Silflay Hraka

In June of last year, the House Committee on Energy and Commerce asked Dr. Edward Wegman, chair of the
Committee On Applied And Theoretical Statistics for the National Academy of Sciences, to asses the statistical data underlying the “Hockey Stick” temperature chart that the many environmental advocates point to when arguing for the anthropogenic theory of global warming, or the idea that global warming is caused by human activities, rather than being driven by other factors.

My position is that, even if global warming is caused by humanity, it’s too late to do anything about it and that the world’s money would be more effectively better spent in a effort to mitigate the effects of global warming, rather than thrown away on increasingly futile efforts to cut C02 emissions.

In any case, Energy and Commerce released the Wegman report today. Both the synopsis( 2 pages) and the full report( 91 pages) are available from the E&C home page.

Value added synopsis excerpt!

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 resented to other statisticians on aspects of his analysis, including the Board of the American Statistical Association.

Prediction: Many of these people will soon find themselves under severe attack, as were earlier global warming heretics Willie Soon and Sallie Baliunas.

Excerpts from the first 9 pages of the full report!

The controversy of Mann’s methods lies in that the proxies are centered on the mean of the period 1902-1995, rather than on the whole time period. This mean is, thus, actually decentered low, which will cause it to exhibit a larger variance, giving it preference for being selected as the first principal component. The net effect of this decentering using the proxy data in MBH98 and MBH99 is to produce a “hockey stick” shape. Centering the mean is a critical factor in using the principal component methodology properly. It is not clear that Mann and associates realized the error in their methodology at the time of publication..

This is a direct attack on the evidence for the idea that the last few years have been the hottest ever.

In our further exploration of the social network of authorships in temperature reconstruction, we found that at least 43 authors have direct ties to Dr. Mann by virtue of coauthored papers with him. Our 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.

The defenders of the anthropogenic theory at Realclimate.org website use that term rather a lot, especially when dealing when engaged in debates over the hockey stick. Together with the next sentence it’s hard not to see this as attack on them.

This committee does not believe that web logs are an appropriate forum for the scientific debate on this issue.

Ouchie. Fortunately, as a popularizer of scientific debate and ill-informed crackpot, the above does not apply to me.

It is important to note the isolation of the paleoclimate community; even though they rely heavily on statistical methods they do not seem to be interacting with the statistical community. Additionally, we judge that the sharing of research materials, data and results was haphazardly and grudgingly done. In this case we judge that there was too much reliance on peer review, which was not necessarily independent. Moreover, the work has been sufficiently politicized that this community can hardly reassess their public positions without losing credibility. Overall, our 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.

Cross-disciplinary science requires cross-disciplinary peer review. More as I run across it.

My posts on the debate over the stellar/human genesis of global warming, A Cloudy Outlook for Global Warming and Eppur, Si Muove have apparently gained me access into a mostly behind the scenes academic kerfuffle between proponents of the Mann Hockey Stick and those who question its authenticity.

At the moment the most frenzied part of the debate is between Professor Michael Mann, the author of the hockey stick, and Drs. Willie Soon and Sallie Baliunas, co-authors of the paper I posted about in Eppur, Si Muove.

You can trace the progress of the debate in the links below, which I’ve arranged more or less chronologically

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The various arguments over the causes of global warming rest entirely on dueling temperature graphs. Proponents of global warming as a result of human activity base their opinions on the “hockey stick” temperature chart produced by University of Virginia professor Michael Mann. Those who posit a more stellar origin for global warming use the 1997 Huang temperature chart, most recently referred to by Drs. Soon and Baliunas in their recent paper, Climate History and the Sun. You can see an earlier post about the differences between the two charts here

Now there’s a third entry into the debate, from Dr. Nir Shaviv, an astrophysicist at the Racah Institute of Physics in Jerusalem, and Professor Jan Veiser, a geochemist at the University of Ottawa, who hypothesize that global temperature levels are heavily affected by cosmic rays.

First, the graph, for those who prefer seeing conclusions to wading through explanations.

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