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“Misdiagnosis of Surface Temperature Feedback”

Filed under: — mike @ 29 July 2011

Guest commentary by Kevin Trenberth and John Fasullo

The hype surrounding a new paper by Roy Spencer and Danny Braswell is impressive (see for instance Fox News); unfortunately the paper itself is not. News releases and blogs on climate denier web sites have publicized the claim from the paper’s news release that “Climate models get energy balance wrong, make too hot forecasts of global warming”. The paper has been published in a journal called Remote sensing which is a fine journal for geographers, but it does not deal with atmospheric and climate science, and it is evident that this paper did not get an adequate peer review. It should not have been published.

The paper’s title “On the Misdiagnosis of Surface Temperature Feedbacks from Variations in Earth’s Radiant Energy Balance” is provocative and should have raised red flags with the editors. The basic material in the paper has very basic shortcomings because no statistical significance of results, error bars or uncertainties are given either in the figures or discussed in the text. Moreover the description of methods of what was done is not sufficient to be able to replicate results. As a first step, some quick checks have been made to see whether results can be replicated and we find some points of contention.

The basic observational result seems to be similar to what we can produce but use of slightly different datasets, such as the EBAF CERES dataset, changes the results to be somewhat less in magnitude. And some parts of the results do appear to be significant. So are they replicated in climate models? Spencer and Braswell say no, but this is where attempts to replicate their results require clarification. In contrast, some model results do appear to fall well within the range of uncertainties of the observations. How can that be? For one, the observations cover a 10 year period. The models cover a hundred year period for the 20th century. The latter were detrended by Spencer but for the 20th century that should not be necessary. One could and perhaps should treat the 100 years as 10 sets of 10 years and see whether the observations match any of the ten year periods, but instead what appears to have been done is to use only the one hundred year set by itself. We have done exactly this and the result is in the Figure..
[ed. note: italics below replace the deleted sentence above, to make it clearer what is meant here.]

SB11 appears to have used the full 100 year record to evaluate the models, but this provides no indication of the robustness of their derived relationships. Here instead, we have considered each decade of the 20th century individually and quantified the inter-decadal variability to derive the Figure below. What this figure shows is the results for the observations, as in Spencer and Braswell, using the EBAF dataset (in black). Then we show results from 2 different models, one which does not replicate ENSO well (top) and one which does (second panel). Here we give the average result (red curve) for all 10 decades, plus the range of results that reflects the variations from one decade to the next. The MPI-Echam5 model replicates the observations very well. When all model results from CMIP3 are included, the bottom panel results, showing the red curve not too dis-similar from Spencer and Braswell, but with a huge range, due both to the spread among models, and also the spread due to decadal variability.



Figure: Lagged regression analysis for the Top-of-the-atmosphere Net Radiation against surface temperature. The CERES data is in black (as in SB11), and the individual models in each panel are in red. The dashed lines are the span of the regressions for specific 10 year periods in the model (so that the variance is comparable to the 10 years of the CERES data). The three panels show results for a) a model with poor ENSO variability, b) a model with reasonable ENSO variability, and c) all models.

Consequently, our results suggest that there are good models and some not so good, but rather than stratifying them by climate sensitivity, one should, in this case, stratify them by ability to simulate ENSO. In the Figure, the model that replicates the observations better has high sensitivity while the other has low sensitivity. The net result is that the models agree within reasonable bounds with the observations.

To help interpret the results, Spencer uses a simple model. But the simple model used by Spencer is too simple (Einstein says that things should be made as simple as possible but not simpler): well this has gone way beyond being too simple (see for instance this post by Barry Bickmore). The model has no realistic ocean, no El Niño, and no hydrological cycle, and it was tuned to give the result it gave. Most of what goes on in the real world of significance that causes the relationship in the paper is ENSO. We have already rebutted Lindzen’s work on exactly this point. The clouds respond to ENSO, not the other way round [see: Trenberth, K. E., J. T. Fasullo, C. O’Dell, and T. Wong, 2010: Relationships between tropical sea surface temperatures and top-of-atmosphere radiation. Geophys. Res. Lett., 37, L03702, doi:10.1029/2009GL042314.] During ENSO there is a major uptake of heat by the ocean during the La Niña phase and the heat is moved around and stored in the ocean in the tropical western Pacific, setting the stage for the next El Niño, as which point it is redistributed across the tropical Pacific. The ocean cools as the atmosphere responds with characteristic El Niño weather patterns forced from the region that influence weather patterns world wide. Ocean dynamics play a major role in moving heat around, and atmosphere-ocean interaction is a key to the ENSO cycle. None of those processes are included in the Spencer model.

Even so, the Spencer interpretation has no merit. The interannual global temperature variations were not radiatively forced, as claimed for the 2000s, and therefore cannot be used to say anything about climate sensitivity. Clouds are not a forcing of the climate system (except for the small portion related to human related aerosol effects, which have a small effect on clouds). Clouds mainly occur because of weather systems (e.g., warm air rises and produces convection, and so on); they do not cause the weather systems. Clouds may provide feedbacks on the weather systems. Spencer has made this error of confounding forcing and feedback before and it leads to a misinterpretation of his results.

The bottom line is that there is NO merit whatsoever in this paper. It turns out that Spencer and Braswell have an almost perfect title for their paper: “the misdiagnosis of surface temperature feedbacks from variations in the Earth’s Radiant Energy Balance” (leaving out the “On”).


282 Responses to ““Misdiagnosis of Surface Temperature Feedback””

  1. 51

    38, Lynn Vincentnathan

    Just garbage, as far as I know (and some pretty outlandish garbage at that), but if you provide a link to where those citations are listed, I’ll be happy to do a little leg work for you, if I have time myself, to try to track down the nature of those “proofs.”

  2. 52
    Chris Colose says:

    simon,

    The “reference system” can be defined in different ways, and if you change the reference system then you change the feedback.

    But it is customary in climate feedback analysis to make the reference system the Planck radiative response, in part because it is well understood. This just says that a warmer planet will increase its emission to space (based on the Planck law). The dependence of the IR emission on temperature is about 3.2 W/m2 per Kelvin. It is this baseline from
    which “positive” or “negative” feedbacks are traditionally referenced. Positive feedbacks lower this value, so that for the same perturbation (e.g., increased CO2), the response is a bit more “sluggish” and the temperature must rise more in order for equilibrium to be established.

    The extreme end of this would be when the planets IR emission does not increase with temperature, so the temperature continues to rise whenever a radiative imbalance can be sustained. This also defines the runaway greenhouse scenario.

  3. 53
  4. 54
    Greg Simpson says:

    @David Wilson
    I think you are setting too high a standard for blog posts. Since you made it through moderation, though, I think a comma would be fine but a “the” would help. That is: “what we can produce, but the use…”

  5. 55
    JamesD says:

    “What this mismatch is due to — data processing, errors in the data or ***real problems in the models*** — is completely unclear.” — Gavin Schmidt

    So are you admitting that this paper *MAY* have identified “real problems” in the models?

    [Response: This is an odd game of gotcha you appear to be playing. Whenever someone does an analysis and shows a difference between a model and the observations there is always the possibility you have revealed something interesting about model imperfections (since no-one is of the opinion they are perfect). In some cases that imperfection is well known (like the double ITCZ problem in tropical rainfall), sometimes it isn’t, and other times the data is wrong. Very often though it is the comparison that is faulty (comparing apples to oranges for instance), or the implication that is at fault and that seems to be the case here – the big differences in this diagnostic between different models is not related to overall climate sensitivity (which you can easily see in Spencer’s figures), but between models that have a reasonable ENSO or not (see above). Some models did not have sufficient ENSO variability (GISS-ER was one) and this appears to affect this particular diagnostics. It is however, unrelated to climate sensitivity. – gavin]

  6. 56
    JamesD says:

    The third graph “All models” shows that the actual satellite data regression coefficient is more than double than what is predicted by “all models”. Granted, it is inside the uncertainty region, but this is what I would call “something interesting about model imperfections”. Thanks to Dr. Spencer for contributing to science. Face it, even if this turns out to be an ENSO artifact, it still has contributed to our knowledge of the climate. And I would also caution people to differentiate what Dr. Spencer actually wrote, and what was written in the Forbes article. They are very different.

    [Response: ENSO isn’t an artifact. And this is one of the cases where averaging models together doesn’t make much sense. Panel a and b show clearly that models with and without good ENSO signals make all the difference to this diagnostic, which makes a lot of sense because over the 10 years of the data, the most important source of variability is related to ENSO. So had Spencer+Braswell said ‘look, the data allows us to see how temperature and radiation co-evolve over ENSO cycles, and some models don’t do a good job – probably because of their inability to reproduce ENSO variability’ – no one would have criticised them. Instead, they erroneously link it to climate sensitivity and encouraged (via their press release) all manner of nonsense. – gavin]

  7. 57
    JamesD says:

    I am quite sure SB11 did not average together the models. I only read through it once, but I believe they study 6 models. Unfortunately both servers with SB11 are currently overwhelmed, and I can’t verify this. Whether any of these 6 models (assuming my memory is correct) have “good ENSO signals”, I do not know.

    An interesting question.

  8. 58
    R. Gates says:

    I certainly appreciate the efforts taken by those of you who are PhD’s to respond to this paper, and think they are certainly worthwhile for those of us non-PhD’s who seriously want to understand the merits (or lack thereof) of such research. So thank you…

    On a the larger question of forcing vs. feedback I do have some questions, and it seems the more I read, the more confusing it becomes. On the broadest scope, aren’t positive feedbacks actually just a new forcing? Take Milankovitch cycles and CO2 for example. At least the notion is that small changes in forcings in this astronomical cycle alter insolation on the planet, releasing more CO2 from the oceans, which in turn, through a positive feedback process, causes more warming (i.e. become a forcing itself). So in this way, what was initially an effect of a forcing(i.e. outgassing of CO2) becomes a new forcing that amplifies that initial forcing through positive feedback.

    In the case of clouds, it seems the entire issue is that sometimes they are forcings (i.e. downwelling longwave from stratus at night for example) and sometimes are serve to reduce forcing by reflecting more sunlight. Certainly this issue of the uncertainty of the net effect of clouds is complex as they can sometimes provide positive feedback and sometimes they can provide negative feedback.

    So at least the current way I understand it, a forcing in the climate system is something that causes a change to the system beyond the natural variability of weather. Positive feedbacks can become forcings of their own, and negative feedbacks serve to dampen the effects of the initial forcing. Clouds can be both?

  9. 59
  10. 60
  11. 61
    Chief Hydrologist says:

    ‘The canonical way to think about clouds is that they are a feedback—as the climate warms, clouds will change in response and either amplify, (positive cloud feedback) or ameliorate (negative cloud feedback) the initial change.

    What this new paper is arguing is that clouds are forcing the climate, rather than the more traditional way of thinking of them as a feedback.’ Dessler today

    ‘Much work has been done on ENSO over the past few decades and pretty much everyone agrees that it’s a stochastically triggered, coupled dynamic mode of the atmosphere, ocean system. I’ve never seen any suggestion that it’s triggered by clouds. To the extent that clouds amplify ENSO, that’s the cloud feedback, and that is what I measure in my paper.’ Dessler yesterday

    ‘Finally, since much of the temperature variability during 2000–2010 was due to ENSO (Dessler 2010) we conclude that ENSO-related temperature variations are partly radiatively forced. We hypothesize that changes in the coupled ocean-atmosphere circulation during the El Niño and La Niña phases of ENSO cause differing changes in cloud cover, which then modulate the radiative balance of the climate system.’ Spencer and Braswell 2011

    ‘It is not controversial to state that climate models are deficient in terms of tropical variability in the atmosphere on many timescales [Lin et al., 2006; Lin, 2007] and a more realistic simulation of ENSO events in coupled simulations remains a high priority for model developers. During El Niño, the warming of the tropical eastern Pacific and associated changes in the Walker circulation, atmospheric stability, and winds lead to decreases in stratocumulus clouds, increased solar radiation at the surface, and an enhanced warming.’ Trenberth et al 2009

    S&B11 say that the CERES radiative flux differs from the models. Uncontroversial. That climate sensitivity can’t be calculated this way because of ENSO radiative and non-radiative feedbacks. Not surprising.

    It seems veracity of science communication is a casualty of the climate wars.

  12. 62
    Pete Dunkelberg says:

    R. Gates …aren’t positive feedbacks actually just a new forcing?

    Or are you confusing yourself semantically? Yes a positive feedback makes it even warmer, but it is a feedback because it happened as a consequence of a prior forcing. And yes, different types of clouds may be either positive or negative feedbacks. On balance, slightly positive it appears.

    But the idea that clouds are an original forcing, not a feedback, thus much more CO2 may be burned before the planet is ruined, is incoherent. What energy source causes the supposed increase in clouds (which cause warming that gets blamed on innocent CO2)? Meanwhile how can CO2 (without feedbacks, notably water vapor) cause the warming that Spencer admits it does, and somehow not cause the water vapor feedback (which would explain clouds)?

  13. 63
    RW says:

    Gavin,

    “I gave you the link above so that you could perhaps learn something. I still urge you to do so.”

    I did follow the link and read what is there. I didn’t really see anything I’ve brought up addressed.

    [Response: Then you aren’t understanding what you saying. Your claim is that climate sensitivity is defined by the solar fluxes, upward long wave flux etc. Use the terminology and algebra in that post to calculate what you think the sensitivity is, compare it to the actual sensitivity and then think about why they are different, – gavin]

    Let me ask you this question: How is the often referenced 1.1 C of ‘intrinsic’ warming from 2xCO2 derived? Also, the +6 W/m^2 incoming surface flux needed for the 1.1 C rise in temperature – can you explain where this is coming from?

  14. 64
    Jan says:

    I do believe the fossil fuel industry is scrambling desperately as they see the global events unfolding. This is clearly about ideology and politics. Spencer reportedly also does not believe in evolution. I think that says much about this and the interests he represents.

  15. 65
    andrewo says:

    FYI post #6 – richard pauli – is flatly wrong. click through to the last result to check the count. it doesn’t take long. http://goo.gl/WSFCO

    more info: http://blog.xkcd.com/2011/02/04/trochee-chart/

  16. 66
    Edward Greisch says:

    34 Kevin McKinney: ““vast morass of the collective denialist mind. . .” Surely it’s only half vast?”

    The minds are few and far between but the morass is vast. I continue to read social science stuff to try to figure it out. I just finished “The Authoritarians” by Bob Altemeyer, which is downloadable free from http://home.cc.umanitoba.ca/~altemey/

    The human mind is indeed amazing[ly flawed]. The more I know the less hope I have.

    Please tell me a textbook that covers “Inter-Decadal Span of Regression.”

  17. 67
    RW says:

    Gavin,

    “Then you aren’t understanding what you saying. Your claim is that climate sensitivity is defined by the solar fluxes, upward long wave flux etc. Use the terminology and algebra in that post to calculate what you think the sensitivity is, compare it to the actual sensitivity and then think about why they are different.”

    Can you be more specific and/or ask me some specific questions?

    You use the term ‘actual sensivity’. What do you mean by this? Also, can you answer the question I posed in my last post?

    [Response: In the simple model of the greenhouse effect one can write down exactly what the climate sensitivity is as a function of a change in the solar irradiance or greenhouse gas (via the absorption). One can also calculate the ratio that you claim defines sensitivity. Compare them. Note that they are different. And then think about why that is. – gavin]

  18. 68
    anthropoggedon says:

    [Response: I’m not sure I follow you. The regressions he is doing are on the deseasonalized monthly anomalies – there is no selection there. – gavin]

    My critique is not related to the model as that is beyond me, I am merely viewing his conclusion backwards that:

    “Yet, as seen in Figure 2, we are still faced with a rather large discrepancy in the time-lagged
    regression coefficients between the radiative signatures displayed by the real climate system in satellite
    data versus the climate models. While this discrepancy is nominally in the direction of lower climate
    sensitivity of the real climate system, there are a variety of parameters other than feedback affecting
    the lag regression statistics which make accurate feedback diagnosis difficult.”

    He claims a discrepancy in the lower climate sensitivity which I think is flawed by his premise if you look at the graph

    http://thumbsnap.com/i/5S5vCMlG.png

    You can clearly see that he does not take the whole period needed. This might be a crude example but apologies, he claims that there is lower sensitivity because he only takes la nina periods into account and discards el nino, I do not know how this would affect his model..

  19. 69
    Settled Science says:

    @ R. Gates, #58

    You are getting confused by Spencer’s incorrect use of terminology.

    Anthropogenic greenhouse gases are a forcing agent because we can DECIDE to increase or decrease our output of them, INDEPENDENT of what the climate is doing.

    Solar radiation is a forcing agent because it increases or decreases INDEPENDENT of what the climate is doing.

    Clouds and water vapor are feedbacks because they are DEPENDENT on other factors within the climate.

    Think of “forcings” as independent variables and “feedbacks” as dependent variables, and you should quickly understand why Spender’s “internal forcing” paradigm is nonsense.

  20. 70
    Craig Nazor says:

    RW – the fact that the climate sensitivity, without feedbacks, is around 1.2ºC is completely non-controversial. It is based on physical properties of CO2 gas that have been known for almost 2 centuries, and cogent explanations of how that number is derived are easy to find. Here is one:

    http://www.skepticalscience.com/empirical-evidence-for-co2-enhanced-greenhouse-effect-advanced.htm

    This is all based on observable phenomena. How the three primary known feedbacks increase the climate sensitivity to 3ºC, with a range of uncertainty from 2ºC to 4.5ºC, is outlined in the IPCC AR4.

    If you disagree with these figures, then what are your figures, and what scientific evidence do you have to support those figures? Or do you have any figures at all? “That’s impossible, it can’t be, it’s too extraordinary!” are not really scientific arguments.

  21. 71
    simon abingdon says:

    It appears that the party line of the forcing/feedback issue is that the climate is the result of external forcings and everything that happens within the climate system is a feedback from these external forcings, with the important exception of human-produced CO2 CH4 SO2 (etc) which are to be regarded as independent forcings.

    Why should some CO2 be regarded as a forcing while the rest is regarded as a feedback? The provenance of a molecule makes no difference to its subsequent behaviour. And can we be sure there are not forcings within the climate system (perhaps to do with oscillations in the biosphere at large for example) which science has yet to investigate?

    It seems to me that the discipline of climatology is not so much concerned with developing a wider understanding of climate as providing a focus for establishing the possible extent of human influence on it. Maybe such exclusive preoccupation is a hindrance.

    [Response: You have this very wrong. The forcing/feedback definition is simply a distinction that allows something that is fairly universal (the feedbacks) to be examined independently of the particular causes (forcings). That the response of the system to increasing solar and increasing GHGs is similar in terms of feedbacks is a very important result. This is important for paleo-climates (the PETM, LGM etc.) as well as the situation today, but I get very tired of people claiming that general results are only because of some supposed political agenda. Please stick to the science or go somewhere else where people like discussing speculations untethered to reality. – gavin]

  22. 72
    simon abingdon says:

    “Maybe such exclusive preoccupation is a hindrance”. Or not, depending on your agenda.

  23. 73
    Marie says:

    #15: richard pauli
    13 J Bowers…right you are. However a PR success is not measured by the sides of an argument… it is measured by putting the issue in front of the audience. Success is by how many people see the controversy continue. The promotion is for the very idea of dispute. Logic is irrelevant to a PR campaign. A wrong paper creates a bigger controversy – and more buzz – than a correct one.
    —-

    But what is happening on the counter-PR side? If logic and solid science is marketed well, and there were enough passionate proponents of good science, and the scientific method, to “echo chamber” as noisily as the deniers do, then there’d actually be a fight. Even highly-conditioned Fox viewers respect the view of the majority of scientists (though a lower proportion of them believe global warming is happening than do viewers of other news channels). IPCC does a great job on collation, but, frankly, a sh*t job of the PR– it is quiet when it should be defending its methods, its scientists, its team. As the producers of THE definitive accepted collective body of climate change related science– on which, btw, the entire Convention on climate change is based, and around which all international climate discussions revolve– they are awfully quiet in all this. I’m sorry, but that’s irresponsible. IPCC does NOT have to get into political discussions to defend its aggregation of the science. AR4 reads like Old Testament revelations; and it errs on the side of the conservative. Communications is about repeated messages combined with new and supportive data– and there is more new and supportive (and SOUND) data emerging all the time than there is against.

  24. 74
    Phil Scadden says:

    Numerous people have tried valiantly to educate RW about this piece of nonsense over at Skepsci. As far as I can see, he either cant learn or wont.

  25. 75

    #67–um, Ed, it was a pun. . .

  26. 76
    Dave123 says:

    Spencer’s pugnacious attitude about the whole thing is revealed in his own blog:

    http://thegwpf.org/science-news/3453-new-paper-the-misdiagnosis-of-surface-temperature-feedbacks.html

    If anyone can verify an IPCC supporter in the GWPF as they claim please post. Any money checking on GWPF and Lord Lawson (another Lord? isn’t Monckton more than enough?)

  27. 77
  28. 78
    RW says:

    Gavin,

    “In the simple model of the greenhouse effect one can write down exactly what the climate sensitivity is as a function of a change in the solar irradiance or greenhouse gas (via the absorption). One can also calculate the ratio that you claim defines sensitivity. Compare them. Note that they are different. And then think about why that is.”

    I need you to be more specific. I’m not quite sure what you are referring to. Which formula specifically?

    And BTW, I’m not claiming that emitted surface radiation/incoming solar radiation precisely ‘defines’ sensitivity – I’m saying it establishes a measured boundary of sensitivity, especially in such a highly dynamic yet tightly constrained system. That the sensitivity to a non-direct ‘forcing’ or slight imbalance such as from 2xCO2 will be greater than this is an extraordinary claim requiring extraordinary proof.

    [Response: You need me to more specific? I really don’t want to have to spell it out for you since working it out for yourself is likely to be the only way you will make any progress (if indeed you make any). Work out what the connection is between your ‘bound on sensitivity’ and the actual sensitivity in a simple model. – gavin]

  29. 79
    chris says:

    62. R. Gates …aren’t positive feedbacks actually just a new forcing?

    Consider a large rise in atmospheric [CO2]. The troposphere warms as a result (say by 1 oC) and induces a rise in atmospheric [H2O vapour]. The troposphere warms further due to the water vapour feedback (let’s say the water vapour rise adds an additional x oC). Your idea might be that this additional warming results in an additional temp rise due to recruitment of more water vapour (i.e. sounds like the water vapour feedback becomes a new forcing). In fact the total temp rise will be 1 + x + x^2 + x^3…

    …which is 1/(1-x).

    So if the primary water vapour feedback is 0.5 oC (say), then the total temperature rise is 2 oC (due to enhanced [CO2] plus water vapour feedback).

    What’s the origin of this 2 oC temperature rise. It’s all due to the rise in [CO2]. Of course the proximate cause of the extra (feedback) 1 oC from the water vapour is due to the water vapour. But the ultimate source is the rise in [CO2]. The [CO2] is the forcing; the change in [water vapour] and its associated contribuion to warming is a feedback. The same would apply if the primary [CO2] and feedback [water vapour] warming produced a reduced albedo (ice melt) with a further feedback contribution to warming.

  30. 80
    Richard says:

    The Spencer – Braswell paper was also featured prominently on Climate Depot, “A project of CFACT” — Committee for a Constructive Tomorrow. CFACT is a 501(c)3 supported by ultra-conservative causes. Climate Depot is a cesspool of anti-global warming propaganda.

  31. 81
    Jeffrey Davis says:

    “Or not, depending on your agenda.”

    Got Projection?

  32. 82
    Jim Eager says:

    Simon Abingdon @71, although it is true that the provenance of a [greenhouse gas] molecule makes no difference to its subsequent behaviour in the atmosphere, your problem of understanding stems from your failure to grasp that those molecules can act as either a feedback or as a forcing, depending on how they got into the atmosphere.

    When added as a result of some initial direct forcing, say an increase in solar insolation that causes CO2 or CH4 molecules to be emitted by a warming ocean or thawing permafrost, for example, they would be acting as a feedback to that initial forcing.

    But when CO2 is added directly in the absence of some initial forcing, such as by the deliberate burning of sequestered fossil carbon, then its addition is not a feedback to some initial forcing, but rather it is itself a direct forcing. No change in earth’s energy budget or in the coupled ocean-atmosphere climate system caused the CO2 to be emitted to the atmosphere in that case, only the deliberate burning did.

  33. 83
    SecularAnimist says:

    In comment #56, JamesD wrote: “I would also caution people to differentiate what Dr. Spencer actually wrote, and what was written in the Forbes article. They are very different.”

    Gavin replied: “… Instead, they erroneously link it to climate sensitivity and encouraged (via their press release) all manner of nonsense …”

    Gavin, by “press release”, are you referring to the Forbes op-ed by the Heartland Institute’s Taylor, or the University of Alabama’s press release?

    As I understand Spencer’s study from the abstract and from the helpful discussions provided by the climate scientists here, it appears that the UA press release does accurately describe the content and claims of the paper (whatever their merit or lack thereof), in lay terms.

    Whereas the Forbes article appears to exaggerate and inflate Spencer’s actual claims into something resembling a sweeping assertion that all of climate science has had a “hole blown through it”, combined of course with belligerent ideological ranting (e.g. repeating the phrase “alarmist models” at least a dozen times).

    It would be interesting to know if Spencer has endorsed the Forbes piece. Presumably such an article would get his review and approval before publication?

    Has Spencer made public statements that go beyond what’s in the actual paper itself? Perhaps on the Rush Limbaugh radio program, where he is the self-proclaimed “Official Climatologist”?

    [Response: I doubt very much Forbes got Spencer’s permission to say what they said about his article, and I very much doubt he would ‘endorse’ it. That said, it would be awfully nice to see him rebut it, since in the paper itself he says nothing (even if you take his study as accurate) that supports what the Forbes article says.–eric]

  34. 84
    Ray Ladbury says:

    Simon Abingdon: “It seems to me that the discipline of climatology is not so much concerned with developing a wider understanding of climate as providing a focus for establishing the possible extent of human influence on it.”

    THIS is absolute horse doo-doo. Have you even cracked a climatology text or journal in the past decade. Only a minor portion of what you will find there relates directly to anthropogenic climate change.

    Really, Simon, don’t you have a Library somewhere near you so you can do some research before spouting off an utterly ignorant and stupid opinion.

  35. 85
    Ray Ladbury says:

    Marie@73,
    The problem is not with people accepting what science tells them. When science delivers good news, it receives accolades. The problem comes when we try to tell people what they don’t want to hear. Americans love to hear that chocolate, wine and coffee are good for them. Research revealing that we are a bunch of lardasses is less well received.

  36. 86
    One Anonymous Bloke says:

    Simon Abingdon #71, #72: “Party line…”? Your “agenda” is showing (again). The difference between a forcing and a feedback is so basic even I understand it. The naturally occurring CO2 is a forcing, not a feedback as you state. The additional anthropogenic CO2 increases this forcing. “It seems to me” that your inability to grasp this is being driven by something other than genuine stupidity.

  37. 87
    Jim Eager says:

    Further to my comment @81:
    The burning of sequestered carbon need not be a deliberate human act, it could be from an entirely natural event, say lightning-ignited large scale forest fires during a normal drought event, or the ignition and slow burn of an exposed coal bed. The injected CO2 doesn’t even need to be from combustion, it could be due to a temporary (on a geologic time scale) excess of volcanic CO2 emissions above the natural rate of uptake of CO2 by silicate rock weathering.

    In all of the above cases the injection of CO2 would *not* be due to changes in earth’s energy budget or in the coupled ocean-atmosphere climate system, so they would not be feedbacks to some initial forcing but instead would themselves be an initial forcing.

  38. 88
    simon abingdon says:

    #81 Jim Eager “those molecules can act as either a feedback or as a forcing”.
    How can you tell which are which?

  39. 89
    Hank Roberts says:

    > the satellite data shows the climate system starting to shed energy more
    > than three months before the typical warming event reaches its peak.
    > “At the peak, satellites show energy being lost while climate models
    > show energy still being gained,” Spencer said.
    > This is the first time scientists have looked at radiative balances
    > during the months before and after these transient temperature peaks.

    — that’s from the UA press release.

    Are those all supported by the paper?
    How much of ‘the climate system’ do the satellites cover, how much is extrapolated?
    What happens during transient temperature valleys?
    Does the result average out including peaks and valleys, over longer spans?

  40. 90
    chris says:

    I have a couple of questions about the graphs in your top article:

    1. You regress TOA radiation against surface temperature, and the y-axis gives values in W.m-2.K-1. A value of 2 indicates that the TOA radiates an excess 2 W.m-2 per 1 oC rise in surface temperature (at that particular lag time and averaged over the 10 year period).

    First Q: Is this globally-averaged?

    2. For the models that deal well with ENSO there is an unlagged component of TOA radiation, but the maximum response occurs with a lag of 2-3 months.

    Second Q: What’s the origin of this lag? Is it simply the time for the troposphere to fully respond to changes in surface temperature? Or is it due to a water vapour feedback that (for El Nino) amplifies the tropospheric temperature change (and thus TOA radiation) during the lag period?

    3. Regressions for negative lags are shown.

    Third Q: Do negative lags have any sensible meaning? Or are these simply influences on TOA radiation resulting from surface temperature events that occurred earlier than the zero lag-timed event?

    4. The amplitude of the regressions.

    Fourth Q: How does this relate to the expected change in TOA arising for example from application of the Stefan-Boltzmann eq.? Is 2 W.m-2.K-1 smaller, equal, or larger than the expected S-B value? Presumably the amplitude is what Spencer uses to assess the rapid component of feedback on which he bases his interpretations re climate sensitivity..

  41. 91
    Carrick says:

    One other brief comment: I think Kevin is just slightly mixed up in his terminology as well, or maybe it’s just that his climate-speak is different than my physics-speak. In any case…

    If you a shift in cloud patterns in relationship to a shift in the ENSO pattern, that could reflect a change in net albedo, which in turn of course would alter radiative forcing. In my parlance, this would be an example of a parametrically forcing associated with internal variability (as opposed to an example of external aka exogenous forcing.

    So in principle, you should be able to use the modulation of radiative forcing by ENSO to estimate climate sensitivity, though it would appear to me you’d need something closer to a full-scale model than the parametric model used by Spencer.

  42. 92
    tamino says:

    Re: response to #82 (SecularAnimist)

    [Response: I doubt very much Forbes got Spencer’s permission to say what they said about his article, and I very much doubt he would ‘endorse’ it. That said, it would be awfully nice to see him rebut it, since in the paper itself he says nothing (even if you take his study as accurate) that supports what the Forbes article says.–eric]

    Here’s what Spencer himself said about the Forbes article on WUWT:

    The short answer is that, while the title of the Forbes article (New NASA Data Blow Gaping Hole In Global Warming Alarmism) is a little over the top (as are most mainstream media articles about global warming science), the body of his article is — upon my re-reading of it — actually pretty good.

  43. 93
    Chris Colose says:

    SecularAnimest, Eric Steig,

    The only thing I have seen Spencer say directly about the Forbes article was:

    ¨The short answer is that, while the title of the Forbes article (New NASA Data Blow Gaping Hole In Global Warming Alarmism) is a little over the top (as are most mainstream media articles about global warming science), the body of his article is — upon my re-reading of it — actually pretty good.¨

  44. 94
    Karmakaze says:

    Looks like Spencer is standing by the Forbes article:

    “The short answer is that, while the title of the Forbes article (New NASA Data Blow Gaping Hole In Global Warming Alarmism) is a little over the top (as are most mainstream media articles about global warming science), the body of his article is — upon my re-reading of it — actually pretty good.

    About the only disconnect I can see is we state in our paper that, while the discrepancy between the satellite observations were in the direction of the models producing too much global warming, it is really not possible to say by how much. Taylor’s article makes it sound much more certain that we have shown that the models produce too much warming in the long term. (Which I think is true…we just did not actually ‘prove’ it.)”

    http://wattsupwiththat.com/2011/07/30/fallout-from-our-paper-the-empire-strikes-back/

  45. 95
    One Anonymous Bloke says:

    Further to Jim Eager #81, #87: perhaps I am a little confused – I can see why additional CO2 released from the oceans as a result of an increase in solar energy can be considered a feedback, but (if I may be allowed a musical metaphor) isn’t one of the characteristics of a feedback that it stops when you switch the amplifier off? Additional CO2 acts as a forcing no matter what else happens. Am I trying to oversimplify?

  46. 96
    Jim Eager says:

    I explained how, Simon. Try reading for comprehension.

    The source of the present increase in atmospheric CO2 has until recently been entirely due to human action, primarily direct injection by combustion of fossil carbon and from our land use changes, although we are starting to see natural feedback emissions in response, such as increased thawing of permafrost and methane hydrates and rising atmospheric water vapour due to the warming caused by our additions.

  47. 97

    57 James D
    Here you go: http://www.thescienceisstillsettled.com/references/bogus
    The rest of the site is a work in progress, but I can upload one pdf easily enough.

    89 Hank Roberts

    I think I can answer some of your questions, not as an expert, but with direct references to the portions of the paper which are the basis of my reasoning, so you can decide how much salt to take with each of my attempts. I hope most of the following is correct.

    > the satellite data shows the climate system starting to shed energy more
    > than three months before the typical warming event reaches its peak.
    > “At the peak, satellites show energy being lost while climate models
    > show energy still being gained,” Spencer said.
    > This is the first time scientists have looked at radiative balances
    > during the months before and after these transient temperature peaks.

    — that’s from the UA press release.

    HR: “Are those all supported by the paper?”

    Just looking at inflection points of the LW and SW radiation in 2b, three months looks about right. After a peak in LW, there is a lag until the next peak in SW, and it’s definitely not always the same, but it is definitely always less than a year. Maybe a little bit “more than 3 months” as their press release states, sure.

    Press Release: “At the peak, satellites show energy being lost while climate models show energy still being gained,” Spencer said.

    I cannot say whether that’s true in the general case, but for the six climate models analysed in SB2011, the lags in Figure 3 look like about 9 months.

    Press Release: “This is the first time scientists have looked at radiative balances during the months before and after these transient temperature peaks.”

    Gosh, that doesn’t seem likely. :-)

    Hank: “How much of ‘the climate system’ do the satellites cover, how much is extrapolated?”

    I don’t pretend to know the exact coverage of the CERES data set, but off-hand, one of the problems I’ve read about repeatedly with satellite measurements for climate science is that satellites tend to orbit about the equator, whereas the impacts of climate change are greatest at the poles. On page 5, Spencer & Braswell refer to temperature data from 60°N to 60°S (ie around the equator, and stopping 30° from each pole) in a way which to me implies that they do extrapolate their findings from non-global data.

    Global monthly anomalies in surface temperature were similarly computed from the HadCRUT3 surface temperature dataset [12] between March 2000 and June 2010. In addition to globally averaged anomalies, we also computed area average anomalies over the ice-free oceans, between 60°N and 60°S, for all variables. (Spencer & Braswell 2011, page 5)

    That only makes sense to me if that matches a limitation in their satellite data, in which case, yes, any inferences they make beyond that 60° N to 60° S range, or which they claim are true globally, would be extrapolations.

    Hank: “What happens during transient temperature valleys?
    Does the result average out including peaks and valleys, over longer spans?”

    The word “variation” appears many, many times throughout the paper, and the following excerpt from page two suggests to me that the entire paper is based on a statistical model only of variations, ie, what the rest of the scientific community calls “natural variability.”

    For the interannual temperature climate variability we will address here, the heat capacity Cp in Equation (1) is assumed to represent the oceanic mixed layer. (Note that if Cp is put inside the time differential term, the equation then becomes one for changes in the heat content of the system with time. While it is possible that feedback can be more accurately diagnosed by analyzing changes in the heat content of the ocean over time [6], our intent here is to examine the problems inherent in diagnosing feedback based upon surface temperature changes.) (Spencer & Braswell 2011, page 2)

    In my experience, phrases like “we will address here” always refer to the topic of the paper. In this case, that clause is “the interannual temperature climate variability.” So it looks to me like they know very well that all they have is a correlation between Random Fluctuation A and Random Fluctuation B and nothing that could possibly help understand or explain any multi-decade surface temperature trend, such as that from 1975, much less any useful predictive model.

  48. 98
    Paul S says:

    #95, One Anonymous Bloke – ‘isn’t one of the characteristics of a feedback that it stops when you switch the amplifier off?’

    If you switched off the power to the Earth there wouldn’t be any feedbacks either. To continue the metaphor, increasing or decreasing the power of an amplifier is a forcing, which will change the amount of feedback.

    ‘Additional CO2 acts as a forcing no matter what else happens.’

    All feedbacks cause a change in radiative forcing so using that definition would mean there are no feedbacks.

    One way to look at it is that there isn’t any absolute distinction between forcing and feedback – the distinction lies in conceptualising what question we’re trying to answer. In this case the question could be ‘What happens if we double the amount of CO2 in this system?’ This has a direct forcing effect but it also has a number of side-effects, one of which could be the release of extra CO2 from various sinks.

    Hopefully you can see from this that something is a forcing if it is explicitly defined in our scenario. In this case our scenario was ‘Doubled CO2′ so that is our forcing. Anything that happens which isn’t a direct radiative effect of doubled CO2 is a feedback.

  49. 99
    Jim Eager says:

    Further to my reply to Simon @88, where he asks: “How can you tell which are which?”

    Other than for determining the source or cause of the flux (by comparing isotope ratios, for example), we really don’t care about the origin of any individual CO2 molecule. What we are interested in is the source and cause of the aggregate change. If the net change is mainly in response to a known forcing then it is a feedback. If it is mainly a direct increase independent of any measurable forcing then it is itself a forcing. The net effect will be to warm the atmosphere and surface, regardless of if it is as a feedback or as a forcing, which may be your point.

    If you are heading down the road of questioning the source of the present increase in CO2, and thus if it is a forcing or a feedback, I’m not interested.
    There are multiple independent lines of evidence that support that it is mainly from burning fossil carbon. See here.

  50. 100
    Jim Eager says:

    Bloke @95, the feedback does stop after the initial forcing ends and the system reaches a new equilibrium state, but that takes a long enough time to happen that it takes place well after the initial forcing has declined or ended.

    For example, the peak increase in northern hemisphere solar insolation occurred well before the end of the last glaciation, yet the peak warming produced by that insolation plus all feedbacks occurred several thousand years later during the Holocene Climate Optimum.


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