Dr. Ken Green claims that "CRU, as I understand it, was the dominant source for information entering the IPCC reports". I found this assertion astonishing and implausible. I decided to come up with a quick test for this.

So I limit myself to chapter 3 of the AR4 WGI report, the one for which Jones is co-coordinating lead author, admittedly an important role. This is the atmospheric observations chapter, the one where CRU would be expected to be most influential.

Other than Jones, there is another co-ordinating author, (Trenberth, American), nine lead authors (one from the UK), by my count 66 coauthors, 10 of whom are from the UK, and three review editors (one from the UK). Of the dozen UK contributors out of the 80 participants from 16 countries, only Jones is currently at CRU.

The chapter cites about 825 papers. I checked the research staff of CRU against the bibliography looking only for first authorships to keep this project small. Of the 825 first authorships, four are P D Jones', one goes to Manola Brunet, four to Nathan Gillett, and two to Malcolm Haylock, for a total of 11 out of 825, a very respectable showing indeed, but hardly the be-all and end-all of climate science. Recall this is in the most CRU-favorable of 11 chapters, so we can conclude that CRU originates roughly between a tenth of a per cent to a per cent of the information in the WGI report.

For comparison here is Trenberth's group, the CAS at NCAR:

Dai seven, Deser six, Hurrell eleven, Madden one, D Schneider one, Trenberth 19, for a total of 45, or quadruple CRU's output just from the one section at NCAR.

While at it I scanned for authors with four or more first author publications in AR4 WGI chapter 3, and came up with:

R P Allan (5)
V R Barros
J R Christy
A Dai (7)
C Deser (6)
C K Folland (6)
N P Gillett
D Y Gong (5)
P Ya Groisman (6)
J W Hurrell (11)
P D Jones
R H Kripalini (5)
D E Parker
T C Peterson (6)
W J Randel (7)
J A Renwick (5)
I Simmonds
B J Soden
B M Sun
D W J Thompson (8)
K E Trenberth (19)
R S Vose
B Wang
X L Wang (5)
P J Webster
X Zhang (6)

of whom I had only heard of Christy, Jones, Parker, Soden, Trenberth and Webster. Chapter 3 is just not my thing.

I leave it to Dr Green or others to find a chapter where CRU is better represented but I doubt that there is one. Conclusion: evidently CRU is not "the dominant source for information entering the IPCC reports". It does appear that Trenberth's Climate Analysis Section group at NCAR carries a lot of weight in chapter 3, and if anyone is a candidate for dominance based on Chapter 3 it would be the NCAR/UCAR/Colorado bunch.