It is striking to me that all of the article laying out the argument for CO2 warming, like
Dr. Tapio Schneider in Skeptic Magazine lay out indirect evidence, but only make assertions when it comes to direct evidence. They would have to do that if there was no direct evidence of AGW.

The opinion of Dr Sodon on the matter is not direct evidence. The spectroscopic measurements the IPCC claims are the crucial direct evidence of increased feedback are from Sodon’s own work, and he is the lead author on the chapter, so he could not be regarded as impartial judge of the importance of his own work.

This claim just won’t die, will it?
http://www.agu.org/pubs/crossref/2008/2007GL032759.shtml
http://www.agu.org/pubs/crossref/2007/2007JD008740.shtml

http://motls.blogspot.com/2008/06/coyoteblog-dont-panic.html

the issues with the reanalysis data are extensively discussed in IPCC Chapter 3 as you noted, as well as the supplementary information available online, and in references therein. Without opening up some links (I’m going to bed now, sorry), I don’t want to give numbers off of the top of my head, but based on the IPCC’s discussion of humidity trends in the upper atmosphere (and my own personal correspondence with Soden, where he uses the term “useless”) it can’t be too good. On the flipside, I can’t just create a graph with random numbers and then ask people why it is wrong, I need to demonstrate with some degree of confidence that I am right…and we cannot now do that with the older data, and even with reanalysis data post-satellite era. Surface-air temperatures are a different climatic variable, and one that I put a lot of confidence in for older data given a relaible global instrumental record after 1850. Still, even this has some problems including SST measurements and southern hemispheric data.

Actually, MD just look around 11 to 14 kilometers from the surface of the Earth and just in the tropics. The overall contribution here is quite small. See Soden and Held 2000. You can also find various quotes around the internet from scientists like Lindzen, Sherwood, Pierrehumbert, and others agreeing with that (NASA has a good page if you google the authors names)

I do not read sites like “john-daly.com” so if there is something in the literature you want to discuss, I will see what they have to say. I wouldn’t be surprised to see the magnitude of the WV feedback slightly altered as time goes on given the uncertanties of the contributions in the upper atmosphere, but it is hard to reconcile the 20th century record or the paleoclimatic record with a WV feedback significantly less than we think.

I read your post, but it seems to just restate WG1 Sect. 3.4. Specifically I would welcome clarification of a number of apparent contradictions in the arguments:

1. “there is very strong reason to suspect that the data is simply not reliable,”
This doesn’t cut it. What is the confidence interval? Are they any worse than global average surface temperatures that also have changes in instrumentation? These data are averaged over many problematic measurements and still broadly useful.

2. Sect 3.4 states: “that the available data do not indicate a detectable trend in upper-tropospheric relative humidity”. “available data” also includes radiosonde data. How do you account for what appears to be denying the existence of “inconvenient” data.

3. Related to the above, the relative humidity trends look much more reliable at all altitudes than specific humidity.

4. Though I haven’t really nailed down the levels of the atmosphere, without wanting to get into ambiguity over that, the levels they model at 200-300hPa are the same levels that models are supposed to exhibit maximum EGE warming. See the figure from Douglass above. Therefore this is exactly the region that should be identified for evaluating the accuracy of GCM modeling of enhanced greenhouse due to feedbacks.

5. The spectroscopic effects are very small, and the stats suspect. See my post on the Harries paper here http://landshape.org/enm/interpretation-bias/ and John Daly extensive review http://www.john-daly.com/smoking.htm. I haven’t read Sodon’s paper yet.

Sorry to seem like I am hammering on this. I really would appreciate clarification, and we try to be civil around here. Regards.

As for NCEP, there is very strong reason to suspect that the data is simply not reliable, especially before the satellite era. See the post in my blog, “Is the atmosphere drying up?”

Very diplomatically said Lucia. I am glad you find it incongruent as well.
I know you lean towards the GHG warming explanation for warming, but I
am having trouble finding any direct evidence for GHG warming now, except for a couple
of fairly minor spectroscopic papers that would probably not stand scrutiny.

This humidity issue is puzzling because the words in the document really don’t seem to match the figures easily available from NOAA. Since the AR4 doesn’t include any of their own, and only quotes results from papers, it’s difficult to quickly see the basis for the statements in the AR4. This means “off to the library”. (Or order the papers from the library.)

It is a puzzlement though.