being alarmist. So shouldn’t planners have access to a “worst-case prediction without this talk of being “alarmist”.

    Thanks in advance for any responses.

    Paul D.

  326. Hank Roberts:

    Paul, what kind of civil engineering are you doing? I’m surprised any sort is _not_ addressing these concerns by now. Well, except areas like utility power transformer replacement
    http://ag.ca.gov/globalwarming/pdf/ee_petition.pdf#xml=http://search.doj.ca.gov:8004/AGSearch/isysquery/3b7944bf-2b14-4344-9efb-f8365e3f5683/1/hilite/
    where DOE still says there’s no reason to consider climate change.

    E.g.
    http://www.google.com/search?q=%22civil+engineer%22%3A+%2BCalifornia+%2BBay+%2BDelta+%2B%22climate+change%22+%2B%22sea+level%22

    ReCaptcha:
    ________________
    “Stark revision”

  327. dhogaza:

    Thanks in advance for any responses.

    Oh, very good points, indeed.

    To be honest, though, I’m more surprised that more conservatives don’t argue that we shouldn’t plan for exceptional low-probability events like large earthquakes.

    Perhaps it’s because that even though such events might be relatively rare, we see the effect of even moderate earthquakes, flooding, etc in parts of the world where stringent standards and planning have not been in effect?

    Scientists, engineers and political leaders can always point to the horror of (say) the last SE asian tsunami event when they upgrade a regional “tsunami danger zone” (such as was just done in Oregon), and people will relate.

    We can’t point to another planet and say, “hey, look, that’s what happened when *that* civilization ignored the consequences of climate change driven by their behavior”. We’ve only got our own planet.

    Also, the damage caused by climate change will never be as dramatic as, say, a huge earthquake, which can cause a great amount of destruction in a few minutes.

    And we don’t see a dishonest, intentional effort to hoodwink the populace about the danger of earthquakes, etc, as we do with climate science. That’s got to play a role :)

  328. Nick Gotts:

    My point isn’t that CO2 isn’t the cause of most of our recent warming. My point is that you can’t extrapolate from a couple of recent decades of solar cycles and assume future solar cycles will be the same. Jim Cross

    But you can look at past climate records, and see no sign, over many thousands of years, that solar variations have had effects of anything like the size needed to cancel out the expected effects of increased greenhouse gas levels in the atmosphere over the next few decades.

  329. Andrew:

    There are some nuclear power plants that had to be re-analyzed. The plants were of course designed with assumptions made for weather extremes (max/min temps, winds, water level and floods) However, some have experienced higher temperatures than originally assumed.

    Both cooling water temperature and ambie_nt have been found to exceed assumptions made during the 1970′s when most were originally sited. The engineering cost of these re-analysis has not been particurly expensive. Of course, the guys doing the work appreciated the pay.

    In the SE US, the prolonged drought has lowered water levels at some sites. I can’t say if they were able to just re-analyze or if they had to do mods or take de-rates. Similar problems have occured at times in the Midwest, but not lately.

  330. Hank Roberts:

    Jim, do you have a library where you can read Science?
    http://www.sciencemag.org/cgi/content/summary/306/5693/68

    If not, see if you can find that online, or the papers referring to and discussing it. Often authors or teachers will have made copies accessible; the citing papers and related papers should help. Searching by the author’s names will also find more.

    http://www.ncbi.nlm.nih.gov/pubmed/15774756?ordinalpos=12&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum

    http://www.ncbi.nlm.nih.gov/pubmed/16971941?ordinalpos=2&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum

  331. Richard Palm:

    Just curious: has the following article been commented on here?

    http://www.telegraph.co.uk/comment/columnists/christopherbooker/3982101/2008-was-the-year-man-made-global-warming-was-disproved.html

    [Response: No. But his previous articles have attracted a fair bit of attention. - gavin]

  332. wayne davidson:

    324 Phil, Stephen Schneider puts it at 324 watts/m2 per standard atmosphere. I am puzzled or rather feel quite the neophyte with this subject, astounding that we do not have more data readily available.

  333. Andrew:

    Re 331: Global warming is expected to lead to greater precipitation during the NH winters. In particular November and December snowfalls have trended higher while rest of year shows decline.

    In other words, expect more snow fall and faster melting!

  334. jyyh:

    Paul D… As a part-time alarmist I would answer that with a little bit of extrapolation added to some warnings of climate scientists I guess the worst case scenario at least includes the total collapse of the WAIS, creating tsunamis at least all over the Pacific rim, the subsequent sea level rise of c.7m will destroy most of the remaining harbours, communication centers near coasts, next up would be the melting of the collapsed ice in the southern ocean altering the climate of the entire southern hemisphere, making it near-impossible to guess what areas are good for similar agriculture as before, leading to massive movements of people. The tsunamis might enter also the Arctic ocean, destabilising the northern part of the Greenland ice sheet, giving a further rise of 3m. I think the runaway methane release suggested by some is not likely as long as there is plenty of ice on Greenland/EAIS as their melting will keep the ocean surfaces cool enough. I’m not saying this is going to happen, it’s just a possibility which might start f.e. with a large volcanic eruption or a large earthquake near or under WAIS, I don’t know how probable those are.
    To RC, if this post is too alarmist, please moderate it away.

    ReCaptcha: Hance Blackwood , I don’t know what that means.

  335. jyyh:

    Heh, Hance Blackwood, the writer of high school physics book.

  336. Ray Ladbury:

    Paul D., The IPCC is not doing engineering, but rather using “scenarios” to highlight trends. Their emphasis is science, so best estimates are what is expected. James Hansen, Lovelock and others are coming closer to specifying WC scenarios, although whether they are really worst-case remains to be seen.

  337. BeetleB:

    The problem with the IPCC “scenarios” is that IPCC is using models or data in the models that are not predicting future events with any degree of certainty. Thus the “scenarios” as published are worthless.

    The marketing(a term I do not use lightly) of the models, before validation, seriously undermines the public’s confidence in the IPCC and if they are wrong will so undermine the public’s confidence in science that it may take generations to recover.

    [Response: Perhaps you could point us to a source of information about the future that is without uncertainty? I'm sure the IPCC would be happy to use it. - gavin]

  338. dhogaza:

    The problem with the IPCC “scenarios” is that IPCC is using models or data in the models that are not predicting future events with any degree of certainty

    Maybe you can help us out by telling us how many tons, with a high degree of precision, of CO2 will be spewed into the atmosphere in 2050?

    Please show your work …

    If you can credibly provide such a number, climate scientists will be able to tighten their predictions by a huge degree of precision.

    If you can’t, then don’t complain.

  339. krisb:

    ‘Response: Perhaps you could point us to a source of information about the future that is without uncertainty? I’m sure the IPCC would be happy to use it. – gavin]’

    Gavin; Newtonian physics can predict the future with a fair amount of certainty.

    [Response: Chaos occurs in purely Newtonian systems (like the weather). That doesn't actually help much (and of course is the basis of climate modelling in any case!). - gavin]

  340. Ray Ladbury:

    BeetleB, Your post is not even logically correct: there are no degrees of certainty. You are either certain or you are not. You are also factually incorrect, as the models have been validated. To paraphrase Pauli, your post doesn’t even rise to the level of being wrong. You are a perfect example of how someone can be certain and yet flat wrong.

  341. Ray Ladbury:

    Krisb, Great, so when can we expect your solution of the 3-body problem?

  342. krisb:

    ‘[Response: Chaos occurs in purely Newtonian systems (like the weather). That doesn’t actually help much (and of course is the basis of climate modelling in any case!). - gavin'

    Gavin, my point is simply that laws of physics can predict the future - hence providing an example for a source of information that provides certainty about the future. I am not specifically talking about climate/weather, just science.

    The basis of climate modelling? what, the laws of physics? i have read that the earth cools primarily through convective currents - and that turbulence equations (the chaotic part) are somewhat unsolvable. correct me if i'm wrong though :).

    [Response: ??? Of course I agree that physics gives us some predictability (otherwise I wouldn't be a climate modeller), but that only goes so far, and the human factor in determining emissions in the future (the 'scenarios') are precisely the bits that aren't reducible to physical equations. - gavin]

  343. krisb:

    ‘Krisb, Great, so when can we expect your solution of the 3-body problem’

    Ray, i dont think your post really says much, can you elaborate?

  344. Hank Roberts:

    krisb, you replied to Gavin saying:

    “Newtonian physics can predict the future ….”

    That’s true within severe limits.
    Two items, Newton will take care of you forever.
    Three or more, Newton won’t help you quite so long.

    How many items involved in the climate of the planet?

    here, this may help.
    http://www.google.com/search?q=%2BNewton+%2B“three+body+problem”

    ______________________
    ReCaptcha? The words offered me for this posting are “Salonica said” which led me quickly to find

    “… the 13th conference in the Recent Developments in Gravity series. It will be held at Salonica (Thessaloniki, Greece) …”

  345. cw00p:

    I’ve been following the blog for a while and have just now decided to post. For the record, I guess you can consider me a “denialist” although I don’t think the term as has been defined in here applies. I just don’t think we have reached the level that our anthropomorphic activities are significant enough to make the type of graphics climate changes attributed to humans. For the record, I sure think we can over time, but I haven’t seen anything that suggests we are there yet.

    My comment, statement, question is:

    The Permian die off, which is attributed to global warming, started when the earth’s climate was very similar to what it is now. I watched a Nation Geo special on the topic (http://science.nationalgeographic.com/science/prehistoric-world/permian-extinction.html ) in which it was determined that the level of CO2 in the atmosphere increased, principally due to the amount of gas released by the Siberian traps until the temperature had increased by 4 degrees c and then all of the methane hydrates began to thaw which put the warming into over drive.

    This warming, of course, lead to the biggest die off in Earth’s history.

    The problems with the global warming community of today relates to timeline. Whereas the CO2 levels increased during the Permian, and the earth did warm by 5 degree c total, it took 70,000 years with Co2 at much high ppm than today (7000 ppm by the time of the die off – http://www.geocraft.com/WVFossils/Carboniferous_climate.html ) to raise it the 3 to 4 degrees c needed to melt the hydrates. The final process took another 10,000 years to occur.

    We are seeing nothing approaching this scale.

    I realize MMGW does not suggest a die off like during the Permian; however, it is important to note that co2 levels were much higher during that period, increased at higher rates that today, and it still took 70k years to increase by 2 to 4 degree c.

    Further, the chart provided in the link above also show how co2 and temperature rarely seem to be in step enough to ever complement one another and bring about the predicted climate changes.

    Again, I don’t deny that humans can’t do grievous damage to our environment, as technology advances; we may have the capability to literally crack the planet in two and to induce Novae in stars (even our own). As it stands now, we don’t quite have the capability to change the climate in such massive ways as suggested by MMGW. But I do have faith we can poison it and, at least, kill ourselves off.

  346. Ray Ladbury:

    Kris B., Just because classical physics is deterministic does not mean that every problem can be solved exactly or that every classical system is predictable. Even fairly simple solutions can exhibit chaotic behavior, where different realizations will end up in very different final states. Weather is an example of a chaotic system.
    My allusion to the three-body problem is because it is one of the most famous insoluble problems in physics.

  347. Tom Guilderson:

    In a series of earlier posts (eg. #177,#100) were queries requesting what do “the models” look like with respect to MSU (mid-troposphere satellite derived) temperature estimates?

    For those interested in such a comparison they could look at Santer et al., Consistency of modelled and observed temperature trends in the tropical troposphere International Journal of Climatology, V 28, n13, Date: 15 November 2008, Pages: 1703-1722. This is mainly a statistical treatment of how to test the reliability of trends in short data-sets but Ben also has graphs of mid-troposphere from an ensemble of results from one of the AR models. Ben also composites the average trends for much of the AR4 suite, even models that only have a single realization.

  348. Hank Roberts:

    cw00p, try this:
    http://scholar.google.com/scholar?q=rate+of+CO2+increase+in+Permian

    (click “recent” to limit it)

    You’ll find the information you’re missing, which is how fast the change is happening. Hits like this one.

    (Elsevier has copies behind a paywall, so you’d need to get this from a library or by searching further)

    Paleophysiology and end-Permian mass extinction – ►stanford.edu [PDF]
    AH Knoll, RK Bambach, JL Payne, S Pruss, WW … – Earth and Planetary Science Letters, 2007 – Elsevier
    … the key variable is rate of change … the rapid, unbuffered increase in P CO2 and not …
    Cited by 15 – Related articles

    Click the “cited by” and “Related articles” links (focus on articles cited by more other articles)
    And look for other papers by the same authors, many of whom likely have copies available online that you can read.

  349. tamino:

    Re: #345 (cw00p)

    Let’s start with the fact that the source you link to in order to support your “7000 ppm by the time of the die off” claim, flatly contradicts you. It shows the CO2 level at the end of the Permian to be about 2000 ppm, not 7000.

  350. dhogaza:

    Gavin, my point is simply that laws of physics can predict the future – hence providing an example for a source of information that provides certainty about the future…

    So the future is predictable

    The basis of climate modelling? what, the laws of physics? i have read that the earth cools primarily through convective currents – and that turbulence equations (the chaotic part) are somewhat unsolvable. correct me if i’m wrong though :).

    Yet the future is NOT predictable, because not everything is solvable (I’ll ignore the “somewhat”, which is meaningless, which ought to give you a clue that you don’t know what you’re talking about).

    Is it true that you don’t recognize the contradiction in your own post?

    You’re pretty much missing everything that chaos theory has told us about determinism at the scale at which Newtonian mechanics works well.

  351. dhogaza:

    I watched a Nation Geo special on the topic …

    National Geographic is entertaining, and educational in its own way, but don’t mistake it for being a definitive resource for understanding the state of science.

  352. Rick Brown:

    Re #345 (cw00p)

    As Hank and dhogaza suggest, your opinions will be better informed if you rely on peer-reviewed articles and sites such as Real Climate that are based on, and cite, them. Nat’l Geo should be taken with a few grains of salt, but while the website you reference (incorrectly, as tamino points out) for the 7000 ppm figure may have some interesting information on West Virginia fossils, given that it’s apparently put together by an engineer for the WV Office of Miner’s Safety, it might best be accompanied by a bucket-full if you’re reading it for information on climate change. A more complex, fully referenced, depiction of estimates of CO2 levels during Permian times can be found at
    http://www.globalwarmingart.com/wiki/Image:Phanerozoic_Carbon_Dioxide_png

  353. JB:

    What about the temperatures and sea levels of the ocean basins? Has the melting at the poles been more or less right on par with most predictions? The trend of ~.2C/decade although significant, is considerably less than a “worst case scenario”. I wonder if the positive feedback of the climatic warming and melting of glaciers will lag behind, not becoming manifest until several decades of warming have already transpired. The ocean, after all, does take quite a while to warm up, but once it does, it retains energy extremely well. Perhaps all of this newly freed up ice-cold water at the poles is temporarily acting as a negative feedback, but as it absorbs more of the solar radiation, over time, it will transform into what we rightly think: a predominately positive feedback system, rapidly intensifying the warming. Therefore, with all other variables being equal, I would suggest a more rapid warming towards the latter part of this century, that is, given the plausibility of the former conjecture.

  354. James:

    Re #342: “…my point is simply that laws of physics can predict the future – hence providing an example for a source of information that provides certainty about the future. I am not specifically talking about climate/weather, just science.”

    We don’t even need to resort to arcane (to the non-physics major, anyway) examples like the 3-body problem. The problem is to predict the climate in 2050, no? So how about a few scenarios:

    1) The world continues more or less on its present course, with recessions, booms, a reasonable amount of technological progress. Business as usual, IOW.

    2) In 2015, scientists at LLNL develop cheap, reliable & portable fusion reactors. Within a few years fossil fuel use plummets to about 1% of its 2008 value.

    3) Al Qaeda (or some other jihadist group) obtains a significant nuclear capability, and the aftermath of the nuclear exchange of 2019 reduces the population to about 5% of the present number.

    None of those scenarios are inherently implausible, and any of them, or many others that even a hack SF author could dream up, would make great differences in the amount of CO2 emitted (and other environmental effects) between now and 2050. Are they predictable by Newtonian physics? I hardly think so…

  355. Chris Colose:

    As for uncertain predictability (which I think krib wants to talk about projectability). Even if you ignore Gavin’s comments about emission scenarios and set a specific target which is independent of human decisions (such as a doubling of carbon dioxide) will you be able to determine the statistics of weather events, or the weather events themselves, etc? Traditional ideas of chaos and climate says yes to the first question and no to the second.

    The large scale climate dynamics are well represented in modern AOGCMs, so failures of treatment in cloud forcing, the MJO, etc are likely due to deficiencies in the model physical parameterizations.

    The microphysical cloud processes, aerosol interactions, etc which are not resolved (spatially) by models or are not reducible to simple algebraic answers must be constrained heavily and talked about with uncertanity. There’s no problem with this except when people believe those uncertanties can be stretched to infinity in either direction.

  356. Chris Colose:

    cw00p,

    Please cite a scholarly source saying CO2 levels rose as fast as today (I don’t think you’ll have success).

    The graph presented in that site on the CO2-temp correlation over geologic time is essentially worthless since it doesn’t account for the *very large* uncertanties in both variables as you’re going back tens of millions of years ago. The error bars on CO2 for instance can exceed 1000 ppmv that long ago.

    You should read some of the work by Dana Royer on the influence of carbon dioxide on climate over geologic time (full text PDF’s available from his home page)

  357. FurryCatHerder:

    In re #316 –

    Don’t say that too loud, Jim, or people will call you a kook, crazy, denialist and other bad names.

  358. Rod B:

    Chris C., You of course make a valid point, but there is a shadow in there that implies CO2 levels going back 100s of millions of years are pretty accurate if supporting AGW but largely uncertain if not. Is this the case?

  359. Chris Colose:

    Rod,

    I don’t think Royer or anyone else ignores these uncertanties.

  360. Jim Galasyn:

    Climate change is accelerating, warns top German scientist

    Climate change is happening more rapidly than anyone though possible, the German government’s expert, Hans Joachim Schellnhuber, warned in an interview.

    The threats posed by climate change are worse than those imagined by most governments, warned Hans Joachim Schellnhuber, the scientist who heads the Potsdam Institute for Research on Global Warming Effects and acts as an adviser to German Chancellor Angela Merkel on climate-change issues.

    Schellnhuber warns that previous predictions about climate change and its catastrophic effects were too cautious and optimistic.

  361. Edward:

    #29 Phil and #35 Pete (in reference to the 12-12-07 BBC article “Artic Summer Ice Free by 2013″)

    Sorry for the delayed response, but it’s my opinion that not many readers or editors of this blog would seriously support the conclusions stated in that article. But you don’t have to take my word for it.

    Let me refer you to William M. Connelly’s blogpost of Nov 27, 2008 in which he stated:
    “And it is not true that The trajectory of current melting plummets through the graphs like a meteorite falling to earth – as we all know, there was marginally more ice this year than last – and if Monbiot, PIRC, or anyone from the Naval Postgraduate School in Monterey, California, or indeed anyone else is stupid enough to believe that all the late-summer ice will be gone by 2013 (or within “within three to seven years”), I’ve got money that says otherwise: wanna bet?”

    My money’s on William.
    Thanks
    Ed

  362. Jim Eaton:

    #345 cw00p Says: “Whereas the CO2 levels increased during the
    Permian, and the earth did warm by 5 degree c total, it took 70,000
    years with Co2 at much high ppm than today (7000 ppm by the time of
    the die off – http://www.geocraft.com/WVFossils/
    Carboniferous_climate.html )”

    I did go to your reference, “Plant fossils of West Virginia” by Monte
    Hieb. The information on that site seemed to conflict with what I
    know about the PT extinction. Wondering who Monte Hieb is, I ran
    across the following:

    http://globalwarmingwatch.blogspot.com/2006/04/end-of-our-epoch-all-
    in-good-time-2.html

    “If I am looking for an ‘education’ on mining engineering, I would
    possibly consult Monte , since he worked as chief engineer for
    the West Virginia Office of Miner’s Safety. If I were an fossil
    hobbyist I would probably look at his amateur fossil website.

    “But he is not a climate scientist, which is why he has not published
    any scientific papers on causes of global warming. A search through
    the peer-review scientific journals where all new claims are tested
    and confirmed by scientists specializing in the field shows no ground-
    breaking advances in understanding by Monte Hieb or Harrison Hieb.

    “However he has published a lot of opinion pieces on global cooling,
    and the role of water vapor in global warming.”

    For a better understanding of the Permian extinction and the role of
    CO2 in it, I would suggest reading Peter Ward’s “Under a Green Sky.”

    ReCaptcha agrees: “today learn.”

  363. Jared:

    One interesting thing that I think is left out when comparing the 1991-00 decadal average to the 2001-08 average is that 1991-00 was heavily influenced by the Pinatubo eruption of late 1991. 1992-94 saw significant global cooling due to Pinatubo, so obviously the 1991-00 average temp is therefore skewed by that.

    In contrast, 2001-07 has seen no such significant volcanic eruption. This should be kept in mind when assessing the decadal trends.

  364. Alf Jones:

    Has RC have any comments on the Met Office’s new forecast for global temperatures in 2009?

    http://www.metoffice.gov.uk/corporate/pressoffice/2008/pr20081230.html

    They are projecting a warmer year than 2008. Is this a useful forecast, or as the uncertainties are so wide not particularly helpful?

    I think I am right in saying that all their forecasts, since the first one for 2000, were warmer than what actually happened.

    Alf

    [Response: All of their press releases are on line, so it should be easy to check. Their release for this last year came in pretty accurate: "Global temperature for 2008 is expected to be 0.37 °C above the long-term (1961-1990) average of 14.0 °C, the coolest year since 2000" (here). - gavin]

  365. Chris Colose:

    Alf,

    2009 will probably be warmer than 2008, because of the La Nina in 2008. It will be much tougher to say 2009 will be warmer than, say, 2005 which didn’t have much “interesting” going on (and is already anomalous in the context of surrounding years anyway).

  366. Jared:

    Chris…

    It appears that another La Nina is rapidly developing just in time for 2009, so depending on how long it persists and how strong it gets, 2009 may not be much warmer than 2008.

    If 2009 does turn out to be a La Nina year, then we will have had three La Nina-influenced years in the 2001-09 decade (2001, 2008, 2009), and four El Nino-influenced years (2002, 2003, 2005, 2007). In the 1991-00 period (minus 92-94 Pinatubo years), we had three El Nino-influenced years (1995, 1997, 1998), and three La Nina influenced years (1996, 1999, 2000). So we should be able to compare 1991-00 (minus Pinatubo years) to 2001-09 and get a fairly accurate, ENSO-balanced look at decadal trends.

  367. Andrew:

    Re #363

    Agree; he should not have included the early 90′s as a comparison. However, if had used a 5 year average, then he could have said that every 5 year period included 1998 was cooler than the last 5.

  368. wayne davidson:

    365-366 Chris and Jared, there are deep distinctions between late 07 and late 08, at least in the Arctic, especially with cloud extent and the resulting not so strong Arctic ice freeze up which exists right now. December just ending is not showing a specter of super deep freezing, despite what it seems in North America. But rather a lack of high Polar stratospheric winds, not as strong as last year, should encourage cloud formations further below. But I see a weak La NIna on the maps just as much as anyone else, mega regions combinations are crucial, it might be cooler at some places in the Pacific equator, but there is not the same synergism coordination for cooling as with winter of 07-08.

  369. Ron:

    Re: Ray Ladbury Says, 29 December at 8:13AM (#340)

    Ray, regarding your statement that BeetleB’s “…post is not even logically correct: there are no degrees of certainty”, maybe you’re being a bit too harsh, and quite a bit too dogmatic here. You might, as a starting point, reflect on Descartes’ distinction between a degree of certainty sufficient for ordinary life, or about things we wouldn‘t normally doubt, and those things that simply cannot be doubted . The former, I seem to recall, he referred to as moral., whereas the latter would be logical, deductive, etc. In fairness to BeetleB, and with what would seem to be “a reasonable degree of certainty“, he was using the word in the other than logical sense.
    On another matter, you speak of the models having been “validated”. As it is difficult to imagine you could be using “validated” as a term that is synonymous with “valid” in its logical sense, I checked Wikipedia. After a cursory reading of the Wikipedia list of about a dozen or so usages, it’s not immediately clear what, if any, of these would apply. Hopefully you’ll be able to help me out. Thanks and a Happy New Year.

    Ron

  370. Ray Ladbury:

    Ron, Last I saw, “certain” meant sure, positive, beyond doubt. I don’t see much scope for degrees there. Rather, in science, we use the more precise term “confidence”.
    As to validated, I was speaking in terms of model validation–verification of trends in the model against data, etc. Certainly the fact that the past 30 years are the warmest 30 in the temperature provides validation, as do many other stringent tests.

  371. Ron:

    Ray, thanks for your quick reply at a time when ours minds and bodies are preoccupied with good cheer etc. First the serious stuff.
    When you say you were,“…speaking in terms of model validation–verification of trends in the model against data, etc”, is it correct for me to say that this can be diagrammed (verbally) as (a) the model produces statements of climate trends, (b) these statements are compared to climate data, and if there is (c) correspondence of the model statements to the data from the real world, then the model is validated. In summary, validation is produced by verification. But is this validation process, “valid“? It may be perfectly clearly so in your use of the terms, but it isn’t in mine. So, here’s how I understand them.

    To say a model is validated is to say that it passes some sort of test that is equivalent to the test of a proper logical argument, e.g. the conditions for a valid syllogism. Thus I understand validation to be a demonstration that a process (method) of doing something or other is capable of producing proper results, i.e. given true inputs the valid process must produce true outputs. So, a validated climate model would be one that takes in all the physical environment data it should have and omits all the data it shouldn’t have, and then is able to processes the data in the proper sequences etc. to produce true results.
    Verifying, on the other hand would relate only to determining the accuracy of the data itself.

    With due regard for complexities of the issue, if my understanding of these terms is basically correct, then I have a problem in that while these two elements must be integrated to produce climate truth, it’s not clear to me how, without a validated model in the first place, all the proper data can be gathered. If we start first with the data before we try to build a model, what bit of data would tell us that our collection is now complete and it’s time to build? So Ray, I hope you can further elaborate on this issue, or show me the alternative uses of these terms that would overcome the appearance of a bootstrapping process here.

    Now for a bit of less serious banter. Ray, with all due respect maybe you should expand your scope about the use of the word “certain”. In addition to your synonyms ( “…sure, positive, beyond doubt…”, included in #6 of my Webster’s New World Dictionary ) there’s also #1, “fixed, settled, or determined” (concepts that suggest the arbitrary positions of an establishment and its counter establishment, e.g. a paradigm shift in science —in fact, didn’t Hume make it clear, what we call “science” is essential not ever logically certain as would be the case with 2+2=4). Then we have #4 which includes “reliable; dependable”. There’s a lot of ,“so far, so good…but let‘s wait and see”, mixed into these concepts. I’m positive you would not want to claim these uses have the same degree of certainty as “beyond doubt”. Or, how about definition #8, “some, but not very much; appreciable [as in the expression, "to a certain extent"]”. But more importantly Ray spend a few hours listening to people talk about a whole lot things and count the number of times you hear, “I’m almost certain”, “I’m pretty certain”, “I’m very certain”, “I‘m positively certain“, “I’m absolutely certain”. That’s the way people really talk, and that suggests to me that there’s a lot of scope for degrees here. But if you want more formal stuff, try a recent article on Certainty in the Stanford Encyclopedia of Philosophy which I came across after deciding to do a bit of homework to backup my somewhat spontaneous earlier remarks.

    Cheers,
    Ron

  372. Alf Jones:

    Re #364

    Here are the met office forecasts for the years 2000-2008 (with uncertainties around +/- 0.15)
    0.41,0.47,0.47,0.55,0.50,0.51,0.45,0.54,0.37 C

    and here are the “actuals” (www.hadobs.org)
    0.24,0.40,0.46,0.46,0.43,0.48,0.42,0.40,0.31 C

    They claim a mean error of 0.06C for those forecasts, but the mean error if your forecast method is to use the same temperature as the current year is -0.005C, doesn’t that suggest “persistence” is more accurate that their forecast?

    My point isn’t that this shows that global warming isn’t happening (clearly the long term trend shows that it is). Rather that these short term forecasts are apparently not that useful, and they give the impression that a forecast is evidence of global warming. Some sceptics are even using their press-releases about “2007 likely to be warmest year”, “2009 in top 5 warmest years”, to claim that global warming is being exaggerated.
    Shouldn’t the met office be a little more careful about how they present the forecasts? It seems to be a very similar problem to the presentation of the Kenylside decadal projections.

    Alf

    [Response: Science is about making predictions and seeing if they pan out. This is a relatively new endeavour and has a number of issues (the limits to predictibiilty of ENSO, other sources of variation etc.). But if you look at that data more in detail, there is definite skill - ie. the forecast outperforms persistence (r=0.74 vs 0.36), OLS regression = 0.98 compared to 0.5 (though the bias is less, -0.01 compared to 0.07). It might not be perfect, but the variations are being tracked quite well. Given that, their estimate of relative warmth in 2009 is probably a good bet. - gavin]

  373. Ray Ladbury:

    Ron, In science, the proper term is not “degree of certainty” which has no meaning in science, but rather confidence, which can be quantified. Moreover, while common usage may sanction “fuzzy” certainty, this is a usage that simply takes a perfectly good word and weakens its meaning even while this is avoidable, as there are other words that serve the purpose better.
    First, Ron, do you understand the difference between dynamical and statistical models? Briefly, a dynamical model is a an attempt to reproduce the mathematics of the physical system as closely as you can. Parameters are determined with data independent from that to be used for the validation test. The validation test for such a model is whether it reproduces trends in the validation dataset. For noisy systems like climate, the validation is based on many realizations of the model. A stringent validation test would be one where the model would be very unlikely to reproduce the observed trends if it is incorrect. Climate models have passed a broad range of validation tests–e.g. a 30-year warming trend,response to perturbations like ENSO and volcanic eruptions…
    On the other hand, in a statistical model, parameters of the model are determined by a fit to the model. Validation here is a matter of goodness of fit (e.g. likelihood, Chi-square…) or an information criterion (e.g. AIC, BIC, DIC…).
    Different aspects of the climate models have been validated to different degrees. Climate sensitivity to doubling of CO2 is among the best determined parameters–it’s very hard to get models to work with a sensitivity less than 2 or more than 5 to look anything like Earth. Clouds and aerosols less so. The way climate models are validated is pretty standard in science for dynamical models.

  374. Hank Roberts:

    Ron, you’re thinking of the wrong kind of model.

    You’ve ended up with an impossible goal that sounds like an argument for doing nothing because each time you move toward perfection you can only go half of the way in each step.

    This isn’t like a model of an airplane at 1:1 where if you put all the pieces together exactly right, it will fly, and otherwise not at all.

    This is more like resolution in an image file, where you’re never going to get close to 1:1 but you’ll be able, once you have enough pixels, to recognize the image.

    Start with the very simple. Add more detail. Reading the history of modeling makes it much easier to figure out how this is done — compare what happened to your long post above.

    Eli gave good advice on how to use one of the online models here:
    http://tamino.wordpress.com/2008/12/26/the-other-anthropogenic-greenhouse-gas/#comment-25656

  375. wayne davidson:

    It is again astonishing to realize that the High Arctic is warmer than further to the South, a common winter feature now a years. Contrarian lobbyists will easily ignore this weather contradiction. Flaunt
    the dreadfully cold temperatures of winter as nails in AGW coffin.

    I am chasing low RH stratums to determine apparent Cp’s (specific heat calculating gravity with altitude), apparent because moisture and other factors distort its dry sea level number, and I am beginning to see a pattern..
    But first can anyone calculate RH forcing vs CO2 384 ppm equivalent at -35 C at 500 mb? What would be the amount of RH giving equivalent forcing as much as CO2 can at 384 ppm in -35 C air at 500 mb (I suspect it to be small). Cp also varies with temperature pressure and RH,,, So its good to know roughly RH/CO2 forcing equivalent… I’ll come back with results in a little while.

  376. FurryCatHerder:

    In re Jared @ 363:

    One interesting thing that I think is left out when comparing the 1991-00 decadal average to the 2001-08 average is that 1991-00 was heavily influenced by the Pinatubo eruption of late 1991. 1992-94 saw significant global cooling due to Pinatubo, so obviously the 1991-00 average temp is therefore skewed by that.

    In contrast, 2001-07 has seen no such significant volcanic eruption. This should be kept in mind when assessing the decadal trends.

    I think that trying to say “This year was affected by this one thing” is dangerous. Because the decade from 1991 through 2000 wasn’t monotonically increasing from, say, 1994 after some number of years of cooling due to Pinatubo. And likewise, the ten years from 1999 through 2008 hasn’t continued in some linearly upward trend now that there aren’t any volcanic eruptions of the magnitude of Pinatubo.

  377. Jared:

    #376

    I’m not sure what you mean here. No one knows exactly what the temperatures of 1992-94 would have been if Pinatubo had not happened…that is why I think it is best (safest) to just leave them out when comparing the 1991-00 decadal average to the 2001-08 decadal average. We do know that there was a strong Nino in 1992, so that year at least would have been much warmer had Pinatubo not occurred.

  378. Jared:

    Alf…do you have a link to those projections from #372?

  379. Ron:

    Re : Ray Ladbury Says: 1 January 2009 at 8:03 AM (373) and Hank Roberts Says:
    1 January 2009 at 10:13 AM (374)

    Just returned and noted your immediate replies. Tied up with other matters, but hope to study them in the next few days. Meanwhile, please accept my thanks.
    Ron

  380. Alf Jones:

    #372
    Gavin, Thanks for the explanations. It is clear that the more normal measures of skill seem to show higher skill for the met office’s projections than persistence. Perhaps they should advertise those measures as well as the bias they use ;-)

    #378
    Jared… I got some of the numbers for the projections from press releases on the met office site but after a bit of digging all the numbers (and science behind them) can be found via a link at
    http://www.metoffice.gov.uk/science/creating/monthsahead/seasonal/index.html
    registration is needed to get the seasonal forecast and the global annual forecasts.

    Alf

  381. Wayne Davidson:

    I would be grateful if someone can use his/her model and answer what I asked for in #375…. I’ll expand a little: what would be the average RH of a stratum of 1 kilometer thick with average temperature of -35 C at 500 mb if all the CO2 was replaced with equivalent forcing strictly with RH? I am getting low RH stratums (10-20%) with lapse rates of 4 or 5 C/km at or about 500 mb. -g/Cp = Lapse rate (the pretty equation) makes the apparent Cp = 1.9 which is perhaps double a Cp should be. If I am not clear with this question let me know!

  382. Mark:

    Wayne, what will an answer tell us?

    I.e. what does the person answering get out of it.

  383. Wayne Davidson:

    Mark, I dont know, I am exploring the invisible sky. I really like to have an answer though. I am seeing some weird stuff, Apparent Cp’s varying a great deal in very low RH stratums. Very interesting stuff…

  384. Mark:

    Wayne, if you want to explore the invisible sky, work it out yourself.

    Then, if you’re skeptical of things, see if you can work out whether you’re wrong and how that could happen.

  385. Hank Roberts:

    Wayne’s got a perspective worth paying attention to, Mark. At least look up prior postings here beforer telling people to go away. The Contributors make the decision about what appears here, not us readers.

  386. Wayne Davidson:

    Thanks Hank! Wow….. Mark how can I be wrong when I have made no conclusions? You seem to lack curiosity, or jump to criticize before there is anything to criticize about! Exploration is never ending and abides to no doctrine, it is the fuel of science.

  387. Mark:

    384, Wayne, read. comprehend.

    Why not answer it yourself and the bonus is you can then check where you’ve got it wrong.

    If you don’t answer your question wasn’t associated with being wrong. You can only be wrong in your answers if you give one.

    Sheesh. English not your first language???

  388. Mark:

    Hank, the contributors don’t make the decision about what I think to say to wayne.

    This isn’t a dictatorship.

    Why don’t you answer it, Hank?

  389. wayne davidson:

    Mark, you absolutely make no sense whatsoever! I am asking for a model calculation
    of equivalent forcing given in RH in place of CO2 for a 1 KM stratum at about 500 mb… Its a question for those who have a model which can calculate this… Cappish? You are getting deeper and deeper nowhere…..

  390. Erkan:

    Rod,

    I don’t think Royer or anyone else ignores these uncertanties.

    :)

  391. Mark:

    Wayne, likewise.

    You said in 386 “how can I be wrong when I have made no conclusions?”

    Which is an odd question since the post you replied to said:

    “Why not answer it yourself and the bonus is you can then check where you’ve got it wrong”

    Which precludes your question since it is predicated on you answering it yourself.

    Hence you make no sense.

  392. Jim Eager:

    Mark, this is a public comments section on a blog dedicated to discussing and educating the lay pubic about the science of global warming/climate change.

    You constant abrasiveness and your quickness to dismiss long-time regular participants as trolls or slackers is more than a little annoying and counter productive to the stated aims of RC.

  393. wayne davidson:

    Mark , there is absolutely no way you can argue yourself out of the hole you dug. Enough, I patiently await the answer to the question I’ve asked, thanks for bringing it up again….