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  1. While I think it’s important to point out that the supposed lull or pause in warming is a result of the Hadley data excluding the fastest warming region on the planet, I think it’s also important to be clear that, against a background of long-term warming, an occasional decade of no warming or even slight cooling is also 100% consistent with the expected global warming trend, as pointed out in the recent GRL paper by Easterling and Wehman (doi:10.1029/2009GL037810).

    That way, if and when there is a genuine pause in warming, you won’t have people pointing back to posts like this and saying, “But you said…”

    Comment by Michael Le Page — 6 Oct 2009 @ 6:59 AM

  2. One objection to this from ‘skeptics’ will be: “OK so perhaps global average temperature is still rising but it’s nothing to do with human activity, it’s all due to the PDO” [or the NAO or some other long-term natural feature of ocean circulation]. They’ll say it would have happened anyway, and is nothing unusual in the context of natural climate fluctuations. Is there a simple way to test that claim?

    Comment by Icarus — 6 Oct 2009 @ 7:10 AM

  3. You really need to name names. Are you referring to George Will’s latest attempt at scientific analysis in the editorial pages of the Washington Post?

    Comment by Dennis — 6 Oct 2009 @ 7:18 AM

  4. Once again, RealClimate takes an issue that is being dragged through the media as a big deal and shows — in a simple and easily digestible way — that they have it dead wrong.

    As for #1 Michael Le Page’s comment, they specifically DO address that in the post. They say that a decade of cooling is not a big deal amidst a long-term anthropogenic warming trend. It’s just not happening now.

    As for #2 Icarus’ comment, they do point out that natural factors should be producing a cooling at the moment, and that the warming that we are seeing is what is predicted from anthropogenic greenhouse warming.

    These questions are answered above. Nice work Stefan. I’ll likely be posting a link to this on my blog as well.

    Comment by Todd Albert — 6 Oct 2009 @ 7:54 AM

  5. Here’s an interesting graph that illustrates the topic somewhat, albeit only in the short term. I have added trend lines to woodfortrees standard example, “All Four Main Temperature Series for the Last Decade”, and the upward trends are clear, if slight.

    http://www.woodfortrees.org/plot/hadcrut3vgl/last:120/plot/uah/last:120/plot/rss/last:120/plot/gistemp/last:120/plot/hadcrut3vgl/last:120/trend/plot/uah/last:120/trend/plot/rss/last:120/trend/plot/gistemp/last:120/trend

    Given our inablity to predict in the short term, we will have to wait, obviously, but as a sneak peek, provided temps don’t move significantly, if you shave off so much as 9 months the almost-decade now looks like:

    http://www.woodfortrees.org/plot/hadcrut3vgl/last:111/plot/uah/last:111/plot/rss/last:111/plot/gistemp/last:111/plot/hadcrut3vgl/last:111/trend/plot/uah/last:111/trend/plot/rss/last:111/trend/plot/gistemp/last:111/trend

    I get it that the concern is about the long-term trends and whether they have predictive value, but it would be wise, I beleive, to acknowledge that something is going on in the short term, rather than say “Don’t look at these graphs. They mean nothing!” Unless, of course, you are willing to say, “Don’t look at those short-term arctic sea melt graphs. They mean nothing!”

    Comment by Walter Manny — 6 Oct 2009 @ 7:58 AM

  6. One other question for the experts… Any idea why the NCEP reanalysis shows only a slight (if any) warming in west-central Greenland while the GC-Net (Greenland Climate Network) shows significant warming there? The GC-Net was geared specifically at filling gaps over Greenland. It doesn’t help if we don’t use the data.

    Comment by Todd Albert — 6 Oct 2009 @ 7:59 AM

  7. It’s futile, stefan. Any time the current year is not the warmest year on record, somebody will try to pick the previous record high as a starting point and convince themselves that warming stopped at the previous high.

    They can do this even with GISS data that includes the Arctic; they could have done this at multiple times in the past (where, with hindsight, we can clearly see the long-term trend amidst the noise), and they will likely do it at multiple times in the future.

    Comment by tharanga — 6 Oct 2009 @ 8:01 AM

  8. [typos fixed]

    Here’s an interesting graph that illustrates the topic somewhat, albeit only in the short term. I have added trend lines to woodfortrees’ standard example, “All Four Main Temperature Series for the Last Decade”, and the upward trends are clear, if slight.

    http://www.woodfortrees.org/plot/hadcrut3vgl/last:120/plot/uah/last:120/plot/rss/last:120/plot/gistemp/last:120/plot/hadcrut3vgl/last:120/trend/plot/uah/last:120/trend/plot/rss/last:120/trend/plot/gistemp/last:120/trend

    Given our inability to predict in the short term, we will have to wait, obviously, but as a sneak peek, provided temps don’t move significantly, if you shave off so much as 9 months the almost-decade now looks like:

    http://www.woodfortrees.org/plot/hadcrut3vgl/last:111/plot/uah/last:111/plot/rss/last:111/plot/gistemp/last:111/plot/hadcrut3vgl/last:111/trend/plot/uah/last:111/trend/plot/rss/last:111/trend/plot/gistemp/last:111/trend

    I get it that the concern is about the long-term trends and whether they have predictive value, but it would be wise, I believe, to acknowledge that something is going on in the short term, rather than say “Don’t look at these graphs. They mean nothing!” Unless, of course, you are willing to say, “Don’t look at those short-term arctic sea melt graphs. They mean nothing!”

    Comment by Walter Manny — 6 Oct 2009 @ 8:02 AM

  9. The simple solution for you, Icarus, is that the PDO and the NAO and all the other natural features of the climate system have been underway for thousands of years but don’t show the kind of warming we’re currently seeing.

    IOW, if what we were seeing for warming now were natural variation due to “X” we’d have seen this sort of variation many times before. We haven’t. Therefore, current warming can’t be natural variation.

    Comment by David Miller — 6 Oct 2009 @ 8:18 AM

  10. Stefan,

    Is ’87 – ’96 the best example you could give of the flat or cooling trends that are nothing special and have happened before repeatedly? Anyone who takes more than a passing interest in these issues knows that that period was significantly affected by a major volcanic eruption, whereas the last decade has not. Apples and oranges.

    Comment by Stephen — 6 Oct 2009 @ 8:18 AM

  11. Most timely appropriate piece, I suspect September 2009 to be impressively warm as well. Observing the sun almost on a daily basis, as every “sun is warming advocate” should do, reveals AGW by the lack of solar activity when compared with current warming trends or data. Also by observing sun disks expand within the Hadley “hole”, year by year, ever so consistently, a completely different method of analyzing Arctic atmospheric temperature as a whole
    reveals the same results as NASA GISS. So skeptics have always looked kind of silly, amateurish, and not worthy of challenging anything unless they come up with evidence (actually working in the field) disproving data acquired by 2 methods agreeing on the same warming. Looking at local Arctic Glaciers big and small, the casi totality of them receding or disappearing combined Sea Ice extent at all time lows, 2 other solid observations confirm again the 2 previous methods cited above. THere is no point arguing with a skeptic claiming recent cooling, however there is a duty to report, to others what is going on. Recent cooling
    is a myth at the detriment of reality…

    Comment by wayne Davidson — 6 Oct 2009 @ 8:28 AM

  12. For beginners: RSS September 2009 is 0.476C+, up from 0.270C plus. The only warmer September per RSS record was in that faithful year 1998 showing 0.498C+, when hallelujah, global ‘Aint True’ deception began. By their logic that’s 0.2C cooling per century, still, see it is not warming ;P

    PS. Dr. Roy’s superior UAH algorithm showed 0.432C+ for September 1998. Would he be able to stay below that, or would he report a higher number for last month?

    Comment by Sekerob — 6 Oct 2009 @ 8:54 AM

  13. I think the point to most denials of Global Warming at the moment has to do with the general mildness of the weather in big media cities more than anything else. For example, New York and Washington have had a mild time of it this year. Calamities have been happening elsewhere in the country which could easily be secondary effects of warming, and to those of us who have paid attention, the mildness has been exceptional to the point of comment. But those who do not pay attention to anything but their own comfort, and live in exceptionally unscientific bubbles, can pretend normalcy for the time being. Maybe I’m just being cynical though.

    Comment by Joseph — 6 Oct 2009 @ 9:01 AM

  14. @stefan: ‘If we want to relate global temperature to global forcings like greenhouse gases, we’d better not have a “hole” in our data set. … Hence the GISS data are clearly more useful in this respect, and the supposed pause in warming turns out to be just an artifact of the “Arctic hole” in the Hadley data’.

    When is data data? There are Arctic holes in the instrumental records for both GISS and Hadley. The difference is that GISS fills its hole with estimates. Wouldn’t it be equally valid to say that the supposed continuation of warming is just an artefact of GISS’s extrapolation? (Or even, to borrow your analogy, that the GISS bank account is padded with Monopoly money?) I’m not saying that GISS’s continued warming is bogus. Ditto Hadley’s hiatus. I’m just puzzled by your apparent assumption that a temperature-record-plus-clever-maths-infill is necessarily more valid than a more straightforward temperature record. Surely both approaches have merit?

    [Response: In essence GISS fills the hole with data from surrounding areas (and there is good evidence to support that this is reasonable, see Rasmus' plot of the NCEP reanalysis shown in Fig. 2), while Hadley assumes the Arctic behaves like the global mean. I believe the latter is an unreasonable assumption. -stefan]

    Comment by Vinny Burgoo — 6 Oct 2009 @ 9:12 AM

  15. Todd: “It doesn’t help if we don’t use the data.”

    It doesn’t help if you haven’t asked an answerable question.

    Why are you expecting something other than what you saw?

    Why are you asking about it?

    If you don’t use the data, what did you use?

    Comment by Mark — 6 Oct 2009 @ 9:13 AM

  16. No, resistance is not “futile,” tharanga! I for one have been significantly educated by this post and will spread the knowledge to everyone I talk to about the subject. Great post — timely, crucial in fact, in a context where even Revkin over at the New York Times speaks of a “plateau in temperatures” over the last decade as if it were a plain fact (http://www.nytimes.com/2009/09/23/science/earth/23cool.html?scp=2&sq=decade%20no%20warming%20climate&st=cse) and ponders its impact on policymakers rather than challenging the “plateau” claim itself.

    My emphatic thanks to the makers of this post and this whole blog. Please: don’t give up on repeating yourselves, answering old fallacies, refreshing the arguments. There are always new people coming along who need to hear the science in an up-to-date form. The denialist fallacies will be trotted out annually in new clothes for as long as the Earth spins and need to be stripped bare all over again. It is a wearisome chore, probably, for scientists with real work to do, but it is an _indispensable_ contribution to the public discourse on climate.

    Comment by Larry GIlman — 6 Oct 2009 @ 9:15 AM

  17. re David Miller, reply 8, and Icarus, reply 2:

    Using paleoclimate to rule out ‘natural variability’ due to ocean dynamics as the cause of global warming is a poor choice. You’ll just end up in endless arguments about tree rings, as the sceptics don’t accept any hockey-stick style reconstructions, anyway.

    Better to point out positive evidence that the greenhouse gas mechanism is indeed at hand. There are several physical fingerprints of the mechanism, and the models are pretty well validated.

    A sustained 30-year surface warming simply due to redistribution of heat in the oceans would surely leave some observable fingerprints: the heat has to come from somewhere. Icarus: don’t let your sceptics use ‘natural variability’ as a magical hand-waving exercise that can explain any and all observations. Require them to explain a mechanism, quantify it, and validate it against observations.

    Comment by tharanga — 6 Oct 2009 @ 9:19 AM

  18. #2:

    Ask the skeptics how natural events such as NAO, PDO, etc. have caused stratospheric cooling and tropospheric warming. :)

    #8:

    The skeptics will claim that the hockey-stick is broken so that PDO, NAO, etc., are not being accurately displayed. Nonsense of course, but then just ask how the stratosphere is cooling due to these things. :)

    http://www2.sunysuffolk.edu/mandias/global_warming/greenhouse_gases.html#stratospheric_cooling

    Comment by Scott A. Mandia — 6 Oct 2009 @ 9:24 AM

  19. Well… I think you’re being a bit harsh on the Hadley data there.

    Is it not the case that they have a “hole” in their dataset because there are few observations in the Arctic? That being the case, the warming in the GISS dataset is reliant on a very small number of data points, which makes them potentially unreliable due to the possibility of their being spurious trends due to local changes that aren’t representative of the Arctic as a whole. [Though the record minimums of sea-ice coverage are an excellent confirmation of this warming trend being real]

    Also, there are no error bars on your graphs! On the Hadley website they show error bars, the biggest contribution to which is sampling issues [because of lack of spatial data coverage]. Surely there must be a way for you to construct an error estimate of your interpolation – perhaps by testing it with model data? I suspect that, with appropriate error estimates, it wouldn’t be possible to conclude that the two records are significantly different.

    One thing we can be certain of is that, should the Arctic region experience a temporary cooling “trend” over the next ten years, resulting in the GISS record exhibiting a lower global trend in temperature than the Hadley record, then the climate “sceptics” will be quoting GISS and rubbishing Hadley/CRU when they are trotting out similar arguments in 2019.

    Comment by Timothy — 6 Oct 2009 @ 9:35 AM

  20. There are proxies for global temperature that reinforce the picture that global temperature was higher in the last decade than any other decade, such as the global glacier mass balance record noted in a previous RealClimate Post http://www.realclimate.org/index.php/archives/2009/01/a-global-glacier-index-update/
    with data from the World Glacier Monitoring Service.
    http://www.geo.unizh.ch/wgms/mbb/mbb10/sum07.html
    The mean for the 1980′s about -0.20 meters per year.
    1990′s about -0.35 meters per year.
    2000-2007 about -0.60 meters per year. The glaciers in the index are from all over the world.

    Comment by mauri pelto — 6 Oct 2009 @ 9:46 AM

  21. Correct, Timothy.

    And, rather like the surfacestations problems were irrelevant to temperature anomalies, all you have to consider is that the differences are because you’re comparing apples with peaches.

    And in that case, you would expect a very *similar* trend, but not necessarily exactness.

    Comment by Mark — 6 Oct 2009 @ 9:54 AM

  22. I went to the “The Wood for trees” interactive graphs and use HADCRUT3 variance adjusted Global mean data from the time period 1997 to 2009 and it shows a flat trend line from at .4C. Thats over the last 12 and 3/4 years.
    FYI
    Ed

    Comment by Edward — 6 Oct 2009 @ 10:10 AM

  23. How is the temperature of the “hole in the Arctic” measured in GISS?

    Comment by Jari — 6 Oct 2009 @ 10:19 AM

  24. re #2 icarus

    This has recently been addressed in a just published paper in PNAS:

    K. L. Swansona, G. Sugihara and A. A. Tsonis (2009) Long-term natural variability and 20th century climate change Proc. Natl. Acad. Sci. 106, 16120-16130

    http://www.pnas.org/content/early/2009/09/09/0908699106.abstract

    The authors analyze 20th century surface warming and attributions to tease out anthropogenic greenhouse forcing contributions and natural variation. The conclude that the anthropogenic forcing has been (and continues to be) a monotonic, accelerating warming during the 20th century. This has been modulated by natural contributions, especially ocean current effects on surface temperature, the net contribution of which to 20th century warming has been close to zero. These authors remark on the possibility that natural variation might result in a suppression of surface warming for a period. However they also point out that “However, global warming could likewise suddenly and without any ostensive cause accelerate due to internal variability”.

    Comment by chris — 6 Oct 2009 @ 10:54 AM

  25. It’s also worth pointing out that while the surface warming may respond to some periods of ocean current-induced heat redistributions that temporarily suppress or enhance the surface temperature, the continuation of global warming is apparent in the continuation of heat uptake into the worlds oceans.

    A recent analysis has just been published that indicates a continuing heat uptake at a rate near 0.8 W.m-2 right through 2008. Obviously this heat penetrating the oceans will eventually have a warming influence on the surface. So there isn’t really a warming pause at all if the world is considered truly globally!

    K. von Schuckmann F. Gaillard and P.-Y. Le Traon (2009) Global hydrographic variability patterns during 2003–2008 J. Geophys. Res. 114, C09007, doi:10.1029/2008JC005237

    http://www.agu.org/pubs/crossref/2009/2008JC005237.shtml

    a concise account can be found on skepticalscience:

    http://www.skepticalscience.com/How-we-know-global-warming-is-happening-Part-2.html

    Comment by chris — 6 Oct 2009 @ 11:07 AM

  26. Excellent post – once again RC delivers a concise and clear summation of the science.

    Since I’m a layman, could I ask a few quick questions that someone might shed some light on for me: is it correct for me to say that the GISS data doesn’t have the actual measurements from the arctic, but rather adjusts its findings based on its existing measurements? If so, is that a process of interpolation or extrapolation (or does that even matter)? Further, does GISS have a larger rate of error than the Hadley results due to the process of adjusting for acrtic temperature? Does that error rate significantly alter the results you’ve shown us above?

    Thank you in advance!

    Comment by Joe — 6 Oct 2009 @ 11:21 AM

  27. As some readers may know, misunderstandings around this topic are a staple at DeepClimate.

    I discussed the confusions inherent in Andy Revkin’s article mentioned above, as well as the misinterpretations and distortions around Mojib Latif’s presentation at the recent World Climate Conference in Geneva. In the latter case, Fred Pearce’s confused New Scientist piece started the ball rolling.

    And, of course, then the PR disinformation spinmeisters like Marc Morano took over and spewed out their falsehoods. Next thing you know you’ve got George Will and Lorne Gunter declaring the end of global warming and “quoting” Mojib Latif in support.

    http://deepclimate.org/2009/10/02/anatomy-of-a-lie-how-morano-and-gunter-spun-latif-out-of-contro/

    http://deepclimate.org/2009/10/02/anatomy-of-a-lie-part-2-gunter-ibd-will/

    http://deepclimate.org/2009/09/25/nyts-andy-revkin-backtracks-but-not-nearly-enough/

    The number of commenters I’ve encounterd who insist that there is a pause in global warming (in the face of all the statistical evidence to the contrary), and then point to the Revkin in NYT and Fred Pearce in New Scientist articles as proof, is really depressing.

    Until the popular science press gets it right, this nonsense will continue.

    Comment by Deep Climate — 6 Oct 2009 @ 11:35 AM

  28. How does this fit in with Professor Mojib Latif from the Leibniz Institute of Marine Sciences at Keil University, who has stated that from recent research he has conducted he has had to conclude that global warning has ceased, that the planet is currently cooling and will likely continue to do so for another 20 years.

    Comment by Phillip Bratby — 6 Oct 2009 @ 11:55 AM

  29. I’ve heard that the satellites do not observe the poles well, is this the reason for lower satellite trends? For that matter, anyone know the reason for the difference between the UAH and RSS trends? That’s bigger than the difference between the surface station trends or between RSS and Had-CRU, (over a 30 year period) and I have no idea what the difference is between these data sets.

    Comment by Eric L — 6 Oct 2009 @ 12:13 PM

  30. Phillip, that is simply not what Latif said. You might find Deep Climate’s posts on the topic interesting (linked above your post) as he replays the telephone game that has been played with Latif’s words. All he says is that it is possible for natural variability to create a one or two decade cooling “trend” within a longer term warming trend, he certainly did not predict cooling in the next decade.

    Comment by Eric L — 6 Oct 2009 @ 12:18 PM

  31. Question for the GISS folks: I read this NOAA notice recently:

    http://www.ncdc.noaa.gov/oa/climate/research/sst/papers/merged-product-v3.pdf

    “In the ERSST version 3 on this web page we have removed satellite data from ERSST and the merged product…Although, the satellite data were corrected with respect to the in situ data as described in reprint, there was a residual cold bias that remained as shown in Figure 4 there.”

    It seems to be a minor issue, but do GISS global mean temperature products rely on the same satellite data that NOAA is reporting has a cool bias? Do you agree with this analysis and does GISS have plans to address it?

    Comment by MarkB — 6 Oct 2009 @ 12:23 PM

  32. Walter Manny says:
    6 October 2009 at 7:58 AM:

    Unless, of course, you are willing to say, “Don’t look at those short-term arctic sea melt graphs. They mean nothing!”

    Over the last 30 years, the arctic sea ice record shows a downward trend.
    You keep re-building this straw man. Beating it up may make you feel good, but it lowers your creditability

    Comment by llewelly — 6 Oct 2009 @ 12:24 PM

  33. re #27

    That’s an odd one Philip considering that Latif has just recently published a paper in which he predicts an extremely large surface warming (around 0.5 oC) in the period around 2010-2030 (see Figure 4 of:

    N. S. Keenlyside, M. Latif, J. Jungclaus, L. Kornblueh & E. Roeckner (2008) Advancing decadal-scale climate prediction in the North Atlantic sector Nature 453, 84-88

    http://www.nature.com/nature/journal/v453/n7191/abs/nature06921.html

    That’s completely at odds with your comment. What has Latif published more recently that indicates he’s reconsidered his forecast??

    [Response: Anyone remember we offered them a bet at the time? -stefan

    Comment by chris — 6 Oct 2009 @ 12:26 PM

  34. Prepare for a new “Svensmark wave” in the blogosphere: Cosmic Ray Decreases Affect Atmospheric Aerosols And Clouds.

    The Forbush decreases are too short-lived to have a lasting effect on the climate…

    But then:

    The director of the Danish National Space Institute, DTU, Eigil Friis-Christensen, was co-author with Svensmark of an early report on the effect of cosmic rays on cloud cover, back in 1996…”the current climate models used to predict future climate are lacking important parts of the physics.”

    Comment by Jim Galasyn — 6 Oct 2009 @ 12:30 PM

  35. Walter Manny says:

    I get it that the concern is about the long-term trends and whether they have predictive value, but it would be wise, I believe, to acknowledge that something is going on in the short term, rather than say “Don’t look at these graphs. They mean nothing!” Unless, of course, you are willing to say, “Don’t look at those short-term arctic sea melt graphs. They mean nothing!”
    As Stefan pointed out in the OP, there is nothing unusual about the last 10 years; it happened before. I updated your own link to run over the period 1987 – 1996:
    http://www.woodfortrees.org/plot/hadcrut3vgl/from:1987/to:1996/plot/uah/from:1987/to:1996/plot/rss/from:1987/to:1996/plot/gistemp/from:1987/to:1996/plot/hadcrut3vgl/from:1987/to:1996/trend/plot/uah/from:1987/to:1996/trend/plot/rss/from:1987/to:1996/trend/plot/gistemp/from:1987/to:1996/trend
    The “trends” here are flat to slightly negative. Why don’t you ask the same question about what was going on then? Or if you don’t think there is anything unusual about that period, why do you think last 10 years are any different?

    Comment by Igor Samoylenko — 6 Oct 2009 @ 12:34 PM

  36. What’s needed is a measure that includes ocean heat content as well as the SST and air temperatures. If you include ocean heat content as part of the overall energy budget (overall global warming), then even with the Hadley data you get global warming during the last decade.

    Murphy, D. M., S. Solomon, R. W. Portmann, K. H. Rosenlof, P. M. Forster, and T. Wong (2009), An observationally based energy balance for the Earth since 1950, J. Geophys. Res., 114 http://www.agu.org/pubs/crossref/2009/2009JD012105.shtml

    and

    von Schuckmann, K., F. Gaillard, and P.-Y. Le Traon (2009), Global hydrographic variability patterns during 2003–2008, J. Geophys. Res., 114
    http://www.agu.org/pubs/crossref/2009/2008JC005237.shtml

    It would do well for scientists to start communincating the idea of heat content instead of air temperatures as the most important index of climate change.

    Comment by Peter Houlihan — 6 Oct 2009 @ 12:36 PM

  37. [Fixed closing blockquote]

    Walter Manny says:

    I get it that the concern is about the long-term trends and whether they have predictive value, but it would be wise, I believe, to acknowledge that something is going on in the short term, rather than say “Don’t look at these graphs. They mean nothing!” Unless, of course, you are willing to say, “Don’t look at those short-term arctic sea melt graphs. They mean nothing!”

    As Stefan pointed out, there is nothing unusual about the last 10 years; it happened before. I updated your own reference to run over the period 1987 – 1996:
    http://www.woodfortrees.org/plot/hadcrut3vgl/from:1987/to:1996/plot/uah/from:1987/to:1996/plot/rss/from:1987/to:1996/plot/gistemp/from:1987/to:1996/plot/hadcrut3vgl/from:1987/to:1996/trend/plot/uah/from:1987/to:1996/trend/plot/rss/from:1987/to:1996/trend/plot/gistemp/from:1987/to:1996/trend
    The “trends” here are flat to slightly negative. Why don’t you ask the same question about what was going on then? Or if you don’t think there is anything unusual about that period, why don’t you think last years are any different?

    Comment by Igor Samoylenko — 6 Oct 2009 @ 12:36 PM

  38. #15 Mark: I am referring to the NCEP figure above. If you look at west-cental Greenland, it is green to yellow, showing little warming. The GC-Net data show a rapid warming in that area (see: http://bprc.osu.edu/~jbox/pubs/Box_et_al_J_Clim_2009.pdf for example). We can also look at ballon soundings: http://bprc.osu.edu/%7Ejbox/pubs/Box_and_Cohen_GRL_2006.pdf or model output. Or, as #20 Mauri Pelto points out, look at the mass loss, glacier acceleration, and grounding line retreat in that area. It seems that it should be a big red spot on that map, not an unremarkable light green to yellow. I am curious as to why these data don’t seem to match. Anyone?

    Comment by Todd Albert — 6 Oct 2009 @ 12:40 PM

  39. Richard Kerr of Science Magazine has picked up the no warming meme that Revkin published in the Times over a week ago. I gather the story started in England as Deepclimate notes above. Joe Ramm at Climate Progress handily debunked the Revkin article and commenters including me put up the link to the debunking in the Times’ comment section but Revkin did not correct or retract his article.

    Reporters have done a miserable job of explaining the science of climate change. They have made it easy for right wing apologists like George Will to peddle disinformation to the public. Will points to Revkin and washes his hands of responsibility for getting the science wrong.

    Perhaps you should forward this post to Andy Revkin. Maybe he will listen to you.

    Meanwhile the climate change confusion and denial goes on.

    Comment by FishOutofWater — 6 Oct 2009 @ 12:54 PM

  40. Many of you may know that the journal Science recently published a new item:

    What Happened to Global Warming? Scientists Say Just Wait a Bit
    Richard A. Kerr. Science 2 October 2009:
    Vol. 326. no. 5949, pp. 28 – 29

    I have written the editor to complain about the reports lack of attention to the issues presented in Stefan’s post and the issues I raised in my previous comment. I feel it is irresponsible for Science to publish such an incomplete and misleading piece just weeks before the Copenhagen conference.

    I hope some of you will join me in expressing your concern to the editors of Science.

    It is also my hope that Gavin and Stefan have penned a comment for Science.

    Comment by Peter Houlihan — 6 Oct 2009 @ 12:54 PM

  41. #27 Philip – he never said, and you have either willfully or naively echoed something Morana picked up and spun. What Latif said was “It may well happen that you enter a decade, or maybe even two, when the temperature cools, relative to the present level.” He did not conclude “that global warning has ceased, that the planet is currently cooling and will likely continue to do so for another 20 years” as you stated.

    Basically what Latif said is the same as what Stefan said in this post “Even under conditions of anthropogenic global warming (which would contribute a temperature rise of about 0.2 ºC over this period) a flat period or even cooling trend over such a short time span is nothing special and has happened repeatedly before (see 1987-1996).”

    Comment by Peter Houlihan — 6 Oct 2009 @ 1:12 PM

  42. Jari #22: by the meteo stations surrounding the Arctic. Essentially what happens compared to Hadcrut is, that these circum-arctic stations are upweighted and made to represent the Arctic as a whole, not just the rim.

    Documented here.

    Comment by Martin Vermeer — 6 Oct 2009 @ 1:21 PM

  43. I said:
    “Until the popular science press gets it right, this nonsense will continue.”

    It also needs to be added that the mainstream press needs to cry foul on the spin doctors. Loudly and unambiguously.

    How is it that Marc Morano can utter blatant falsehoods day after day, or CEI or Patrick Michaels, or George Will and Glenn Beck for that matter, and Andy Revkin says nothing?

    And, I’m sorry, but the respectful coverage of Steve McIntyre, serial utterer of false unfounded accusations of malfeasance against the world’s top climate scientists, is even worse. But that’s another thread, I suppose.

    Comment by Deep Climate — 6 Oct 2009 @ 2:01 PM

  44. The trouble is when people make vague statements, such as Prof Latif saying “It may well happen that you enter a decade, or maybe even two, when the temperature cools, relative to the present level.” (from the link given). So how are people to interpret “may well happen”? Is this the same as “likely” as defined by the IPCC, i.e. a >66% probability of occurrence? It “may well happen” certainly suggests >50% probability of occurrence to me. Am I wrong?

    Comment by Phillip Bratby — 6 Oct 2009 @ 2:41 PM

  45. #27 Phillip Bratby

    The misunderstanding you are talking about has been discussed. I was in the room in Geneva when he discussed the issue. He did not state we are going to cool. He discussed natural variability and potentials in the context of dcadal predictability and potential. If you listen to his words you can hear his contexts. He is talking to scientists of course. He discusses challenges. It is easy to take words out of context, which is what a lot of people did, unfortunately. It is important to understand that he is discussing decadal predictability, not the AGW climate trend.

    Listen for yourself, listen to the end of his talk:

    http://www.wcc3.org/wcc3media/mp3/WCC3_PS3_ClimatePredictionScience.mp3

    His talk starts around 23 minutes and goes to around 40.

    Comment by John P. Reisman (OSS Foundation) — 6 Oct 2009 @ 2:52 PM

  46. Phillip Bratby @43, yes, you are wrong. Latif said “may well happen” in the context of a public oral presentation, not in scientific paper. He was saying exactly what Stefan is saying in this post: that even during a period when there is an long term upward warming trend there will be times when there may well be a shorter term when natural variability temporarily cancels out or even overcomes that underlying warming trend. Igor Samoylenko @36 provides just such a an example from the recent record up thread.

    What is so effing hard to understand about this?

    Comment by Jim Eager — 6 Oct 2009 @ 3:20 PM

  47. A couple of questions regarding the solar inputs into all of this:

    1. How long does a change in the solar brightness get reflected in, say, the GISS surface temperature analysis (or other indicators of climate)? I ask because in this blog post Stefan seems to imply that the record low brightnesses measured over the past 3 years should have been reflected in the GISS data by now, and my understanding that the timescale for such changes in solar forcing is longer.

    2. The earth’s orbit is elliptical, being ~3% closer to the sun at perihelion than at aphelion. This would seem to cause an annual 1% variation (via the inverse-square law) in the solar energy incident at earth, which is an order of magnitude stronger than the 0.1% variation in solar luminosity over the course of the 11-year solar cycle that is mentioned here. What response does the climate have to this (stronger but more faster varying) annual variation in incident radiation from the sun?

    Comment by Marc DeRosa — 6 Oct 2009 @ 3:20 PM

  48. I am uneasy about the GISS data. Surely it’s estimates of Arctic temperatures are educated guesswork. Does guesswork have any validity as evidence?

    Comment by dave p — 6 Oct 2009 @ 3:40 PM

  49. Philip, #43, yes you are wrong.

    People may have to take a course in statistics, but they can work out the veracity themselves.

    But having someone give them the comforting lie “AGW is not happening” is far easier and nicer.

    Comment by Mark — 6 Oct 2009 @ 3:55 PM

  50. Marc, #45. Think of impulse.

    Force times time.

    If you smack a heavy ball hard but briefly it won’t move much.

    If you push the heavy ball for an hour it will eventually move with alacrity.

    By the time the earth has noticed the fractional change in insolation, it’s already moved and the insolation is going down.

    Have a think about how much energy the earth’s temperature needs to rise 1C.

    Comment by Mark — 6 Oct 2009 @ 3:58 PM

  51. The issue that I see and hear about is that warming was predicted to increase as CO2 increased. This has not happened. So folks are now left thinking that because the predictions of only the past recent few years are observed to be incorrect (in fact temperatures have gone down) what confidence do I have in predictions of 50-100 years ahead.
    You can change your story but the facts remain.
    It’s a fair point I think and needs a full public analysis and assessment. Especially as so much is resting on this.
    Best
    Tim

    Comment by TimJ — 6 Oct 2009 @ 3:59 PM

  52. “I went to the “The Wood for trees” interactive graphs and use HADCRUT3 variance adjusted Global mean data from the time period 1997 to 2009 and it shows a flat trend line from at .4C. Thats over the last 12 and 3/4 years.”

    a) no, it doesn’t. A trend of +0.13C for a linear trend from my calculation from the numbers.

    And why did you pick those two particular dates?

    Why not 15 years, or 25 (a single human generation). You *do* know that the sunspot cycle is about 11 years, don’t you? And that the “D” in “PDO” is *decadal* yes? So when you’ve only selected one cycle, how can you determine the cycle length?

    You can’t.

    You need *at least* two full cycles to see what the amplitude of such a variation is and likewise at least two cycles to have any hope of guessing the average variation of the process.

    So why pick one or less cycles?

    Comment by Mark — 6 Oct 2009 @ 4:03 PM

  53. I ask because in this blog post Stefan seems to imply that the record low brightnesses measured over the past 3 years should have been reflected in the GISS data by now, and my understanding that the timescale for such changes in solar forcing is longer.

    On the other hand, I’ve spent quite a bit of time in the high desert, where the temporary disappearance of solar forcing causes the temperature to often drop from the 35C range to the -5C range each and every spring night.

    Comment by dhogaza — 6 Oct 2009 @ 4:03 PM

  54. “The issue that I see and hear about is that warming was predicted to increase as CO2 increased. This has not happened.”

    Really?

    Have a look at this:

    http://data.giss.nasa.gov/gistemp/graphs/Fig.A2.lrg.gif

    Can you look at that graph and say “temperature has not increased”?

    Comment by Mark — 6 Oct 2009 @ 4:05 PM

  55. PS Such a decadal difference from monotonic increases in temperature were

    a) predicted by the models
    b) predicted by the scientists
    c) seen in the record several times before

    That you missed the last one despite the entire thread explaining that one leaves me baffled.

    Comment by Mark — 6 Oct 2009 @ 4:06 PM

  56. Phillip,

    “May well happen” sounds like something between 20% and 60% to me, but I don’t think this term is defined and I don’t think it is used in IPCC reports. But to me the more egregious error isn’t the probability but the prediction itself and the time table — it is very different to suggest that this coming decade will show cooling with some probability versus saying with some probability there will be some decade during this century that shows cooling, and it seems pretty clear to me that he meant the latter.

    Comment by Eric L — 6 Oct 2009 @ 4:08 PM

  57. dave_p asks: “Surely it’s estimates of Arctic temperatures are educated guesswork. Does guesswork have any validity as evidence?”

    Yes, of course it does.

    Why would it not?

    After all, EVERY SINGLE TIME you take a measurement, you are making an educated guess as to the reading on the scale.

    Have you never taken temperature readings in school lab?

    Were you never told “you have to guess where the base of the liquid is, not read where the miniscus is on the scale” and how you can read a fraction of an interval if the intervals are wide enough?

    They are educated guesses.

    That you made them, did this prove that parafin wax doesn’t coagulate and show the phase change causing temperature stasis?

    Comment by Mark — 6 Oct 2009 @ 4:09 PM

  58. re #47

    The effect of solar cycle variation on the surface temperature is around 0.1 oC peak to trough (and vice versa of course) with around a 1 month lag, according, for example, to:

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

    With an anthropogenic warming near 0.2 oC per decade, the descending part of the solar cycle should have fully countered the warming since around 2003. Presumably the equilibrium response would be somewhat greater than 0.1 oC, and with an extended solar minimum, the surface response will have tended somewhat further towards the equilibrium response and so we expect to have had a solar contribution somewhat larger than -0.1 oC.

    Of course some elements of the climate response to reduced forcing have much slower relaxation times (e.g. the ocean response)…Stefan’s comments refer to the elements of the climate system with faster response times (troposphere and surface).

    Comment by chris — 6 Oct 2009 @ 4:14 PM

  59. To me, the decrease in temperatures is natural. Temperatures warmed from 1850 to 1880, decreased to 1920, warmed to 1950, decreased to 1980. warmed to 1998 and have decreased since. What is so strange? That is how our planet seems to work at present though it has been capable of decreasing 5 C in 10 years in the past and the reverse. My question is why state that this is abnormal or frightening?

    Comment by Eve — 6 Oct 2009 @ 4:21 PM

  60. TimJ @51, you could start by actually reading this post before typing.

    Next you could not repeat what has been shown over and over again to be not true (“in fact temperatures have gone down”).

    http://www.woodfortrees.org/plot/gistemp/from:1990/plot/gistemp/from:1990/trend/plot/gistemp/from:1999/trend

    You can assert your story, but the facts do not support it.

    Comment by Jim Eager — 6 Oct 2009 @ 4:22 PM

  61. If a layman may ask a question, How much of the current estimated rise in temp (.02 degrees C per year?) is due to the increases in atmospheric CO2, and how much to the other greenhouse gasses?

    And if the total heat content of the earth were estimated, would it show a consistent annual increase rather than the variability in the average temperture graph?

    Comment by Krog — 6 Oct 2009 @ 4:25 PM

  62. The issue that I see and hear about is that warming was predicted to increase as CO2 increased. This has not happened.

    Yes it has. What was never predicted, and is not now and has not at any time in the past century happened, is that CO2 would be the only thing that affected the climate, and that the climate would not swing up or down from year to year due to purely internal cycles like El Nino, but rather would pick a temperature that could be exactly computed from CO2 levels alone and thus would go up a little each year just as CO2 levels have been doing.

    Climate can be predicted statistically — you can give an expected value and an expected error, and then your predictions can be validated or falsified statistically, and if you give huge expected errors someone else can show they do a better job. Without CO2, there is no reason to predict the 2000s should be warmer on average than the 1990s, which were warmer than the 1980s. If this decade had been as cool as the 1980-1999 average, while CO2 rose and every other known factor such as solar activity remained basically flat, then it would have been outside the range of model predictions and would have presented some problems, requiring the theory to be modified to have a lower sensitivity or something else we weren’t looking for working to cool the climate. As it has easily been the hottest decade on record, the fact that there are still year-to-year fluctuations does not present a problem for the theory.

    So folks are now left thinking that because the predictions of only the past recent few years are observed to be incorrect (in fact temperatures have gone down)

    Over the last few years, temperatures have gone up, down, up, down, and up again. This tells us… well, nothing.

    Comment by Eric L — 6 Oct 2009 @ 4:32 PM

  63. Your first question is answered in the IPCC reports:

    http://www.ipcc.ch

    “And if the total heat content of the earth were estimated, would it show a consistent annual increase rather than the variability in the average temperture graph?”

    No, it would only show a consistent annual increase if CO2 was the SOLE AND ONLY cause for temperature globally.

    It would likely be a LOT smoother an increase, since things like the PDO et al are movements of heat energy from places we don’t measure it to places we do (and vice versa).

    But please, consider how hard it will be to read the temperature of the ocean. How expensive is it to manage to do the temperature of 1/3 the earth’s surface ALONE. Now figure you’d need twice that just to cover one layer and that you won’t have the ocean bulk energy content unless you have several dozen layers to even an order-of-magnitude approximation.

    And it’s a lot easier to walk to the stepenson screen than kit up and go to 2 miles under the ocean to read one there.

    Comment by Mark — 6 Oct 2009 @ 4:45 PM

  64. Eve, only denialists say that this change is significant.

    But you’ve lost a lot of information.

    It went up, then down a little, then up a lot then down a little, then up a lot then down a little, then up…

    Now given that the “down” is on average less than the “up”, do you think you maybe are forgetting something just a *little* important here?

    Or do you think Hannibal was a wuss crossing the alps, because it went up, then it went down…?

    Comment by Mark — 6 Oct 2009 @ 4:47 PM

  65. Marc DeRosa (47) — The variations over a solar cycle are manifested with a lag between 0 and 2 years. A better estimate is 6–12 months. The annual variation is invsible to global temperature product yearly averages, yes?

    Comment by David B. Benson — 6 Oct 2009 @ 4:51 PM

  66. re #61,

    Krog, these two very short articles on skepticalscience.com address
    your questions:

    This one (see Figure 2 taken from Murphy et al 2009, cited previously on this thread) gives the estimated cumulative forcings from each of the greenhouse gases (CO2, CH4, chlorofluorocarbons, N2O etc.)

    http://www.skepticalscience.com/Measuring-Earths-energy-imbalance.html

    This one (see Figure 1 from Schuckmann et al. 2009, cited earlier on this thread) shows that during the period that shows relatively litle apparent surface warming, that there has been a steady increase in the heat content of the oceans. If one uses earlier data to extend the ocean heat content measure further back in time, there has been a broadly steady increase in total ocean heat content. Since much of the energy absorbed by the earth under a positive radiative imbalance due to enhanced greenhouse forcing has gone into the oceans (likely >90%), this does indicate that there is a broadly consistent annual increase in total heat content.

    http://www.skepticalscience.com/How-we-know-global-warming-is-happening-Part-2.html

    Since the surface and troposphere are very small parts of the whole system, and have low heat capacity and generally respond quickly to changes in forcings (and to the variability in ocean surface heat due to ocean current fluctuations), there is much more variability in the year on year surface temperature than there is in the year on year accumulated heat in the oceans….

    Comment by chris — 6 Oct 2009 @ 5:03 PM

  67. Just to replicate Stefan’s original graph on WFT so people can play with it:

    http://www.woodfortrees.org/plot/gistemp/from:1980/compress:12/plot/gistemp/last:300/trend/plot/gistemp/from:1998/to:2008/trend/plot/gistemp/from:1999/to:2009/trend

    Taking the trend from the monthly values rather than the decimated annual ones gives marginally different trends, but still in the range 0.17-0.19 K/decade – check the ‘data’ link for the numbers.

    Comment by Paul Clark — 6 Oct 2009 @ 5:03 PM

  68. The trouble is when people make vague statements, such as Prof Latif saying “It may well happen that you enter a decade, or maybe even two, when the temperature cools, relative to the present level.” (from the link given). So how are people to interpret “may well happen”? Is this the same as “likely” as defined by the IPCC, i.e. a >66% probability of occurrence? It “may well happen” certainly suggests >50% probability of occurrence to me. Am I wrong?

    I agree that people reading that statement out of context could be forgiven for misinterpreting it (although I did provide that context in my post).

    But the real problem with attributing “misunderstanding” to Latif is that Fred Pearce was there. He was reporting on a conference. He was presumably present for the entire presentation, so context should not have been an issue. He had the presentation and chart in front of him, and presumably could refer back to it, or ask Latif if he wasn’t sure.

    I’m an admitted climate science amateur with an undergrad math/comp sci degree. So how is it that I can look at the statements and presentation and easily discern Latif’s meaning in retrospect (i.e. describing a *hypothetical situation*) and Pearce could not? What does that say about the state of popular science journalism?

    Comment by Deep Climate — 6 Oct 2009 @ 5:04 PM

  69. Great post, RC, and great comments, as always.

    While I understand the facts of the situation re: the size of measurement windows, natural variation, etc., and how “our friends” misuse the details to their advantage, this seems like a good excuse to ask about something related to some of the comments here that’s intrigued me for some time.

    We know beyond all doubt that the world is losing an immense net amount of polar (+ Greenland) ice every year–easily into the hundreds of billions of metric tons per year. Is there any measurable climate effect from melting all that ice? The extra heat needed to effect the solid-to-liquid phase change (80 cal/g) times such a huge amount of ice seems like it would suck up such an enormous amount of heat that it would slightly decrease the observed, higher-than-the-global-average temperature increase in the Arctic.

    Or am I missing something here (like a few orders of magnitude, perhaps)?

    Comment by Lou Grinzo — 6 Oct 2009 @ 5:11 PM

  70. Re 57. does he seriously equate missing data with taking measurements on a scale?

    Comment by dave p — 6 Oct 2009 @ 5:13 PM

  71. Krog 6 October 2009 at 4:25 PM:

    If a layman may ask a question, How much of the current estimated rise in temp (.02 degrees C per year?) is due to the increases in atmospheric CO2, and how much to the other greenhouse gasses?

    A typical breakdown of how much various GHGs are currently altering the climate can be found in the IPCC AR4 WG1 summary for policy makers., on page 4.

    And if the total heat content of the earth were estimated, would it show a consistent annual increase rather than the variability in the average temperture graph?

    No. Variability due to internal weather would be eliminated, greatly reducing the total variability in the graph, but other sources of variability, primarily Total Solar Irradiance would remain.

    Comment by llewelly — 6 Oct 2009 @ 5:24 PM

  72. Krog (#61), ask a simple question and you risk getting a really complicated answer:

    http://www.realclimate.org/index.php/archives/2006/10/attribution-of-20th-century-climate-change-to-cosub2sub/

    Comment by CM — 6 Oct 2009 @ 5:25 PM

  73. … and a comparison with HADCRUT3 which indeed has lower recent trends, although the long term one is pretty similar:

    http://www.woodfortrees.org/plot/hadcrut3vgl/from:1980/compress:12/plot/hadcrut3vgl/last:300/trend/plot/hadcrut3vgl/from:1998/to:2008/trend/plot/hadcrut3vgl/from:1999/to:2009/trend

    … and also with RSS …

    http://www.woodfortrees.org/plot/rss/from:1980/compress:12/plot/rss/last:300/trend/plot/rss/from:1998/to:2008/trend/plot/rss/from:1999/to:2009/trend

    Does the “missing poles” explanation also apply to satellite?

    Comment by Paul Clark — 6 Oct 2009 @ 5:27 PM

  74. Why not also use the UAH data series along with GISS and HADCrudley?

    Comment by BlondieBC — 6 Oct 2009 @ 5:29 PM

  75. Krog,
    first question:
    here ya go:
    http://www.google.com/search?q=ipcc+forcing+co2+“other+gases”

    second question:
    That estimate would do whatever you want it to; without sensors everywhere, you can’t do an actual measurement of “total heat content” so you pick the numbers you like.

    Comment by Hank Roberts — 6 Oct 2009 @ 5:38 PM

  76. Oops, I always forget the double quotes don’t paste in here properly. Use this search, it’s fairly close. Remember there’s no Wisdom button so consider what you find.

    http://www.google.com/search?hl=en&safe=off&q=ipcc+forcing+co2+other+gases

    First 2 hits are good:

    ESRL Integrating Themes: Radiative Forcing of Climate by non-CO2 … Figure 1. Major climate forcing agents and their forcing from the …
    http://www.esrl.noaa.gov/research/themes/forcing/

    gases and aerosols, or radiative forcing scenarios, often based …. radiative forcing from carbon dioxide. A carbon dioxide increase by …. Forests and Devegetation of Other Vegetation Types (IPCC, 2003). …
    http://www.ipcc.ch/pdf/glossary/ar4-wg1.pdf

    Comment by Hank Roberts — 6 Oct 2009 @ 5:41 PM

  77. Mr. Krug: Re: total heat into the earth

    A very nice paper is Murphy et al., J. Geophys. Res., v114, D17107 previously cited by Mr. Houlihan, and Mr. Chris, together with a summary at

    http://www.skepticalscience.com/How-we-know-global-warming-is-happening-Part-2.html

    The rest of this comment probably belongs in the recent sea level rise post, but that thread seems dead, so I hope the moderators will bear with me.

    In para 29 of the Murphy paper, they note an anomaly beginning in the middle 1990′s, and go on to speculate as to the cause. In para 30, they trace the anomaly to a decrease in estimated heat uptake by the ocean. They note that the inconsistency between heat uptake and sea level rise might be resolved by increased melting of land ice, although they mention alternatives such as errors in heat content data, or possibly heat uptake into the deep ocean.

    Would someone care to comment?

    Comment by sidd — 6 Oct 2009 @ 5:49 PM

  78. Mr. Grinzo: Re: latent heat of melting ice

    I did this calculation in a previous post, for 500 gigaton of ice melt

    500GT x 1e9(T/GT) x 1e3 (Kg/Tonne) x 1e3 g/Kg x 80 Cal/g x 4.2 J/Cal = 1.7e20 J

    this is 1.7% of my estimate of yearly oceanic heat increase (averaged over the last decade) of 1e22J from the Levitus (2008) graf.

    Comment by sidd — 6 Oct 2009 @ 5:57 PM

  79. Thank you CM. I intend to read that IPCC report as soon as I get done with War & Peace. But truly, I realize that there is no simple answer.

    Comment by Krog — 6 Oct 2009 @ 6:03 PM

  80. Tharanga says:
    “It’s futile, stefan. Any time the current year is not the warmest year on record, somebody will try to pick the previous record high as a starting point and convince themselves that warming stopped at the previous high.”

    Very well put. Yhis is it in a nutshell.You’ve stated the essence of what skeptics have done time and time again.If you start with 1998, there may be a slight dip from that takeoff point. Whereas if you start with 1997 or 1999 you’ll get a different,result.

    Anyhow shoudn’t all this be moot. There’s much ado about decadal records, whether valid projections can be made, whether this decade is warmer(cooler) that the last. Doesn’t all this mask the fact that decades aren’t representative of long term climate. A lot of this may be of some interest, but it’s just conversation as far as trends are concerned.

    Comment by Lawrence Brown — 6 Oct 2009 @ 6:21 PM

  81. Igor (37), thanks for the reply, and I apologize for not be able to read these threads as thoroughly as I can in the summer when I am not teaching. The graphs over the period you selected and Stefan apparently discussed are indeed flat, which doesn’t surprise me — I would assume any decades in the past come in any of three flavors: up, down or flat — and I haven’t asked the question becuase I had thought the topic was the current decade and what it might say about future temperatures. I would understand if that’s not actually what folks here are most interested in. Be careful, though, not to refer to the current decade as flat, because, as we are being told, it is not! More seriously, are you saying that because after the previous flat period it then warmed, that means after this flat period it must therefore warm as well? If you are not saying that, sorry for the wrong inference.

    Comment by Walter Manny — 6 Oct 2009 @ 6:51 PM

  82. #50 Mark: “Force times time. If you smack a heavy ball hard but briefly it won’t move much. If you push the heavy ball for an hour it will eventually move with alacrity. By the time the earth has noticed the fractional change in insolation, it’s already moved and the insolation is going down. Have a think about how much energy the earth’s temperature needs to rise 1C.”

    #65 David B. Benson: “The variations over a solar cycle are manifested with a lag between 0 and 2 years. A better estimate is 6–12 months. The annual variation is invsible to global temperature product yearly averages, yes?”

    These two responses seem a bit contradictory. If the climate response timescale due to changes in solar insolation are as fast as 6-12 months (as comment #65 suggests), then wouldn’t the annual variation in insolation due to the ellipticity of the Earth’s orbit be manifested in the global temperature data (in conflict with what is said in comment #50)? Or is it slower than 6-12 months?

    I agree, the annual ellipticity variation would obviously not be reflected in annual temperature plots. But I guess I was asking more generally: Is the annual variation in energy incident at Earth from the sun (due to the ellipticity of the Earth’s orbit) visible in, say, monthly or weekly temperature averages? I’m thinking that a 1% variation in insolation is fairly large. If it translates into even 0.1% variation in global temperatures, that should still be visible in the global temperature data, yes?

    Comment by Marc DeRosa — 6 Oct 2009 @ 7:10 PM

  83. People are leaving behind fuel drums and other items form Arctic expeditions. How hard would it be to leave behind some temperature stations, with enough batteries to last?

    Comment by MikeN — 6 Oct 2009 @ 7:25 PM

  84. Eve @ 4:21PM
    The increases were greater than the decreases, resulting in a long term increase overall; see http://woodfortrees.org/plot/hadcrut3vgl/from:1900/to:2010/trend/plot/hadcrut3vgl/from:1850/to:1880/trend/plot/hadcrut3vgl/from:1880/to:1920/trend/plot/hadcrut3vgl/from:1920/to:1940/trend/plot/hadcrut3vgl/from:1940/to:1980/trend/plot/hadcrut3vgl/from:1980/to:2000/trend/plot/hadcrut3vgl/from:1850/to:2010/mean:3
    Note that current temperatures are above the trend from 1900, despite “recent cooling” claims.
    Why is this frightening? Because some of the additional energy captured by increasing CO2 is going into melting glaciers on which billions depend for agriculture; see http://www.grid.unep.ch/glaciers/img/5-9.jpg. A lot of those glaciers are in the mountains on the China-Indian-Pakistan borders; if they go to war over dwindling water supplies that their people need to survive, they will fight with nuclear weapons.

    Comment by Brian Dodge — 6 Oct 2009 @ 7:46 PM

  85. Marc DeRosa (82) — The seasonal lag, at least in northern hemisphere summer, is about 7 weeks; mid-August is warmer, on average, than around summer soltice. The ellipticity variation is just which hemisphere happens to be having warmer summer and cooler winters than the other, all other things being equal, which they are not. You could check monthly data for both hemispheres separately to see the variations.

    Over a standard solar cycle, it is just barely possible to ascertain a lag between solar minimum/maximum and global temperature variations. This will happen in both hemisphers at the same time. Various attempts to pin down the lag suggest 6–12 months is more likely than 0 months or 24 months.

    Comment by David B. Benson — 6 Oct 2009 @ 8:02 PM

  86. You say:

    ” but it does not show in the GISS data, see Figure 1.”

    It actually does show in the GISS data from 2001. We must remember that the years between 1998 and 2001 was a period of an intense El-Nino followed by a deep La-Nina. If one examines the monthly data, the warming trend becomes statistically insignificant after 2000.

    Comment by Richard Steckis — 6 Oct 2009 @ 8:25 PM

  87. Eric L #62 says:

    “Without CO2, there is no reason to predict the 2000s should be warmer on average than the 1990s, which were warmer than the 1980s.”

    Why not? The laws of physics do not preclude a temperature increase in the absence of Greenhouse Gas Forcing.

    Comment by Richard Steckis — 6 Oct 2009 @ 8:32 PM

  88. Mark #63 says”

    “No, it would only show a consistent annual increase if CO2 was the SOLE AND ONLY cause for temperature globally.”

    Rubbish. This is a toally nonsensical statement. It precludes all the other GHGs and other causes of climate forcing.

    Comment by Richard Steckis — 6 Oct 2009 @ 8:36 PM

  89. Edward says:
    6 October 2009 at 10:10 AM
    I went to the “The Wood for trees” interactive graphs and use HADCRUT3 variance adjusted Global mean data from the time period 1997 to 2009 and it shows a flat trend line from at .4C. Thats over the last 12 and 3/4 years.
    FYI
    Ed

    Here it is:
    http://www.woodfortrees.org/plot/hadcrut3vgl/from:1997/to:2009/plot/hadcrut3vgl/from:1997/to:2009/trend

    We know why too. Decreased solar activity has offset the increase in greenhouse gases at the same time.

    To prove that:
    Solar activity, 1997 to 2009:
    http://www.woodfortrees.org/plot/pmod/from:1997/to:2009/plot/pmod/from:1997/to:2009/trend
    Note the downward trend line.

    The CO2 levels, same period:
    http://www.woodfortrees.org/plot/esrl-co2/from:1997/to:2009/plot/esrl-co2/from:1997/to:2009/trend
    See the upward trend line.

    So, what was Edward’s point?

    Comment by Dale Husband — 6 Oct 2009 @ 8:37 PM

  90. Stefan,

    you are saying that there is a hole in the Hadley and that there is no shortfall in the GISS data. You also state that the missing warming is in this hole.

    I had a look at the GISS station data and it seems that there is the same hole in the GISS data. There is only three stations north from 80N (81.6N, 80.6N and 80N) and only about 12 stations between 70N – 80N reporting up to date temperature measurements.

    A huge part of the arctic in the GISS data has no temperature measurements at all, the area between 70N-81.6N is covered by about 15 temperature measurement points.

    Your animated graph in the spinning globe shows the biggest warming in the area where there is no measured data. Is it true that the arctic temperature anomaly shown in your graph comes from an atmospheric model (re-analysis) data which takes spatial correlation into account through an extrapolating/interpolating in space and not from actual measurements?

    In the previous RC post about this issue, Rasmus said “it’s important to note that the NCEP re-analysis and other re-analyses (e.g. ERA40) are not regarded as being appropriate for trend studies”. How come your trend analysis in this post is OK? Rasmus also said that “GISTEMP does not really have a better empirical basis in the Arctic”.

    I do understand the need to reassure people that the global warming has not stopped. I have no problems understanding that there are ups and downs in the temperature data when the long term data shows overall warming. However, what really bugs me is the continuous effort to put data in where there is no data.

    [Response: See my response to #14. It is a data-sparse region, and the issue is the assumptions that were made to cover this region. -stefan]

    Comment by Jari — 6 Oct 2009 @ 8:56 PM

  91. David B. Benson #84: “The seasonal lag, at least in northern hemisphere summer, is about 7 weeks; mid-August is warmer, on average, than around summer soltice. The ellipticity variation is just which hemisphere happens to be having warmer summer and cooler winters than the other, all other things being equal, which they are not. You could check monthly data for both hemispheres separately to see the variations.”

    I’m not sure I’m being entirely clear. I’m referring to measured global temperatures (not simply just one hemisphere or the other), since the insolation occurs over the entire Earth and not simply one hemisphere. I do understand the hemispheres are heated unevenly throughout the year due to the earth’s axial tilt, and maybe this plays a factor (but I don’t know for sure). Or is the fact that the southern hemisphere is more oceanic than the north more of a factor?

    I guess what I’m asking is whether there is a noticeably higher global surface temp, on average, in January (perihelion) + climate response time (whatever that turns out to be) vs the average surface temp in July (aphelion) + the same climate response time.

    What started this train of thought in my mind is that in the original blog entry, the unusually low solar irradiance (0.1% lower than at solar max) was called out as a factor in climate, when in fact the orbital ellipticity causes a 1% variation in insolation. Shouldn’t a 1% variation be more easily seen in the climate data? I’m mainly trying to ascertain what effect solar insolation has on climate, and how long it takes for the climate to respond to variations in the insolation.

    Comment by Marc DeRosa — 6 Oct 2009 @ 9:08 PM

  92. Marc, you write ‘I’m referring to measured global temperatures’
    Do you know of anyone who has measured the global temperature for Earth?

    You can do it for other planets — because we are far enough away from them to point an infrared telescope at them and capture the entire planet in the image.

    You can do it with the Moon, by pointing an infrared thermometer at it and capturing numbers over enough of the surface over enough of the time.

    You may be imagining that it’s already been done for Earth. But if it could be, in such a simple straightforward way, there would be no need for most of what’s being discussed here.

    Think about it. When someone asks you what your temperature is, how do you measure it, where do you measure it, what number are you reporting — and if you put the thermometer somewhere else, would the number be different?

    Comment by Hank Roberts — 6 Oct 2009 @ 9:52 PM

  93. Remarking on (14), which is a question about different ways to obtain a global
    average for non-uniformly distributed data points:
    I would look upon this as a mathematical exercise in numerical integration. We have N data points distributed on a 2D space, that we want to integrate. The
    simplest rule would be to give all points equal weight (this is probably even
    cruder than the Hadley averaging). This relatively unsophisitacted quadrature
    rule converges slower (i.e. if we assume stations are say randomly placed the
    error norm of the method declines pretty slowly towards zero). More
    sophisticated quadratures can be created. To my knowledge all these methods
    boil down to fitting some set of 2D functions to the observed data. The most
    natural 2d functions to use would be spherical harmonics, although other basis
    functions could be choosen. As as result of this process (fully determined
    once the set of basis functions is selected) each station would be asigned a
    weight value. The global average temperature is the a simple weighted sum. In
    the simple case where no stations are added or lost, these weight don’t change
    (I suspect with real world data, that things get a bit messier). In any case
    an intuitive if mathematically inexact measure of confidence would be if all
    weights are non-negative. So here we have the basis of a question that can be
    answered, “What do the individual station weights look like?”

    (17) The problem with validation, is that it is an inherently mathematical
    process. Over 99% of humans are innumerate (using the standard that one
    must be able to judge the mathematical correctness of the validation process).
    So inevitable, in the political context, it comes down to the persuasiveness
    of intuitive handwaving arguments, and the degree of trust the various experts
    can create in the target audience. It is all too easy to be completely correct
    in the academic sense, but badly lose the public debate.

    (47) Actually the sensitivity of the inverse square law means the fraction
    difference in distance should be doubled, so your 3% becomes, 6%. But this is
    overwhelmed at any given location (or even hemisphere), by the seasonal
    effects. And even averaged globally, the average albedo of the two
    hemispheres is unequal, as is the nonatmospheric heat storage (more water
    in the southern hemisphere, means its seasons are more smoothed out than
    in the northern hemispehere).

    Comment by Thomas — 6 Oct 2009 @ 10:01 PM

  94. PS, Marc, this might help:
    http://schools-wikipedia.org/wp/m/Milankovitch_cycles.htm

    Comment by Hank Roberts — 6 Oct 2009 @ 10:04 PM

  95. No, resistance is not “futile,” tharanga!

    Indeed. All the old records will be broken one day as they were in the past. When that day comes people will remember the claims of “global warming stopped in …” and give the proponents of those claims the credibility they deserve.

    Comment by Chris O'Neill — 6 Oct 2009 @ 10:34 PM

  96. “No, it would only show a consistent annual increase if CO2 was the SOLE AND ONLY cause for temperature globally.”

    Rubbish. This is a toally nonsensical statement. It precludes all the other GHGs and other causes of climate forcing.

    Rubbish. Mark (who I dislike) is referring to natural variability, among other things.

    Actually, it’s a Steckis own goal … Mark doesn’t claim that CO2 is the only cause for rising temps, and Steckis takes him to the woodshed for suggesting that Mark claims that CO2 is the only cause.

    Own goal, Steckis.

    Comment by dhogaza — 6 Oct 2009 @ 11:02 PM

  97. This may be a silly question, but why is there an Arctic hole in Hadley’s data? What is the rationale for not including the region which is clearly experiencing the fastest/most extensive warming on Earth?

    Any explanation on this would be helpful for future reporting.

    Cheers,

    -Andrew

    Comment by Andrew Freedman — 6 Oct 2009 @ 11:40 PM

  98. June and August 2009 saw the warmest land and ocean temperatures in the Southern Hemisphere ever recorded for those months.

    August 2009 broke that month’s maximum temperature anomaly record for continental Australia by a whole degree Celsius. Also the highest ever maximum temperature anomaly for any calendar month.

    G.

    Comment by GlenFergus — 6 Oct 2009 @ 11:46 PM

  99. Marc DeRosa #87: I think you have a valid point. Note however that the effect you’re after is in temperatures, not in the more commonly discussed temperature anomalies.
    You may like this reference: http://www.sciencemag.org/cgi/content/abstract/268/5207/59 . I have no strong opinion on its correctness.

    Comment by Martin Vermeer — 7 Oct 2009 @ 12:20 AM

  100. Marc DeRosa,

    Just for a few general points:

    The amplitude of the 11-year solar cycle is large compared to long-term trends, but the full temperature response you’d expect at equilibrium doesn’t show up because of the large thermal inertia of the oceans and the short-term oscillatory pattern of the solar behavior.

    The amplitude of the solar change at the top-of-atmosphere for the much longer eccentricity cycle is very small, and only corresponds to a fraction of the late 20th century forcing. You also don’t expect it to show up in a decadal to century timescale climate record since the corresponding forcing is negligible compared to the shorter-term solar variations, the internal variability of the climate system, or other external forcings acting on the system on timescales of years to decades. To explain glacial-interglacial cycles you need to also incorporate the latitudinal distribution of sunlight and the ice sheet physics which are responsive to enhanced summer melt. Greenhouse gas feedbacks also play a big role in establishing a global pattern of temperature change.

    Comment by Chris Colose — 7 Oct 2009 @ 12:28 AM

  101. http://www.cdc.noaa.gov/map/images/rnl/sfctmpmer_30a.rnl.gif

    Very warm indeed. Its amazing to even ponder on the possibility of a cooling when viewing such a display.
    Although the evidence is very short term, cooling means cooling, and there ain’t much of it going around.

    Comment by wayne davidson — 7 Oct 2009 @ 1:00 AM

  102. From the comments made here, it seems that a 10 (or even 20) year pause in warming wouldn’t be enough to refute the AGW thesis. So I wonder how long of a pause/cooling trend would be required to send you all back to the drawing board/super computer?

    Leaving aside the possibility of cooling, there is still the issue of how rapid the warming will be. Within the simulation results, there does seem to be a pretty wide range of outcomes, with some models predicting much higher rates of warming than others. These more dire outcomes are often cited when trying to create a sense of urgency for policy actions. So how long of a period of ‘below trend’ warming would be required to discredit the more dire predictions?

    Comment by Karl — 7 Oct 2009 @ 1:05 AM

  103. “Rubbish. This is a toally nonsensical statement. It precludes all the other GHGs and other causes of climate forcing.”

    Correct, Skeksis.

    Ergo the position that marc was asking “would the temperature go up evenly” is false.

    It is also why your denialist friends’ insistence that AGW is wrong because CO2 has gone up recently and over two selected points the temperature has gone down is likewise totally nonsensical, since that too precludes any other cause of climate forcing.

    In your glee at this apparent attack vector, I’m afraid you’ve shown that you CAN think this through, but that you merely don’t.

    Which isn’t skepticism.

    Comment by Mark — 7 Oct 2009 @ 4:53 AM

  104. TimJ:

    The issue that I see and hear about is that warming was predicted to increase as CO2 increased. This has not happened.

    Yes it has:

    http://BartonPaulLevenson.com/Correlation.html

    So folks are now left thinking that because the predictions of only the past recent few years are observed to be incorrect (in fact temperatures have gone down)

    No, they have not:

    http://BartonPaulLevenson.com/Ball.html

    http://BartonPaulLevenson.com/Reber.html

    http://BartonPaulLevenson.com/VV.html

    what confidence do I have in predictions of 50-100 years ahead.

    Depends on how much in the way of greenhouse gases we emit, doesn’t it?

    Comment by Barton Paul Levenson — 7 Oct 2009 @ 4:59 AM

  105. “From the comments made here, it seems that a 10 (or even 20) year pause in warming wouldn’t be enough to refute the AGW thesis”

    Well, one reason is that the temperatures on the decade average are still going up, so no pause at all.

    Without such a pause, there’s no expectation that a hypothetical pause for 10 or even 20 years will (in the absence of such a pause) cause AGW to be refuted by the evidence.

    Comment by Mark — 7 Oct 2009 @ 5:25 AM

  106. Brian Dodge:

    some of the additional energy captured by increasing CO2 is going into melting glaciers on which billions depend for agriculture; see http://www.grid.unep.ch/glaciers/img/5-9.jpg. A lot of those glaciers are in the mountains on the China-Indian-Pakistan borders; if they go to war over dwindling water supplies that their people need to survive, they will fight with nuclear weapons.

    India and Pakistan have already exchanged fire and had troops killed over the question of which side owned a glacier.

    Comment by Barton Paul Levenson — 7 Oct 2009 @ 5:36 AM

  107. Marc, if you’re talking just about taking the surface temperature of the earth as a whole, then this won’t help any, since you’ll be ignoring the considerable sink of energy known as “The honking great big lump of ocean”. Satellites not being all that great at looking deep into the oceans.

    Comment by Mark — 7 Oct 2009 @ 5:38 AM

  108. Thomas and Hank:

    You take the average temperature recorded in each equally-sized grid square, then average those figures. I think Arrhenius was using 15 C in 1896 (288 K), and I know Hulbert got 287 K in 1931. The web page for the ISCCP gives 288.4 K as the average for 1983-2008.

    Comment by Barton Paul Levenson — 7 Oct 2009 @ 5:39 AM

  109. Jari #90, note that the picture is only for illustration — and nothing more was claimed. GISTemp doesn’t use any reanalysis products.

    Comment by Martin Vermeer — 7 Oct 2009 @ 6:06 AM

  110. Excellent post – but it is amazing how much rubbish is out there about the “global cooling”! But, tell me, why we don’t rely more on the satellite record as more years are accumulated wtih it? Ultimately, it should be the most reliable temperature record.

    Comment by Richard — 7 Oct 2009 @ 6:07 AM

  111. Andrew Freedman (97),
    There are no measurements in a large part of the Arctic, and the Hadley centre decided not to fill it in (because they don’t want to introduce extra uncertainty), whereas GISS uses a filling procedure based on nearby stations to estimate the temperature in the uncovered part of the Arctic. If the Arctic warms faster than the global average (which it does), Hadley’s approach results in an underestimate of the global average temperature anomaly.
    This post has more:
    http://www.realclimate.org/index.php/archives/2008/11/mind-the-gap/

    Comment by Bart Verheggen — 7 Oct 2009 @ 6:16 AM

  112. For Karl @102, who asks the question that seems to come up at least once in practically every thread, since there was already a ~30 year period of cooling or flat temperatures in the mid 20th C (~1945-1976) yet the trend for the century as a whole was not only positive, but steeply so, 10, 20, or even 30 years of less steep warming or even cooling does not and can not refute or discredit the AGW thesis.

    In addition, Karl seems to be unaware that the more dire model projection outcomes occur with the larger assumed emission scenarios, which are entirely unpredictable and dependent not on physics, but on what we as a species decide to do in terms of burning fossil carbon fuels. Don’t blame the modelers for not being able to predict future human behavior.

    Comment by Jim Eager — 7 Oct 2009 @ 7:34 AM

  113. #79 Krog

    My interpretation based on your answer is that you don’t care about learning the answer to your questions… So why did you ask? Is it that:

    1. You like to ask questions you don’t want answers for?
    2. You are ignoring the facts?
    3. You like disrupting the thread?
    4. You like wasting peoples time?
    5. You are inconsiderate?
    6. You like seeing your words online?
    7. You are bored and have nothing better to do?

    You should read page for of the IPCC report as suggested. It’s only one page (actually about two paragraphs and a graphic with a description). But I guess two paragraphs are a bit much to ask you to read. Are you opposed to educating yourself and science?

    To compare ‘a page’ in a report to War and Peace… Hmmm… How moronic.

    BTW The answer is more simple than you think. Just add up the positive and negative numbers and their ranges that are contained in the two paragraphs.

    Or am I grossly misinterpreting that which you apparently infer/state in your post?

    Comment by John P. Reisman (OSS Foundation) — 7 Oct 2009 @ 7:59 AM

  114. Climate Denial Crock of the Week takes on the distortions of this issue -
    http://www.youtube.com/watch?v=khikoh3sJg8

    Comment by Peter Sinclair — 7 Oct 2009 @ 8:08 AM

  115. Marc (#47), Mark is right–the thermal “inertia” of the system means that there’s not much result on short time scales from orbital eccentricity. (The various orbital cycles have been well studied, and are nicely illustrated at the Wikipedia article on Milankovitch cycles–though the animation there seems to cause my browser some hiccups these days.)

    However, there is a longer-term climatic result as the eccentricity and axial precession affect the hemispheres differentially. This is briefly discussed in this story about Kaufman 2009:

    http://www.cbc.ca/technology/story/2009/09/03/climate-environment-arctic-change.html

    (The original press release for the Kaufman paper goes into more detail, IIRC.)

    WRT your first question: if you recall, the marked effects of Pinatubo on global temps showed up fairly immediately, and they were a result of (essentially) reducing the effective insolation. So you can see that solar effects can indeed show up on relatively short timescales.

    There’s a bit more discussion here:

    http://trs-new.jpl.nasa.gov/dspace/bitstream/2014/20804/1/98-1888.pdf

    Comment by Kevin McKinney — 7 Oct 2009 @ 8:32 AM

  116. Karl 7 October 2009 at 1:05 AM:

    From the comments made here, it seems that a 10 (or even 20) year pause in warming wouldn’t be enough to refute the AGW thesis. So I wonder how long of a pause/cooling trend would be required to send you all back to the drawing board/super computer?

    For the past several decades, climatologists have agreed that 30 years is usually enough data to show long-term global trends in global surface temperature data. Most weather cycles (ENSO, NAO, AO, etc) have a much shorter period than 30 years. A 30-year period with no upward trend in global surface temperature would be strong evidence that the global climate was no longer warming. Even 20 years would be substantial evidence.
    However, a non-warming earth would not be evidence that CO2 (for example) was not a greenhouse gas. There are numerous other factors affecting climate (as has been covered here many times in the past). One example would be some aerosols, which cause cooling. From about 1940 to about 1970, global surface temperature trended slightly downward. The cause was probably cooling from aerosols being sufficient to offset greenhouse gasses like CO2. Note that aerosols are still causing some cooling, but greenhouse gasses are more than sufficient to offset that cooling. A typical breakdown of factors affecting climate can be found on page 4 of the IPCC AR4 WG1 summary for policy makers, which I have linked to in a previous post. (Keep in mind that CO2 accumulates, while aerosols rain out, so if emissions of both CO2 and aerosols were constant, CO2 levels would rise, while aerosol levels would stay constant, and the warming from CO2 would eventually overpower the cooling from aerosols.)
    GISTEMP and Hadley CRU are not the only evidence in favor of a warming climate. The ranges of plants and animals which are limited by temperature are expanding toward the poles. Gardeners and farmers in New England can now regularly grow many crops which were once on viable in the south. Glaciers are melting world wide.

    Comment by llewelly — 7 Oct 2009 @ 8:58 AM

  117. “Actually, it’s a Steckis own goal … Mark doesn’t claim that CO2 is the only cause for rising temps, and Steckis takes him to the woodshed for suggesting that Mark claims that CO2 is the only cause.

    Own goal, Steckis.”

    On reflection. You might be right.

    Comment by Richard Steckis — 7 Oct 2009 @ 9:49 AM

  118. re 116:

    No. Am.

    Comment by Mark — 7 Oct 2009 @ 10:05 AM

  119. Don’t treat skeptics as a lumped phenomenon. Most don’t claim to have the scientific background to make judgements. They are expressing intuitive doubt which has been developed over years over reading and listening to popular crap that ultimately proved wrong. Medical advice is one common area in which they’re told one thing today only to be made fools of later. They don’t know what else to do, but remain skeptical. This is a separate sociological issue. You can pounce on high-profile skeptics if you want, but the average citizen that remains skeptical makes a good point – their friends who seem sure about climate change can’t explain their own view. In other words non-skeptics can’t explain why, they simply chose to get on that side of it. And most people just don’t care because they don’t believe anything can or will be done about it. So quit waging war like this, as if the real problem is that everyone is stupid, except for you.

    Comment by Jack — 7 Oct 2009 @ 10:28 AM

  120. I think that one difficulty folks have with the orbital eccentricity/aphelion thing is that most haven’t lived far enough north or south to really experience the “midnight sun” effect. They know about it in an academic sort of way, but tend not to integrate that knowledge into other topics.

    So, thinking about the global effect of orbital eccentricity, you want to remember that there are big chunks of the globe at high latitudes that have zero solar exposure for periods of up to several months. (And conversely, of course, corresponding periods of 24-hour solar exposure at the other end of the seasonal cycle.)

    On another sub-topic, the lower trop anomaly on UAH for September is up on Roy Spencer’s UAH graph page as .42–maybe the 4th- or 5th-highest value ever, according to Eyeball Mk. I. Of course it’s a fairly volatile metric; May was about 0, IIRC. (And then there’s that whole UAH seasonal artifact question.)

    Comment by Kevin McKinney — 7 Oct 2009 @ 10:32 AM

  121. Temperatures are continuing to rise.Check it out:

    “A simple mathematical calculation of the temperature change over the latest decade (1998-2007) alone shows a continued warming of 0.1 °C per decade. The warming trend can be seen in the graph of observed global temperatures. The red bars show the global annual surface temperature, which exhibit year-to-year variability. The blue line clearly shows the upward trend, far greater than the uncertainties, which are shown as thin black bars. The recent slight slowing of the warming is due to a shift towards more-frequent La Niña conditions in the Pacific since 1998. These bring cool water up from the depths of the Pacific Ocean, cooling global temperatures.”
    http://www.metoffice.gov.uk/climatechange/guide/bigpicture/fact2.html

    A (slight) slowing of the warming, of course, doesn’t indicate a cooling. It merely means that the warming isn’t keeping up the same pace as in prior decades.

    Comment by Lawrence Brown — 7 Oct 2009 @ 10:50 AM

  122. Mark(57) says, “After all, EVERY SINGLE TIME you take a measurement, you are making an educated guess as to the reading on the scale.”

    Now that is just plain silly bombast!

    Sorry; couldn’t resist.

    Comment by Rod B — 7 Oct 2009 @ 11:49 AM

  123. Create the problem, Steer the reaction, Those who created the problem propose the solution. Manufacture cognitive dissonance. Do it over and over again.

    This is the Hegelian Dialectic.

    What is the Hegelian Dialectic?
    http://www.crossroad.to/articles2/05/dialectic.htm

    Comment by Michael — 7 Oct 2009 @ 11:58 AM

  124. Well Dr. Roy’s UAH put’s September 2009 at just 0.012C anomaly less than the 0.432C+ anomaly of 1998. Global cooling pause and all during this century deep solar minimum? All that snow cover missing in Northern Siberia and 1.7 million km square sea ice area per the Cryosphere might have something with that as well… no wait, it’s adiabatic cooling due atmospheric pressure reduction at sea level, because of Carbon binding to O2, which then is absorbed by the oceans… I read it here somewhere, post 594 by Tony. A Wicker Man?

    Comment by Sekerob — 7 Oct 2009 @ 12:01 PM

  125. The applicable IPCC projection charts, emissions history and observational data (mean of Hadcrut/GISS/NCDC) on global surface temperature:

    http://i161.photobucket.com/albums/t231/Occam_bucket/IPCCTemperatureProjection.png

    Astonishing that anyone could honestly infer an underlying cooling trend from this data. It clearly shows a warming trend that closely follows the IPCC A1F1 scenario projection – the path we are most closely following so far. The cherry picking of subsets of this data is naive or purposely missleading as even this complete data set has only recently become long enough to adequately gauge IPCC projections – hence my omission of the AR4 projections.

    Comment by Occam — 7 Oct 2009 @ 12:16 PM

  126. One trend that has always bothered me is this one:

    http://www.woodfortrees.org/data/hadcrut3vgl/from:1910/to:1940/plot/hadcrut3vgl/from:1910/to:1940/trend

    1910-1940, trend ~= 1.5K/decade. Mauna Loa doesn’t go back that far, so I can’t plot it on WFT, but surely CO2 was relatively stable until after WWII? It was around 315ppm in 1958, and if you extrapolate it linearly by eye back to 1940 you hit somewhere near 280ppm, which I gather is the estimate of pre-industrial CO2:

    http://www.woodfortrees.org/plot/esrl-co2/plot/esrl-co2/trend/plot/square:10/from:1940/scale

    I understand the aerosol explanation of the dip from 1940-1970 that ‘llewelly’ referred to @116, but I’ve never heard (or can’t remember!) one for the earlier pronounced rise, for which the trend almost matches the last 30 years:

    http://www.woodfortrees.org/plot/hadcrut3vgl/from:1910/to:1940/mean:36/plot/hadcrut3vgl/from:1910/to:1940/trend/plot/hadcrut3vgl/last:360/mean:36/plot/hadcrut3vgl/last:360/trend

    If it wasn’t CO2, what process could have caused that earlier rise, and has this process stopped now?

    Comment by Paul Clark — 7 Oct 2009 @ 12:23 PM

  127. Michael, you’ve confused Big Coal with the government.
    This isn’t unusual, and has been true sometimes, in some places. But that’s not so-cia-lism, it’s corporatism.

    The people who caused the problem are long since dead, and the companies they founded are now the people trying to fool you into thinking they’re your friends and the gummint is your enemy.

    Comment by Hank Roberts — 7 Oct 2009 @ 12:47 PM

  128. The rotating globe shows some interesting details besides the larger-scale trends – there seem to be some di/multipole pairs of warming and cooling – in southwest-central Asia, part of the Andes, and cool(ing) spots around some islands and protrusions of Eurasia enveloped and next to the Arctic warm spot. Any thoughts? (Is their more snow or cloud cover over the islands near the warm water, for example? Are these trends associated with changes in circulation patterns?)

    Comment by Patrick 027 — 7 Oct 2009 @ 12:57 PM

  129. Also a hot-spot over Lake Superior. Ice albedo feedback, I’d suspect. (not related much, but I saw on the Weather Channel several days ago that there was lake effect rain.)

    Comment by Patrick 027 — 7 Oct 2009 @ 1:02 PM

  130. “Now that is just plain silly bombast!”

    No, Bob bob. THAT was plain silly bombast.

    When you read a thermometer with gradients on the side, you cannot see the EXACT line that the volume of the thermometer content settles at.

    But you can see it isn’t exactly at one of the markings either side.

    So do you throw your hands up in disgust because you can’t make a reading, or do you GUESS whether it’s on one line or another, or even figure some fraction between the two and interpolate?

    Because from your comments it seems like you are a very poor lab worker.

    Comment by Mark — 7 Oct 2009 @ 1:33 PM

  131. Jack says:
    “Most don’t claim to have the scientific background to make judgements.”

    The DO claim enough expertise to override those who DO have the scientific background to make judgements.

    “They are expressing intuitive doubt which has been developed over years over reading and listening to popular crap”

    Yes, the denialist creed. Definitely populist crap.

    ” that ultimately proved wrong”

    Getting the denialists to understand that they’ve been proven wrong is the hard part.

    They’re adamantly opposed to understanding.

    Comment by Mark — 7 Oct 2009 @ 1:35 PM

  132. Jack, if it’s true “They don’t know what else to do, but remain skeptical. ” then why are they so selectively credulous?

    If you were skeptical about whether that plug was live or not, would you

    a) touch it to see
    b) find a way to turn off all power

    ?

    (b) one would hope.

    So if you hear that CO2 will warm the planet and are shown that the planet HAS warmed, when you hear that there may not be a problem, do you pick

    a) there’s nothing to worry about so keep pouring out CO2
    b) stop pouring out CO2 until you’re certain it’s OK

    ?

    And if the answer is (a) why was your answer to the earlier one different?

    If you are not one of these people who are skpetical because they have no choice but to be, maybe you can answer why so many seem to choose (a) wrt CO2 emissions yet wouldn’t consider choosing (a) on the possibly live plug scenario (one assumes this to be the case since the hospitals would otherwise have a much higher casualty waiting list with elecrical burns).

    Comment by Mark — 7 Oct 2009 @ 1:40 PM

  133. Karl (102), for an example of how to approach this question, see Tamino’s article about betting on global warming:

    http://tamino.wordpress.com/2008/01/31/you-bet/

    Comment by Alfio Puglisi — 7 Oct 2009 @ 1:49 PM

  134. Jack, maybe an example of the populist crap that people swallow because they are NOT skeptical can be shown by this informative piece by Greenfyre:

    http://www.youtube.com/watch?v=khikoh3sJg8

    Bottom line:

    Scientist says “we may see periods of 10, maybe even 20 years where we get some cooling”

    Populist crap says “an IPCC scientist says we’re looking at 30 years cooling. 40 years. At least”.

    And guess what: when it warms over the next 10 years, it won’t be shown as proof there’s AGW by the populist crap, but as how the IPCC scientists got it wrong again.

    Comment by Mark — 7 Oct 2009 @ 1:56 PM

  135. Hank,
    Clearly you are the one who is confused. That is clearly inferred by your response. I know how your mindset came about.
    I made no mention of any current government, corporate, or political entity in my post. Nor did I cast blame on anyone.

    Here is a little more homework for you to do.

    The Hegelian Dialectic if you are interested.

    http://nord.twu.net/acl/dialectic.html

    http://nord.twu.net/acl/evolution.html

    Comment by Michael — 7 Oct 2009 @ 2:12 PM

  136. Re #129 Mark

    The problem is that there are a lot of people who insist that the only two options to see if the plug is live are:

    a) touch it to see
    b) burn the house down to be safe

    in which case a) looks like the sensible option, because their plumber friend says that if you just touch the plug quickly, you won’t get a shock. Who would you rather trust, some smart-ass physicist who is just in it for the money, our a plumber who actually earns a decent living by doing this stuff?

    Comment by CTG — 7 Oct 2009 @ 2:38 PM

  137. You guys have got it all wrong when it comes to divining the 10 year trend. A poster on the Science Blog of the Year shows the correct method …

    ok, so plotting a ten year period from 2000-2010

    http://www.woodfortrees.org/plot/hadcrut3vgl/last:111/plot/uah/last:111/plot/rss/last:111/plot/gistemp/last:111/plot/hadcrut3vgl/last:111/trend/plot/uah/last:111/trend/plot/rss/last:111/trend/plot/gistemp/last:111/trend

    shows that temperatures have been flat for the last 10 years

    Now d’ya see where you’re going wrong? The key is to include months that haven’t happened yet in your 10 years, then you can get the answer you want….I mean get the right answer.

    I don’t think it was meant ironically…

    Comment by pjclarke — 7 Oct 2009 @ 2:48 PM

  138. Good post, but I still think that we have to think about other ways to present temperature charts. See:

    Discussion @ Deltoid and pointers there, but key observations are:

    a) Humans are not good at doing regressions in our heads. We do not easily estimate the actual SLOPE of a segment of a jaggy trendline.
    b) Our visual systems are drawn to extremes, one of the reasons people draw lines between end points.

    Meanwhile, people constantly cherry-pick the exact start date and interval lengths, but just showing a longer one is not necessarily convincing.
    SO, see Fig 1 which plots HadCRUT2v at the top, and at the bottom, shows 25,30, 35-year SLOPEs, year-by-year, so there is no arguing about cherry-picking a start-year or interval-length.

    This converts a difficult task of estimating slopes into a first-derivative-like display, in which people can do the much easier task of looking at data on a normal scale. Specifically, in the last 110 years, there have been only a few decades in which 25,30, or 25-year SLOPES were negative.

    This can also be compared with Fig 4: 5,10,15,30-year SLOPEs. 5-year trends are all over the map, but even 10-year ones haven’t been negative since mid-1950s.

    I don’t know that these are optimal, and Bob Grumbine and I have argued somewhat about the use of endpoints versus midpoints, but the *general idea* is that human perceptual systems are rather sensitive to noise, and the usual temperature charts unfortunately are not as compelling as they might be.

    Comment by John Mashey — 7 Oct 2009 @ 3:18 PM

  139. #121, I’ll repeat something I said a long time ago on Dot Earth:

    If you inserted a thermometer into the rectum of a denier (or skeptic, as they prefer to be called), withdrew it, and announced a reading of 98.6, they would say that it actually said 97.4. You would then be treated to weeks of posts and justifications to that effect.

    Comment by mike roddy — 7 Oct 2009 @ 3:26 PM

  140. Jack (~#118, 10:28 AM):

    You are not talking about skeptics, you are describing people who are clueless. Being disappointed with popularized information about medicine, global warming, or whatever is a problem for those who are ignorant and unwilling to learn what the science actually says. On a website where there are science learning resources and scientists willing to answer questions, how do you propose that someone who repeatedly refuses to learn should be treated? Do you believe that the people who come here and continue to post disinformation are members of your “just don’t care” group?

    Steve

    Comment by Steve Fish — 7 Oct 2009 @ 3:35 PM

  141. Marc DeRosa (91) — You have posed a fine and useful question: what is the role of eccentricity upon global (and hemispheric) temperatures (temeprature anomolies) and how long is the lag?

    I’m particularly interested in the lag question, although I haven’t thought previously about this annual effect. My amateur first stab is this should be about the same as the lag from summer solitice to the warmest part of summer, almost 2 months around here.

    There might be papers in the journals about this; dunno.

    Comment by David B. Benson — 7 Oct 2009 @ 4:25 PM

  142. Re:3135,by mike r.

    Heaven forgive me, but there have been frustating times when I’ve wondered whether a hockey stick might be a more appropriate instrument.

    Comment by Lawrence Brown — 7 Oct 2009 @ 4:53 PM

  143. Make your own analysis at woodfortrees.org!
    That should show every engineer and scientist a little about the temperature record…

    Here, I did it with HadCRU and GISS:
    http://tinyurl.com/yc5pnfv

    Comment by gravityloss — 7 Oct 2009 @ 5:21 PM

  144. The ice trend in the Arctic can be seen here:

    http://www.sciencedaily.com/images/2009/10/091006122328-large.jpg

    Despite what some commentators have said, this is not exactly recovery, any more than 2007 was a collapse – more like fluctuations around a downward trend.

    Nevertheless, the New York Times climate section ran with this headline:

    “Over the Summer, a Spread of Thicker Arctic Ice – Revkin”

    This is side-by-side with a lot of predictive news headlines:

    “Obama Adviser Says No Climate Change Law This Year New York Times”
    “Obama Aide Concedes Climate Law Must Wait New York Times”
    “Obama Unlikely to Sign Climate Bill Ahead UN Meet New York Times”

    Does the New York Times have a horse in this race? Are they engaging in something other than unbiased journalism on this issue?

    The obvious conflict of interest here is that the major institutional investors in the Times of New York are also some of the largest shareholders in fossil fuel corporations, from Exxon and Chevron to Duke and Southern. The Times also has an unfortunate habit of using industry front groups set up by these financial and industrial conglomerates as their ‘expert source’ for all matters relating to the national electricity supply, as well – and instead of sending their star climate reporters to Copenhagen, they sent them to the industry front group meeting on the subject – and Revkin justified this behavior on the basis of the carbon emissions saved by not engaging in air travel (yes, that’s true).

    As far as the sea ice recovery that Revkin trumpets? Look again at that graph – notice that the >2 year old ice (green) is still in decline and has shown no recovery?

    There is really very little evidence to support Revkin’s published claim that we are “at a time when global temperatures have been relatively stable for a decade and may even drop in the next few years.” – no matter how authoritative he tries to sound about it, this is slanted journalism.

    Maybe we need to pass a law banning banks and institutions that invest in fossil fuels from also investing in media corporations – maybe then you’d see some unbiased science reporting, and maybe even honest reporting on the energy industry as well.

    Comment by Ike Solem — 7 Oct 2009 @ 6:33 PM

  145. John Mashey 7 October 2009 at 3:18 PM:

    This can also be compared with Fig 4: 5,10,15,30-year SLOPEs. 5-year trends are all over the map, but even 10-year ones haven’t been negative since mid-1950s.

    Looking at the thick red line – which I read to be the 10-year slopes – I see a negative region at about 1965 – 1961 and another at about 1975 – 1979. Looking at the pale blue line – which I take to be the 15-year slopes – I see another negative region at about 1970 – 1978.
    However I agree with your thesis that the human brain is bad at calculating trends.

    Comment by llewelly — 7 Oct 2009 @ 8:03 PM

  146. Another good post, guys.

    A minor, minor point, though. In the caption to fig. 1, perhaps the phrase “all ten data points” should read “all 11 data points”, given that it refers to 1998 to 2008.

    Comment by Garry S-J — 7 Oct 2009 @ 8:33 PM

  147. For the folks who want a monotonic increase as proof of global warming, do you think the temperature was the same every year before we started pumping out enough CO2 to make a difference? It’s instructive to look at the first 50 years of the HadCRUT3 dataset. The trend is slightly up but not significantly so, and there are big inter-annual variations, as much as 0.4K. Now imagine you have added an upward trend to that data, by adding a linear increase to each data point. Will it increase monotonically? No, not unless your new trend is bigger than any inter-annual increase. See my blog for discussion of this.

    Comment by Philip Machanick — 7 Oct 2009 @ 9:26 PM

  148. Paul Clark @126, First, why did you pick 1940, instead of 1945, which looks to be the peak of the pre-WWII warming?:
    http://www.woodfortrees.org/plot/hadcrut3vgl/from:1910/to:1950/plot/hadcrut3vgl/from:1910/to:1950/trend

    Second, why would you think that CO2 was relatively stable prior to WWII, when we began burning fossil carbon fuels on an industrial scale in 1750, and the rate industrialization and burning increased exponentially from then?

    Third, if you extrapolate the atmospheric CO2 linear trend line by eye back to 1940 you do indeed hit somewhere near 280ppm. But notice that the slope of the actual CO2 curve reduces as you move further back in time. Extrapolate it back to 1940 and you get to ~310 ppmv:
    http://skepticalscience.com/The-CO2-Temperature-correlation-over-the-20th-Century.html

    As per above, rising CO2 was one of the forcings during the 1910-1945 warming, but so was an increase in solar activity:
    http://www.globalwarmingart.com/wiki/File:Solar_Activity_Proxies_png

    Comment by Jim Eager — 7 Oct 2009 @ 9:37 PM

  149. Phlip Machanick @147, two questions I like to ask those who ignore natural variability and expect monotonic temperature increases:

    1) Was every year warm during the Medieval Warm Period?
    2) Was every year cold during the Little Ice Age?

    We all here know the answer to both questions is of course not, but the questions cause strong cognitive dissonance among “sceptics”/deniers.

    Comment by Jim Eager — 7 Oct 2009 @ 9:47 PM

  150. re: #145 llewelly
    Thanks, that was a slip of the fingers before going out.
    I meant to write “but even 10-year ones haven’t been negative since mid-1970s”, not 1950s.

    Actually, this accidentally illustrates the point: you found that error quickly on a slope chart, where it is obvious … but on anormal temerpature chart, it’s not so obvious.

    Here’s a wish, for anyone out there that still writes serious code: it woudl be nice to have an interactive view of Figure 1 (which had both temperature and slopes), and had a slider bar that was the number of years.

    Comment by John Mashey — 7 Oct 2009 @ 9:58 PM

  151. OT but … I wanted to send a friend the web address for the “FAQ on climate models” parts I and II; I found part II but part I is missing – there is this website:
    http://www.realclimate.org/index.php/archives/2008/11/faq-on-climate-models/
    but it is not what it should be. Where did it go?

    Comment by Patrick 027 — 7 Oct 2009 @ 10:19 PM

  152. Mark, if you don’t know the difference between making a guess — even a smart one, and having an sensor error in an actual measurement, I suggest, in Hank’s words, you google it.

    Comment by Rod B — 7 Oct 2009 @ 10:28 PM

  153. I am confused by just what natural variability means and how it can cause a cooling trend. It would appear that it depends on how what is being measured. If increased greenhouse gases are increasingly trapping heat, then that heat doesn’t disappear due to variability, or does it?

    This flattening of temperatures reflects surface temperatures. Therefore if these gases are trapping heat 1) I would expect the the total ocean heat content to still be increasing, despite declines in the average of surface temperature caused by natural variability. Is that true?

    or 2) If natural variability means that there is a mechanism that allows heat to escape, so that ocean heat content also flattens or drops, then I don’t see how the heating trend can just resume. I would only expect that with natural variability, the greenhouse gases trap heat during warming years and that merely balances out the lost heat during cooliong years. Can you explain how natural variability works more specifically?

    Comment by Jim Steele — 7 Oct 2009 @ 10:33 PM

  154. Paul Clark #126: see http://tamino.wordpress.com/2009/08/17/not-computer-models/
    Summary: lull in volcanism, bit of solar, and — yes — some CO2.

    Comment by Martin Vermeer — 7 Oct 2009 @ 11:05 PM

  155. Jim, experiment.

    Take a glass of water, some ice cubes, and a thermometer.

    Put the ice in the water and the thermometer in the water.

    Check the temperature.

    Put the whole thing on a table and watch it for a while.

    The ice melts.

    The temperature doesn’t change.

    What’s happening?

    Comment by Hank Roberts — 7 Oct 2009 @ 11:07 PM

  156. Jim Eager <a href="http://www.realclimate.org/index.php/archives/2009/10/a-warming-pause/comment-page-3/#comment-137710"#149. Another thing now you’re on the Medieval Warm Period: I’ve found a lot of data suggesting higher temperatures at different parts of the world, but when I line up the dates, they often don’t match. So there’s a case that there were multiple periods of regional warming, but not one single warm period. Ironically I found this at a denial site, where they were trumpeting this great find of dozens of papers to support their case (apparently a conspiracy to suppress all this evidence; some conspiracy if a bunch of amateur bloggers and retired scientists found so many papers). Sadly they did not appear to be able to assemble their own evidence and weigh it up.

    Comment by Philip Machanick — 7 Oct 2009 @ 11:16 PM

  157. Jim Steele #153: the key thing to understand is that natural variability is not a trend: it’s blips that get cancelled out by other blips.

    There’s a great tool on Macs called Grapher. If you have a Mac, plot yourself sin x + 0.02x. Look at it in a highly zoomed in scale, and it looks like sin x. Look at it at a highly zoomed out scale, and it looks like y = 0.02x (a slowly rising straight line).

    Now think of the weather as having short-term cycles like sin x that vary up and down, but average out to zero, and climate change as a function that long-term looks like 0.02x. As with our graph, periods where the natural cycle goes down enough to overwhelm the long-term trend don’t count. The long-term trend is there in that the “down” phases of the cycle don’t go down as far as they otherwise would. If the sun puts out less energy, the earth will cool (low point of the solar cycle). If we have extra CO2 in the atmosphere that cooling will be reduced. If we have a big La Niña, the earth will cool – but not as much with extra CO2.

    Comment by Philip Machanick — 7 Oct 2009 @ 11:27 PM

  158. Jack #119

    You can pounce on high-profile skeptics if you want

    So in other words, “carry on?”

    the average citizen that remains skeptical makes a good point

    No, they probably don’t really have a point. As long as people expect to get news from infotainment, they will have those expectations disappointed. I wish you could just turn on your trusty TV and get a one-stop-shop for reliable, intelligent and unbiased information in digest form. The reality is you can’t be a passive consumer of news AND be well informed. That’s just the way it is these days.

    So quit waging war like this, as if the real problem is that everyone is stupid, except for you.

    Um, I’ll admit that the heat surrounding this issue can be a little disconcerting, but I think it’s fair to say that there’s no assumption here that “everyone” is a stupid enemy. In fact, it seems to me that your hostile rebuke assumes that the scientists and others visiting this site are too stupid to understand the nature of the political attacks on AGW.

    Comment by Radge Havers — 8 Oct 2009 @ 12:15 AM

  159. Hank I am not sure what your point is. Are you attributing natural variability to latent heat? Are you saying that the flattening of global surface temperatures is due to heat latent heat absorbed as ice melts? That makes limited sense. During this flattening/cooling trend, there has not been any dramatic increase in melting glaciers and global sea ice has been increasing the past 2 years.

    I think your logic is too simplistic, For example southern hemisphere ice has been significantly increasing the past years http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.anom.south.jpg
    So why couldn’t I equaly argue that the latent heat released as the sea ice increases is masking a real cooling trend?

    Comment by Jim Steele — 8 Oct 2009 @ 1:02 AM

  160. My prediction: The next IPCC report will either (i) replace the HAD CRU graph with the GISS graph or (more likely (ii) combine them together. Option (i) would look just a bit too much like picking the result that fits the argument.

    Comment by oakwood — 8 Oct 2009 @ 2:01 AM

  161. Bob Bob, if you don’t realise that interpolating between two values IS a guess, your capabilities in the lab are seriously hampered.

    Comment by Mark — 8 Oct 2009 @ 3:26 AM

  162. CTG in 176 proclaims:

    “The problem is that there are a lot of people who insist that the only two options to see if the plug is live are:

    a) touch it to see
    b) burn the house down to be safe”

    I think the number of people who do that figure into “a handful” at most. Out of the 6+Billion on the planet.

    I.e. to all intents and purposes: nobody.

    I.e. your point is bull.

    Comment by Mark — 8 Oct 2009 @ 3:30 AM

  163. pjclarke @ 137: WFT data is all monthly, so actually that link doesn’t include any mythical Oct/Nov/Dec 2009 data, it just gives you the last 111 months, from June 2000. I suspect the poster was trying to get all data from 2000 – not sure why they didn’t use 117 if it was posted recently – so “from:2000″ would have been easier. The funny thing is, using “last:111″ on a live linked graph means that the graph will change as time goes by, so in a few year’s time it may go directly against the point they were trying to make. An interesting problem for historians… :-)

    Jim Eager @ 148: Thanks for your response and useful links – I chose 1910-1940 because it’s a 30 year period, and joins to the 1940-1970 period that someone else was talking about re cooling above. As you point out, if you go to 1945 the trend is even higher.

    I was aware of the acceleration of C02 and that linear trend wasn’t quite right, but I had also guessed (wrongly) that there was a step change shortly after WWII which would compensate for it – but your link shows this isn’t the case, thank you. Clearly the change in C02 over the period isn’t anything like what’s happened in the last 30 years, but it’s definitely there.

    On solar… Looking at sunspot numbers as a proxy, there was indeed an upward trend 1910-1940, but the much larger 11-year cycle has only a small effect on temperature (it is there in the noise if you filter for it) – or is this an issue of thermal inertia? Is the 11-year cycle being low-pass filtered by the Earth, so only the long-term trends remain?

    http://www.woodfortrees.org/plot/hadcrut3vgl/from:1910/to:2000/mean:36/plot/hadcrut3vgl/from:1910/to:1940/trend/plot/hadcrut3vgl/from:1940/to:1970/trend/plot/hadcrut3vgl/from:1970/to:2000/trend/plot/sidc-ssn/from:1910/to:2000/scale:0.01/mean:36/plot/sidc-ssn/from:1910/to:1940/trend/scale:0.01/plot/sidc-ssn/from:1940/to:1970/trend/scale:0.01/plot/sidc-ssn/from:1970/to:2000/trend/scale:0.01

    Martin Vermeer @ 154 also mentions a lull in volcanism as a cause of the 1910-1940 rise… Are there datasets for this I could put on WFT? What do they actually measure?

    Comment by Paul Clark — 8 Oct 2009 @ 4:22 AM

  164. “It does show up to some extent (no cooling, but reduced 10-year warming trend) in the Hadley Center data”
    Perhaps we should look at the Hadley graph, seems to show an accelerating cooling trend for the past 4 years!
    http://hadobs.metoffice.com/hadcrut3/diagnostics/comparison.html

    Comment by Alan Ross — 8 Oct 2009 @ 4:57 AM

  165. Re #162 Mark.

    I’m not a denialist.

    You don’t need to put me down.

    I was agreeing with you, only you didn’t realise it.

    [edit]

    you think you are the only person in the entire world that is right, and that everyone else needs to be put in their place.

    So, although you believe in AGW, and mostly are on target, please don’t take it personally if I say (along with most readers here, I think):

    [edit]

    Comment by CTG — 8 Oct 2009 @ 6:22 AM

  166. i love my nasa giss i love my nasa giss
    2005 is getting warmer and warmer, hansen is going crazy and you idiots
    try to find global warming with methods, i can only LOL

    YOU ARE SIK!

    Comment by Dan Hover — 8 Oct 2009 @ 7:32 AM

  167. Dan Hover,
    Off the meds again, huh?

    Comment by Ray Ladbury — 8 Oct 2009 @ 8:29 AM

  168. Jim Steele, By “natural variabliity” we mean the energy sources and sinks that influence global temperatures but tend not to result in a long-term trend. Volcanic eruptions, ENSO, PDO, NAO, the solar cycle, etc are examples. Volcanic eruptions occur at random, but rarely, and so can be modeled as a Poisson process occurring at some mean rate. As long as the mean doesn’t change, they don’t induce a long term trend. Other processes may affect cloud cover or the amount of heat going into the deep oceans. However, these processes donot continue indefinitely, and so over long time scales they don’t affect climate.

    In contrast, an increase in greenhouse gasses will over time push temperatures higher as the climate works toward a new state of radiative equilibrium. Hope that helps.

    Comment by Ray Ladbury — 8 Oct 2009 @ 8:39 AM

  169. Jim Steele …

    Skeptical Science has a good piece up which might help you with your question.

    Comment by dhogaza — 8 Oct 2009 @ 8:43 AM

  170. Paul Clark #163: the forcings are here:

    http://data.giss.nasa.gov/modelforce/RadF.txt

    Column 8 “StratAer”. Don’t know how you could put these on WoodForTrees. Perhaps by downloading their software.

    Comment by Martin Vermeer — 8 Oct 2009 @ 8:57 AM

  171. Jim Steele — dhogaza’s pointer to SkepticalScience is a much better answer than mine. That ought to be very helpful to you.

    One other thought — If your questions arise based on something that you have been reading elsewhere, please tell us your source or sources for your puzzles.

    Having a pointer can avoid a whole lot of recreational typing on everyone’s part if you’re reading something somewhere else and trying to check it out.

    Comment by Hank Roberts — 8 Oct 2009 @ 9:06 AM

  172. “Re #162 Mark.

    I’m not a denialist.

    You don’t need to put me down.”

    CTG, I don’t put people down for being a denialist. I put people down for [edit] their arguments.

    Now, almost all denialist arguments are idiotic, however, don’t let that make you think that that is the criterion.

    You [edit]

    [no more of this inflammatory stuff from either side, please. -editor]

    Comment by Mark — 8 Oct 2009 @ 9:07 AM

  173. Jim: “For example southern hemisphere ice has been significantly increasing the past years ”

    No, the extent of sea ice has increased.

    Sea ice extent increase != sea ice increase

    Please try again.

    Comment by Mark — 8 Oct 2009 @ 9:09 AM

  174. Nice articles by Joseph Romm and Gavin in October issue of Physics World that is being offered as a sample copy for free download http://physicsworld.com/cws/download/oct2009
    Clever titles “Publicize or Persih” and “Wrong but Useful” respectively.

    Comment by Hugh Laue — 8 Oct 2009 @ 9:12 AM

  175. Martin Vermeer @ 169: Thanks for the link to the forcing data; I could easily add these (most sources are tabular files like this), but I’m not sure they are quite what I’m looking for, because this is model output rather than raw data. It would be an interesting addition to add model outputs but I’m not quite sure I’m ready for that yet… Presumably the GISS forcing model must have taken some raw data about vulcanology (number? total mass ejected?) to create these? If so, where from?

    Comment by Paul Clark — 8 Oct 2009 @ 9:43 AM

  176. Mark,
    Despite your self image of superior intelligence I must point out that it’t not too tough to reduce the opposition to “almost all denialist arguments are idiotic” when you make up and/or morph their arguements to sound idiotic.

    As you did with your 134:
    “Scientist says “we may see periods of 10, maybe even 20 years where we get some cooling”
    Populist crap says “an IPCC scientist says we’re looking at 30 years cooling. 40 years. At least”.
    And guess what: when it warms over the next 10 years, it won’t be shown as proof there’s AGW by the populist crap, but as how the IPCC scientists got it wrong again.”

    I follow both sides of this debate and have never seen this denialist claim by anyone. Where did you find it?

    I suspect you made it up.

    In reality the skeptics case grows in specifics and weight which you are avoiding.
    It would be much more meaningful if you addressed their actual arguments instead of your own versions.

    You see there are many people who can tell the difference.
    Who do you think you are fooling?

    You could easily select and quote a specific skeptics argument to refute.

    In the RC camp you are the number one advocate. IMO

    Comment by Howard S. — 8 Oct 2009 @ 9:45 AM

  177. Jim Eager (148), saying “we began burning fossil carbon fuels on an industrial scale in 1750″ is quite a stretch. While that is when the first coal was mined in the U.S. industrial scale use came almost 100 years later.

    Comment by Rod B — 8 Oct 2009 @ 10:14 AM

  178. Ray Ladbury, That was a clear explanation, and I basically understand exactly what you are saying. However the point I was asking more specifically was about heat input or release or redistribution of heat. Too often I read “natural variability” as a vague catch all that is thrown around to explain every change.

    I think there is a great need to distinguish “variability” caused by “heat redistribution processes” like ENSO vs changes in input and release such as the sun or green house gases. It seems that the distinction is currently based on the fact that CO2 is steadily climbing and other events are more “random” around a mean. But that seems dangerously overly simplistic to have predictive value.

    I think of ENSO as simply redistributing heat from the ocean to the atmosphere. That oscillation around a mean would have no effect on trends because it does not significantly impact the heat balance. However If variability is due to input, ie the sun, then the observed drop in solar activity, magnetism, and sunspots which is now approaching multi-century lows is changing our calculation of the mean. If this change in solar input is similar to other historic changes, then we may approach a new mean or set point similar to that seen in the early 1800′s of the Dalton minimum or 1600′s of the Maunder minimum. If the the heat content is lowered (using OHC as the best metric) then the trapping of heat by greenhouse gases would continue but at this lower set point.

    Also conversely that suggests the solar input during the 1900′s was above the mean. So if the sun input is reverting to a lower mean then it suggests a cooling trend is in store and we might not see the high average temperature’s of the 90′s or 2000′s for another hundred years. Would that still be called natural variability?

    Comment by Jim Steele — 8 Oct 2009 @ 10:35 AM

  179. PS doesn’t significantly alter your basic point, though…

    Comment by Rod B — 8 Oct 2009 @ 10:37 AM

  180. Mark #172 “Please try again.” ??? I can’t decipher the meaning of your reply!

    Comment by Jim Steele — 8 Oct 2009 @ 10:37 AM

  181. Minor nitpick:

    Back at post #24, the name of the first author got the footnote letter appended: it should be Swanson, not “Swansona”

    Great post, and good discussion thread too. Thanks everybody!

    Comment by Jim Prall — 8 Oct 2009 @ 10:47 AM

  182. Mark (172), isn’t sea ice extent highly proportional/related to sea ice (volume). Like “extent” is partially defined by concentration. Though, maybe concentration is only loosely correlated to volume??

    Comment by Rod B — 8 Oct 2009 @ 11:03 AM

  183. Jim Steele, please tell us where you are reading or hearing the information you are quoting (we assume you didn’t go there yourself and do your own study).

    Once you say where you are getting what you believe, it will be much easier to help you go from that to the underlying science. If the source you are reading does not cite to the science papers, I suggest you look for a better source. Lots of people are pushing opinions based on other people’s opinions.

    Look at the definitions at the sea ice science sites for thickness, extent, and area covered. You know where to look? That should help make this clearer.

    Comment by Hank Roberts — 8 Oct 2009 @ 11:03 AM

  184. “Mark (172), isn’t sea ice extent highly proportional/related to sea ice (volume). ”

    Nope.

    The knob of butter on my knife is only a couple of grammes.

    Yet after I spread it on my bread it now occupies a greater surface area than the 500g tub of it.

    Comment by Mark — 8 Oct 2009 @ 11:16 AM

  185. “that oscillation around a mean would have no effect on trends because it does not significantly impact the heat balance. ”

    It does change the trends, though, if you pick your points of reference poorly.

    And even then, it DOES make a small difference: a cold ocean radiates less heat out, so the heat balance is “more in”.

    “Also conversely that suggests the solar input during the 1900’s was above the mean.”

    Period of that being…?

    “So if the sun input is reverting to a lower mean then it suggests a cooling trend is in store and we might not see the high average temperature’s of the 90’s or 2000’s for another hundred years.”

    Check up “begging the question”.

    The answer however is “no”. Because the warming from CO2 is bigger than the variation we see in the solar constant from the sun at a defined distance.

    Comment by Mark — 8 Oct 2009 @ 11:19 AM

  186. “Despite your self image of superior intelligence”

    Superior to some.

    But that’s a consequence of “we are not all alike”.

    So please get on to the point.

    “I follow both sides of this debate and have never seen this denialist claim by anyone. Where did you find it?”

    In the link I gave to the most recent Greenman Crock of the Week.

    Link given.

    That you missed this and made such a song-and-dance about it is WHY I deem [edit]

    http://www.youtube.com/watch?v=khikoh3sJg8

    Watch it. It’s in there.

    [edit-lets watch the inflammatory comments. we'll discontinue this thread if you guys can't keep it civil and on topic]

    Comment by Mark — 8 Oct 2009 @ 11:24 AM

  187. ” Jim Steele says:
    8 October 2009 at 10:37 AM

    Mark #172 “Please try again.” ??? I can’t decipher the meaning of your reply!”

    Please try again: your evidence is not evidence of there being more ice.

    Comment by Mark — 8 Oct 2009 @ 11:25 AM

  188. Rod B says:
    8 October 2009 at 11:03 AM
    Mark (172), isn’t sea ice extent highly proportional/related to sea ice (volume). Like “extent” is partially defined by concentration. Though, maybe concentration is only loosely correlated to volume??

    No.
    It is not the same.
    Extent is not partially defined by concentration.
    Concentration is not correlated to volume.

    Comment by Nefastus — 8 Oct 2009 @ 11:40 AM

  189. My point is that if you’re smart but don’t use it, [edit]

    And bad arguments are [edit]

    [edit]

    A good argument well made, even if wrong, remains a good argument and helps learning.

    A bad argument, or a good one poorly one, even if right doesn’t.

    [editor-ok, that's enough of this particular thread]

    Comment by Mark — 8 Oct 2009 @ 11:43 AM

  190. 113.#79 Krog

    My interpretation based on your answer is that you don’t care about learning the answer to your questions… So why did you ask? Is it that:

    1. You like to ask questions you don’t want answers for?
    2. You are ignoring the facts?
    3. You like disrupting the thread?
    4. You like wasting peoples time?
    5. You are inconsiderate?
    6. You like seeing your words online?
    7. You are bored and have nothing better to do?

    You should read page for of the IPCC report as suggested. It’s only one page (actually about two paragraphs and a graphic with a description). But I guess two paragraphs are a bit much to ask you to read. Are you opposed to educating yourself and science?

    To compare ‘a page’ in a report to War and Peace… Hmmm… How moronic.

    BTW The answer is more simple than you think. Just add up the positive and negative numbers and their ranges that are contained in the two paragraphs.

    Or am I grossly misinterpreting that which you apparently infer/state in your post?

    Comment by John P. Reisman (OSS Foundation) — 7 October 2009 @ 7:59 AM
    Only #6 is correct.
    I meant no offense.
    I thought that my ? would get a simple answer.
    The idea of heat content being a more meaningfull metric than temp was brought up by another poster. It made sense to me.
    I clicked to the IPCC site, was overwhelmed. Not a scientist, don’t have time to research the answer to my dumb questions.
    I learned that even simple questions have complicated answers.
    Was attempting humor, yes you may have “grossly misinterpreted” my post.
    Krog

    Comment by Krog — 8 Oct 2009 @ 12:41 PM

  191. Mark, but if a couple of grams of butter melted and spread on its own (lets assume on a non-absorbing surface), wouldn’t its extent be far less than 500 grams doing the same thing?

    Comment by Rod B — 8 Oct 2009 @ 1:24 PM

  192. Nefastus (188), the Colo ice monitoring site defines “extent” as sea H2O where the ice concentration exceeds 15%. …as near as I understand it. Is this wrong? Or am I interpreting it incorrectly?

    Comment by Rod B — 8 Oct 2009 @ 1:33 PM

  193. The evidence I have seen from DMI doesn’t suggest any warming over the last ten years.. it shows arctic tempreatures more or less at the 1958 – 2008 mean apart from 2007 and 2008. Wher do they get their temperature data from? Anybody know?

    Comment by colin Aldridge — 8 Oct 2009 @ 1:34 PM

  194. Paul Clark #175: would that be http://data.giss.nasa.gov/modelforce/strataer/ ?
    Found by backtracking from tamino to GISS data file to GISS documentation… a useful skill to acquire ;-)

    Comment by Martin Vermeer — 8 Oct 2009 @ 1:45 PM

  195. Re Jim Steele 178, 180 (aside from others’ responses) -

    There might be a conflation between natural variability and internal variability. Internal variability is a subset of natural variability. The other part of natural variability is forced variability. Obviously, if there is/were a significant unreversed change in natural forcings (which can be in the form of a change in temporal averages), the climatic response to that will be tend to be something more than fluctuation about a the same constant mean (if the time scales of positive and negative feedbacks are different in the right way, though, a sharp change in forcing could cause a large initial change that then decays with time – for example, ice sheet growth following continental drift, then followed by CO2 increase due to reduced chemical weathering (very long timescales, there)).

    Internal variability is unforced variability. Some form(s?) are approximately like internal clocks – for example, the QBO, which is a quasi-cyclical reversal of winds in the equatorial stratosphere that is caused by processes (vertical propagation of equatorial Rossby-gravity and Kelvin waves, etc, followed by wind-shear selected absorption of wave momentum fluxes.) that are not organized by any cause with such a periodicity. Other forms are more irregular (ENSO, NAM and SAM, sudden stratospheric warmings, shorter term weather). Consider small-scale vertical convection – radiative forcing tends to reduce static stability; sufficient perturbations can force lifting to the point where latent heating powers the updrafts. This is highly episodic over small time intervals but tends to approach an average rate as determined by energy supply, etc. ENSO variability is an example where a sea surface temperature anomaly drives or reinforces atmospheric circulation change (via latent heat releases) which itself can reinforce the sea surface temperature anomaly. It is also possible for redistributions of momentum (wind) to be self-reinforcing by shaping the momentum transports by waves/eddies. Droughts tend to sustain themselves. But even where longevity is not inherently finite to the subcomponent of the system, external perturbations (from other parts of the system) (which can be expected to come along with some probability distribution in time) can knock the weather patterns out of these conditions just as they can initiate them – if they can’t, then the climate would sooner or later settle into such a state for the long term and so it would no longer be a form of internal variability.

    Comment by Patrick 027 — 8 Oct 2009 @ 2:01 PM

  196. Jim Steele #178: the distinction you’re after is between unforced and forced natural variability.
    Unforced NV looks random, sort-of, but is the result of the chaotic nature of the climate system; deterministic in principle, but ill-predictable. Some of it has a name, like el Nino; much of it has not. We have a pretty good idea how much variance there is here; this is the “real” NV that explains why model runs differ from each other and from the real world, and why temps don’t climb from year to year even if forcings do.
    Forced NV is greenhouse gasses, solar, Milankovich, etc. Fully deterministic and a very mixed bag.
    BTW I don’t think you’re being quite realistic about the kind of effect a quiet Sun could produce. The numbers I’ve seen are a few tenths of a degree max, meaning at best a postponement of the ongoing warming (at 0.2 degrees/decade!), hardly cooling.

    Comment by Martin Vermeer — 8 Oct 2009 @ 2:04 PM

  197. 191 Rod asks, ” if a couple of grams of butter melted and spread on its own (lets assume on a non-absorbing surface), wouldn’t its extent be far less than 500 grams doing the same thing?”

    Not if the “butter” (ice) is constrained to a “bowl” (the arctic basin). Then, the volume will drop tremendously before the extent changes much at all.

    Comment by RichardC — 8 Oct 2009 @ 2:08 PM

  198. > if a couple of grams of butter melted and spread on its own
    > (lets assume on a non-absorbing surface)….

    Analogy FAIL

    Sea ice — water ice. Open water can produce more sea ice. Solid ice can split up and blow around and make more open water.

    Comment by Hank Roberts — 8 Oct 2009 @ 2:09 PM

  199. Lets have fun with the skeptical argument, otherwise all people of reason would despair at the waste of time spent to deal with it!

    THe Northeast passage appears still open!

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

    for the Cryosphere today critics:

    http://manati.orbit.nesdis.noaa.gov/ice_image21/D09280.NHEAVEH.GIF

    this to compared with the skeptics favorite year:

    http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/ARCHIVE/19981008.png

    See a resemblance? Are you satisfied of the cooling effect over the Polar ice cap?

    HAHA do you want me entertained further with your comedy?

    Comment by wayne davidson — 8 Oct 2009 @ 2:15 PM

  200. Mark, but if a couple of grams of butter melted and spread on its own (lets assume on a non-absorbing surface), wouldn’t its extent be far less than 500 grams doing the same thing?

    But one of the key attributes of sea ice is that it’s not melted …

    And the way sea ice extent is measured by NSIDC and IJIS, just over 15% coverage by thin ice counts the same as if it were 100% covered by thick multiyear ice.

    Comment by dhogaza — 8 Oct 2009 @ 2:18 PM

  201. 200: Absolutely.

    Bob bob, even though there is not butter on every square mm of my bread, that slice of bread is 100% buttered.

    And that is the measure of sea ice extent.

    Comment by Mark — 8 Oct 2009 @ 2:36 PM

  202. “Mark, but if a couple of grams of butter melted and spread on its own (lets assume on a non-absorbing surface), wouldn’t its extent be far less than 500 grams doing the same thing?”

    Rod, who said anything about spreading the 500g?

    Talking merely about extent of butter, a couple of grammes can be spread over a much greater area than the top of the tub containing 500g.

    Therefore, if you were to look merely at the raw “how much area does this cover” (as you wish to maintain) you would come to the conclusion that a couple of grammes of butter was more butter than 500g.

    Are you seriously saying that is wrong?

    No.

    So extent is not equal to volume.

    You have to know the depth too.

    Comment by Mark — 8 Oct 2009 @ 2:42 PM

  203. Krog, 190 if the postulate #6 from Hank is correct, then there’s no need to actually answer your question: answering doesn’t make your original query any more published.

    Comment by Mark — 8 Oct 2009 @ 2:45 PM

  204. “for example, ice sheet growth following continental drift, then followed by …”

    Bad example – obviously the time scale for continental drift is not short, even compared to chemical weathering.

    My other point was that internal variability could conceivably redistribute or change clouds, humidity, temperature distributions, relative to top-of-atmosphere insolation and relative to surface types and relative to each other, so as to cause changes not just in regional radiative fluxes but on the global short-time average, and do so in such a way as to cause a net gain or loss in heat. It is entirely possible, however, that this does nothing to help sustain anomalous conditions if the anomalous conditions did not originally involve a global average temperature change. Anyway, there is ultimately a tendency for the system to get pulled back from anomalous conditions… (to be continued.)

    Comment by Patrick 027 — 8 Oct 2009 @ 2:52 PM

  205. OT, but this looks to be potentially a pretty significant paleo study:

    http://www.sciencedaily.com/releases/2009/10/091008152242.htm

    Comment by Kevin McKinney — 8 Oct 2009 @ 2:57 PM

  206. “It is noteworthy in this context that despite the record low in the brightness of the sun over the past three years…”

    Do you mean solar radiation instead of ‘brightness’? Aren’t they different measures? Has anyone argued that climate might have been altered by changes in sun ‘brightness’?

    Comment by CM — 8 Oct 2009 @ 2:58 PM

  207. CM, did you click the link behind the words? Why quibble over definitions? That leads only to long digression.

    Brightness is in the eye, or instrument, of the beholder.

    http://www.pmodwrc.ch/pmod.php?topic=tsi/composite/SolarConstant

    It’s hypertext — words that are clickable links refer to the paper.

    Comment by Hank Roberts — 8 Oct 2009 @ 3:26 PM

  208. Hi, CM (#206), I also go by ‘CM’ and have come to comment here rather frequently over the past year. If you’re going to stick around, I’d like to ask you to please consider using a different tag, or there’ll be lots of confusion.

    Comment by CM — 8 Oct 2009 @ 3:26 PM

  209. #177 ‘Jim Eager (148), saying “we began burning fossil carbon fuels on an industrial scale in 1750″ is quite a stretch. While that is when the first coal was mined in the U.S. industrial scale use came almost 100 years later”. Well, maybe, but the industrial revolution didn’t begin in America.

    Comment by David Horton — 8 Oct 2009 @ 4:04 PM

  210. I was just thinking how this sort of resembles stock market charts. The advice they always give is to invest for the long haul, bec the overall trend is up….until, of course, global warming finally pushes the stock market and the economy itself into a never-ending nose-dive, esp if we do nada to mitigate it.

    Comment by Lynn Vincentnathan — 8 Oct 2009 @ 4:18 PM

  211. #190 Krog

    Then my apologies. Certainly it is difficult to read inflection and tone in the written word. At the same time, going to the IPCC site might seem daunting, but you were given a link to a PDF and a reference to a single page. That is easy to look at.

    ‘Simple’ is a relative term of course but the page 4 in the report is pretty straight forward. The positive forcing of Co2 is about 1.6 W/m2 and the other GHG’s are around 1 W/m2.

    Of course there are other effects that are positive and some negatives. Total positive estimated forcing around 1.6 W/m2.

    That is about 1.6 above natural cycle by my estimations. And yes, there are error bars too.

    It’s a challenge to figure it out the communications are getting better, but it is still a challenge.

    Comment by John P. Reisman (OSS Foundation) — 8 Oct 2009 @ 4:21 PM

  212. Hank, Again I am not sure what you are asking for. My reference to increased southern hemisphere was linked to a graph produced by Cryosphere. Why didn’t the url http://arctic.atmos.uiuc.edu/cryosphere” point you” to the source. Or did you visit their website and you are now suggesting their data is wrong or just opinion?

    regards the Skeptical Science article referenced by dhogaza. I agree with the the context of the article that the proof of a continued global warming trend must be measured in terms of heat content. I was surprised to see his graph of a continued uptrend that was rather sharp. His data was based on a couple of estimations that were published but I have seen other published articles stating very different trends.

    I confess that I have only read the abstracts and have not purchased any of these articles but in the paper “Ocean heat content and Earth’s radiation imbalance” by David H. Douglassa and Robert S. Knox the abstract reads “Earth’s radiation imbalance is determined from ocean heat content data and compared with results of direct measurements. Distinct time intervals of alternating positive and negative values are found: 1960–mid-1970s (−0.15), mid-1970s–2000 (+0.15), 2001–present (−0.2 W/m2), and are consistent with prior reports. These climate shifts limit climate predictability..”

    They are stating that there is a drop in heat content since 2001. Do people have links to the full article of this paper and the Skeptical Science reference so I can compare how these diverging measures of heat content were determined?

    Comment by Jim Steele — 8 Oct 2009 @ 4:27 PM

  213. Martin. I agree that your distinction makes the most sense. I hope in the future people are careful to distinguish between forced and unforced natural variation.

    Regards your final comment “BTW I don’t think you’re being quite realistic about the kind of effect a quiet Sun could produce. The numbers I’ve seen are a few tenths of a degree max, meaning at best a postponement of the ongoing warming (at 0.2 degrees/decade!), hardly cooling.”

    You may want to call it unrealistic, and perhaps it is, but still I think it is a valid hypothesis. It is simply based on correlations of temperatures and observed solar minimums. Given our present state of solar knowledge, calculations based on incomplete assumptions may be much less reliable than simple historic correlations, and thus those calculations may be equally unrealistic. We have gathered an immense body of solar data, but still the consensus was that this year we would witness one of the greatest sunspot years. But now we see we are in a major minimum approaching the Dalton and Maunder, and the observations completely contradict the scientific consensus.

    Comment by Jim Steele — 8 Oct 2009 @ 4:47 PM

  214. There’s another logical explanation for the current cooling, and that is that we are entering, or have entered the cool phase of the PDO cycle.
    Looking at a long term chart of temperatures, and overlaying it with a graph of the PDO cycles shows a very strong correlation between the two.
    We seem to have had three warm phases and two cool phases of the PDO, and if this cooling phase is typical, it will likely end around 2030, with temperatures about 0.8degC warmer than they were in 1880, and CO2 levels at around 420ppm.
    The fact that temperatures will be higher means that there is some forcing at play, but given that we will have had an even amount of cold and warm cycles, will that not mean that the forcings are less “forceful” than current thinking?

    Comment by Paul Hanlon — 8 Oct 2009 @ 6:06 PM

  215. very surprising article given all the attention that has been given to the idea the last decade has seen the world cooling.

    please explain how the ten year trend lines were calculated. Your average denier will look at the graph and say that you are ignoring the last couple of years.

    Comment by matthew — 8 Oct 2009 @ 6:49 PM

  216. So why hasn’t the jan-aug 2009 figure been included in the 10 year trend line? Perhaps it is because it is below the trend, and so tilts the line?

    Comment by nick — 8 Oct 2009 @ 7:04 PM

  217. please explain how the ten year trend lines were calculated. Your average denier will look at the graph and say that you are ignoring the last couple of years.

    It appears to end in 2008. 2009 isn’t over yet. Which “last couple of years” do you think have been ignored?

    Comment by dhogaza — 8 Oct 2009 @ 7:55 PM

  218. Sorry CM, am now using a different name.
    Hank, thanks for the response (#207). Someone on a forum I frequent (where digression is a specialty!) has questioned why the word ‘brightness’ was used. He states that ‘Visual brightness is a distinct and different measure from irradiance’. So I thought I’d ask if there was any reason for choosing ‘brightness’. From your response it appears there was no reason behind it. That’s all I was after, wasn’t attempting to say anyone was wrong or being misleading.

    Comment by KiwiCM — 8 Oct 2009 @ 8:23 PM

  219. re: #215 matthew
    So, please try post #138 an look at Figs 1 & 4.
    Those trendlines were computed using Excel SLOPE, using all the data up that point, an plotting the SLOPE at the *endpoint* of the period.

    Think of it is a plot of something like akin to a first derivative, and you need to pick exactly the right short intervals to get a negative first derivative, and if you use 30-year SLOPEs, you have to go back to 1975-ish to get even slightly negative slopes.

    To get flat temperatures, SLOPES have to stabilize at 0, to actually get cooling, they have to go negative.

    Comment by John Mashey — 8 Oct 2009 @ 8:41 PM

  220. Rod @177, it is not a stretch at all, you are merely being US-centric. The Industrial Revolution, which started in England, not in its colonies, is generally accepted as beginning circa 1750.

    Do you have any other nits to pick?

    Comment by Jim Eager — 8 Oct 2009 @ 8:57 PM

  221. Mr. Steele: Re ocean heat content (OHC)

    I refer you to the papers by Murphy et al. and Schuckmann et al (I really like the Murphy paper) referred to earlier on this thread. They demonstrate quite clearly that OHC is increasing. I quote from the Murphy paper:

    “Since 1950, only about 10 +/- 7 % of the of the forcing by greenhouse gases and solar radiation has gone into heating the Earth, primarily the oceans. About 20 +/- 9% has been balanced by increased outgoing radiation. About 20% of the forcing by greenhouse gases and solar radiation has been offset by volcanic aerosols. The remainder, about 50% has been balanced by the direct and indirect effects of anthropogenic aerosols.”

    And I note that para 40 refers to realclimate.org

    The oceans are absorbing heat at the rate of 1e22J/yr.

    Comment by sidd — 8 Oct 2009 @ 9:13 PM

  222. Jim Steele – “Given our present state of solar knowledge, calculations based on” … “We have gathered an immense body of solar data, but still the consensus was that this year we would witness one of the greatest sunspot years. But now we see we are in a major minimum approaching the Dalton and Maunder, and the observations completely contradict the scientific consensus.”

    My impression is that it is a lot easier to project the effects of solar, CO2, volcanic, etc, forcing on Earth’s climate than to forecast the internal variability of the sun.

    You have to be careful with those historical correlations, by the way. Some people might think that the correlation between temperature and CO2 is ‘The’ evidence for cause and effect. It is not; physics predicted such a relationship before it was ever observed. Physics also predicts a relatiohnship for solar forcing and climate, but aside from efficacy variations (see another recent comment of mine (~ week ago, try search)), the effect of the same magnitude of forcing would be the same change in climate, all other things being equal. Maybe there is some way in which climate is more sensitive to solar forcing, but there could also be some way in which it is less sensitive, … and the burden of proof is on that which is yet unsubstantiated; also, there may be evidence (?) against such sensitivity enhancement (or that would place an upper limit on it).

    Back to the correlation studies. We know that CO2 (along with glaciation itself and some other things) was likely a positive feedback in glacial-interglacial variations because there is no evidence of an externally-driven CO2 forcing, there is a lag time between climate and CO2 changes suggesting that climate acted on CO2 (although this may not be the case for temperature at some locations ??), there is strong persistent correlation of CO2 and climate, and orbital forcing seems a likely external forcing, and we know that CO2 is a greenhouse gas that would tend to cause global warming when increased or the reverse if reduced (as supported by further study of these time periods (how do you explain the full extent of the climate change) as well as other time periods in the distant past, the 20th century and afterward, other planets, and the physics).

    Correlation studies can be useful but you have to be careful about how you do it – simply looking at the amount of variation at different frequencies and ascribing all the variation in some band of frequencies to a forcing with a frequency within that band is likely to overestimate the amount of variation that can be attributed to such a forcing.

    —-

    so about the internal variability – vertical heat transport through the ocean can cause global surface and tropospheric temperature changes without radiative forcing. ENSO in particular is not just about horizontal rearrangements in temperature but also, in El Nino, about a pool of warm water spreading over a colder mass of water. There is a global average temperature increase with El Nino. The radiation feedback from the temperature increase …

    (note – this is the feedback that is often not identified as a climate feedback because, I would guess, it is so basic that it is taken as a given (not that it isn’t studied and calculated appropriately). This may lead to some confusion – when we say that the net feedback is positive, this does not include the radiative feedback directly to the temperature change with optical properties held fixed; if that were included, having any stable climate requires that the total feedback be negative. But it should be apparent that climatologists mean that the net feedback besides the – what I think we can call the blackbody radiation feedback (or maybe the Planck function feedback) – is not meant to be included – otherwise, it wouldn’t make sense to identify a climate sensitivity with zero feedback as being anything besides constant increase or decrease.)

    (Actually there is a temperature feedback wherein optical properties are temperature dependent for a given composition and physical phase, but that’s generally a small effect that can be ignored; the radiative feedbacks that are generally called feedbacks are due to changes in composition and physical state.)

    is a negative feedback that will then tend to cause the Climate system to lose heat. However, this is slowed (but not stopped) by positive feedbacks such as the water vapor feedback. It is not necessarily the same as the response to a non-ESNO global warming because of different spatial-temporal distributions, but … I have to take a break now.

    Comment by Patrick 027 — 8 Oct 2009 @ 9:23 PM

  223. Jim Steele: are you saying you found the material for your questions _at_ the Cryosphere site, or are you working from another site that mentioned it?

    When you have something mentioning a particular paper, look that up in Google Scholar, then look at citing papers and see what others have made of it in the actual journals.

    But also, the site-limited search approach can be useful (for any website):

    http://www.google.com/search?q=site%3Arealclimate.org+douglass+knox

    From there you can narrow your search, for example by searching for
    [
    which finds inline comments, for example this one summing up Douglass:

    http://www.realclimate.org/?comments_popup=595#comment-98036

    Comment by Hank Roberts — 8 Oct 2009 @ 10:05 PM

  224. #209, The (1st) Industrial Revolution in Britain started in the late 1700s though it was birthing before 1750. None-the-less its growth was rather slow and I still don’t think one can see “industrial scale” fossil fuel use until (beginning) mid-1800s.

    Comment by Rod B — 8 Oct 2009 @ 10:10 PM

  225. #220, I admitted it is a nit, and, no, I have no others. As a helpful suggestion (at no charge) though, I would offer that even nits should not be grossly misstated. They’re red meat for other skeptics not as objective as me.

    Comment by Rod B — 8 Oct 2009 @ 10:19 PM

  226. Re 150 John Mashey

    “Here’s a wish, for anyone out there that still writes serious code: it woudl be nice to have an interactive view of Figure 1 (which had both temperature and slopes), and had a slider bar that was the number of years.”

    Okay, I have written a Java applet that does that. It shows all the trends of whatever length you pick in the slider – essentially a visualisation of Robert Grumbine’s analysis. It shows quite nicely why shorter trends don’t mean that much.

    So, does somebody want to host it? Gavin?

    Comment by CTG — 8 Oct 2009 @ 10:28 PM

  227. Mark, et al, I didn’t say extent equals volume. I said (asked) it was proportional/related to volume. If your saying the 500 gram tub of butter does not spread at all then I agree its volume is much greater but extent much smaller than the spread out 2 grams. But I think the analogy does not apply to sea ice. Clearly on the forming side, sea ice is not going to form and build a big mesa-type structure with lots of volume but without any sea ice formation a meter or two from the precipice boundary of the ice mesa. It seems the volume will increase as the extent increases and vice versa. There is the possibility that melting might form a mesa, but I think that is so odd and the probability so remote to not even count.

    Comment by Rod B — 8 Oct 2009 @ 10:35 PM

  228. regards the Skeptical Science article referenced by dhogaza. I agree with the the context of the article that the proof of a continued global warming trend must be measured in terms of heat content. I was surprised to see his graph of a continued uptrend that was rather sharp. His data was based on a couple of estimations that were published but I have seen other published articles stating very different trends.

    Where, and how recent? Out-of-date Argo shallow-depth stuff later shown to be wrong, or what?

    Generally, the more recent a paper, the more likely it is that it’s incorporating more recent information on correcting calibration errors, etc.

    Comment by dhogaza — 8 Oct 2009 @ 11:03 PM

  229. Given our present state of solar knowledge, calculations based on incomplete assumptions may be much less reliable than simple historic correlations, and thus those calculations may be equally unrealistic. We have gathered an immense body of solar data, but still the consensus was that this year we would witness one of the greatest sunspot years. But now we see we are in a major minimum approaching the Dalton and Maunder, and the observations completely contradict the scientific consensus.

    And yet, September’s nearly as warm as September 1998 during a huge El Niño …

    If we’re to ponder the Maunder, we’re going to be pondering why it’s so much warmer this time ’round.

    Why do you think it would be?

    Comment by dhogaza — 8 Oct 2009 @ 11:05 PM

  230. So why hasn’t the jan-aug 2009 figure been included in the 10 year trend line? Perhaps it is because it is below the trend, and so tilts the line?

    Perhaps because they’re plotting annual data, and 2009 isn’t done yet?

    Comment by dhogaza — 8 Oct 2009 @ 11:07 PM

  231. But now we see we are in a major minimum approaching the Dalton and Maunder, and the observations completely contradict the scientific consensus.

    Oh, and BTW, regarding the solar cycle stuff, it’s pretty much out in the open that it’s not well understood and whatever predictions are made are pretty much WAGs. That’s the real scientific consensus.

    But even if the sun went cold tonight, out, snuffed, no energy output …

    You do realize that wouldn’t affect the fact that CO2 warms the planet or the feedback amplifications that follow?

    All these “it’s the sun, stupid!” miss exactly what they accuse climate scientists of missing – there are multiple factors that impact climate.

    You’re sounding more and more like an outright denialist the more you post.

    Comment by dhogaza — 8 Oct 2009 @ 11:15 PM

  232. Rod (177) Don’t forget that Europe was essentially deforested by the 18th century (all those sailing ships; charcoal for forges; wood for heating; etc). That’s one reason why coal mining took off in Britain and elsewhere about that time.

    Comment by William T — 8 Oct 2009 @ 11:41 PM

  233. So, including the blackbody/Planck function feedback, the climate is generally stable; to a first approximation, unforced variation tends to decay back to an equilibrium state. However, the equilibrium state could be described as a strange attractor – within limits, there are positive, negative, and ‘sideways’ feedbacks such that conditions fluctuate, but outside certain limits, the likelihood of an unforced fluctuation generally decays with greater magnitude. Also, it should be mentioned that the characteristics of these fluctuations – not the specific trajectory which never exactly repeats, but the patterns/textures that will appear similar among different sufficiently long time periods within the same long-term climate, are part of that climate, and can change with climate change.

    Unforced variations may change the global average surface and tropospheric temperatures by redistributing heat away or into those levels, to or from, for example (and necessarily if for significant time periods) the deep ocean. Radiative ‘thermal relaxation’ will tend to cause such a variation to decay with time, which interestingly implies that a time period dominated by El Ninos could actually produce some global cooling, as the surface warm water cools without compensating warming of deep water, which may resurface. Assuming finite climate sensitivity to forcing and similar feedbacks to unforced variation, this will tend to be slowed but not stopped by positive feedbacks such as water vapor (just as positive feedbacks would tend to enlarge climate sensitivity to forcing, but not to infinity, assuming all other feedbacks combined are not a net positive larger than the blackbody/planck function feedback).

    However, it isn’t obviously true that the global average feedbacks will be the same as they would to forced climate change, and it is possible to imagine that they are different;

    likewise internal variability without a global average change (after subtracting average seasonal and/or diurnal variations, etc, for the longer-time scale climatic state, depending on the time scales being dealt with) could concievably result in some global average radiative feedback (or for that matter, drive a net vertical transport of heat into or out of the ocean); this could happen because the radiative effects of local temperature variations depend on local clouds and humidity and any spatially-temporally varying greenhouse gases (and surface LW emissivity, though for some purposes that is approximated as being near 100 % and doesn’t generally vary much), the radiative effects of clouds and humidity depend on other clouds and humidity above or below, and temperature at the surface and in the atmosphere, and incident solar radiation and the angle of the sun, and the albedo of the underlying surface, etc. – and so on, and internal variability may involve some rearrangments that are of a different shape than the response to an external climate forcing.

    (BUT I’m not claiming to know any specifics beyond that; there may be arguments for expecting such differences to be limited – ie how likely or possible is it that all clouds would happend to be concentrated at high latitudes in winter, or that the poles would get warmer than the equator (obliquity as it is) – these things would require something quite exotic and unearthly. There will be physical-caused tendencies for clouds, temperature, humidity, surface type, etc, to correlate in various ways.)

    (Interesting point – if nothing else changed, keeping the average surface temperature the same while reducing variations in space and time would reduce average LW emission (by a small amount) and thus tend to cause a global average positive radiative feedback (by a small amount – in so far as the radiation emitted from the surface is concerned (setting the greenhouse effect aside), I estimated that the global annual average emitted radiation is the same as the radiation that would be emitted from a surface that is only about 1 K warmer than the average surface temperature, so it’s actually not that big of an effect).)

    But these feedbacks wouldn’t necessarily do anything to prolong the anomalous state and might in some cases act to reverse it.

    Anyway, the evidence is not in favor of a large part of the warming of the last century being caused by internal variability, even of the sort with global average radiative feedbacks. – In case you were wondering.

    Comment by Patrick 027 — 8 Oct 2009 @ 11:51 PM

  234. Now, can anyone help me with this?

    http://www.realclimate.org/index.php/archives/2009/10/a-warming-pause/comment-page-4/#comment-137713

    Comment by Patrick 027 — 8 Oct 2009 @ 11:57 PM

  235. Jim Steele: by 2030 we will have a transient warming of over 1C due to CO2 and its feedbacks alone… do you know the size of the LIA cooling?
    About Douglass and Knox, this is very fresh paper… you’ll have to wait how it holds up, but it contradicts the findings of others… read, e.g., here:
    http://earthobservatory.nasa.gov/Features/OceanCooling/ and refs therein.
    When you’re in this business, you get a certain feeling about what papers are worth, and I have this dark brown feeling about, e.g., the company Prof. Douglass keeps and the places he publishes: see http://www.pas.rochester.edu/~douglass/recent-publications.html No, it doesn’t prove anything. But life is short and it has been a useful heuristic for me.

    Comment by Martin Vermeer — 9 Oct 2009 @ 12:26 AM

  236. Stefan, I’m looking at http://data.giss.nasa.gov/gistemp/tabledata/GLB.Ts.txt and the global temperature anomalies given in that file are about 0.1 C greater than the points on your graph. What’s your baseline?

    Comment by llewelly — 9 Oct 2009 @ 12:48 AM

  237. #190 Krog

    Important of course to consider water (H2O) which accounts for about half the forcing (and is a variable gas). H2O can vary dramatically and is not well mixed in the atmosphere.

    The additional CO2, CH4, N2O and CFC’s tipped the balance. Now the oceans are warming and more moisture is evaporating and trending up, which is a critical feedback. The industrial GHG’s may have tipped the scale, but H2O, combined with the atmospheric lifetime of CO2 combines to create a positive feedback that, at this point, has risk written all over it.

    Once the cycle tips positive (which it has), it may be very hard, or possibly impossible to return to a manageable balance (equilibrium or reducing forcing). In the mean time, special interests are protecting their profit potentials not realizing that doing so has the potential to strongly degrade the entire global economy (monetary, biological, chemical) as it pertains to reliance of the human system and important species, in which case any profits they are chasing become increasingly meaningless anyway.

    The onus of action is on limiting CO2 to reduce potential future impacts and further exacerbation of the forcing feedbacks, while simultaneously working on other mitigation and adaptation strategies.

    If you want to see where this all can go, review this page (it’s a short read):

    http://www.ossfoundation.us/projects/environment/global-warming/summary-docs/2009-may-leading-edge

    Comment by John P. Reisman (OSS Foundation) — 9 Oct 2009 @ 2:57 AM

  238. Jim, I go into the solar argument here:

    http://BartonPaulLevenson.com/Solar.html

    Comment by Barton Paul Levenson — 9 Oct 2009 @ 4:16 AM

  239. #214 Paul Hanlon

    I don’t believe we know enough about the PDO to predict that it will remain cool for 30 years.

    Plus there is strong positive bias in the system (the combined effects of human caused GHG’s and albedo) which further complicates the potentials.

    In my opinion, anyone stating we will be in a negative PDO for 30 years is merely guessing.

    I sure wouldn’t bet on it ending in 2030.

    In reality, we don’t know when it will return to positive and for how long… unless of course someone can add to this and show where we now have a better handle on PDO fluctuation???

    Anyone?

    Comment by John P. Reisman (OSS Foundation) — 9 Oct 2009 @ 5:43 AM

  240. John P, something to clear up:

    Water vapour is quite well mixed, if constrained mainly to the troposphere if you consider its value by RH.

    Water vapour is quite variable if you consider its value by columnar weight.

    I bring this up because there was another discussion about the 80%RH figure in climate models and someone thought that this was a parameter just put in to make the model work, rather than an output.

    Water vapour’s effect as a GHG is based on total water content, not RH. So John is talking about total H2O content which is variable, not RH which is much less so.

    Comment by Mark — 9 Oct 2009 @ 5:56 AM

  241. #215 matthew

    Why might you, or anyone else, care about a couple of years (any couple of years) in the context of the clear long term climate trend:

    http://data.giss.nasa.gov/gistemp/graphs/Fig.A2.lrg.gif

    The last couple of years are inside natural variation, therefore they are not a part of the trend of the signal, but rather a result of the noise of natural variation.

    http://www.ossfoundation.us/projects/environment/global-warming/natural-variability

    We have the attribution on the signal.

    http://www.ossfoundation.us/projects/environment/global-warming/myths/images/climate-forcing/Radiative_Forcing_Components_IPCC_AR4.png/image_view_fullscreen

    So why do people keep insisting that the noise is more important than the signal?

    Why are you even bringing it up? Do you think natural variation is overriding the anthropogenic effect in the long term climate trend?

    Comment by John P. Reisman (OSS Foundation) — 9 Oct 2009 @ 5:58 AM

  242. #227 Mark

    Thank you.

    Comment by John P. Reisman (OSS Foundation) — 9 Oct 2009 @ 7:31 AM

  243. “http://data.giss.nasa.gov/gistemp/graphs/Fig.A2.lrg.gif

    The last couple of years are inside natural variation, therefore they are not a part of the trend of the signal, but rather a result of the noise of natural variation.”

    In fact, one should say that AGW is only really proven wrong when the temperature line gets to the level of the 1900′s.

    After all, you don’t decide that you’re looking at a simple harmonic oscillator because you see values going up quicker then slowing down (but still going up), do you.

    You wait for a cycle before saying there IS a cycle.

    At least if you’re a scientist you do.

    Comment by Mark — 9 Oct 2009 @ 8:01 AM

  244. RodB

    “Mark, et al, I didn’t say extent equals volume. I said (asked) it was proportional/related to volume. ”

    But it doesn’t.

    The proportion of butter spread on my slice of bread this morning to go on as eggy soldiers was much lower than the proportion of open butter surface on the tub of 500g of butter I took my spread from.

    If surface area was related to volume, this means the more surface area, the less volume.

    You aren’t saying that this is true.

    Are you?

    If you want to spread the 500g of butter and compare it to how far a couple of grammes spread, then to do the same area only comparison with ice records, you have to go back in time and spread all the ice from 1980 etc so that it is as thick as the ice is today.

    Got a handy time machine? And a really BIG shovel?

    Comment by Mark — 9 Oct 2009 @ 8:22 AM

  245. Rod, you’re trying to say that this equation I learned when I was about 8 is wrong:

    V=W x L X D

    and is instead

    V=W x L

    It isn’t.

    And you can’t say “but they are proportional” because that requires a constant of proportionality.

    DEPTH IS NOT A CONSTANT.

    Comment by Mark — 9 Oct 2009 @ 8:24 AM

  246. I think it would be more helpful if someone were to define “flat temperatures”. If one defines flat temperatures as an anomaly of 0.0 for 30 yrs, then the world will never see “flat temperatures”. What is a realistic expectation of flat temperatures… 0.0 +/- ?? for X number of years?

    Comment by G. Karst — 9 Oct 2009 @ 8:41 AM

  247. Regarding #226

    CTG, contact me (riley_4_prez … d.sparks.net). Let me know what you need and I can probably provide it.

    Comment by David Miller — 9 Oct 2009 @ 9:02 AM

  248. Mark:

    You seem to be saying that one dimension (depth) is more important than the other two (area). In general, ice volume varies with ice extent (ice melts from it’s edges, top, bottom and all around). There are papers that support this basic premise. You need to find them.

    Comment by G. Karst — 9 Oct 2009 @ 9:39 AM

  249. G Karst, a question that can only be answered by the negative:

    A six sided dice rolled 30 times will not show 0.0 difference from the calculated mean (3.5) in the mean values rolled. Neither if you rolled 100 times. Or a thousand.

    All you can say is “we are confident to [a certain confidence level] that this is a fair dice”.

    Perhaps it would be more helpful to explain what science you think will make the temperature flat and then ascertain what would show that that science is taking effect. And then give a confidence level to which you have found or rejected your science.

    Comment by Mark — 9 Oct 2009 @ 10:08 AM

  250. Rod @224, Newcomen invented his coal-fired steam engine in 1712 and it was widely employed to pump water from British coal and tin mines, which sounds like a purely industrial application to me, even if of limited scope. Watt’s improved steam engine was introduced in 1775, which rapidly enabled steam power to displace water power in industrial manufacturing on a wide scale well before the mid-1800s.

    I will agree that neither of these events support the oft-cited 1750 date, but the application and spread of steam power was in fact rapid and widespread, and pretty much all sources agree that it had reached critical mass by the 1830s-1840s with the adaptation of steam power to produce rotary motion. Use of fossil carbon fuels got it’s next significant boost with the 1858 introduction of the Bessemer process for making steel, btw.

    Comment by Jim Eager — 9 Oct 2009 @ 10:36 AM

  251. Re: #236 (Llewelly)

    The file GLB.Ts.txt is an average based on meteorological station data only. Stefan’s graph is from the global average based on both meteorological stations and sea surface temperatures; it corresponds to the file GLB.Ts+SST.txt.

    Comment by tamino — 9 Oct 2009 @ 10:44 AM

  252. Karst, look at an introductory statistics book. You haven’t understood how noisy data are worked with. How probable is the detection of a trend, either up or down? See Grumbine’s explanation at the high school level. Or this:
    http://www.stat.columbia.edu/~cook/movabletype/archives/2009/09/whats_the_diffe.html#comment-927483

    What you want is the ability to argue like a scientist, without doing the math.

    Comment by Hank Roberts — 9 Oct 2009 @ 11:06 AM

  253. RodB, you’re trying to use logic.
    In the real situation that would get you killed.
    This is a wonderful read, recommended:

    http://forums.steves-digicams.com/landscape-photos/139226-high-arctic-eskimo.html

    “If that wind ever shifts, to south strong wind, we have to run like heck to get out of here a.s.a.p. that means everything, everybody, off the ice. it takes 8 hours to set up that whaling camp correctly, It takes just 20 minutes to “Killigvuk” EVACUATE,… RUN…One huge mass panic of over 600 people… run for your lives because it is that sudden. Ice is headed our way and it will run right over everything in its path. This advancing ice will pile up into gigantic piles.”

    At least, look at the one picture: http://majikimaje.com/images/ICE.jpg

    Comment by Hank Roberts — 9 Oct 2009 @ 11:12 AM

  254. “Mark:

    You seem to be saying that one dimension (depth) is more important than the other two (area).”

    You seem to believe that depth doesn’t exist.

    Without depth, the volume of ANY surface is zero.

    Comment by Mark — 9 Oct 2009 @ 11:31 AM

  255. “In general, ice volume varies with ice extent”

    In general, ice volume varies with depth.

    Thousands of experiments have shown this.

    So why do you ignore it?

    Comment by Mark — 9 Oct 2009 @ 11:34 AM

  256. You know, this ignorance of the variation of ice volume with ice depth is an astounding contrast to the complaints from many people made about how tree growth depends on lots of other things and so why is it assumed that it varies with CO2.

    Strange how those people aren’t complaining at Bob bob’s and Karst’s avoidance that volume depends on depth.

    Comment by Mark — 9 Oct 2009 @ 11:36 AM

  257. re #113 and your comments:

    “We have gathered an immense body of solar data, but still the consensus was that this year we would witness one of the greatest sunspot years. But now we see we are in a major minimum approaching the Dalton and Maunder, and the observations completely contradict the scientific consensus.”

    That’s simply wrong on several levels Jim Steele. What “consensus” about solar cycle sunspots are you talking about!? There are very few groups that make solar cycle predictions, and by and large they produce a broad range of forecasts since this is a poorly predictable phenomenon. Here’s the NOAA prediction for solar cycle 24 from 2007, for example:

    http://www.swpc.noaa.gov/SolarCycle/SC24/index.html

    They didn’t predicted that “we would witness one of the greatest sunspot years” at all. The high prediction was similar to solar cycle 23 which was actually a relatively low sunspot cycle in the context of the last 50-odd years; the low prediction was somewhat lower. The updated prediction (May 2009) forecasts a solar cycle near the low prediction of 2007.

    We’re not “in a major minimum approaching the Dalton and Maunder” at all. What lends you to think so?

    Let’s say anyway, that we were to go into a “Maunder minimum” solar state. The “immense body of solar data” that you speak of indicates that this will produce something like 0.2 oC of cooling relative to a more “normal” evolution of solar cycles (e.g. that we’ve had during the last couple of hundred years):

    e.g. see Y.-M. Wang, J. L. Lean and N. R. Sheeley, Jr. (2005)Modeling the Sun’s Magnetic Field and Irradiance since 1713 Astrophysical J. 625 522-538

    http://www.iop.org/EJ/abstract/0004-637X/625/1/522

    and: Lean, J. L., and D. H. Rind (2008), How natural and anthropogenic influences alter global and regional surface temperatures: 1889 to 2006 Geophys. Res. Lett., 35, L18701

    http://www.agu.org/pubs/crossref/2008/2008GL034864.shtml

    Comment by chris — 9 Oct 2009 @ 11:38 AM

  258. Hank Roberts #252

    So your definition for flat Ts is: Gosh darn, there ain’t no such thang.

    Interesting, especially as it is the subject under discussion.

    Comment by G. Karst — 9 Oct 2009 @ 12:02 PM

  259. re: #226 CTG
    Thanks. If RC doesn’t want it, maybe Grumbine would?

    Comment by John Mashey — 9 Oct 2009 @ 12:35 PM

  260. CTG (#226) – I’d be happy to host also – apsmith at altenergyaction.org

    Comment by Arthur Smith — 9 Oct 2009 @ 1:22 PM

  261. I’ll repeat my OT comment:

    OT but … I wanted to send a friend the web address for the “FAQ on climate models” parts I and II; I found part II but part I is missing – there is this website:
    http://www.realclimate.org/index.php/archives/2008/11/faq-on-climate-models/
    but it is not what it should be. Where did it go?

    Please, help. Thank you.

    Comment by Patrick 027 — 9 Oct 2009 @ 1:28 PM

  262. Thank you, tamino. I feel like I should have known that.

    Comment by llewelly — 9 Oct 2009 @ 1:52 PM

  263. “So your definition for flat Ts is: Gosh darn, there ain’t no such thang.”
    Yup.

    Show me something flat.

    Anything.

    But it has to be absolutely flat.

    Find one thing flat.

    Comment by Mark — 9 Oct 2009 @ 2:02 PM

  264. Patrick027 #261

    The link your provide IS part 1. without the number in the title or?

    Comment by Sekerob — 9 Oct 2009 @ 2:18 PM

  265. Since people have been talking a bit about sensitivity and feedbacks, I just finished a post on the subject. I tried to treat the topic somewhat comprehensively while still keeping it within the limits of blog post length. Hopefully it will re-iterate or expand upon Patrick’s and other posting or clarify some matters.

    Comment by Chris Colose — 9 Oct 2009 @ 2:36 PM

  266. Re 264 – thanks; the link I gave is the link given to the previous post (part I, though it may not have been called part I before there was a part II) at the part II post (or put another way, within the part II there is a link to part I; that is the link). It looks like the comments may be the comments to the original, but the post itself is just a few words in what I’m guessing is a Scandinavian language, with a link to another website that I’m guessing is in the same language. I remember the original post – it was very good, and I wish I could find it.

    Comment by Patrick 027 — 9 Oct 2009 @ 3:23 PM

  267. Thanks John, and the others who have offered. Bob Grumbine is kindly going to put it on his blog, so we’ll add a link when it is up.

    Comment by CTG — 9 Oct 2009 @ 3:41 PM

  268. re the various comments on CO2 versus time – I downloaded data on CO2 from the following 2 sites

    ftp://ftp.ncdc.noaa.gov/pub/data/paleo/icecore/antarctica/
    http://chartsgraphs.wordpress.com/2009/08/13/excel-chart-misrepresents-co2-temperature-relationship/

    plugged it into a spreadsheet (Appleworks – kinda primitive, but presented in the spirit of open data & code)
    and (X-Y) plotted the data. The results (CO2 over 500, 2000, and 10k years) can be seen at
    http://www.imagenerd.com/uploads/co2vstime-hbg1b.jpg

    Regardless of the advent of the industrial revolution fueled consumption of fossil fuels, atmospheric CO2 concentrations didn’t really take off ’til after 1800.

    Comment by Brian Dodge — 9 Oct 2009 @ 5:55 PM

  269. Applause to John Mashey for wishing out loud, CTG for encoding the wish, and Robert Grumbine for hosting. Wonderful idea.

    I hope you also send it to the MIT climate people: http://web.mit.edu/globalchange/www/climate.html

    You could add a “create long flat stretches” for Karst — nah, too wishful.

    Comment by Hank Roberts — 9 Oct 2009 @ 8:01 PM

  270. Chris #257. Your comments suggest that you are most likely a newbie to to looking at solar cycles. And if my my use of the word “consensus” bothers you then your beef is with the panel that releases a statement they all the “CONSENSUS STATEMENT OF THE SOLAR CYCLE 24 PREDICTION PANEL”

    My assertion was simply that despite our knowledge about the sun we in fact no very little, and therefore calculations about changes in solar output should have very low confidence levels. Granted the predictions vary quite a bit, I never said otherwise. But that diversity of predictions simply supports my contention that we still know very little. If some one predicted the final score of a baseball game before the game started but then changed their prediction each inning as the game progressed, you probably would not put much stock in the robustness of their predictive skills. Yet that is exactly what has the panel does. And no solar scientist I know (I am sure there may be a few) feels comfortable with their understanding to predict sunspots further out than the next cycle.

    Granted it was not the consensus prediction but NASA released the following statement suggesting an above average cycle 24. I will call 2006 the first inning of the game:

    “March 10, 2006: It’s official: Solar minimum has arrived. Sunspots have all but vanished. Solar flares are nonexistent. The sun is utterly quiet. Like the quiet before a storm. This week researchers announced that a storm is coming–the most intense solar maximum in fifty years. The prediction comes from a team led by Mausumi Dikpati of the National Center for Atmospheric Research (NCAR). “The next sunspot cycle will be 30% to 50% stronger than the previous one,” she says. If correct, the years ahead could produce a burst of solar activity second only to the historic Solar Max of 1958.
    “History shows that big sunspot cycles ‘ramp up’ faster than small ones,” he says. “I expect to see the first sunspots of the next cycle appear in late 2006 or 2007—and Solar Max to be underway by 2010 or 2011.” ”

    http://science.nasa.gov/headlines/y2006/10mar_stormwarning.htm?list791008

    Notice the prediction that solar max will occur in 2010-2011. Then check whatever source makes you happy and you will realize we are still in a minimum. Although predictions varied about the strength of the cycle, every prediction I read thought max would happen around 2010-2011.

    As the game progressed the panel then issued

    CONSENSUS STATEMENT OF THE SOLAR CYCLE 24 PREDICTION PANEL
    March 20, 2007
    The Solar Cycle 24 Prediction Panel anticipates the solar minimum marking the onset of Cycle 24 will occur in March, 2008 (±6 months). The panel reached this conclusion due to the absence of expected signatures of minimum-like conditions on the Sun at the time of the panel meeting in March, 2007:

    http://www.swpc.noaa.gov/SolarCycle/SC24/Statement_01.html

    So if you found anything in my statement confusing again your beef would be with the panel or NASA. In May 2006 they said minimum was “officially” here. Now in 2007 they predict minimum will occur in March 2008 =/- 6 months. Well minimum is still here in late 2009.

    Now in 2009 just 3 years after NASA released the statement (see above) predicting “the most intense solar maximum in fifty years.” the are now predicting “he lowest of any cycle since 1928″

    May 29, 2009: An international panel of experts led by NOAA and sponsored by NASA has released a new prediction for the next solar cycle. Solar Cycle 24 will peak, they say, in May 2013 with a below-average number of sunspots.
    “If our prediction is correct, Solar Cycle 24 will have a peak sunspot number of 90, the lowest of any cycle since 1928 when Solar Cycle 16 peaked at 78,” says panel chairman Doug Biesecker of the NOAA Space Weather Prediction Center.

    So Chris I have to use your words that your response is “wrong on so many levels”.

    So I will restate that science does not know enough to robustly predict and calculate the effect of changes in solar cycles and their effects on the climate. So until our skill improves historical correlations suggest extended solar minimums produce several decades of cooling.

    Comment by Jim Steele — 9 Oct 2009 @ 9:46 PM

  271. “My assertion was simply that despite our knowledge about the sun we in fact no very little, and therefore calculations about changes in solar output should have very low confidence levels”

    However, the solar cycle can’t be too different from what we see since we have instruments that measure the solar output.

    Again we have someone say “we know very little” when we know quite a lot:

    Its age
    Its weight
    Its composition
    Its size
    Its position in the galaxy
    Its heliopause, heliosheath etc
    How it will die
    Its power output
    Its past power output
    Its variability in power
    Its magnetic strength

    and so on

    Actually, we know very little about you.

    This doesn’t mean you don’t exist and it doesn’t mean that the climate models, not knowing a lot about you, therefore must be wrong.

    Comment by Mark — 10 Oct 2009 @ 4:39 AM

  272. Mark:

    Find one thing flat.

    Beer left on a table with the cap off?

    Comment by Barton Paul Levenson — 10 Oct 2009 @ 4:55 AM

  273. Jim Steele, your many words are pretty much wasted: chris said that solar events are “poorly predictable,” and you’ve really said no more than that.

    Well, that is, up until your last paragraph, where you abruptly change the subject to the effects of solar cycle changes on climate. Then, without support, you assert the insufficiency of our knowledge.

    But we are not, in fact, limited to “historical correlations.” (And a good thing, too, since the “historical atmosphere” no longer exists, having been replaced by a new higher GHG model.)

    Comment by Kevin McKinney — 10 Oct 2009 @ 5:00 AM

  274. Jim Steele,
    You are discussing solar conditions as if they were normal, when the last solar minimum was the longest in ~100 years. The “consensus” you refer to was quite weak and was hardly a consensus in the scientific sense. I think you are attributing a level of accuracy to solar forecasting that just isn’t there yet. This isn’t too surprising, given the Sun is a magnetohydrodynamic mystery. We don’t even have 4-pi steradian coverage of our great plasmic meatball in the sky, and helioseismology–which probably offers the best hope we have for illuminating solar dynamics==is a technique in its infancy.
    This is largely irrelevant to long-term climate dynamics, as even the most intense deviations of solar behavior from the mean last decades, and the contributions of CO2 last centuries to millennia.

    Comment by Ray Ladbury — 10 Oct 2009 @ 8:57 AM

  275. Jim Steele #270, you may restate the same misconception as often as you like, it still is a misconception.
    Yes, the predictors of Solar activity update their predictions as time moves forward — just like weather predictors do, and for pretty much the same reason: it is an inherenty ill-predictable thing. That doesn’t mean that the physics is not understood. To the contrary: it’s the physics that tells us that it’s ill predictable…
    I asked you if you knew how deep the cooling was during the Little Ice Age / Maunder minimum. Assuming (debatable) that this was caused by the quiet Sun, it would give you an upper bound on the cooling to be expected. The number is the same 0.2C chris quotes above from the literature — little comfort when CO2 is piling up that same amount every decade.

    Comment by Martin Vermeer — 10 Oct 2009 @ 9:05 AM

  276. My assertion was simply that despite our knowledge about the sun we in fact no very little, and therefore calculations about changes in solar output should have very low confidence levels. Granted the predictions vary quite a bit, I never said otherwise. But that diversity of predictions simply supports my contention that we still know very little.

    Don’t conflate the problem of not being able to accurately predict the end of the current solar cycle (for instance) with the problem of being able to predict the range of TSI variance due to solar cycles.

    (I’m going to break this into parts because the spam filter hates me for some reason)

    Comment by dhogaza — 10 Oct 2009 @ 9:07 AM

  277. OK onwards oh spam filter:

    To user your baseball analogy, predicting who will win and by what score isn’t possible at the beginning of a game.

    However I can predict with 100% confidence that the two scores will each be >= 0 at the end of the game, and I can predict with 100% confidence that the sum of the two scores will be > 0.

    Comment by dhogaza — 10 Oct 2009 @ 9:10 AM

  278. And lastly (it probably thought my further discussion of the baseball analogy was gambling-related?)

    So until our skill improves historical correlations suggest extended solar minimums produce several decades of cooling.

    Yet the current minimum sees us with the warmest decade in the instrumental record …

    Comment by dhogaza — 10 Oct 2009 @ 9:10 AM

  279. Last try …

    Baseball: Most likely that sum (of the two scores) will fall on a normal distribution centered around “a few runs”.

    Since I’m not actually doing an analysis I won’t attempt to define “a few” more precisely, but with the data at hand one could, though the center of the distribution may be different year-to-year. For instance, the end of the dead-ball era led to higher scores.

    For climate predictions, being able to predict the exact start and end of solar cycles isn’t really important, it’s being able to pin down the range of variability of TSI over time.

    Comment by dhogaza — 10 Oct 2009 @ 9:12 AM

  280. Brian Dodge @268 wrote: “atmospheric CO2 concentrations didn’t really take off ’til after 1800.”

    Which pretty much agrees with what I wrote @250, no?.

    But on your long scale 10k plot, note that post-glacial natural CO2 levels peak just under 270 ppmv ~8.5-8k ago, just before the Holocene Climate Optimum, and then begin a shallow 3000 year decline to ~260 ppmv as northern hemisphere summer solar insolation decreases, only to reverse and begin an even longer shallow 5000 year rise to ~280 ppmv at the beginning of the industrial revolution (1750, 1800+, or whenever you choose to mark it).

    William Ruddiman contends that this is the initial anthropogenic greenhouse signature produced by the development of agriculture, through land clearance and removal of a carbon sink and release of stored carbon by burning wood for cooking and heating fuel, and rice cultivation and an increase in methane emissions from paddies, which are engineered wetlands, with that CH4 oxidizing to CO2 in the atmosphere. Ruddiman’s hypothesis is that this anthropogenic forcing became strong enough to first offset and then reverse orbital insolation forcing as long as 5000-6000 years ago.

    Comment by Jim Eager — 10 Oct 2009 @ 9:19 AM

  281. ” Find one thing flat.

    Beer left on a table with the cap off?”

    You’ll given him ideas.

    Anyway, the beer’s never flat.

    I drank it…

    Comment by Mark — 10 Oct 2009 @ 11:35 AM

  282. Arctic ice could be part of the issue. “Extra” ice melt which reveals open water centers in the late summer and fall, when the sun is quickly declining. Yes, open water absorbs more heat from what little sun there is, but it also emits more heat to space. As open water remains further into winter, the energy budget changes towards cooling of the planet. This seems to be a natural “speed bump” which has to be overcome in order for warming to continue. Thus, it is possible that we’re just in a temporary and necessary period which will last until ice melt gets earlier in the season, enough to counteract this negative feedback. My guess is that once the multi-year ice is essentially gone, we’ll head down the far side of the speed bump and enter a warmer world.

    Comment by RichardC — 10 Oct 2009 @ 12:31 PM

  283. Mark, this is becoming surreal, though in an odd reverse sort of way I think you answered my question. No one has said that volume does not depend on depth. It most certainly does… along with Length and Width — the latter two (strangely???) directly tied to extent — of either butter or ice. No matter how pedantically you slice it, and ignoring the improbable freaks of nature, the greater the extent of sea ice, the greater the volume of the sea ice riding the extent. Though the volume grows faster than the extent because of the buildup of the thickness (depth — TA DA!) as you back away from the extent edge. (Though not always smoothly as Hank points out). That’s just how ice, which has no concept of butter knives and bread slices, forms. Also things can be proportional without having a specific and unique constant of proportionality.

    Jeeeze.

    Comment by Rod B — 10 Oct 2009 @ 12:52 PM

  284. Mark says, “Anyway, the beer’s never flat. I drank it…”

    Oh, that explains a lot…

    Comment by Ray Ladbury — 10 Oct 2009 @ 2:17 PM

  285. Jim Steele, You seem to be falling victim to the “we don’t know everything, so we know nothing” fallacy–a favorite of creationists, denialists and other anti-science types. Don’t go there. First, you need to understand what is unknown, but then you need to understand if it is relevant for the phenomena at hand.

    Comment by Ray Ladbury — 10 Oct 2009 @ 2:24 PM

  286. Rod it is area rather than extent which important, for example a 12.5×12.5 km pixel which is deemed to be sea ice could have as little as 15% ice coverage whereas the area would be 23.5 compared with 156.25 (for 100% coverage). Also the ice thickness has been steadily decreasing so the same extent/area from year to year represents less ice than before.

    Comment by Phil. Felton — 10 Oct 2009 @ 2:25 PM

  287. “No one has said that volume does not depend on depth”

    You’ce consistently ignored it though.

    Area doesn’t give you volume.

    “along with Length and Width — the latter two (strangely???) ”

    But you are using area. not length and width.

    “Though the volume grows faster than the extent because of the buildup of the thickness (depth — TA DA!)”

    Nope. Not necessarily.

    Please prove.

    Here’s a very simple example: homogeneous ice can reduce its volume drastically by thinning. If the ice is a flat rectangular block like a domino, then the volume drop is more dependent on the thinness of the ice not its extent (it melts from the top, which reduces depth, not area).

    “That’s just how ice, which has no concept of butter knives and bread slices, forms.”

    No, wrong again. Prove that the sea ice has done this.

    Here’s how this is trivially wrong: when ice breaks up, there is more water per ice area. But as long as it is more than 15% ice, it remains counted as ice extent.

    You can easily therefore get a fivefold difference in ice extent without changing volume on iota.

    1) Shepherd all the ice together so that there is no gap between each lump of ice.

    Measure the extent.

    2) Cut each square meter of ice top surface up and place them so that there is one cube of ice in each 5m square area.

    Measure the extent.

    Both count as “ice extent” but #2 has a figure 5 times that of #1 yet no change in volume.

    Now when panice breaks up, what happens?

    Something like what happens in #2.

    So how can you have measured ice total when all you’ve measured is the ice extent?

    You cannot.

    Hence “try again”: your figures are not comparable since you have ignored depth.

    You can afford to miss depth out no more than you can afford to miss surface area. But in the graph pointed to, that isn’t what’s being measured.

    So it’s not even surface area you’re trying to make out to be ice volume.

    Please try again.

    Comment by Mark — 10 Oct 2009 @ 3:37 PM

  288. Rod, you’re using logic again, and it’s still failing you.

    You write
    > the volume grows faster than the extent … That’s just how ice … forms

    You can’t generalize like this unless your only aim is to prolong a digression for the amusement of whoever’s encouraging it. Please stop.

    Large expanse of open water in the fall, as freezing starts.
    Large amount of pancake ice, agglomerating into larger sheets with time.
    Typical extensive first year sheets of sea ice, all very thin.

    Seriously, man, go back ’round to the stables and count the teeth in the horse, don’t tell us what logic says must be the right number.

    Comment by Hank Roberts — 10 Oct 2009 @ 3:37 PM

  289. “Also things can be proportional without having a specific and unique constant of proportionality. ”

    It does have to be constant, though.

    If it changes, then it’s not a proportionality.

    So, has the depth remained unchanged over the years?

    No.

    Sheesh.

    Comment by Mark — 10 Oct 2009 @ 3:38 PM

  290. Hello,

    The BBC has just published a really dreadful article on this theme, full of errors, misrepresentations, sceptical voices given equal weight to mainstream science… the author seems to have picked most of it up from sceptical web sites on the internet.

    Any chance of somebody getting in touch with the BBC and tell them how dreadful the article is?

    http://news.bbc.co.uk/2/hi/science/nature/8299079.stm

    Comment by Donald — 10 Oct 2009 @ 3:50 PM

  291. No matter how pedantically you slice it, and ignoring the improbable freaks of nature, the greater the extent of sea ice, the greater the volume of the sea ice riding the extent.

    Well, except NASA satellite observations support the following claim:

    Even in years when the overall extent of sea ice remains stable or grows slightly, the thickness and volume of the ice cover is continuing to decline

    This includes 2008 vs. 2007 – minimum extent was above the record 2007 level, yet 2000 cubic kilometers were lost.

    Comment by dhogaza — 10 Oct 2009 @ 4:47 PM

  292. #237 JPR
    Thank you for the info & URL. It is bookmarked.
    I that the CO2 problem will be on the way to solution when a consensus forms to tax oil, gas, & coal at the drillhead and mine. Then let the market do what it does best.

    Comment by Krog — 10 Oct 2009 @ 5:20 PM

  293. #289 I have just put the following into the “contact us” section on the BBC web site. Other RCers might like to try their own versions.

    “The article by Paul Hudson”What happened to global warming?” is unworthy of the BBC. To answer Mr Hudson’s rhetorical question, it is getting worse. Can we expect further in the series of meaningless “balance”? “What happened to evolution?” “What happened to relativity?” “What happened to the germ theory of disease?” “What happened to atomic theory?” Does Mr Hudson want to try his hand at any of these? Come on, lift your game BBC, this rubbish could have appeared on any of the notorious denialist sites around the world. We expect better of you.”

    Comment by David Horton — 10 Oct 2009 @ 6:17 PM

  294. Greenman3610 has created a video that starts with video of Latif speaking, and follows with Beck, Hannity, and so on’s wild distortions. Highly recommended! http://www.youtube.com/user/greenman3610#p/a

    Comment by Tom Dayton — 10 Oct 2009 @ 6:17 PM

  295. Tom Dayton says, “Greenman3610 has created a video that starts with video of Latif speaking, and follows with Beck, Hannity, and so on’s wild distortions. Highly recommended!”

    You supplying the anti-emetics and the special glasses to protect us from the 3rd degree stupidity burns as we watch geniuses like this?

    Comment by Ray Ladbury — 10 Oct 2009 @ 8:40 PM

  296. From the BBC article.

    “Piers Corbyn….claims that solar charged particles impact us far more than is currently accepted, so much so he says that they are almost entirely responsible for what happens to global temperatures.

    He is so excited by what he has discovered that he plans to tell the international scientific community at a conference in London at the end of the month.

    If proved correct, this could revolutionise the whole subject.”

    Any thoughts on what this “discovery” could be?

    [Response: Corbyn has been hyping a supposed solar based forecasting system that he has never described for years. James Annan had a whole series of posts on how it doesn't produce good forecasts, so this discovery is very unlikely to punt to anything. Significant black mark against the Beeb's coverage. - gavin]

    Comment by Wolff — 10 Oct 2009 @ 10:14 PM

  297. #283 Rod Black

    In addition to Ray and Mark, and Hanks comments…

    It is clear in the observations that ice extent increases in width before the multiyear (thickness/volume) builds.

    I just added some new images (more to come). Some of these graphs may provide perspective:

    http://www.ossfoundation.us/projects/environment/global-warming/myths/images/arctic

    First, ice extent grows, then, if things stay cold enough, it is added to and 1st yr ice becomes 2nd year ice, and so on.

    If conditions don’t warrant multiyear ice growth, then the thickness does not build. The general (non linear) trend is down for ice mass/volume/thickness.

    Comment by John P. Reisman (OSS Foundation) — 11 Oct 2009 @ 2:36 AM

  298. Thank you ray, for that meaningless, but heartfelt comment.

    Comment by Mark — 11 Oct 2009 @ 3:37 AM

  299. Will the cooling phase of the Pacific Oscillation be a big drag on the warming trend?

    Comment by dave p — 11 Oct 2009 @ 12:03 PM

  300. 291 dhogaza said, “NASA satellite observations support the following claim:
    Even in years when the overall extent of sea ice remains stable or grows slightly, the thickness and volume of the ice cover is continuing to decline
    This includes 2008 vs. 2007 – minimum extent was above the record 2007 level, yet 2000 cubic kilometers were lost.”

    Yes, but other data doesn’t always agree. According to the polar 5 survey, ice thickened somewhat. Now, polar 5 was a linear and limited survey, but its technique seems more reliable.
    http://www.sciencecentric.com/news/article.php?q=09050433-research-aircraft-polar-5-finishes-arctic-expedition

    Comment by RichardC — 11 Oct 2009 @ 12:48 PM

  301. September (month end averages) NSIDC (sea ice extent)

    2007 Northern Hemisphere = 4.3 million sq km
    2008 Northern Hemisphere = 4.7 million sq km
    2009 Northern Hemisphere = 5.4 million sq km

    ftp://sidads.colorado.edu//DATASETS/NOAA/G02135/Sep/N_200709_extn.png
    ftp://sidads.colorado.edu//DATASETS/NOAA/G02135/Sep/N_200809_extn.png
    ftp://sidads.colorado.edu//DATASETS/NOAA/G02135/Sep/N_200909_extn.png

    Please explain how this ice is getting thinner. Remember these are extent minimum averages.

    [Response: Since 'extent' is not 'thickness' it's hard to see your numbers justify any statement at all. However, if you are interested in thickness, you should look at thickness - i.e. ICEsat thickness estimates. - gavin]

    Comment by G. Karst — 11 Oct 2009 @ 3:22 PM

  302. What was the thickness of the ice, Karst?

    Volume = Area x DEPTH.

    Comment by Mark — 11 Oct 2009 @ 4:07 PM

  303. “According to the polar 5 survey, ice thickened somewhat. Now, polar 5 was a linear and limited survey,”

    It was also (IIRC) countered by even more limited but even more rigorously correct land survey:

    http://news.bbc.co.uk/1/hi/sci/tech/7897392.stm

    It’s a lot easier to say the thickness is “however long this rod had to go down before it left the ice” than to work it out by the differential reflections of radar echoes.

    Comment by Mark — 11 Oct 2009 @ 4:10 PM

  304. Gavin:

    I believe it was Mark’s concern over thickness (not mine). I merely provided minimum extent data. The question merely followed and is as yet unanswered.

    Comment by G. Karst — 11 Oct 2009 @ 4:43 PM

  305. Mark:

    Older ice is thicker ice, in general. When last years ice doesn’t melt, it becomes older, thicker, 2yr. ice and on and on. What the minimum (september) averages show is ice getting older. That is all I have to say in this matter.

    Comment by G. Karst — 11 Oct 2009 @ 4:59 PM

  306. Life is just a bowl of cherries — as selected by Karst:

    September (month end averages) NSIDC (sea ice extent)
    2007 Northern Hemisphere = 4.3 million sq km
    2008 Northern Hemisphere = 4.7 million sq km
    2009 Northern Hemisphere = 5.4 million sq km

    From the same source Karst used:
    http://nsidc.org/data/seaice_index/images/n_plot_tmb.png

    Those last three dots — the ones Karst selected — are cherrypicked.

    Comment by Hank Roberts — 11 Oct 2009 @ 6:04 PM

  307. This has gone from surreal to ridiculous and on its way to sublime.

    Mark said sea ice extent is not related to volume. I questioned that and said I thought extent is probably related/proportional to volume (implying directly, as opposed to inversely.) Mark replied I was wrong because V=L*W*D, and some other stuff. Then a bunch weighed in, most, it seems, insinuating or implying I am wrong, a couple insinuating I might be correct.

    I’m not using democracy to determine physics; but I’m simply curious and would be appreciative of everyone’s position. Post a reply with a single letter for the multiple choice answers if you’re inclined.

    A. Extent is directly related to volume.
    B. Extent is usually directly related to volume
    C. Extent is usually not related to volume.
    D. Extent is not related to volume.
    E. I’m unable to properly choose one of the above.

    Then I’m inclined to follow Hank’s suggestion and quit talking about it.

    Comment by Rod B — 11 Oct 2009 @ 6:20 PM

  308. Rod B … this statement by you:

    No matter how pedantically you slice it, and ignoring the improbable freaks of nature, the greater the extent of sea ice, the greater the volume of the sea ice riding the extent.

    Has been falsified by observation. So why are you asking us questions?

    My answer, BTW, would be “F. It’s more complex than the simple picture you’re trying to paint”.

    Comment by dhogaza — 11 Oct 2009 @ 6:57 PM

  309. F. Fail: arguing with Mark pleases him and goes on as long as you’re willing;
    and
    G. Gavin gave the appropriate link, where it’s explained — look DOWN the page, til you get to the answer.

    Comment by Hank Roberts — 11 Oct 2009 @ 7:04 PM

  310. Somewhat off-topic, but “… the rate of climate change over the next century could be higher than previously anticipated …”:
    Nitrogen Cycle: Key Ingredient In Climate Model Refines Global Predictions
    http://www.sciencedaily.com/releases/2009/10/091009204032.htm

    Comment by David B. Benson — 11 Oct 2009 @ 7:10 PM

  311. #305 Rod Black

    Hmm…, sort of reminds me of word play

    http://www.realclimate.org/index.php/archives/2007/10/did-you-stop-beating-your-wife-yes-no/

    http://uscentrist.org/news/2007/word-play/

    http://www.realclimate.org/index.php/archives/2007/11/did-we-call-it-or-what/

    Rod, think of it this way: extent is the book cover, volume is the thickness and/or content of the book.

    As per your statement:

    No matter how pedantically you slice it, and ignoring the improbable freaks of nature, the greater the extent of sea ice, the greater the volume of the sea ice riding the extent.

    1. What does sea ice riding the extent mean, or have to do with anything, and if it does have something to do with something, in what reality?
    2. Extent is not volume.
    3. Read 2 again.

    Comment by John P. Reisman (OSS Foundation) — 11 Oct 2009 @ 8:03 PM

  312. September 2009, should be in the warming “pause” zone?
    Fun to be so accurate with predictions when September is #1 in temperature world wide

    http://data.giss.nasa.gov/gistemp/tabledata/GLB.Ts.txt

    Can some contrarian x’plain this?

    I need a bit of Sunday night comedy….

    Comment by wayne davidson — 11 Oct 2009 @ 10:19 PM

  313. 305 Rod, extent is NOT related to volume because ice melts ONLY in the thickness dimension. Your visualization of ice being a big lump with a standard shape and defined edges is just plain wrong. The ice is fragmented and the Arctic ocean is a bowl. Thus, volume will decrease tremendously before any significant change in extent is noted. The ice just gets thinner and more spread out. That’s what happened over the last 30 years or so. The thickness decreased by 50% or so over the last 5 years alone! Thickness has to drop to zero to affect extent. Take a bowl of water, add some big ice cubes, and agitate. The extent of ice in your bowl will be essentially unchanged even as 90% of the ice’s volume melts. Only after the ice has fragmented and spread out does extent start to drop appreciably. You can see this in action on any lake. The ice cover’s extent stays near 100%, then near 100%, then near 100%, then suddenly it’s near 0%. Again, ice ONLY melts in the thickness dimension.

    Comment by RichardC — 11 Oct 2009 @ 10:29 PM

  314. 310
    David B. Benson says:
    11 October 2009 at 7:10 PM

    “Somewhat off-topic, but “… the rate of climate change over the next century could be higher than previously anticipated …”:”

    I have lost count of the number of times I have seen this or similar statements. Do not people who propogate these statements realise that it is like crying wolf? The average person in the street will start to ignore them and regard them for what they are: Scaremongering.

    Comment by Richard Steckis — 11 Oct 2009 @ 11:09 PM

  315. Rod B, do you know the definition of ‘extent’? If you do, you can trivially answer your own question. If not, read up. In neither case bother the rest of us.

    Comment by Martin Vermeer — 11 Oct 2009 @ 11:35 PM

  316. This “extent vs volume” argument is ridiculous. Surely those claiming that greater extent means greater volume can see how silly they are being? I’m not a scientist (surprise!) but even I can see how silly it is.

    My attempt at a basic analogy to show why the argument is silly:

    Take a 1m x 1m x 1m block of ice – a volume of 1m^3. The top surface area is thus 1m^2. Now take that block and cut it horizontally into 10cm deep slabs, then arrange those slabs side by side. You’ll end up with say a 5m x 2m x 10cm slab of ice, giving a top surface area of 10m^2. The volume is still 1m^3 however.

    So now we have ice that can occupy a surface area of 1m^2 or 10m^2 without any change in volume. Extent is not “area”, but “area containing at least 15% ice”, so lets arrange those slabs so there is one 1m^2 slab of ice in every 2m^2 area of floor. Each 2m^2 has more than 15% ice cover and as such counts. Now our 1m^2 block of ice can have an extent of 40m^2, and this is without any change in volume of the ice.

    So, from this mental experiment we can conclude that volume is totally independent of extent as the same volume of ice can represent many different “extents” depending on how that volume of ice is divided up, and different volumes can represent the same extent depending on how the volume is arranged spatially.

    Basically, there are three different terms in use here “area”, “extent” and “volume” all of which are related to each other but not proportional. Greater extent does NOT always mean greater volume. In fact it is possible to have greater extent and LESS volume. In my example, simply take each clab and cut it again so it is now only 5cm deep and Discard the rest. We now have half as much volume occupying 40m^2 compared to a 1m x 1m x 1m block occupying 2m^2 area of floor.

    To really settle this, split the 1m^3 block of ice up into small enough blocks spread over a large enough area that no single 1m^2 of floor area contains more than 15% ice coverage. TADA! 0m^2 ice extent without any change in ice volume!

    Comment by Karmakaze — 11 Oct 2009 @ 11:50 PM

  317. RichardC – Water and snow at the same temperature will emit the same radiant energy – NO wait, I think snow is actually closer to being a perfect blackbody, so snow should emit more radiation.

    Solar heating will raise the temperatue of the water but by a small amount because of heat capacity. That is a large amount of heat which must be lost before and during freezing. This keeps temperature warmer during the fall/winter, which will tend to increase radiation to space, but that is what happens everywhere when the temperature increases (with modulation by varying water vapor, clouds, vertical distribution of temperature increase, etc.), which is why the climate doesn’t simply change without end in response to a (change in) forcing but instead tends to reach a new equilibrium where fluxes are balanced over time, provided the positive feedback is not too large.

    ——–

    PS I still need help with this:

    OT but … I wanted to send a friend the web address for the “FAQ on climate models” parts I and II; I found part II but part I is missing – there is this website:
    http://www.realclimate.org/index.php/archives/2008/11/faq-on-climate-models/
    but it is not what it should be. Where did it go?

    Please, help. Thank you.

    Comment by Patrick 027 — 12 Oct 2009 @ 12:07 AM

  318. Here’s the problem and we all know it. If there is a cooling trend, even if it’s only small, relative one, that will be enough for the professional deniers to scream that “it’s all a HOAX!” and further delay any mitigation efforts. I mean, look how difficult it’s been to get ANYTHING at all substantial done about it up to now even in the face of obviously increasing temperatures.

    I’ll tell ya, I don’t hold much hope out for anything real EVER happening with regard to climate change amelioration.

    Comment by Ron R. — 12 Oct 2009 @ 1:54 AM

  319. “F. Fail: arguing with Mark pleases him and goes on as long as you’re willing;”

    F- Epic Fail: I hate terrible arguments. They piss me off.

    Thank you so VERY much Hank, for that leap to a conclusion. I take it that since you’re still arguing with Rod that global warming is good that you too live to argue and get your jollies from it..?

    Comment by Mark — 12 Oct 2009 @ 3:04 AM

  320. “Mark said sea ice extent is not related to volume.”

    U: Unmarked.

    Super fail.

    I said that sea ice volume isn’t proportional on sea ice area.

    Funny how you miss that out of your “exhaustive” list of possibilities.

    Comment by Mark — 12 Oct 2009 @ 3:05 AM

  321. “Older ice is thicker ice, in general.”

    True.

    “When last years ice doesn’t melt, it becomes older, thicker, 2yr. ice and on and on.”

    True.

    ” What the minimum (september) averages show is ice getting older”

    False. It won’t be older until next year.

    ” That is all I have to say in this matter.”

    Based on past actions, no.

    You’ll continue to parrot the same old snake oil until the sea ice minimum reaches 0. Then you’ll probably go on about how sea ice is mending each winter because it’s coming back.

    Comment by Mark — 12 Oct 2009 @ 3:10 AM

  322. One question comes to mind regarding this. During the melt process of the sea ice it develops cracks within itself, how much can an 1km2 fresh and solid ice expand during this process? It actually turns whiter during the process (if its not snow covered), thus changing the albedo, the air streams above it, and the movements of ice flows (though mainly they are due currents) somewhat. Does this have an effect large enough to explain my failed guess at lablemmings? Well now there’s two queestions, the other was meant to be rhetorical, you decide which one.

    Comment by jyyh — 12 Oct 2009 @ 6:56 AM

  323. “Here’s the problem and we all know it. If there is a cooling trend, even if it’s only small, relative one, that will be enough for the professional deniers to scream that “it’s all a HOAX!” and further delay any mitigation efforts.”

    Ron R, that’s not the problem: the data WILL show that. Because reality IS doing that.

    The problem is that deniers are entirely credulous when it comes to anything that might mean there’s no AGW.

    That’s the sole problem.

    E.g. if RodB were as skeptical of his arguments as he is of the IPCC’s we’d have a lot less noise on the boards.

    Comment by Mark — 12 Oct 2009 @ 9:05 AM

  324. I have lost count of the number of times I have seen this or similar statements. Do not people who propogate these statements realise that it is like crying wolf? The average person in the street will start to ignore them and regard them for what they are: Scaremongering.

    “Scaremongering” is a strange word for a self-proclaimed scientist to use in regard to published research.

    Comment by dhogaza — 12 Oct 2009 @ 9:22 AM

  325. Well here is an intersting post that suggests that the main post here is based on cherry-picked data. http://masterresource.org/?p=5240 . It summarizes in an easy to understand manner the data for all major temperature indexes and their trends for a a variety of periods over the last twenty years or so.

    [Response: Vaguely ok, but he has failed to take the clear auto-correlation in the monthly data series into account and so his statements about significance are all biased to be over-definitive. - gavin]

    Comment by PaulD — 12 Oct 2009 @ 9:53 AM

  326. #314 Richard Steckis

    So are you saying that the US Department of Energy, The Oak Ridge National Laboratory, The National Oceanographic Atmospheric Administration, The National Center for Atmospheric Research and the involved Universities are scare mongering?

    Comment by John P. Reisman (OSS Foundation) — 12 Oct 2009 @ 10:10 AM

  327. dhogaza, sorry to violate my inclination right off the bat, but I’m curious. As a general rule does sea ice with an extent of 1,000,000 sq km have less ice (volume) than that with an extent of, say, 800,000 sq km? Or even 990,000 sq km?

    Comment by Rod B — 12 Oct 2009 @ 10:23 AM

  328. 317 Patrick said, “Water and snow at the same temperature will emit the same radiant energy – NO wait, I think snow is actually closer to being a perfect blackbody, so snow should emit more radiation.”

    I believe the primary difference is convection. Water convects while ice and snow don’t. Thus, open water will lose far more heat to space than water covered by ice. Igloos use the same physics to keep occupants warm.

    Comment by RichardC — 12 Oct 2009 @ 10:27 AM

  329. RichardC (313), interesting sensible assessment. But one anomaly: why does the Arctic sea ice extent retreat? Why not stay constant until the thickness all over and all at once reaches zero, and the extent in turn goes to zero like your lake example?

    Comment by Rod B — 12 Oct 2009 @ 10:38 AM

  330. Karmakaze (316), is that a reasonable facsimile of how Arctic sea ice actually forms?

    Comment by Rod B — 12 Oct 2009 @ 10:43 AM

  331. RodB, various people have pointed you to various resources on the web, for instance NSIDC.

    Please quit asking people to do your homework for you.

    Comment by dhogaza — 12 Oct 2009 @ 11:46 AM

  332. “As a general rule does sea ice with an extent of 1,000,000 sq km have less ice (volume) than that with an extent of, say, 800,000 sq km? Or even 990,000 sq km?”

    Why did the change occur?

    If it occurred because of panice breakup, then the extent is greater but the volume smaller.

    Comment by Mark — 12 Oct 2009 @ 12:13 PM

  333. In the general case.

    Comment by Mark — 12 Oct 2009 @ 12:13 PM

  334. Rod B says:
    12 October 2009 at 10:38 AM
    RichardC (313), interesting sensible assessment. But one anomaly: why does the Arctic sea ice extent retreat? Why not stay constant until the thickness all over and all at once reaches zero, and the extent in turn goes to zero like your lake example?

    Edges, wind, currents and inhomogeneity of thickness.

    Comment by Phil. Felton — 12 Oct 2009 @ 12:45 PM

  335. Which is the taller man?

    one who is 10st 8 and one who is 11st 0.

    ?

    Comment by Mark — 12 Oct 2009 @ 1:20 PM

  336. Maybe the problem with sea ice is that people are thinking of the tendency for plastic deformation under weight – any thickness variation in ice will tend to drive flow towards a state of constant thickness, in which case at equilibrium the extent = area = volume/thickness (within a given isolated body of water)… Of course, sea ice is not generally thick enough for flow under it’s own weight to be a big factor, right? – regardless of that, there’s breaking up, variations in ocean currents and wind, precipitation, air temperature, water temperature, and so such an isostatic equilibrium doesn’t play much of a role. As opposed to Snowball Earth conditions where there may have been a general flow to the equator…

    Comment by Patrick 027 — 12 Oct 2009 @ 1:50 PM

  337. Sea ice isn’t given the chance to rest to deform either, Patrick.

    Comment by Mark — 12 Oct 2009 @ 3:01 PM

  338. @Rod B

    “is that a reasonable facsimile of how Arctic sea ice actually forms?”

    To be honest, I have no idea. Actually not true – I have an idea but I don’t have complete confidence in it.

    What I do know is there is one aspect of say Arctic sea ice that is pretty close to what I’m talking about and that is the breakup of shelves into icebergs. That scenario is essentially the same as my idea of having a 5m x 2m x 10cm sheet of contiguous ice be broken up into smaller bits and spread around the ‘room’. When the sheets break up they don’t just sit there, they cast hundreds or thousands of icebergs adrift on the currents, increasing the extent of THAT ice sheet.

    It appears that you are assuming the ice melts in place, and are ignoring the iceberg formation that goes on.

    Comment by Karmakaze — 12 Oct 2009 @ 3:07 PM

  339. My last comment was poorly written, in that it may have seemed that I was trying to imply that volume and area would vary together instead of area and extent being constant – neither is of course true. It is understandable why a person might expect some correlation and I would expect some tendency – if it is cold enough to get ice to freeze to a certain thickness within a certain time then it seems likely the temperature must be cold enough to freeze sea water within some area surrounding that point, since horizontal temperature gradients are finite, but of course, winds and currents can act to pile up or disperse ice; snow can fall on top of ice and accumulate and if anything this would happen more at warmer temperatures below freezing (even if above freezing for sea ice). And there’s salinity variations, etc. Also I used the term isostatic equilibrium but of course sea ice is just about always in isostatic equilibrium with water (except where shear stresses are supported to spread out variations in pressure), just not in gravitational equilibrium.

    Comment by Patrick 027 — 12 Oct 2009 @ 3:15 PM

  340. “I believe the primary difference is convection. Water convects ”

    Yes, especially when there is wind-driven (or other) mixing, the surface temperature is dropping (down to 4 deg C for fresh water, lower for sea water) and phase changes concentrate salinity.

    That adds to the heat capacity available to the sea surface to moderate temperatures while heat is added or removed. The extra heat released in winter, up to the point at which ice forms and thickens, is still related to if not the same as the extra heat that was absorbed in summer after the point when the ice thinned and melted.

    Comment by Patrick 027 — 12 Oct 2009 @ 3:22 PM

  341. Richard Steckis (314) — Did you actually read the science article? Did you understand it? Looks to me to be another accelerating feedback.

    Another which IPCC AR4 did not, it seems, consider.

    Comment by David B. Benson — 12 Oct 2009 @ 5:18 PM

  342. 341
    David B. Benson says:
    12 October 2009 at 5:18 PM

    “Richard Steckis (314) — Did you actually read the science article? Did you understand it? Looks to me to be another accelerating feedback.

    Another which IPCC AR4 did not, it seems, consider.”

    David. It seems to me that none of these accelerating feedbacks have actually accelerated into REALITY. That is what I am trying to get at. Scaremongering is scaremongering wherever it is published.

    Comment by Richard Steckis — 12 Oct 2009 @ 10:58 PM

  343. David,

    One thing I have to agree with in the study is the need to incorporate human land use change into the climate models. I have always argued that it is in land use changes that the greatest human impacts on climate are to be found. Forget about CO2, it is too minor (and relies on an overwhelming impact of negative compared with positive feedbacks which is a ridiculous concept). It is incorporating areas such as land use change, biotic feedbacks and forcings, geologic and cosmic feedbacks and forcings that will allow the models to more accurately represent the climate system.

    [Response: Land use changes are used in climate models and give a negative forcing (i.e slightly cooling the planet) (Hansen et al, 2005;2007). You were saying?- gavin]

    Having said that. Once, just once I would like to see when a new parameter is incorporated into a model, it shows a NOT AS BAD AS WE FEARED outcome. That would make them more believable in a real world.

    Comment by Richard Steckis — 12 Oct 2009 @ 11:15 PM

  344. “Sea ice isn’t given the chance to rest to deform either, Patrick.”

    That’s what I said :)

    Comment by Patrick 027 — 13 Oct 2009 @ 12:09 AM

  345. “David. It seems to me that none of these accelerating feedbacks have actually accelerated into REALITY.”

    Rather like the “we’re on a cooling phase” hasn’t actually accelerated into REALITY.

    Comment by Mark — 13 Oct 2009 @ 4:37 AM

  346. Can someone tell me what has happened to Gistemp since 2002?
    http://woodfortrees.org/plot/gistemp/from:2002/plot/gistemp/from:2002/trend

    [Response: Seems to be fixed now. - gavin]

    Comment by Steve — 13 Oct 2009 @ 5:37 AM

  347. Richard Steckis, you seem to be saying that you will not believe the models until they begin to confirm your wishful thinking.

    Comment by Ron Taylor — 13 Oct 2009 @ 8:19 AM

  348. re:343

    “Once, just once I would like to see when a new parameter is incorporated into a model, it shows a NOT AS BAD AS WE FEARED outcome.”

    I imagine your counter-part on Rapa Nui saying the same thing.

    Me, I fear what happens when the tundra starts to put more carbon into the atmosphere than we’re capable of sequestering. When does that happen? At 2C of total warming? Isn’t that 40 years from now? Do you think we’re capable of acting decisively?

    Comment by Jeffrey Davis — 13 Oct 2009 @ 9:11 AM

  349. Steve, when you select 2002 to present, that range just happens to start with the 2002 unusually warm year, and end with the 2008 low number plus a few months of 2009. You’ve fooled yourself there. Use a longer time span for meaningful global temperature trends.

    http://scienceblogs.com/stoat/2007/05/the_significance_of_5_year_tre.php#

    Comment by Hank Roberts — 13 Oct 2009 @ 9:15 AM

  350. Richard Steckis, you seem to be saying that you will not believe the models until they begin to confirm your wishful thinking.

    Yeah, despite having said this:

    Once, just once I would like to see when a new parameter is incorporated into a model, it shows a NOT AS BAD AS WE FEARED outcome.

    you can bet he won’t like this, by Gavin:

    Land use changes are used in climate models and give a negative forcing

    since he fervently believes this:

    I have always argued that it is in land use changes that the greatest human impacts on climate are to be found.

    And I love the chutzpah of this:

    Forget about CO2, it is too minor

    There we go. All you climate scientists can go home, now, Richard Steckis has spoken!

    Comment by dhogaza — 13 Oct 2009 @ 9:17 AM

  351. “Steve, when you select 2002 to present, that range just happens to start with the 2002 unusually warm year, and end with the 2008 low number plus a few months of 2009. You’ve fooled yourself there. Use a longer time span for meaningful global temperature trends.”

    Or, better, don’t use the difference between two temperatures.

    Use proper grown-up statistics, not what you’d been taught in junior school.

    Comment by Mark — 13 Oct 2009 @ 10:29 AM

  352. Gavin #346, that’s terrible cherry picking, but it did make me laugh.

    Comment by Steve — 13 Oct 2009 @ 10:29 AM

  353. With regard to comment #290 regarding the sub-standard bbc piece by “climate correspondent” Paul Hudson, it would be useful for those who are displeased to communicate your concerns to BBC’s Online editor Jim Todd (jim.todd@bbc.co.uk).

    Comment by group — 13 Oct 2009 @ 11:47 AM

  354. Gavin says:

    “Response: Land use changes are used in climate models and give a negative forcing (i.e slightly cooling the planet) (Hansen et al, 2005;2007). You were saying?- gavin”

    You state Hansen et al 2005; 2007. Could you please provide the full references. I have serious doubts as the veracity of the claim that human land use changes are a negative feedback to the climate system.

    [Response: What are your serious doubts based on? The most important impact is clearance of forests for cropland which has an albedo effect (crops are more reflective), roughness effect and impacts evapotranspiration. The Hansen papers are here and here. - gavin]

    To Ron Taylor: No. I do not wish the models to fit my “pre-conceived” notions. Not what I said and not what I meant.

    To Dhogaza: Wrong as usual on all counts. I stand by my statement on the impacts of land use on climate change. You must understand Sir that climate change is NOT about just warming. It is about CHANGE which can be either warming or cooling. I repeat. I have always argued that it is in land use changes that the greatest human impacts on climate are to be found. No inconsistency here.

    Comment by Richard Steckis — 13 Oct 2009 @ 12:29 PM

  355. Supplementary:

    Climate change due to land use changes is not just about temperature (e.g. albedo). It is also about changes in precipitation patterns, wind changes and humidity changes due to evapotranspiration among others. I believe the picture is not as simple as using albedo as a primary guide to land use feedback. In fact in my searches, it seems that there is a robust research effort in trying to refine the feedback model of land use change on climate.

    Comment by Richard Steckis — 13 Oct 2009 @ 12:57 PM

  356. Group, the BBC are too scared of complaints to the government.

    Have a look at the eternal repeat of “There is no Greenhous Effect because the greenhouse stops convection” and “CO2 ***preceeds*** temperature rises” and all the same tired old cack.

    But they are left because Monckton complains about the BBC if such ideas are sent to moderation because they’re repeats.

    Comment by Mark — 13 Oct 2009 @ 1:04 PM

  357. 329 Rod asks, ” why does the Arctic sea ice extent retreat? Why not stay constant until the thickness all over and all at once reaches zero, and the extent in turn goes to zero like your lake example?”

    1. Ocean currents and wind break up the ice, pile it up, and otherwise de-homogenize the ice
    2. The Arctic Ocean is big. Weather conditions vary. Solar insolation varies.
    3. variations are amplified by salt-rejection. Ice that survives a summer will contain less salt, and so be more resistant to melting.
    4. Albedo changes also amplify differences. Open water increases local heating and so local melting.

    Your original premise can be restated as, “With no other knowledge except increases or decreases in extent from year to year, our best guess is that volume tends to increase or decrease along with extent, so extent is a reasonable proxy for volume.”

    That’s a quite reasonable first-order guess, but it is only a guess, and it is outdated. We have other knowledge now. There is no need to take a stab in the dark. 2008 had less ice than 2007. 2009 may have had less ice than 2008. (Anyone seen any figures yet? ) Are you suggesting we go back to the stab-in-the-dark guess technique instead of using up-to-date volume measurements?

    Comment by RichardC — 13 Oct 2009 @ 1:08 PM

  358. 343 Richard S said, “Having said that. Once, just once I would like to see when a new parameter is incorporated into a model, it shows a NOT AS BAD AS WE FEARED outcome. That would make them more believable in a real world.”

    About a year ago a study found that the deep permafrost wasn’t likely to melt for a long time (sorry, no cite) Another study earlier this year estimated that Greenland’s ice melt would have a fairly tame upper bound. There’s two examples. I’m sure there are more.

    You also noted that none of the scaremongering has come to pass. It seems you’re looking for proof in the form of a passed tipping point. You’ll believe WHEN the Arctic Ocean is ice-free in September. You’ll believe if clathrates and shallow permafrosts start belching more methane than mankind spews carbon dioxide. You’ll believe AFTER all the coral dies. Essentially, you’re looking for the wreckage which won’t exist until after the crash.

    Remember, the predictions we’ve heard over the last ten years have been laughable. Ice free Arctic Ocean in 2100?!? 20-40 cm of sea level rise by 2100?!! The reason things always seem to be “worse than they expected” is because most people suck at holistic predictions and scientists tend to be rediculously conservative.

    The field is advancing rapidly, so current estimates, using longer and more data sets and better understanding should produce more accurate results. people generally don’t like being proven wrong, so the tendency of bias would be for no change in projections. Either it’s a vast conspiracy to pull an April Fool’s joke on humanity – after all, what else would account for your description (scaremongering) — OR– things are actually worse than they thought.

    Comment by RichardC — 13 Oct 2009 @ 1:54 PM

  359. “I believe the picture is not as simple as using albedo as a primary guide to land use feedback.”

    Now show your reasoning.

    Belief isn’t enough. It certainly isn’t science.

    PS Will you now at the very least admit that you didn’t say that before? I.e. from an outsiders’ point of view it is pretty accurate to say that you are changing your arguments on the fly?

    This may not be what you are *doing*. but there’s absolutely no way for anyone other than yourself to know. Hence is an eminently practical assumption to make.

    Comment by Mark — 13 Oct 2009 @ 2:35 PM

  360. Let’s see, Richard Steckis claims:

    To Dhogaza: Wrong as usual on all counts.

    I had predicted:

    you can bet he won’t like this, by Gavin:

    Land use changes are used in climate models and give a negative forcing

    And what’s Richard’s response?

    You state Hansen et al 2005; 2007. Could you please provide the full references. I have serious doubts as the veracity of the claim that human land use changes are a negative feedback to the climate system.

    Just as predicted.

    And then he says:

    I stand by my statement on the impacts of land use on climate change. You must understand Sir that climate change is NOT about just warming. It is about CHANGE which can be either warming or cooling. I repeat. I have always argued that it is in land use changes that the greatest human impacts on climate are to be found. No inconsistency here.

    Except, of course, just befre you said that you don’t believe land use changes are a negative feedback.

    You’re transparent as glass, Steckis.

    RichardC: trying to educate him is a lost cause.

    Comment by dhogaza — 13 Oct 2009 @ 2:47 PM

  361. You write: “Every single year of this century (2001-2008) has been warmer than all years of the 20th Century except 1998 (which sticks out well above the trend line due to a strong El Niño event).”

    But Figure 1 shows a data point at 2005 that is above the one at 1998. Why does the graph differ from the statement?

    Comment by Bill Brent — 13 Oct 2009 @ 3:19 PM

  362. Bill Brent @361, the graph does not differ from the statement because 2005 is not “every single year of this century (2001-2008).”

    Read more carefully.

    Comment by Jim Eager — 13 Oct 2009 @ 3:42 PM

  363. #354 Richard Steckis

    “You always argued…”

    But who cares?

    When it comes to science, it doesn’t matter what you think. It doesn’t matter what I think. It only matters where the evidence trail takes us.

    If you have some groundbreaking theory, please do present it and get it peer reviewed and let’s see what the scientific community has to say, but if you are not going to do that, then how are you going to support your arrogant hubristic statements? And no, opinions are not support, and you should know better.

    Comment by John P. Reisman (OSS Foundation) — 13 Oct 2009 @ 4:40 PM

  364. RichardC (357), Your four rationales, though, would seem to support my assertion (which started out as a question…) which you paraphrased very well — better than I. Also the general overall trend in the Arctic for the past few decades has been lesser extent and correlated lesser volume/concentration. On the other hand you do see some odd yearly variations and some “strange” regional correlations that run counter to my assertion. So I guess it looks like the standard legal answer: sometimes, yes; sometimes, no! Thanks for your input.

    Comment by Rod B — 13 Oct 2009 @ 4:59 PM

  365. Richard Steckis (343) — A high value for Charney equilibrium climate sensitivity has become less probable due to research conducted since IPCC AR4 appeared. However, a more thorough climate sensitivity, which I believe is called Earth System Sensitivity, has been fairly recently developed. It seems to be a rather alarming 4.5–6 K for 2xCO2.

    So the shorter range Charney sensistivy is not as bad, most likely, as some have feared but in the longer term, it gets way too hot, way too hot I fear.

    Comment by David B. Benson — 13 Oct 2009 @ 6:04 PM

  366. http://nsidc.org/news/press/20091005_minimumpr.html

    Comment by Hank Roberts — 13 Oct 2009 @ 6:06 PM

  367. While the total forcing associated with land use is important, it is also important if different uses of land cause different effects on forcing and have occurred at different times. For instance, if deforestation at high latitudes is a particularily strong negative forcing and took place mostly before 1950 and irrigation is a positive forcing and took place mostly after 1950 then it would actually show up as an increase in temperatures although these temperatures may still be at a lower level then they would have been otherwise.

    Comment by stevenc — 13 Oct 2009 @ 6:35 PM

  368. I believe that you have to understand, we did have ice caps all around the poles at one point. When the earth got warmed up, those ice caps melted. What happens to ice when it melts, they cool the surroundings, thus causing what seems to be a paused or “reversed” warming effect. Now will this cooling effect be able to reverse all that humans have done to the earth, I would not know, but for sure that if it does not, once the water warms up to temperature beyond what can be done, you can expect us to go in a GLOBAL WARMING stage. I understand no one knows for sure what’s going on and I am no scientist nor have I done my research, I am just basing this on whatever evidence I see. The fact that we have lost our glaciers are evident in alot of pictures, and if you reason it, those glaciers when melted will give a period of cooling time, but once that cooling stops, you can do the math and tell me what’s suppose to happen?

    Comment by Vesyl — 13 Oct 2009 @ 8:37 PM

  369. Dhogaza #360 says:

    “And then he says:

    I stand by my statement on the impacts of land use on climate change. You must understand Sir that climate change is NOT about just warming. It is about CHANGE which can be either warming or cooling. I repeat. I have always argued that it is in land use changes that the greatest human impacts on climate are to be found. No inconsistency here.

    Except, of course, just befre you said that you don’t believe land use changes are a negative feedback.”

    My doubts on negative feedback of land use do not change anything about my thoughts on the impact of land use on climate. Land use has a greater regional influence on climate than global (Hansen et. al. 2007).

    The feedbacks (actually a climate forcing in Hansen et. 2007) are all related to albedo and roughness. There is no mention in Hansen et. al. 2005; 2007 of dynamic vegetation changes, changes in precipitation patterns due to land use change, influences of fire regimes in land management etc. In fact Hansen et. al. 2005 state “The small land use global climate forcing that we find may not fully represent land use effects, as there are other land use activities, such as irrigation, that we have not included.” They admit that the question of the actual climate forcing of land use change is open to further investigation.

    Hansen et. al. 2007 go on further to state: “We exclude land cover changes occurring as a feedback to climate change, except to the extent they are implicitly included in the Ramankutty and Foley (1999) data set.”

    and:

    “Our subjective estimate is that the global mean land use forcing for 1880–2000 lies between zero and -0.2 W/m2. However, the global value is less relevant than the regional forcing, which can be as much as several W/m2, as shown in Fig. 7 of Efficacy (2005). ”

    Note the word subjective used by Hansen et. al. 2007. Their papers regard land use as more of a forcing than a feedback. This would indicate that their knowledge of the overall impacts of land use to climate is limited to those effects that affect albedo, roughness and evapotranspiration changes. I argue that land use changes affect far more than those parameters alone.

    Comment by Richard Steckis — 13 Oct 2009 @ 10:37 PM

  370. It’s interesting (or not) that Richard Steckis several times mentioned land use feedback when he apparently meant land use forcing.

    Richard Steckis – while some forcings do have various idiosyncracies in regional affects, there are general tendencies associated with global average warming or cooling, perhaps especially for changes due to forcings such as solar and greenhouse gas changes.

    Because:

    Regional solar forcing varies by latitude and season and time of day, cloud cover and humidity, ozone…

    Greenhouse gas forcing varies with temperature and vertical temperature variation – which varies with latitude, season, height, and clouds and humidity.

    But aside from that

    Feedbacks are not evenly distributed in space and time. Hence temperature will not increase everywhere uniformly or in the same way in every season or for every ENSO index value (also a climate dependent variable in a pattern of fluctuation sense), etc. Convection tends to even out the temperature changes within the troposphere, working against vertical variations in forcing and feedbacks within the troposphere, thus that affects convection. Uneven temperature changes result in change in circulation patterns, humidity and cloud cover distributions, oceanic circulation and salinity, and surface type on land (albedo, soil moisture, vegetation) – which results in changes in temperature, in circulation patterns, humidity and cloud cover distributions, oceanic circulation and salinity, and surface characteristics – etc.

    “Land use has a greater regional influence on climate than global (Hansen et. al. 2007).”

    Land use having greater regional impact than land use has global impact does not mean that it will have greater regional impact than CO2 forcing.

    “They admit that the question of the actual climate forcing of land use change is open to further investigation.”

    Sure, but you have to take a big leap from that to the idea that land use overwhelms or even compares to CO2 effects even regionally. Can you build that bridge?

    “Hansen et. al. 2007 go on further to state: “We exclude land cover changes occurring as a feedback to climate change, except to the extent they are implicitly included in the Ramankutty and Foley (1999) data set.””

    Land cover feedback is not the same as land use, though one can affect the potential of the other.

    How CO2 affects land cover and results – well, in so far as CO2 fertilization occurs outside regions with zero runoff, a reduction in evapotranspiration could enhance runoff and result in greater river flow, and perhaps increase the near-surface lapse rate.

    Otherwise, see climate-related impacts – shifting tree lines, changing soil moisture, ecological interactions and albedo and evapotranspiration changes.

    “I argue that land use changes affect far more than those parameters alone.”

    Effects that are more than those parameters alone can come about through those parameters alone.

    Or,

    You mean changes in CO2 and CH4 fluxes that result from land use changes? Those are included in the CO2 and CH4 forcing. There can and likely will be CO2 and CH4 feedbacks from climate change, perhaps including through changes in land cover.

    Comment by Patrick 027 — 13 Oct 2009 @ 11:44 PM

  371. Correction:


    Because:

    Regional solar forcing varies by latitude and season and time of day, cloud cover and humidity, ozone…

    Greenhouse gas forcing varies with temperature and vertical temperature variation – which varies with latitude, season, height, and clouds and humidity.

    Those are actually examples of how a forcing in general might have some idiosyncratic effect, but for solar and greenhouse gas forcing, my understanding is that either they do not vary so much (more so for greenhouse forcing, as solar forcing must vary by latitude, season, and time of day, but the resulting cycles and geographic variations from uneven solar heating do affect greenhouse forcing. For changes from a familiar baseline, both might be a maximum in the subtropics (few clouds, high lapse rate?), though I’m not sure…

    But the similar uneven feedbacks generally dominate the idiosyncracies of well-mixed greenhouse gas forcing and solar forcing, so far as I know.

    Comment by Patrick 027 — 13 Oct 2009 @ 11:50 PM

  372. I thought you were wanting only accuracy, stevenc. But this

    “While the total forcing associated with land use is important, it is also important if different uses of land cause different effects on forcing and have occurred at different times”

    Is inaccurace.

    It isn’t important.

    We know from studies of what happens in the past that temperature sensitivity is between 2 and 4.5C per doubling. Even though the land use change was extraordinary: it went from mostly growing to mostly ice covered. That’s a pretty dramatic land use change.

    And for ACCURACY, are the uncertainties cause for complacency or worry?

    And for ACCURACY, where is the idea that land use could have had the opposite effect you allude to?

    Comment by Mark — 14 Oct 2009 @ 2:57 AM

  373. Richard Steckis (354), and Gavin’s inline reply:
    Could it be that the confusion arises of which forcing factors are included in “land use”: Clearance of forests causes a negative forcing because of albedo change (forests are generally darker than what it is replaced by), but it has a positive forcing because of CO2 release (which is in the short term partly masked by simultaneous aerosol emissions). Even though a consequence of changes in land use, the latter two are not included in the traditional land use term AFAIK, but rather under GHG and aerosols. Please correct me if I’m wrong.

    Comment by Bart Verheggen — 14 Oct 2009 @ 3:56 AM

  374. The main article tlaks about cherrry picking the data to the most recent decade of data on the chart still showing a warming trend. However, if the range of data is taken to start at 2001 through to the present day projected 2009 temperature, there IS a slight cooling trend.
    A simple comparison of best-fit simple straight line slopes for all 9-year periods 2001-2009, 2000-2008, 1999-2007 etc shows that the 9-year period until 2009 has the strongest negative slope in the 1980-2009 chart. Negative slopes do also appear for periods after Pinatubo, but the most recent 9 years downward slope is 3 times that of such post-Pinatubo 9-year periods.
    But what does this mean?
    Aside from the fact that cherry-picking can turn things either way.
    Cherry-pick back to 1998, you get warming.
    Cherry-pick back to 2001, you get cooling.

    Comment by Level3 — 14 Oct 2009 @ 6:05 AM

  375. “And for ACCURACY, where is the idea that land use could have had the opposite effect you allude to?”

    Help me out here Mark, I am always ready to learn. Name a reverse example for me. There almost certainly is one but I can’t think of it at the moment.

    Comment by stevenc — 14 Oct 2009 @ 8:17 AM

  376. Mark, perhaps you would have been better off pointing out to me that not all studies show irrigation as having a warming effect instead of just going off on a tirade. A much better example for my purposes would have been urban sprawl. Regardless, the point is that the land use changes chronology matters.

    Comment by stevenc — 14 Oct 2009 @ 8:24 AM

  377. “And for ACCURACY, are the uncertainties cause for complacency or worry?”

    My last comment on this blog for a while since I grow weary of the attacks and eschews. I will decide if the uncertainties are cause for complacency or worry when the warming starts up again, which I agree with you it will. Should this happen before other scientists believe the models have been invalidated then I will consider the models accurate since I can think of no better test then the one they are currently undergoing. Should this happen after other scientists, not just the usual skeptics but scientists such as those at the NOAA, believe the models have been invalidated then I also will believe the models invalidated. Thanks to those of you that have been civil and educational such as, but not inclusive to, Gavin and Martin.

    Comment by stevenc — 14 Oct 2009 @ 8:56 AM

  378. stevenc, like you, I just want accuracy…

    Comment by Mark — 14 Oct 2009 @ 9:33 AM

  379. Post 325: 325.Well here is an intersting post that suggests that the main post here is based on cherry-picked data. http://masterresource.org/?p=5240 . It summarizes in an easy to understand manner the data for all major temperature indexes and their trends for a a variety of periods over the last twenty years or so.

    [Response: Vaguely ok, but he has failed to take the clear auto-correlation in the monthly data series into account and so his statements about significance are all biased to be over-definitive. - gavin]”

    Further analysis in response to Gavin’s comment http://rankexploits.com/musings/2009/adding-apples-and-oranges-to-cherry-picking/

    Comment by PaulD — 14 Oct 2009 @ 10:18 AM

  380. Can you print the full reference information for the Simmons article in JGR? Thank you.

    Comment by Richard Sycamore — 14 Oct 2009 @ 10:26 AM

  381. Which explanation of the warming “pause” is more plausible: (1) Simmons hypothesis that there is no pause, it’s just that the Arctic region is under-sampled. Or (2) Hank Robert’s suggestion that the pause is real and it’s a result of polar ice melting? Which effect is stronger?

    Comment by Richard Sycamore — 14 Oct 2009 @ 10:36 AM

  382. Sycamore, you’re just playing debating games by misstating what was said. Done pretending yet?

    Comment by Hank Roberts — 14 Oct 2009 @ 12:27 PM

  383. PS, Steckis’s “b” choice is a fantasy on my reply to 153 in 155, about measuring temperature in a glass of icewater.

    Comment by Hank Roberts — 14 Oct 2009 @ 12:35 PM

  384. stevenc, I’m sorry to hear that. FWIW (bit late now), I am puzzled by some remarks made here lately, as I have found you very reasonable in discussion.

    Comment by CM — 14 Oct 2009 @ 12:44 PM

  385. #382 Hank Roberts: Sorry, did I misunderstand what you were trying to imply with that model? Would you like to clarify what you did mean?

    Comment by Richard Sycamore — 14 Oct 2009 @ 2:29 PM

  386. #383 Hank, I just read the report linked to by dhogaza n #169 and it didn’t discuss the magnitude of the effect of polar ice cubes melting on earth temperature. (But you will understand why I missed this comment when you consider the number of pages to leaf through in these threads.)

    Comment by Richard Sycamore — 14 Oct 2009 @ 3:14 PM

  387. level3:

    if the range of data is taken to start at 2001 through to the present day projected 2009 temperature, there IS a slight cooling trend.

    No, there is not. A “trend” has to be statistically significant.

    Comment by Barton Paul Levenson — 14 Oct 2009 @ 4:20 PM

  388. 383
    Hank Roberts says:
    14 October 2009 at 12:35 PM

    “PS, Steckis’s “b” choice is a fantasy on my reply to 153 in 155, about measuring temperature in a glass of icewater.”

    I think you are talking about someone else.

    Comment by Richard Steckis — 15 Oct 2009 @ 8:42 AM

  389. Yep, replace ‘Steckis’ with ‘Sycamore’ in that PS.
    My mistake, somehow I confused the two momentarily.

    Comment by Hank Roberts — 15 Oct 2009 @ 9:10 AM

  390. And if the trend is taken through another year, you get a warming.

    What does this prove about trends?

    Comment by Mark — 15 Oct 2009 @ 9:25 AM

  391. Our host Stefan points out that it is “pointless to look for explanations for a warming pause.”

    It seems that perhaps the whole discussion about temperature has limited meaning. I assume the surface temperature data is from measurements with a satellite radiometer. The problem is that heat and temperature are not that clearly related, especially in the ocean. One might assume that on average, there is a direct connection. For solid earth that might be true. However, the vertical mixing process along with the vast cold reserves in the ocean makes temperature a poor indicator, and in fact temperature should usually be lower than it would be without that vertical mixing. Simply stated, the heat tends to stay put on solid ground but it can fairly quickly descend, especially if the wind is active. And if heat stimulates weather action, that wind might be produced by the heat and thus made to reduce the surface temperature.

    As I see Fig. 2 of the spinnng globe it seems like the ocean is doing a good job of leveling the surface temperature effect of heating due to global warming, except in the arctic. (and it seems there are hotter spots on many of the large land masses) I guess some of the comments here relate to the Arctic ice effects. As I would say it, it looks like the temperature data is unclear here as well. Thick ice can be much colder than the water underneath, but as it thins and disappears the water temperature dominates. The red color coded temperatures of the Arctic seem to be showing the disappearance of the ice. Clearly there would be the heat of fusion (melting in this case) that would represent quite a lot of energy being taken into the ocean due to the global heat imbalance.

    So the main point I am trying to make is that the discussion needs to be shifted away from temperature, which is bound to lead to erroneous ideas, some of which would exagerate the problem and some of which would empower those that would deny the problem.

    The disappearance of Arctic ice should be strongly noted. Sea level measurements should also get more emphasis.

    I have a particular concern for the warming over the north end of Greenland. The several degrees C warming shown here is alarming, subject to some interpretation as to how cold is the base temperature, and whether there is land ice melting or a danger of it going on.

    Comment by Jim Bullis, Miastrada Co. — 15 Oct 2009 @ 6:18 PM

  392. My statement in #391, “Clearly there would be the heat of fusion (melting in this case) that would represent quite a lot of energy being taken into the ocean due to the global heat imbalance,” has to be confusing. I skipped too many steps. I am supposing that deeper ocean regions are warmer than usual due to vertical mixing which ‘takes energy into the ocean and this warmer water is circulating into the Arctic Ocean. This causes sea ice to melt which cools that otherwise warmer water. The Arctic region surface temperature is somewhat indirectly related to this process, since the upper sea ice surface is significantly colder than the water in any case, and when it goes away the water temperature would get measured, at the surface of course. This would show up as the significant warming.

    Comment by Jim Bullis, Miastrada Co. — 16 Oct 2009 @ 2:03 PM

  393. When I copy a post from here and paste it into MS Word the spell checker goes crazy because it gets told that the language is French.

    Comment by Jim Bullis, Miastrada Co. — 16 Oct 2009 @ 2:08 PM

  394. Wouldn’t it be good to have two different names for two kinds of trend?

    (a) The populist one based on the slope of a straight line drawn through or between the data points. This comes with no error bars and no estimate of statistical significance.

    (b) The same as (a) but with a specified and reasonably large statistical significance or fractional error bars significantly lower than 100%.

    Tamino, Grumbine and RC have all discussed this difference which requires no knowledge of climatology or even advanced statistics. Yet it is still the case that type (a) trends crop up all over the place and not only in the recent BBC article mentioned e.g. at #356. Consider e.g.

    # 115 Kevin McKinney who says

    “A (slight) slowing of the warming”

    I could not open your link Kevin, but having read Tamino et al I beg to differ. There is unlikely to be any evidence there either for a slight warming or the opposite because a slight slow down would require several more years to detect. A large slow down might be detectable sooner but there has not been one. We appear to be stuck with the boring but worrying old trend of 0.18K per decade +/- error just as before.

    Having written that, I am seriously troubled by Senator Barton’s choice of Wegmann to chair that “impartial” investigation into the original hockey stick papers. According to his recent signing of the Bali letter he appears to be employing trends of type (a). That letter asserted

    “Consistent with this, and despite computer projections of temperature rises, there has been no net global warming since 1998.” “

    Please see

    http://tamino.wordpress.com/2009/06/26/embarrassing-questions/#comment-32298

    Comment by Geoff Wexler — 18 Oct 2009 @ 6:18 PM

  395. Just spent the afternoon reviewing the new projects to inventory the ice with newer technology and adjust the remote sensors. Study after study show that remote sensors are in need of improvement. Sensor drift provided another flaw this month as well. At this point in time, it would seem that sensor technology is still emerging. Basing an entire world economy on it is not sound science.

    I am not so sure that the radiant heat from the sun was not higher in the last few years and lower in conjunction with the absence of sunspots.
    The claim that the sun has been cooler for the entire 11 year cycle needs some evidence as well.

    It is difficult enough to take accruate readings in small environments. The research presented here on a global scale has a taste of cherry picking the data to support the conclusion. The conclusions with the associated cause and effect are not sound.

    Comment by Tom Bone — 18 Oct 2009 @ 10:42 PM

  396. Geoff, it was Lawrence Brown, not me, who made the “slight slowing” comment. (See #121. My #115 was about orbital cycles.)

    And yes, it’s tempting to wonder just how impartial Wegman is/was, despite his distinguished career in stats.

    Comment by Kevin McKinney — 19 Oct 2009 @ 7:32 AM

  397. Kevin

    Thanks for that correction; sorry about the mistake. I also called Barton a senator instead of a congressman. But I should have gone further than raise the issue of his impartiality. Being partial need not have prevented him from being reliable.

    Comment by Geoff Wexler — 19 Oct 2009 @ 8:04 AM

  398. “Wouldn’t it be good to have two different names for two kinds of trend?”

    We do:

    a: wrong
    b: also wrong

    A trend isn’t taking two points and drawing a line between them.

    Even if the two points are 30 years apart.

    It IS taking all the data within those 30 years and working out the answer to the question: “If I had to given ONE number for the trend, which is most likely to be far from the truth?”.

    Remember, a trend allows you to say “if you don’t know what the next number is, what equation would give you the most nearly right one most often?”.

    A trend line drawn between 1998 and 2008 would be much more wrong and more often than a proper trend run by a least squares fit.

    Comment by Mark — 19 Oct 2009 @ 8:33 AM

  399. #369 Richard Steckis

    Just to keep things in context of the bigger picture:

    Climate change is warming and cooling.

    AGW is warming due to human cause.

    Human impacts have warming and cooling influences. The warming influences are outweighing the cooling ones.

    Comment by John P. Reisman (OSS Foundation) — 19 Oct 2009 @ 8:35 AM

  400. #389 Now who’s prone to “mis-statements”, Hank?

    Comment by Richard Sycamore — 19 Oct 2009 @ 9:20 AM

  401. > When I copy a post from here and paste it into MS Word
    Use “Paste Special, Unformatted” (Safe Text) when pasting into Word.

    Comment by Hank Roberts — 19 Oct 2009 @ 9:22 AM

  402. Tim Bone, Your post is sufficiently vague that it is effectively meaningless. What data? What sensors? What research? Vague accusations are not helpful and merely establish you as an ignoramus who is too unfamiliar with the research to be specific.

    Comment by Ray Ladbury — 19 Oct 2009 @ 9:33 AM

  403. Mark

    Misunderstanding?

    I don’t agree with parts of your comment. Definitions cannot be ‘wrong’. Considering them again:

    (a) Populist. Just one parameter= slope. No use for establishing that a stable change is occurring and yes to quote you, very poor for making extrapolations.

    (b). This includes the existence of an additional parameter (statistical sig. or error bars). Depending on the values of this parameter this addition can lead to a trend with useful properties.

    I did not attempt to justify why (b) can provide evidence of sustained change. The comment was never intended to reproduce the excellent discussion by Grumbine or the various versions by Tamino. If you haven’t yet done so, I suggest you go there before replying to me again, even if you think that you know enough about the topic. Unfortunately Tamino has hurt his hand and we have to wait for part 2 of his essay on the Kullback-Leibler divergence ; perhaps that may provide a better handle for separating out noise from a linear change. Why call it noise? Because it makes no progress and does not involve sustained change.

    Comment by Geoff Wexler — 19 Oct 2009 @ 11:58 AM

  404. Of course definitions can be wrong, if you want to be understood.

    There are definitions of ‘trend’ that don’t mean a statistically detectable likelihood of a change. But they’re not used for good reason here.

    ——
    `I don’t know what you mean by “glory”,’ Alice said.

    Humpty Dumpty smiled contemptuously. `Of course you don’t — till I tell you. I meant “there’s a nice knock-down argument for you!”‘

    `But “glory” doesn’t mean “a nice knock-down argument”,’ Alice objected.

    `When I use a word,’ Humpty Dumpty said, in rather a scornful tone, `it means just what I choose it to mean — neither more nor less.’

    `The question is,’ said Alice, `whether you can make words mean so many different things.’

    `The question is,’ said Humpty Dumpty, `which is to be master — that’s all.’
    ——
    http://www.sabian.org/Alice/lgchap06.htm

    Comment by Hank Roberts — 19 Oct 2009 @ 12:40 PM

  405. Re: #404 ; Hank.

    “There are definitions of ‘trend’ that don’t mean a statistically detectable likelihood of a change. But they’re not used for good reason here.” [My italics]

    First the italicised sentence is not strictly true ; see e.g. #121 which provoked my earlier criticism and also my final example below. Secondly I may have not made myself clear. I was not welcoming the use of one word (trend) for both usages , just the opposite. Finally, in the words of an earlier article

    “Don’t be such a scientist” .

    The problem is that the populist usage, which I called type (a) is used by many of the lay public (and most deniers) all of the time as well as some experts some of the time (often with caviats).

    Consider Figure 1 at the top. The term ’10 year trend’ happens to be correct because it is equal to the 25 year trend which can be justified statistically. On the other hand Stefan also points to the slope of a least squares fit to an 11 year set. Even if this fit is not stat. sig. his point would be worth making, but my point is that it would have been better if the the stat. sig. of the result 0.11 degs.C /decade had been quoted.

    Otherwise we cannot complain when deniers draw their own least squares fits and fail to tell us that they are stat. insignificant which they do .

    Comment by Geoff Wexler — 19 Oct 2009 @ 5:46 PM

  406. > I was not welcoming the use of one word (trend) for
    > both usages, just the opposite.

    Thanks, that makes more sense, I hadn’t understood that.

    > 121

    There Lawrence quotes the MetOffice’s “Quick Guide” — I found the word “trend” there only once, though my search may be missing something

    http://www.google.com/search?q=site%3Ahttp%3A%2F%2Fwww.metoffice.gov.uk%2Fclimatechange%2Fguide%2Fquick%2F+trend

    Seems to me they have to use the word most people use to explain what’s happening in the world — then try to explain what the scientists are doing.

    > don’t be such a scientist

    Sorry; I haven’t gotten nearly good enough to quit trying yet.

    Comment by Hank Roberts — 19 Oct 2009 @ 6:23 PM

  407. A new contrarian voice?

    Andrew Revkin interviews Canadian futurist Vaclav Smil, who claims that a looming (unspecified) pandemic is a much greater threat than global warming.

    Oh, and did you know that there has been “no global warming in the past ten years”, and James Hansen should have been able to predict that global warming would “basically stop for 10 years”?

    See:
    http://deepclimate.org/2009/10/19/vaclav-smil-no-global-warming-in-past-ten-year/

    Revkin’s highlihjts are at DotEarth (but don’t include the “no global warming” comments):
    http://dotearth.blogs.nytimes.com/2009/10/19/smil-on-hummers-hondas-meat-heat

    Comment by Deep Climate — 19 Oct 2009 @ 8:38 PM

  408. Geoff: “Even if this fit is not stat. sig. his point would be worth making, but my point is that it would have been better if the the stat. sig. of the result 0.11 degs.C /decade had been quoted.”

    Uh, people don’t WANT the error bars.

    Denialists NEVER USE error bars. Though they do admit that the IPCC doesn’t tell everyeone about their errors, then they crow about how the IPCC has admitted to an error (without ever saying that they’ve just proven their earlier assessment wrong).

    The trend line DOES pass through 0.11C. Please prove that wrong.

    It’s impossible because the definition of the trend line is mathematical and the maths is based on all the data available used correctly.

    Missing out the error bars has been fixed before.

    Do you know what the denialists did?

    They took the lower bound and said “SEE! The IPCC themselves say there’s nothing to worry about” because the lower bound was less than zero at the time.

    When you’re dealing with simpletons, you have to make things simple.

    So please prove the 0.11 trend in the short period data is wrong.

    You can’t.

    You may be able to prove it’s not the actual trend, but you have to use more data than the short trend the denialists want to use and incorrectly (because the trend you get is positive) state it’s cooling.

    And if you DO use more data, you’d find the cooling is not on the cards at all.

    Comment by Mark — 20 Oct 2009 @ 2:59 AM

  409. “(a) Populist. Just one parameter= slope.”

    Nope. Wrong.

    Just one parameter made incorrectly is not a trend.

    You were talking about TRENDS not slope.

    If you want to talk about slope, you need two numbers: gradient and intercept.

    “(b). This includes the existence of an additional parameter (statistical sig. or error bars).”

    Nope, still wrong. You have error bars around an incorrectly calculated number. It still isn’t a trend. If you want a slope, you need two numbers for the slope and you’d need another number for errors. Except, since you have the WRONG trend, the error in the future number from the calculated slope that isn’t the trend will always be higher than the standard error you calculated on the graph and therefore your error bars are also wrong.

    The trend is “calculate the best idea of where the numbers in the future are going to go”. You can check your figures by having someone give you a smaller selection of numbers and then asking you to guess the value of the missing numbers.

    What are the missing numbers of this series?

    1, 2, ?, 8, 16, 32, 64, 128, ?, 512

    ?

    Now if you did YOUR “correct” calculation, we’d say the slope was 51.2.

    IS that the trend?

    Would that make the two missing numbers?

    Would the next number be between your calculated error bars or outside the three sigma limit? Heck, it’s probably outside the five sigma limit. If not, the number after that would be.

    Comment by Mark — 20 Oct 2009 @ 3:11 AM

  410. Re: #407 and Vaclav Smil

    Your links are most informative, Re: Vaclav Smil.
    I don’t think you need a question mark at the top of #407.
    He has been cherry picking his sources of reading matter. It is just possible that his forecasts on non climatological matters might be less lazy, but I prefer to read experts who demonstrate that they can be trusted on important matters. So I shall not be buying his book. Unfortunately there might well be a disastrous pandemic but we don’t need to use him as a source of information on it.

    Comment by Geoff Wexler — 20 Oct 2009 @ 4:27 AM

  411. Geoff, is the slope 51.2? Would any standard deviation hold for the next five numbers? If it cannot, how can it be the standard deviation?

    Comment by Mark — 20 Oct 2009 @ 8:46 AM

  412. PS there’s a difference between error bars and standard deviation.

    It’s one reason why climatology is 30 years and that a decade or more of flat lining is no proof of an end to global warming.

    Each year, the temperature varies from the year before by ~1C.

    THAT is an error bar. I.e. you could see 1C difference between any two measurements.

    After 30 years the average difference between the average from that sample and the true sample (given there is no trend) the standard deviation will be 1/sqrt(30) C. This is 0.2C and warming over this period is approximately 2-3 times that, so above the noise level.

    That 30 year figure of trend with standard deviation is not the trend with error bars. It is saying “the trend we get from the data we have is THIS, but the real trend could be anywhere from HERE to THERE”.

    Comment by Mark — 20 Oct 2009 @ 8:56 AM

  413. Mark.

    #409 “When you’re dealing with simpletons, you have to make things simple.”

    First not all contrarians are simpletons, secondly not all insignificant trends are short term, thirdly climatological articles are not just addressed to contrarians, fourthly you should follow your own advice about simplicity.

    If you use a repertoir which includes an “actual trend”, a “short trend” (line 4 up) , an “incorrectly used trend” and a mathematically defined trend based on correctly used data, you will then need a few extra lines on each occasion to explain and justify what you talk are talking about.

    To really make things simple restrict the discussion to 25 years (say) or more. But that would be insufficient to rule out insignificant long term estimates based on other kinds of cherry picking. It would also ban Figure 1 above with its reference to 10 year trends. I originally suggested using two different words. If you don’t want to mention the stat.sig.or the error bars the very least would be a reference to a “statistically insignificant 11 year estimate of the trend”. I don’t like your ‘mathematically defined estimate’ , its almost meaningless and would open the way to the abuses which I have seen by various professors.

    #409. Yes I forgot to mention the intercept.

    Comment by Geoff Wexler — 20 Oct 2009 @ 9:53 AM

  414. “#409 “When you’re dealing with simpletons, you have to make things simple.”

    First not all contrarians are simpletons,”

    Never said so. But are NO contrarians simple?

    No.

    So the simple explanation has to be made.

    The less simple explanations can work if you have a minimum pass level for intelligence.

    Blogs don’t do that too well.

    Proper journals do.

    Ta.

    Comment by Mark — 20 Oct 2009 @ 10:29 AM

  415. > “statistically insignificant ….”

    —–
    “Statistically Insignificant”? Watch out!

    Experts can detect non-experts just by the way they use technical terms. Something is said that no one trained in the field would actually say. It gets one’s teeth grating to hear it…
    —–
    http://financialrounds.blogspot.com/2005/06/statistically-insignificant.html

    Comment by Hank Roberts — 20 Oct 2009 @ 10:41 AM

  416. “I don’t like your ‘mathematically defined estimate’ , its almost meaningless and would open the way to the abuses which I have seen by various professors.”

    You don’t have to like it.

    It IS.

    But saying you don’t like the mathematical definition of trend doesn’t mean you can take two points and draw a straight line between them and call it a *trend*.

    Because a trend is defined mathematically.

    Now, is the slope of that graph y=51.2x?

    Or would both of your definitions of trend (which is a slope, not a trend) be wrong?

    Comment by Mark — 20 Oct 2009 @ 11:00 AM

  417. Mark

    I do not have time to check those parts of your comments which have nothing whatsoever to do with my suggestions concerning the spec.or name of a trend. There is a danger that the number of misunderstandings on this sub-thread could diverge. You could always try displaying your non-linear convex sequence at another thread e.g that following Tamino.

    Comment by Geoff Wexler — 20 Oct 2009 @ 11:03 AM

  418. #415

    I plead guilty. Please don’t report me to the chief of police for statistics , especially as I referred to him earlier.

    Comment by Geoff Wexler — 20 Oct 2009 @ 11:25 AM

  419. It does have a lot to do with how both your (a) and (b) options were wrong.

    There already IS a name for trend and a meaning for trend and as Hank points out, the meaning for trend in science and the meaning for trend in everyday use are the same.

    Neither requires error bars or standard deviation.

    And denialists aren’t creating a trend when they say “it’s been cooling for the last 10, sorry, 11 years!” they’ve created a slope between TWO years and called it a trend.

    Neither of your options, not even the option b you were pushing is a trend and would still be abused by denialists drawing a slope between two points and calling it “cooling trend”.

    It just isn’t a trend.

    And neither were your two options.

    Hence the name for those two different slope definitions are “wrong” and “also wrong”. Replacing the wrong definition of denialists by another also wrong definition of trend is not going to solve anything. We use the right one.

    Comment by Mark — 20 Oct 2009 @ 11:26 AM

  420. The point of all this is not whether you can find any trends within the overall data set that in themselves are statistically significant.

    You can take any 11 points from the overall data series, do a linear regression on them, and come up with a fit that you could call statistically significant. But is it?

    You have to bear in mind that those 11 points are not independent – they are part of a time series. The time series as a whole expresses two modes of variance. If you take a series of 11 points, then all you are looking at is the short-term mode of variance. You cannot say anything about the long-term variance of the whole data series, because an 11-year trend is not measuring the long-term variance.

    The shortest trend for which most or all of the variance comes from the long-term variance is 20 years. Bob Grumbine will soon be posting my Java applet that shows the effect of trend length. You can also see it at Hot Topic here.

    Comment by CTG — 20 Oct 2009 @ 3:15 PM

  421. “Robust trend” and trend; That would be a possible compromise. Stefan used those terms in an earlier article.
    ——————–
    Re: #420. Thanks CTG I’ll look out for your work when I get the time.
    ————–
    Re: #419. The signal strength is falling to zero. You are not discussing my comments but a fantasy. Perhaps if we were in the same room we could be more efficient.

    I previously suggested that you go to Tamino or Grumbine. But I see that you have been to Open Mind already and dhogaza warned what can happen when the communication channel gets blocked:

    http://tamino.wordpress.com/2009/08/13/do-you-believe-ian-plimer/#comment-34285

    On that occasion one of the best articles about Plimer was followed by a thread which got diverted into 40 or more comments centred on a single trivial misunderstanding. When you avoid pitfalls like that you have some useful points to make.
    —————-

    Comment by Geoff Wexler — 20 Oct 2009 @ 4:08 PM

  422. I love the “trend lines” when you have an R^2 of about .5!!!!! It means absolutely nothing – you draw a line through random numbers and then extrapolate out 50 years.

    Comment by John — 21 Oct 2009 @ 7:34 AM

  423. John,
    You obviously don’t have much data analysis experience. An R^2 of .5 simply means you have a lot going on BESIDES the increasing trend. This is where physics comes in handy. You really ought to try it sometime–you know, actual science.

    Comment by Ray Ladbury — 21 Oct 2009 @ 9:19 AM

  424. What’s trend, then? What’s the difference between robust trend? And how are these differences going to change anything?

    The trend is still the trend and it isn’t the “draw a line between two points 11 years apart and call it a trend”. Doing the calculation on all 11 yearly averages doesn’t produce a “robust trend”. It produces ***a trend***.

    A robust trend would be the trend you’d get from an 11 year trend (done properly) that you could expect to be replicated in the next 11 years.

    But that isn’t a trend and the draw-a-line-between-two-points is still not a trend and isn’t made a trend by calling the real trend “robust”.

    Comment by Mark — 21 Oct 2009 @ 9:59 AM

  425. “The shortest trend for which most or all of the variance comes from the long-term variance is 20 years.”

    CTG, and this falls out because of the known cyclical elements controlling weather but not climate.

    PDO, ANSO, Sunspots, etc.

    Now you can draw *some* inference of the long term result if you remove the effects you know change the weather but not the climate. It’s been done the other way around once before by denialists (that has been a long thread on a previous RC thread): they’ve removed the effect of CO2 and found that the majority of what remains is caused by the PDO.

    Denialists then drew the conclusion that the PDO was the main climate driver.

    Go figure.

    Comment by Mark — 21 Oct 2009 @ 10:05 AM

  426. > robust trend

    You can’t just pick words you like and decide you want to use them in explaining things to the public without looking up how they are being used in current practice, or you will make people even more confused about meanings.

    ‘Robust’ has a meaning. You need to understand what people mean by it.

    http://scholar.google.com/scholar?q=statistic+robust+trend

    Comment by Hank Roberts — 21 Oct 2009 @ 11:15 AM

  427. “It’s nice to know that a lot of people have been pushing efforts to make planet earth a better place. With biofuels, and all other alternative resources for energy, we might be able to curb the growing problem that is global warming and at the same time preserve the ecosystems of the world. The Earth’s natural forces such as wind, hydro and solar power are limitless and effective ways to gain energy. So unless the winds stop blowing, the seas stop roaring or the sun dies out, there’ll always be a place to go for energy. Kudos mother earth!”

    Comment by Richard — 22 Oct 2009 @ 12:03 AM

  428. Well, here is one lay person who claims that you may use GIS Temp and start the trend calculation from any year during 2001-2007 to now, and get a downward trend.
    It’s not 10 years, but it sure is 8 years telling the same chilling tale for AGW.

    Comment by Patrik — 22 Oct 2009 @ 12:47 PM

  429. Patrik says: 22 October 2009 at 12:47 PM

    Think you should draw the trend line based on monthly data from 1.1.2008. Might put some shiffers up your spine.

    Comment by Sekerob — 22 Oct 2009 @ 1:29 PM

  430. Patrik:

    you may use GIS Temp and start the trend calculation from any year during 2001-2007 to now, and get a downward trend.

    It’s not a “trend” unless it’s statistically significant and you use an appropriate time scale. The appropriate time scale for climate is 30 years. Eight years tells you exactly nothing.

    Comment by Barton Paul Levenson — 22 Oct 2009 @ 1:37 PM

  431. re: 428
    All of which is quite irrelevant to the long-term (i.e. well-defined as 30+ years) warming trend re: AGW. “…8 years telling the same chilling tale for AGW” is essentially a non sequitor.

    As has been said before, the idea that someone who is not an expert in climate science somehow knows something that literally thousands of peer-reviewed climate scientists and every major professional climate society/organization across the world do not is nothing more than scientific arrogance.

    Comment by Dan — 22 Oct 2009 @ 1:42 PM

  432. Patrik, this one lay person can’t be not more than 9 years old.

    Here’s the applet
    — move the slider and tell us how old you have to be:

    http://hot-topic.co.nz/keep-out-of-the-kitchen/

    Choose between data series with the button at the top. Blue lines show negative trends, red ones positive trends.

    Comment by Hank Roberts — 22 Oct 2009 @ 1:43 PM

  433. Well, here is one lay person who claims that you may use GIS Temp and start the trend calculation from any year during 2001-2007 to now, and get a downward trend.

    Here’s one lay person that notices that you’ve left out 2008. Why would that be? I couldn’t possibly guess.

    It’s not 10 years, but it sure is 8 years telling the same chilling tale for AGW.

    Yes, it tells us that CLIMATE SCIENTISTS ARE RIGHT then they tell us that the warming signal overlayed on natural variation in temps can lead to flat or even declining stretches of several years.

    This is why, decades ago, meteorologists settled on 30 years as being a reasonable length of time for discerning real climate trends.

    Not 1, 2, 3, 4, 5,6, 7, 8, 9 or 10 years. 30 years.

    Isn’t it nice to see another basic tenet of climate science shown to be true?

    Wouldn’t it be nice if you actually understood it? You can, it’s not that hard … click on the “start here” link at the top of the page and have at it. Learn some science, then come back and join in the fun.

    Comment by dhogaza — 22 Oct 2009 @ 2:20 PM

  434. #431 Dan

    Actually, it is not arrogant to speak of something that is well known in ones field. You may be trying to point out that it is not considerate of the lack of knowledge that others have.

    That is an odd argument. One should not feel offended by not knowing, but rather happy to learn. Also, you should consider the fact that when you visit another country, the customs and the culture may be different. You don’t just barge in and tell them that they are all wrong for living the way they live. You observe and learn about the new environment and then it is easier to blend in. Asking questions is a good way to learn though. Making statements about how you know its cooling based on 8 years of data only shows that you are in the wrong country, or in the right country and speaking arrogantly about your own understanding of the culture.

    Comment by John P. Reisman (OSS Foundation) — 22 Oct 2009 @ 3:15 PM

  435. Here is a nice video by Nasa illustrating how ice thickness varies with ice extent. Enjoy.

    http://www.nasa.gov/mov/391782main_sea_ice_concept.mov

    Comment by G. Karst — 23 Oct 2009 @ 9:16 AM

  436. “Here is a nice video by Nasa illustrating how ice thickness varies with ice extent.”

    Please.

    Show us where thickness is driven by extent.

    Where there was NO ice and now there is, well, obviously.

    But if that ice comes from a break off of another sheet of panice, it’s also thinned just as much (or more) somewhere else. Yet despite no new ice, the extent has increased.

    You have not yet shown that sea ice thickness depends on sea ice extent. And the movie makes no such connection either.

    Comment by Mark — 23 Oct 2009 @ 9:51 AM

  437. Mark:

    You are aware that “varies as” and “driven by” are two different statements. Maybe most of your comments are “driven” instead of “reasoned”.

    Comment by G. Karst — 23 Oct 2009 @ 10:41 AM

  438. Mark: I’ve viewed the movie (and watched Tom Wagner’s associated interview) and it seems to be showing that the thickness of ice under the non-melted areas adjacent to areas that melt and re-freeze each year is thinned by the melting action.

    Comment by Alistair Knox — 24 Oct 2009 @ 2:41 PM

  439. Arctic ice extent and thickness is cyclical.

    n early May, a paper appeared in Nature that created quite stir in the media by showing how by including long term ocean cycles in models the recent global cooling or at least lack of warming may continue to 2020. The same week, a story by NASA’s Earth Observatory reported on the flip of the Pacific Decadal Oscillation to its cool mode. “This multi-year Pacific Decadal Oscillation ‘cool’ trend can intensify La Niña or diminish El Niño impacts around the Pacific basin,” said Bill Patzert, an oceanographer and climatologist at NASA’s Jet Propulsion Laboratory, Pasadena, Calif. “The persistence of this large-scale pattern tells us there is much more than an isolated La Niña occurring in the Pacific Ocean.”

    Comment by common_man — 24 Oct 2009 @ 6:43 PM

  440. Evidence of global warming in the form “ n of the last m years have registered record temperatures” where n approaches m in magnitude is not very useful. It would be true for even the slightest warming trend and such a natural trend is to be expected at this stage in climate history. Measuring the magnitude of changes in temperature trends is more instructive. Trends in the temperature record between 1850 and 2007 changed direction five times. While the forces changing temperature trends from cooling to warming have weakened over time, those effecting the opposite change have strengthened. It takes more force to switch the climate system to a cooling trend than to a warming one. If emissions are the main climate force and if emissions have increased over time then they are a cooling force not a warming one.

    Comment by John Millett — 27 Oct 2009 @ 5:54 AM

  441. John Millett,
    Your post is just about the dumbest thing I’ve read on the internet this week. Congratulations. I would refute it, but looking over it, I see only a bunch of unsubstantiated assertions devoid of any evidence or logic, so you’ve already done my job for me. Thanks!

    Comment by Ray Ladbury — 27 Oct 2009 @ 7:59 AM

  442. “Evidence of global warming in the form “ n of the last m years have registered record temperatures” where n approaches m in magnitude is not very useful.”

    Why not?

    When looking at whether there are unsafe practices at a construction site, they will use the number of deaths per worker-year compared with the industry average. A workplace with more than the last n deaths in the last m years is considered a priori unsafe and is investigated.

    “It would be true for even the slightest warming trend and such a natural trend is to be expected at this stage in climate history.”

    Only if your n and m is small and the n much smaller yet. But when the last 8 warmest years on record are in the last 10, then it’s pretty solid.

    But if you can prove this is not reliable, please do so.

    “Trends in the temperature record between 1850 and 2007 changed direction five times.”

    Far more than that. Roughly 314 times. Each march it started getting warmer. Each October it started getting cooler.

    “While the forces changing temperature trends from cooling to warming have weakened over time, those effecting the opposite change have strengthened.”

    The opposite change from what?

    “It takes more force to switch the climate system to a cooling trend than to a warming one.”

    Nope. It takes more energy. But that’s because it requires the addition of energy to raise the temperature of anything. Tautological BS.

    “If emissions are the main climate force and if emissions have increased over time then they are a cooling force not a warming one.”

    No they aren’t. And this statement does not follow on at all from your earlier sentences, so where you get this idea from is anyone’s guess.

    But if you can tell us how CO2 and methane emissions can become a cooling forcing, I’m all ears.

    Comment by Mark — 27 Oct 2009 @ 9:13 AM

  443. “Mark: I’ve viewed the movie (and watched Tom Wagner’s associated interview)”

    I don’t have sound here, so all I had was the images.

    Which didn’t show thickening of the ice when it expanded in extent.

    “You are aware that “varies as” and “driven by” are two different statements.”

    Yes I do.

    But what does that have to do with saying increased ice extent shows there’s more ice?

    If my comments are more driven than reasoned it’s because there’s no logic behind your arguments, therefore no logical basis to argue from in their relation.

    Ice extent measurements doesn’t measure ice volume.

    Comment by Mark — 27 Oct 2009 @ 9:15 AM

  444. hmmmm. There’s a John Millett of Neutral Bay who writes to The Australian a lot — same kind of thing, pure copypaste word salad stuff, e.g.
    http://www.theaustralian.news.com.au/story/0,25197,26226979-7583,00.html

    Comment by Hank Roberts — 27 Oct 2009 @ 9:18 AM

  445. #441, #442, #444: Ray Ladbury, Mark, Hank Roberts: My method and numbers.

    The system switches from warming to cooling trends at maxima; and vice versa at minima. Trend change is the sum of the separate trends, measured as degrees Celsius per year.
    Temperature maxima: 1877, 1942, 1998; period: 65, 56 years
    Trend change: 0.0138, 0.0183, 0.0188 (assuming flat trend since 1998)
    Minima: 1909, 1974; period: 65 years
    Trend change: 0.0258, 0.0204
    Warming to cooling trend changes are rising over time; and vice versa. The two series are converging. They are likely to intersect within the next period, when cooling trend changes would exceed warming trend changes and temperature would peak. If rising emissions are contributing warming to this pattern, it must be minor. Alternatively, the contribution could be a cooling one? The data are HADcrut.

    Comment by John Millett — 28 Oct 2009 @ 4:28 AM

  446. #442 Mark

    “But if you can tell us how CO2 and methane emissions can become a cooling forcing, I’m all ears.”

    The natural greenhouse effect is defined as the difference in the whole-of-sphere average surface temperatures of an imaginary, atmosphere-free planet and the real one. Instead, consider day and night hemispheres separately. The imaginary day hemisphere, lacking a radiation reflecting and attenuating medium, would be hotter than the real one. That is, the day-time greenhouse effect is negative. The imaginary night hemisphere would begin and end with higher temperatures than the real one because the imaginary day hemisphere is hotter than the real one. The temperature of the imaginary night hemisphere, which lacks an external energy source, can’t fall below the end temperature. That is, the imaginary night hemisphere is hotter than the real one and the night-time greenhouse effect is also negative. What roles do CO2 and methane play in this cooling atmosphere? None, probably.

    Comment by John Millett — 28 Oct 2009 @ 5:03 AM

  447. Re 446–

    “Atmosphere-free planet”=NO greenhouse effect. (Not negative–the temperature patterns described may be correct but are irrelevant to “greenhouse.”)

    “No atmosphere”=”no cooling atmosphere”=no CO2 or methane.

    Analysis fail. (Or maybe it’s just so badly written as to be incomprehensible.)

    And note that we have a real instantiation of this “imaginary” planet–one which is well-studied, and of which climatologists are very well aware:

    http://www.asi.org/adb/m/03/05/average-temperatures.html

    Comment by Kevin McKinney — 28 Oct 2009 @ 7:30 AM

  448. On another topic, predictions are always dangerous, and perhaps nowhere more so than in the fickle domain of Arctic sea ice extent. And the larger significance of short-term events is always questionable.

    However, with those caveats, it’s interesting to note that there appears to be a real chance that November 2009 sea extent may feature some all-time lows, as the fall freeze-up continues to be quite slow. (Something I certainly didn’t see coming a month or two back!–FWIW.)

    Comment by Kevin McKinney — 28 Oct 2009 @ 7:35 AM

  449. “That is, the imaginary night hemisphere is hotter than the real one and the night-time greenhouse effect is also negative.”

    This is incorrect. The real imaginary hemisphere is hotter than it would be if there were no CO2/methane. Therefore the greenhouse effect is positive.

    “What roles do CO2 and methane play in this cooling atmosphere? None, probably.”

    Then it probable doesn’t answer the query posed either:

    “But if you can tell us how CO2 and methane emissions can become a cooling forcing, I’m all ears.”

    Comment by Mark — 28 Oct 2009 @ 8:17 AM

  450. ”The system switches from warming to cooling trends at maxima; and vice versa at minima.”

    Tautology.

    A local minima is always followed by an increase. Hence the term “minima” if it dropped after a minima, it would not have been a minima, at most it would have been an inflexion point and that would be very hard to attain.

    What the clucking bell are you going on about? This is inane babbling, not even streamofconsciousness BS.

    Temperature maxima: 1877, 1942, 1998; period: 65, 56 years

    No, that’s not the period, that’s the interval.

    And you missed out the following maxima:

    August 1878, August 1879, August 1880, …

    Period: 1 year +/- 1 month.

    Comment by Mark — 28 Oct 2009 @ 8:22 AM

  451. John Millett, You are SOOOO confused! Dude, the greenhouse works both day and night. The atmosphere is largely transparent in the visible, which coincides with god ol’ Sol’s emission spectrum, and the ghgs are absorbing in the IR 24/7. Maybe you should stop dealing with imaginary planets and learn the science related to this very real one.

    Comment by Ray Ladbury — 28 Oct 2009 @ 8:40 AM

  452. It’s epicycles all the way down, Mr. Millet?

    Have a look at for example this, which Google Books lets you page through a bit of this, from a Woods Hole conference proceeding:

    Biotic feedbacks in the global climatic system: will the warming feed the warming? By G. M. Woodwell, Fred T. Mackenzie
    ISBN 0-19-508640 Oxford 1995

    http://books.google.com/books?id=Tyrc32Pk5MkC&dq=%22planetary+atmosphere%22+lacking+%22greenhouse+gases%22&lr=&source=gbs_navlinks_s

    Comment by Hank Roberts — 28 Oct 2009 @ 10:14 AM

  453. #452 Hank Roberts, thanks for the reference.

    Contradicting the AGW hypothesis, the authors conclude that increases in atmospheric CO2 concentration are not the primary cause of surface warming. They refer to a “lag of days to weeks between a change in temperature and the resultant change in CO2 concentration”.

    They suggest that difficulty in balancing the carbon cycle is due to over-estimation of net carbon loss from forests. However, they say that net carbon loss from forests will increase in a warmer climate as they shrink in size, are subject to heightened attack by disease, insects and fire and increase respiration rates. Consequently, they say, growth in atmospheric CO2 concentrations will be higher than projected from human behaviour alone; and so too, via positive feedback, will the temperature increase.

    The trouble is, the authors don’t explain the positive feedback mechanism – why, if a given concentration does not cause warming, would a higher concentration do so?

    Comment by John Millett — 28 Oct 2009 @ 10:35 PM

  454. #451 Ray Ladbury, this site’s “The CO2 problem in 6 easy steps” led me astray to imaginary, atmosphere-free planets. Putting the issue as a question: Is it sensible to distribute the sun’s energy, as the referenced tutorial does in computing the magnitude of the natural greenhouse effect, over the full spherical surface when in reality it falls only over the day-time hemisphere?

    Comment by John Millett — 28 Oct 2009 @ 11:10 PM

  455. the new glamor boy on the blogs seems to be h abdussamatov the ice age cometh
    is there a short answer to this ,much appreciated

    Comment by john byatt — 31 Oct 2009 @ 2:35 AM

  456. I predict that this time next year, when there’s been another year of no more warming that this discussion will be had again. Except this time there will be another year that doesn’t fit the late 90′s warming trend.

    The problem is that the “Hockey Stick” and its pro-AGW fanatic supporters (not AGW realists, the “AGW Is My Religion” crowd) worked very well so long as there was a giant uptick, but hasn’t worked so good since.

    I’ll also note that with the Atlantic hurricane season winding down, we’ve had three years in a row of nothing at all like 2005, despite assurances that we’d better get our act together because 2006^H7^8^9^H^H10 is going to be worse.

    Forecast for 2010? Continued cooling trend, with increased denialism caused by poor science understanding and reporting. I sure hope the scientists in this crowd figure out how to explain AGW in a way that WORKS before the present flat-to-cooling period ends (my prediction — around 2020 to 2025) and the situation gets really ugly.

    Comment by FurryCatHerder — 2 Nov 2009 @ 10:29 AM

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