Tuttle Buttle Rebuttal Scuttled

Posted: September 6, 2011 by tallbloke in atmosphere, climate, Energy, flames, Ocean dynamics, Politics

Click for movie clip

It seems Andy Dessler is so confident of his ability to see off those pesky contrarians Lindzen and Choi and Spencer and Braswell that he takes them all on in his rebuttal paper now in press with GRL:

Cloud variations and the Earth’s energy budget
A.E. Dessler
Dept. of Atmospheric Sciences
Texas A&M University
College Station, TX

I’ve had a quick look through the paper and it’s rubbish.

It opens with this:

““Abstract: The question of whether clouds are the cause of surface temperature changes, rather than acting as a feedback in response to those temperature changes, is explored… ”

Bzzzzzzt. Logical fallacy of the excluded middle (false dichotomy). these are not the only two possibilities. Spencer is saying it’s the mixture of the two which confounds diagnosis of feedback amplitude (and sign in the warmist case). – FAIL

Then in the introduction there is this gem:

“In recent papers, Lindzen and Choi [2011, hereafter LC11] and
Spencer and Braswell [2011, hereafter SB11] have argued that reality is reversed:
clouds are the cause of, and not a feedback on, changes in surface temperature.”

Bzzzzzzt. Strawman argument. L&C and S&B do not argue that clouds are the cause of changes in surface T, but that unforced cloud variation contributes to changes in surface T. – FAIL

What about the meat? Dessler says:

“the conclusion here is robust: energy trapped by clouds
can explain only a few percent of the surface temperature changes. This is
consistent with previous work showing that heating of the surface and atmosphere
during ENSO comes from ocean heat transport [e.g., Trenberth et al., 2002;
Trenberth et al., 2010] and it means that clouds were not causing significant climate
change over this period.”

So according to Dessler the only way clouds can affect surface T is by absorbing energy on its way out of the Earth’s climate system. But Andy, what about the energy that clouds reflect which thereby never gets into the Earth’s climate system? No wonder Dessler thinks cloud feedback is positive, he ignores more than half of their effect. Doh! – FAIL

So, let’s head for the conclusion. Andy Dessler says:

“observations presented by LC11 and SB11 are not in
fundamental disagreement with mainstream climate models, nor do they provide
evidence that clouds are causing climate change. Suggestions that significant
revisions to mainstream climate science are required are therefore not supported.”

Well, Andy was the one who said earlier in the paper that if L&C and S&B were right
“then significant revisions to climate science may be required” [my bold]
So far as I’m aware neither Spencer nor Lindzen have said this. So since it’s his own suggestion which isn’t supported, we can conclude it is another strawman argument. – FAIL

So far as the observations not being in “fundamental disagreement with the models” is concerned, it comes down to a question of just how much disagreement there has to be for the models to be wrong enough to lead to the kind of mis-estimation of cloud feedback L&C and S&B suspect. I’ll leave that to them to determine. Let’s hope that they can get a rebuttal of this sorry assed piece of nonsense published before the AR5 cut-off date.

I see Lubos Motl has also made a critique of Dessler’s paper, far more amusing than my own:


[UPDATE 07/09] Steve McIntyre has a nice take on this, with a kicker in the tail showing that now Dessler goes along with Spencer’s four month lag, his 2010 positive cloud feedback becomes negative. 🙂


  1. Ed_B says:

    published by reote sensing? Should be GRL

  2. PaulM says:

    Not to mention the typo in equation 1, which seems to have escaped the notice of the author and the referees.

  3. Stacey says:

    Sorry for my ignorance but do clouds also absorb incoming energy as well as reflecting.

    Take care

  4. tallbloke says:

    Hi Ed_B and welcome to the talkshop. Given that the mainstream scientists like Dessler prefer to write a new paper as a rebuttal rather than replying to the paper in the original journal, I think it reasonable that Lindzen and Choi or Spencer and Braswell may wish to do the same. They probably have more chance of a quick turnaround too.

    Paul, what typo? I missed it too.

    Stacey, they certainly do. More of it than models predict in fact.

  5. p solar says:

    Equation 1 is a lie .

    Spencer et al does not attribute any terms to cloud or sea , this is Desslers own fiction that he then goes about proving to be wrong.

    He is deliberately misrepresenting what Spencer is showing.

  6. tallbloke says:

    P. Solar: Welcome. Here are the definitions from the two papers to assist in developing your argument:

    Dessler Eq1: C*dTs/dt= ΔRcloud + ΔFocean − λΔ Ts
    C is the heat capacity of the ocean’s mixed layer, ΔTs is the surface temperature, and
    ΔFocean is the heating of the climate system by the ocean. The term -λΔTs
    represents the enhanced emission of energy to space as the planet warms. λ is the
    climate sensitivity and it contains the Planck response as well as the climate
    feedbacks. ΔRcloud is the change in TOA flux due to clouds. Note that ΔRcloud is not
    a feedback in this formulation — it is a forcing and is independent of surface
    temperature (the cloud feedback is in the -λΔTs term). All quantities are global
    monthly average anomalies

    Spencer & Braswell Eq 1: Cp dΔT/dt = S(t) + N(t) − λΔT (1)
    Equation (1) states that time-varying sources of non-radiative forcing S and radiative forcing N
    cause a climate system with bulk heat capacity Cp to undergo a temperature change with time away
    from its equilibrium state (dΔT/dt), but with a net radiative feedback ‘restoring force’ (−λΔT) acting to
    stabilize the system. 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.
    Radiative forcings (N) of temperature change could arise, for example, from natural fluctuations in
    cloud cover which are not the direct or indirect result of a temperature change (that is, not due to
    feedback) [7]. Examples of non-radiative forcing (S) would be fluctuations in the heat exchange
    between the mixed layer and deep ocean, or between the mixed layer and the overlying atmosphere.
    Importantly, satellite radiative budget instruments measure the combined influence of radiative forcing
    (N) and radiative feedback (−λΔT) in unknown proportions.

  7. tallbloke says:

    The paper from page 5 in this GEWEX newsletter is an interesting read. In the month K. Trenberth was appointed chair of the GEWEX science steering committee. I wonder if someone was getting this in before he took the reins…


  8. vukcevic says:

    Sun is the energy suplier to clouds – temperature – humidity – clouds
    a stable self regulating negative feedback loop. An external input is required to move response levels a notch up or down.

  9. eilert says:

    I live at 19 Degrees South Latitude, that is between the equator and the Southern summer solictice. This means we have two days in the year were the sun is straight up at local noon, the one is middle November and the other near end of January. We also have a very destinct summer rainfall season, which usually starts only at the end of November and Jannuary is the month with most of the rain and a lot more cloud cover. Our mean November temperature is about 5 Degrees Celsius higher than the January, which schould be about the same if only the incomming solar radiation is taken into account.
    So how can Dessler claim that temperature increase can only come through trapping of outgoing radiation.

  10. PaulM says:

    The typo is that the symbol on the left should be the same as the thing on the right so it should be C dΔTs/dt.

    Another error is that ΔTs is the deviation of the temperature from its equilibrium value, not as Dessler says the surface temperature itself.

    Both these things are correct in SB and LC but wrong in Dessler.

    These are trivial errors but they show up the sloppyness of Dessler himself and the reviewers who waved the paper through so quickly.

  11. Ron Cram says:

    Thanks for this writeup. Very well done.

    I found the following statement in Dessler very surprising:

    Thus, the lead- lag relation between TOA flux and ∆Ts tells us nothing about the physics driving ∆Ts.

    Radiative imbalance doesn’t affect temperature? Really? That’s his position? Has he told Jim Hansen?

    Regarding the Stephens paper in GEWEX, Stephens is saying that clouds with rain or drizzle decrease albedo – so this is closer to Trenberth’s position (which seems to ignore cloud albedo altogether). Spencer cited a 2005 paper by Stephens, but not this paper. Of course, it does not appear Stephens paper in GEWEX was peer-reviewed so there is no reason for Spencer to cite it.

    Keep up the good work! Your blog posts are always very interesting!

  12. Viv Evans says:

    tallbloke says:
    September 6, 2011 at 3:25 pm
    The paper from page 5 in this GEWEX newsletter is an interesting read. In the month K. Trenberth was appointed chair of the GEWEX science steering committee. I wonder if someone was getting this in before he took the reins…

    Well, he’s got the Trenberth/Fasullo 2010 paper in his bibliography – so Trenberth will be quite happy, no need for him to make a fuss like with SB11.

    Thanks for the analysis of the Dessler paper!

  13. tallbloke says:

    Vuk, Agreed. I wonder when they’ll step outside and experience it.

    Eilert: good observation. Rainclouds make things cooler! The warmista say that non rain bearing cloud is warmer, but the paper I linked https://tallbloke.files.wordpress.com/2011/09/gewex-feb2010.pdf says a lot more cloud has drizzle and raindrops in than previously thought.

    Paul, good one, I think you’re right, well spotted. Don’t shout about it though, and the mistake may still be in the final published version. 😉

    Ron, I don’t see that in what Dessler said. He’s trying to say that Spencer can’t draw conclusions from the lead lag, but of course Spencer can draw conclusions from the different lead lag seen in models and real observations.

  14. tallbloke says:

    WUWT has found a supporting video made by Dessler

  15. Rob Z says:

    Regarding the second to the last sentence. I think you mean that they get a rebuttal piece in Remote Sensing to counter this piece of rubbish. Didn’t read that way or it could be mis-read.

  16. cementafriend says:

    One of the reviewers was probably Trenberth -see the acknowledgements. “Team” review instead of peer review. GRL is now compromised by letting this fiction through.

  17. tallbloke says:

    Rob, it was confusing so I edited it out.

    CF: It wouldn’t surprise me if Trenberth was one of the reviewers. That would partly explain the low quality and uncorrected mistakes.

  18. tallbloke says:

    See update. Good discussion at Climate Audit.

  19. AusieDan says:

    Tallbloke – Steve McIntyre emphasises the extremely poor R squared values of Dresner’s paper.
    With R squared like that, you are looking at random noise.
    That’s well worth emphasising on your blog.
    Dresner has NOT disproved his own NUL hypothesis.

    I won’t mention that Dresner has carefully failed to address the formulae used in Spencer’s paper.
    He just made up his own straw man or rather straw formula.

  20. tallbloke says:

    AD: Well, maybe it isn’t random noise, as the phase/time plots in Spencer 2010 show. When you join the dots in date order, striations appear which are telling us there are meaningful relationsghips occurring, with real lag times.

    R2 is a blunt instrument not always appropriate to complex data. However, the most important aspect of Spencer’s paper is the uncertainty it shows to be inherent in quantification of cloud feedback. Dessler wants to avoid that.

  21. P.G. Sharrow says:

    It would appear that Andy Dessler does his climate / weather postulations from an airconditioned office. I would offer him a chance to study the effects of various cloud covers to the heating effects, out in my fields, in the “noon day sun” in sunny California. 😎 pg

  22. Gilbert K Arnold says:

    Tallbloke: First visit here. Looking at this whole kerfluffle and reading various articles and comments in a variety of “internet fora”, I am convinced that the “Team” is terrified that S&B and L&C may be right and their whole house of clouds is about to come crashing down around their ears. To use a phrase I hated to see in a Calculus text: “it should be obvious to the most casual of observers”, that clouds not only make things warmer based on cloud height, but also can cool things too.

  23. Gilbert K Arnold says:

    Hmm… “house of clouds” should have been “house of cards”. On second thought maybe the first is more apropos…

  24. tallbloke says:

    Gilbert: Welcome. Various papers are coming out of the woodwork, some written a decade ago which indicate that more energy is absorbed in clouds than previously thought/admitted. This means water vapour is a bigger player in the climate system than the IPCC would have us believe. This means co2 is a smaller player than they try to make out.

    For them, it’s all a balancing act to maximise the importance of co2. For us it’s a treasure hunt finding the disregarded science which will help us to a better understanding of the ocean-atmosphere energy flows, feedbacks and balances.

  25. Steven Mosher says:

    ‘ll take it you saw my you tube post. best movie ever

  26. Steven Mosher says:

    its on Judiths.. somebody dinged me for mispelling rebuttal so I linked to brazil. Thot you saw it. hehe turns out great minds think alike

  27. tallbloke says:

    Heh, all time great movie isn’t it?
    Orwell and Kafka rolled into one.