As noted in an earlier post, I’ve now managed to synchronize 48 of 49 Santer tropo series with KNMI surface temperature series and have looked at versions of some key figures in CCSP 1-1 and previously inaccessible figures in Santer.
First here is an important figure from CCP 1-1 showing a histogram of relative trends (surface minus T2LT) for models, together with observations (RSS and UAH T2LT versus CRU and NOAA/GISS). CCSP stated in the caption that “each histogram is based on results from 49 individual realizations of the 20CEN experiment, performed with 19 different models (Table
5.1)”. These are the same numbers as in Santer et al 2005 and Santer et al 2008. The “Convening Lead Author” of this CCSP section, to no surprise, turns out to be Santer himself. So I think that we can prima facie assume that Santer did the same amount of “independent” due diligence on Santer et al 2005 as Mann, in his capacity as IPCC TAR lead author, did on MBH98.
Figure 1. CCSP 1.1 Figure 5.3G, showing a histogram of T_surface minus T2LT trends, against corresponding observed trends for RSS and UAH T2LT versus CRU (lowest line) and NOAA (upper line). GISS said by CCSP to be close to NOAA.
Next here is my attempt to replicate this figure from my laborious matching of surface and Santer T2LT information. It’s quite close, but it’s a bit different. I’ve used 48 models as opposed to 49 – I was unable to match one CCSM3.0 model with a KNMI surface series; I truncated the Santer-screwed up version of CNM3.0 before 1965. I got a few more outliers than shown in the CCSP report. I got three runs with trends in lapse rate more negative than -0.1 deg C/decade – these result from highly positive model runs in the singleton Canadian CGCM3.1 run, in the singleton HadGEM1 run and in a GFDL2.1 run. I didn’t get a run above 0.05 and only got three positive runs i.e. runs with low T2LT trends relative to surface: a singleton run from INM CM3, a singleton from MRI hi-res and a MRI med-res run. As bridge players know, singletons are not incidental. No models overlap CRU minus UAH T2LT (or UAH T2) in my calculation – CCSP shows one overlap. My observational trends show differences up to 2009 (while model trends are only to 1999). As Santer says in his SI, it’s reasonable to project the model trends forward. (AIB runs where available may be another alternative.)
Figure 2. Simulation of CCSP Figure 5.3G.
As an exercise, I did a similar plot for the T2 lapse rate, which proved to yield less favorable results for the CCSP consistency argument, as you can see below. In this case, no models overlapped GISS minus RSS_T2 and only one model (INM CM3.0) overlapped CRU minus RSS_T2.
Figure 3. As CCSP Figure 5.3G, only for Surface minus T2.
It definitely seems odd that they argue so strenuously that there is no “statistical” inconsistency between models and observations.
Tomorrow I’ll continue the parsing of these results for individuals models, re-visiting Santer et al 2008.
Climate Audit 
18 Comments
A question for clarification: a difference of 0 degree implies no climate feedbacks (i.e. constant absolute humidity), and as a result climate sensitivity to 2x CO2 of 1.1 degree Celsius or so obtained from simple radiative calculations, correct?
Steve: you’re asking the wrong person. If you find a clear derivation of climate sensitivity, let me know. Until someone provides such a reference, I prefer that people refrain from exchanging personal opinions on the matter at this venue, as there are many other places to do so.
I dont know if its just me, but your posts seem to get more condensed. I’m having a hard time understanding what you’re actually doing.
Do you spend less time explaining what you are doing and what is means than before or am I getting smart enough to understand that I’m clueless?
Re: Joachim (#2),
Steve starts this post:
He should have included a link to that post, and perhaps this reply will induce him to do so. Once you have read / reread that post, it shouldn’t be too hard to figure this one out.
Re: Joachim (#2),
A quick look at Figure 3 and the comment in the the thread introduction excerpted below summarizes it all very nicely for me.
Joachim, I hope you get up to speed quickly as this is all good stuff.
Re: Joachim (#2), “or am I getting smart enough to understand that I’m clueless?” that is priceless–in my opinion more people should strive for this level of smart! It is so easy for the brain to gloss over the inconsistencies.
Interesting! What happens when you throw NCDC into the mix along with CRU and GISS?
Steve;
Great work!
My colleague, Ben Pearson, spent several months attempting to duplicate Santer’s fig5.3G for (Ts-T2LT) when we were writing our paper [“A comparison of tropical temperature trends with model predictions” IJC (2007].
We could not duplicate that histogram. It appears from your work that this was not possible. I note that you have only 3 models showing positive values while Santer has 8 — a big difference!
I would like to compare our old unpublished calculations with your new calculations. Would you list the models and values from which your histogram was made?
Re: david douglass (#7),
I’ve placed the information online.Here’s a turnkey script that generates the histogram (without the observed trends which will follow.) The script is in R, which is lingua franca here. I don’t have time right now to make everything in ASCII; if you need ASCII versions, I’d prefer that you do enough R to make your own conversions.
Re: Steve McIntyre (#8),
that script makes it look pretty easy, but there’s a lot of work in the collation. The run identifications are in the info.pcmdi table (which is in csv form online – see script above.) These identifications were scraped off the tropo data placed online by PCMDI following my FOI request (though they say that placing the data online had nothing whatever to do with my FOI request). The surface versions are KNMI tas versions where I located a corresponding run. There were collation problems with CCSM3.0, CNRM3.0 and also HadGEM2 where the “natural” order is not observed: run2 was used instead of run1.
Re: Steve McIntyre (#8),
I hope that the download script here for the collation of 48 Santer tropo models together with matching KNMI surface models facilitates the handling of this material by others.
I noticed that the provision of handy download data and info for Antarctica stimulated excellent work by others and hopefully the same thing happens here.
Joachim (5-18-09, 2:36)–
For what it’s worth to you (or not), lately I have the same impression as you: the writing is more arcane, more abstruse, more dense. It seems to me as though Mr. McIntyre (I have never met him–can’t call him “Steve”) is writing here for the most kindred in background, of which I am not one. Of course it’s his blog: let him write as he wants. So even though I am often left in the dust by his writing, I still put money in the tip jar, as I much appreciate his work and his blog. And, for what it’s worth, that, conversely, is a big part of the reason why I always like Willis Eschenbach’s guest-posts here, as he writes both humbly and understandably: I can focus on the point(s) he is making, putting all my mental energy into that, rather than having to put a good deal of energy into trying to figure out what is actually being said. (Thanks for your comment.)
Re: Shallow Climate (#11),
Steve has noted on other occasions that at times he treats this blog as if it is an open diary of his thoughts, in which case he is writing as much for himself as for the more advanced readers.
Usually at some point someone kindly summarizes and translates the concepts for the rest of us.
Joachim (again)–
Many years ago, when I was at UCLA, I attended a guest seminar by Richard Feynman. I was struck not only by his enthusiasm for his subject but also by how well he communicated, as I, a chemist, could understand him quite easily: I a chemist in an audience of physicists.
(Hmm, maybe I’ll get a reprimand here from Steve–er, Mr. McIntyre–for being OT. We’ll have to see.)
This may be premature as you will post it up tomorrow but did you see any substantial reduction in the trend autocorrelation, for both models and observed-derived data, using the difference between surface and troposphere?
It seems that Santer is now busy making movies: http://www.youtube.com/watch?v=x7zMQII8qOo&feature=related
Gag me!
Shallow Climate and Joachim,
can I try to summarize, although I am also just an interested layman, and by no means “advanced reader”. As far as I could see Steve tried to replicate Santer’s results allegedly showing good agreement between models and observations in tropics (models predict vertical amplification i.e. increase in rate of warming as we go up in the atmosphere, so called tropical “hot-spot”). Steve reproduced predictions of climate models for difference between surface lower and mid-tropospheric trends on one hand and surface data on the other, and compared that difference with observations of the same difference, that show very different picture. Instead increase in amplification with altitude, observations show lower rates of warming up in atmosphere than at the surface, and what is specially important, less amplification in the mid than in the lower troposphere.
Patrick M. and Ivan–
Yes, thanks. I suppose, in my ideal world, my edenic world, Mr. McIntyre would write his posts however it would please him to do so, and then someone else (such as one of you), in your comment, would REWRITE the entire post in a more comprehensible (I won’t say “dumbed down”) way. That would be a win-win for us all. So I suppose.
Re: Shallow Climate (#17),
There is always the option of framing some pertinent questions with regards to what you are having difficulty understanding. I was suprised, given the criticism, that I saw none of that in this thread.