McIntyre & McKitrick's claim of errors was factual. The employment backgrounds of those two individuals has nothing to do with the the accuracy of their claims. I see that's all you GW devotees pay attention to.
But you don't have to take my word for this - the Wegman study has resolved this - as you should know - this has been explored on SI:
The report commissioned by the House Energy Committee, due to be released today, backs up and reinforces that conclusion. The three researchers -- Edward J. WEGMAN of George Mason University, David W. Scott of Rice University and Yasmin H. Said of Johns Hopkins University -- are not climatologists; they're statisticians. Their task was to look at Mr. Mann's methods from a statistical perspective and assess their validity. Their conclusion is that Mr. Mann's papers are plagued by basic statistical errors that call his conclusions into doubt. Further, Professor WEGMAN's report upholds the finding of Messrs. McIntyre and McKitrick that Mr. Mann's methodology is biased toward producing "hockey stick" shaped graphs." (Wall Street Journal)
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Critics questioned the statistical methodology; now the House Energy Committee has released the long-awaited WEGMAN Report. Some excerpts from their factsheet:
"Questions about the reliability of the Mann studies were of interest because they raised policy-relevant questions concerning the objectivity of the IPCC and its reliance upon and “promotional” use of the studies’ ‘hockey stick’ shaped historical temperature reconstruction.
Following receipt of the letter responses, committee staff informally sought advice from independent statisticians to determine how best to assess the statistical information submitted. Dr. Edward WEGMAN, a prominent statistics professor at George Mason University who is chair of the National Academy of Sciences’ (NAS) Committee on Applied and Theoretical Statistics, agreed to independently assess the data on a pro bono basis. WEGMAN is also a board member of the American Statistical Association.
About the WEGMAN committee: Dr. WEGMAN assembled a committee of statisticians, including Dr. David Scott of Rice University and Dr. Yasmin Said of The Johns Hopkins University. Also contributing were Denise Reeves of MITRE Corp. and John T. Rigsby of the Naval Surface Warfare Center. All worked independent of the committee, pro bono, at the direction of WEGMAN. In the course of WEGMAN’s work, he also discussed and presented to other statisticians on aspects of his analysis, including the Board of the American Statistical Association.
Among the panel’s findings and recommendations:
• Mann et al., misused certain statistical methods in their studies, which inappropriately produce hockey stick shapes in the temperature history. WEGMAN’s analysis concludes that Mann’s work cannot support claim that the 1990s were the warmest decade of the millennium."
So, fill me in - is WEGMAN credible, did the House Reps take this committee into the tank, what?
John Quiggin at Crooked Timber looks at the other aspect of the report, which dealt with a possible breakdown in the peer review process.
justoneminute.typepad.com
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Leading US statistician Edward WEGMAN, of George Mason University, who is chairman of the US National Academy of Sciences' committee on applied and theoretical statistics, agreed to assemble a group of statisticians to assess the Mann data. Their report was released last Friday and supported McKitrick and McIntyre's criticisms of the hockey stick, finding Mann's statistical work flawed and unable to support the claims of the hottest century, decade and year of the past millennium.
Yet the IPCC used the hockey stick in its publications, media releases, press conferences - where senior IPCC figures sat with the chart as a backdrop - and, for a time, incorporated it into the IPCC's logo.
It is important to understand that this is a debate about the use of statistics. Mann did no original scientific work, using available data and manipulating it in a new way.
However, it destroys the idea of an alarming escalation in global temperatures and, as the Wall Street Journal remarked on Friday, brings the present temperature rise within the range of natural historical variation.
There remains plenty of room for argument about the projections of future temperature rises and their implications, based on what are still primitive climate change models. But there is no escaping the damage done to the IPCC's reputation. It has relied heavily on a badly flawed piece of work, produced by what WEGMAN discovered was a small, insular group of paleoclimatologists who incestuously peer review, reinforce and defend each others' work.
Significantly, former commonwealth statistician Ian Castles and his colleague David Henderson, former head of the Organisation for Economic Co-operation and Development's economics department, have also exposed statistical and analytical flaws in the economic scenarios underlying the IPCC's climate change projections. As with McIntyre and McKitrick's criticism of the hockey stick, the IPCC establishment initially tried to ignore, then discredit, their work.
However, last year a House of Lords committee looking at the economics of climate change praised their work and said that without them the debate on emissions scenarios would not have taken place.
The Lords committee also expressed concerns that the IPCC was an increasingly politicised body that tried to suppress dissent. It warned of a risk it was becoming a knowledge monopoly, "in some respects unwilling to listen to those who do not pursue the consensus line".
In an article last week in Canadian newspaper the National Post, McIntyre and McKitrick say the IPCC's lead author, who selected Mann's hockey stick for prominent display, was none other than Mann himself. They quote eminent US climate science academic Kurt Cuffey as saying the IPCC's use of the hockey stick sent "a very misleading message".
They ask a pertinent question.
If the IPCC process isn't fixed, and there is no evidence the IPCC intends to do anything about it, how do we know it won't send out another very misleading message in its upcoming Fourth Assessment report?
theaustralian.news.com.au
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