I'd also suggest you read this link:
en.wikipedia.org
Pay particular attention to the National Research Council Report and the Committe on Energy & Commerce Report.
Please note that non other than Roger Peilke Jr commented on who "won".
I copy the Wegman comments from the link here. Please try to understand them.
Committee on Energy and Commerce Report (Wegman report)
A team of statisticians led by Edward Wegman, chair of the National Academy of Sciences’ (NAS) Committee on Applied and Theoretical Statistics, was assembled at the request of U.S. Rep. Joe Barton and U.S. Rep. Ed Whitfield .[41] The report primarily focused on the statistical analysis used in the MBH paper, and also considered the personal and professional relationships between Mann et al and other members of the paleoclimate community. Findings presented in this report (commonly known as the "Wegman Report"[42][43]) at a hearing of the subcommittee on oversight and investigations, chaired by Whitfield, included the following:
* MBH98 and MBH99 were found to be "somewhat obscure and incomplete" and the criticisms by McIntyre and McKitrick were found to be "valid and compelling".
* The report found that MBH method creates a PC1 statistic dominated by bristlecone and foxtail pine tree ring series (closely related species). However there is evidence in the literature, that the use of the bristlecone pine series as a temperature proxy may not be valid (suppressing "warm period" in the hockey stick handle); and that bristlecones do exhibit CO2-fertilized growth over the last 150 years (enhancing warming in the hockey stick blade).
* It is noted that there is no evidence that Mann or any of the other authors in paleoclimatology studies have had significant interactions with mainstream statisticians.
* A social network of authorships in temperature reconstruction of at least 43 authors having direct ties to Mann by virtue of coauthored papers with him is described. The findings from this analysis suggest that authors in the area of paleoclimate studies are closely connected and thus ‘independent studies’ may not be as independent as they might appear on the surface.
* It is important to note the isolation of the paleoclimate community; even though they rely heavily on statistical methods they do not seem to interact with the statistical community. Additionally, the Wegman team judged that the sharing of research materials, data and results was haphazardly and grudgingly done.
* Overall, the committee believes that Mann’s assessments that the decade of the 1990s was the hottest decade of the millennium and that 1998 was the hottest year of the millennium cannot be supported by his analysis.
The Wegman report has itself been criticized and supported on several contentious grounds:
* The report was not subject to formal peer review [44] [45] However, at the hearing, Wegman lists 6 people that participated in his own peer review process and had no objection to the subcommittee submitting it for another one of their own.[46]
* The result of fixing the alleged errors in the overall reconstruction does not change the general shape of the reconstruction. [47]
* Similarly, studies that use completely different methodologies also yield very similar reconstructions,[47] although there is some overlap in proxies used.
* The social network analysis is not based on meaningful criteria, does not prove a conflict of interest and did not apply at the time of the 1998 and 1999 publications. [46] Such a network of co-authorship is not unusual in narrowly defined areas of science.[48] During the hearing, Wegman defined the social network as peer reviewers that had "activly collaborated with him in writing research papers" and answered that none of his peer reviewers had.[46]
* Gerald North, chairman of the National Research Council panel that studied the hockey-stick issue and produced the report Surface Temperature Reconstructions for the Last 2,000 Years, stated the politicians at the hearing at which the Wegman report was presented "were twisting the scientific information for their own propaganda purposes. The hearing was not an information gathering operation, but rather a spin machine."[44] However, in testimony when asked if he disputed the methodology conclusions of Wegman's report, he stated that "No, we don’t. We don’t disagree with their criticism. In fact, pretty much the same thing is said in our report." followed by the caveat the results could still be correct anyway "But again, just because the claims are made, doesn’t mean they are false."[46]
* Mann has himself said that the report "uncritically parrots claims by two Canadians (an economist and a mineral-exploration consultant) that have already been refuted by several papers in the peer-reviewed literature inexplicably neglected by Barton's 'panel'. These claims were specifically dismissed by the National Academy in their report just weeks ago."[49]
In his opening remarks, Chairman Barton (at the hearing ex officio) commented on the politically charged nature of the entire process, and the level of disagrement on a great many of these issues, in fact:
So I want to thank Dr. Wegman and his colleagues for giving us an unvarnished, flat out non-political report. Now, admittedly, that report is going to be used probably for political purposes but that is not what he did, and I want to thank Dr. North for the work that he did in this document. Now, it is a lot thicker than Dr. Wegman's document, and Dr. North and his colleagues have kind of looked at the same subject and they have come to a somewhat little--they are little bit more, I don't want to use the technical term wishy-washy but they are kind of on both sides of it, but even Dr. North's report says that the absolute basic conclusion in Dr. Mann's work cannot be guaranteed. This report says it is plausible. Lots of things are plausible. Dr. Wegman's report says it is wrong.
Now, what we are going to do after today's hearing, we are going to take Dr. Wegman's report, and if my friends on the Minority want to shop it to their experts, so be it. We are going to put it up there, let everybody who wants to, take a shot at it. Now, my guess is that since Dr. Wegman came into this with no political axe to grind, that it is going to stand up pretty well. If Dr. Mann and his colleagues are right, their conclusion may be right--Dr. Mann's conclusion may be right but you can't verify it from his statistics in his model so if Dr. Mann's conclusion is right, it is incumbent upon him and his colleagues to go back, get the math right, get the data points right, get the modeling right. That is what science is about.[46]
This contention is further illustrated by the first sentence of the subcommitte's Ranking Member Bart Stupak's remarks:
"Thank you, Mr. Chairman. It is a little bewildering to me why the committee is holding its very first hearing on global warming to referee a dispute over a 1999 hockey stick graph of global temperatures for the past millennium." [46] |
