Friday, September 16, 2011

Whacking the Moles in their Holes


Objection has been raised about whacking moles after they have emerged from their holes and are wandering about, Trenberth, Fasullo and Abraham take up where Dessler left off and whack the blind in Remote Sensing
Issues in Establishing Climate Sensitivity in Recent Studies
Kevin E. Trenberth, John T. Fasullo and John P. Abraham
Remote Sens. 2011, 3(9), 2051-2056; doi:10.3390/rs3092051

Abstract: Numerous attempts have been made to constrain climate sensitivity with observations [1-10] (with [6] as LC09, [8] as SB11). While all of these attempts contain various caveats and sources of uncertainty, some efforts have been shown to contain major errors and are demonstrably incorrect. For example, multiple studies [11-13] separately addressed weaknesses in LC09 [6]. The work of Trenberth et al. [13], for instance, demonstrated a basic lack of robustness in the LC09 method that fundamentally undermined their results. Minor changes in that study’s subjective assumptions yielded major changes in its main conclusions. Moreover, Trenberth et al. [13] criticized the interpretation of El NiƱo-Southern Oscillation (ENSO) as an analogue for exploring the forced response of the climate system. In addition, as many cloud variations on monthly time scales result from internal atmospheric variability, such as the Madden-Julian Oscillation, cloud variability is not a deterministic response to surface temperatures. Nevertheless, many of the problems in LC09 [6] have been perpetuated, and Dessler [10] has pointed out similar issues with two more recent such attempts [7,8]. Here we briefly summarize more generally some of the pitfalls and issues involved in developing observational constraints on climate feedbacks.
It's open source, so have at it, but the take home is that a) the earth radiation budget data is to be treated as radioactive (e.g. with extreme caution). Data for the last ten years might be trusted b) Add in natural variability and you have the prototypical trap for the unwary. c) Roy Spencer and his sidekick Braswell were exceedingly unwary.

This is hilarious given the "press" that the uncertainty monster and her friends have given to Spencer and Braswell, because as Trenberth, Fasullo and Abraham point out, the SBers did not address these issues and
Addressing these questions in even a cursory manner would have avoided some of the study's major mistakes. Moreover, the description of their method was incomplete making it impossible to fully reproduce their analysis. Such reproducibility and openness should be a benchmark of any serious study.
Eli senses a certain schadenfreude there, but never mind. TFA look at the CERES EBAF data, and come to the conclusion, much as Dessler had, that the tale it tells is that ENSO is dominant in the TOA response over a decade, and that models that handle ENSO better, do better in matching the result. They extend Trenberth and Fasullo's Real Climate commentary on SB. As a matter of fact, you can pretty much use the RC commentary as the preprint. TFA look at ten year chunks of the 20th century data to eliminate the long term trend and show that contrary to SB, the analysis of ten years of the CERES data is NOT a probe of climate sensitivity, but a probe of ENSO sensitivity.


TFA show that models with good ENSO sensitivity (see middle graph above) do a reasonable job of reproducing the decadal variation, certainly within the limits of natural variability as shown in the figure above from the paper which also appeared at RC.

They add a number of points that Dessler (who took first official turn at bat by a few days) made, that the ocean in SB is a puddle, not an ocean, that the ocean heat capacity that Dessler SB (thanks to the pink editors) used is delusional, etc. anyhow, the paper is only three pages long and easy to read, so RTFR.

This trend, of mole whacking first in reputable blogs and then refining slightly for publication is, as they say, the new thing.

16 comments:

  1. " that the ocean heat capacity that Dessler used is delusional"

    that SB used?

    ReplyDelete
  2. "the ocean heat capacity that Dessler used is delusional"?

    ReplyDelete
  3. "SBers"?

    Do you suffer from dyslexia?, Eli?

    Or do you just assume the rest of us do?

    ReplyDelete
  4. DNA: "National Dyslexics Association"

    ReplyDelete
  5. I believe in create spelling and keying.

    ReplyDelete
  6. Talking of delusional, some people really do have a warped sense of reality and a distorted sense of their own worth:

    http://www.drroyspencer.com/2011/09/an-open-letter-of-encouragement-to-dr-dessler/

    Sigh.

    ReplyDelete
  7. Skepticalscience is also doing some mole whacking, this time with Pielke senior.

    http://www.skepticalscience.com/one-sided-skepticism.html

    Pielke is not playing nice, my goodness but the bunnies at SkepticalScience are tolerant...Pielke it seems, likes to ask questions, but does not like answering them.

    He also seems to be still in the habit of cherry-picking.

    Maybe Eli could shed some more light on Roger's exploits?

    ReplyDelete
  8. I like the method of Trenberth, Falluso, Abraham and Dessler : not whacking the mole, but putting several nukes in his hole so that he doesn't want to go out anymore.
    But maybe they could have done better : they could have split arguments in order to make 4 articles instead of 2. Death by multiple jabs. We should try that the next time.

    Bratisla

    ReplyDelete
  9. Roger Pielke Senior:

    "The comments keep bringing up Anthony Watt's website. First, I have worked with Anthony and he is devoted to the highest level of scientific robustness."

    See here:
    http://www.skepticalscience.com/news.php?p=3&t=125&&n=1000#62759

    Thoughts bunnies?

    ReplyDelete
  10. I half agree with Pielke about Watt's devotion to 'the highest level of scientific robustness'. Watts is indeed devoted to demanding, in cases where the evidence points in the 'wrong' direction, levels of scientific robustness so high they could never be achieved by any body of scientific evidence on any topic. On the other hand, he imposes no demands whatsoever on 'evidence' against global warming.

    Bryson Brown

    ReplyDelete
  11. In the interests of predicting the next denialist hissy-fit, I present this line from the header of Trenberth's paper:

    Received: 8 September 2011 / Accepted: 8 September 2011 / Published: 16 September 2011

    Well, I haven't checked the usual suspects, but I'd be surprised if that's not more a hindcast than a forecast by now.

    ReplyDelete
  12. TF&A was either solicited, or more likely they got in contact with the editor and said, you got a problem here and we have a comment, and they convinced Prof. Wagner.

    ReplyDelete
  13. I agree with the points given in this post but I have some doubts related to the same topic. This post is very informational. The graph given in this post helped a lot in understanding the given concept. Thanks for all the useful information you have provided.

    ReplyDelete

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