[RLB: The paper, according to Lindzen, has been revised and returned to JGR."]

While the champions of the climate alarm would like to make the long-term “f” more positive, I am convinced that the long-term “f” is actually smaller, or more negative, than the short-term “f”. That’s because of La Chatelier’s principle – also promoted in the context of economics by Paul Samuelson in 1947.

Why?

It’s because the longer time scale you consider, the more processes you will find that will “adapt” to the changes and “consume” (and therefore reduce) the heat that you have added into the system. So my bet would be that the short-term “f” is very close to zero and the long-term “f” is somewhat negative.

So Luboš basically agrees with Lindzen’s observation that the IPCC has over emphasized the CO2 forcing.

“I have great respect for people outside this field who
bother to seriously examine matters, and we will address your
questions explicitly as soon as we can. ”

Now meanwhile, in a separate development, Luboš Motl picked up on my findings and contacted Dr. Roy Spencer for comment :

http://motls.blogspot.com/2009/11/spencer-on-lindzen-choi.html

Dr. Spencer published his own findings of the ERBE data yesterday, which support my criticism of Lindzen and Choi 2009 :

http://www.drroyspencer.com/2009/11/some-comments-on-the-lindzen-and-choi-2009-feedback-study/

In this publication, Dr. Spencer essentially points out the same problems that I found in the Lindzen and Choi paper as well :

(1) The ERBE data shows no significant feedback
(2) The AMIP models that Lindzen used (Graph C above) are not suitable for comparison with ERBE data
(3) The short term analysis done makes conclusions on climate sensitivity questionable.

I have not seen the ‘long’ version of the paper yet and I am certainly looking forward to seeing errors corrected. In this case however, that would also mean that the conclusions (about feedback and climate sensitivity and models being incorrect) need to be completely redone.

But looking at Dr. Lindzen’s response, I doubt that the long version addresses the severity of the errors in the paper.
Since I may not have been entirely clear in my first post, allow me to clarify how the errors in the paper nullify the conclusions that Lindzen draws.

The main conclusions of the paper are two-fold, and my comment on them is embedded :

(1) Lindzen claims that ERBE data shows that the Earth’s climate imposes a negative feedback mechanism (resistance to change sea-surface temperatures). He calculates feedback factor -1 overall.

However, at 4 W/m^2/K, ERBE data is consistent with the Stephan Boltzmann derivative at the mean radiating temperature of the tropics, and thus ERBE data is consistent with a feedback factor 0.

This mistake affects the formula where the mistake is made (in the FSW calculation) and Figure 3, pane 2 and 3.
But most of all, this mistake changes the conclusions of the paper, regarding feedback factor and climate sensitivity.

(2) Lindzen claims that ERBE data proves the models wrong.
In text and in Figure 2, and table 1, Lindzen claims that ‘models’ do not match with the ERBE data. The ERBE plot shows a 4 W/m^2/K slope, while the ‘models’ show a mildly negative slope. However, in the text, Lindzen himself correctly points out that a ‘negative’ slope is physically unreal, as it would imply a climate system with infinite positive feedback. That is clearly not the case for planet Earth, and clearly not what ‘models’ predict.

Even the simplest model (Stephan Boltzmann equation) will show a positive 4 W/m^2/K slope, in line with ERBE data.
So I am not sure how Lindzen got to the plots for the models in Figure 2, but he is either using the wrong models (as other bloggers suspect) or he is using the right models incorrectly. Either way, Figure 2, which is so highly praised by climate sceptics, is incorrect and highly misleading.

In reality, models predict a mildly positive feedback for the short-term, which is in the statistical error bounds of the ERBE data. Correcting this mistake (re-doing Figure 2 and table 1) nullifies the conclusion about models being incorrect.

Besides these two major “conclusion-altering” errors, there are a few other minor problems with the paper, which should be much easier to correct :

- In the text, Lindzen mentions that he used ERBE Edition 3 data. However, the plots (Figure 1a and 1b) show old Edition 2 graphs.

- I would recommend that Lindzen uses the latest (rev 1) revision of the ERBE Edition 3 set, since minor corrections have been done on OLR and SW data. A quick analysis on that data shows a small reduction in OLR and a small increase in SW. Overall flux may be the same, so this data should not be conclusion altering.

Some final notes :
This data analysis covered short periods (of months). To extrapolation these results with conclusions about the ‘climate sensitivity’ factor when analysis’ were done over such short periods seem to be utter speculation. It seems to me that what Lindzen really found (short-term feedback factor 0, at least for the tropics) is already highly valuable to climate science by itself. There is no need to exaggerate the implications of that finding and there is certainly no need to misrepresent models or ERBE data.

Rob
Alameda, CA