There has been renewed interest in the Wegman Report, which purported to critique the work of paleoclimatolgists Michael Mann, Raymond Bradley and Malcolm Hughes and their controversial “hockey stick” millennial temperature reconstruction.
Today we’ll take a closer look at Wegman et al’s key passage on tree-ring proxies and do a detailed side-by-side comparison with its apparent main antecedent, chapter section 10.2 in Raymond Bradley’s classic Paleoclimatology: Reconstructing Climates of the Quaternary.
That comparison leaves no doubt that Wegman et al’s explication was substantially derived from that of Bradley, although the relevant attribution appears to be missing. There are, however, several divergences of note, also in the main unattributed, and some of Wegman’s paraphrasing introduces errors of analysis.
But the real shocker comes in two key passages in Wegman et al, which state unsubstantiated findings in flagrant contradiction with those of Bradley, apparently in order to denigrate the value of tree-ring derived temperature reconstructions.
[Update, Dec. 19: This post has been substantially revised to remove speculation about Donald Rapp’s possible role in the Wegman report. I apologize for any embarrassment caused to Donald Rapp or Edward Wegman by that speculation.
The post has also been updated to reflect new information about the provenance of Wegman et al’s section on tree ring proxies, as well as more background detail on some of the events leading up to the Wegman report. There are also more details about large swathes of unattributed material found in the Wegman report and in Donald Rapp’s book Assessing Climate Change.
It is clear that the circumstances and contents of both the Wegman report and Rapp’s text book deserve closer scrutiny.
Dec. 20: Comments are now open again.]
As Climategate devolves into a rerun of old battles about the “hockey stick” graph, I thought I would revisit the roots of that benighted controversy and take a look at the chaotic events of a few years back when the politicization of science (also known as the Republican war on science) really took hold.
I was planning to write another installment of the “In the beginning” series on Steve McIntyre. So I decided to take a look at the infamous Wegman report that Republican congressman Joe Barton relied on to ensure that the “numbers added up” (or not, as he was sure was more likely). The 2006 report was the work of a mysterious “ad hoc” committee led by George Mason University statistics professor Edward Wegman, along with David Scott and Yasmin Said. With its near-veneration for putative hockey-stick destroyers Steve McIntyre and Ross McKitrick, and its scornful denunciation of Michael Mann and his “social network” of like-minded researchers, the report has been a touchstone for contrarians.
But then I started thinking about something that had always bothered me. How could a trio of statistical experts, all on their own, hope to write a report on a field, climate science, of which they had no previous knowledge or experience?
Part of the answer lies in the close examination of the Wegman report. Surprsingly, extensive passages from Wegman et al on proxies have turned up in a skeptic text book by contrarian author Donald Rapp. And at least one of these common passages on tree ring proxies closely follows a classic text by noted paleoclimatologist Raymond Bradley, but with a key alteration not found in the original. Moreover, Wegman’s section on social networks appears to contain some unattributed material from Wikipedia and from a classic sociology text.
By now, anyone who follows the climate blog wars knows that a new battle is underway over the standard temperature reconstruction popularly known as the “hockey stick”. Although it has been declared thoroughly shattered many times, apparently it must be attacked again and again.
Over the last few days, self-appointed climate “auditor” Steve McIntyre has made several insinuations concerning the work of UK dendro-climatologist Keith Briffa, focusing on the recently released Yamal series of tree-ring measurements. Along the way, he has once again rehashed an oft-repeated accusation that “cherry-picking” of proxy sites is endemic in the paleo-climatological community that he disdainfully calls the “Hockey Team”. But this time, McIntyre has outdone himself, comparing the repeated use of the Yamal tree-ring chronology in paleoclimatology studies to a “crack cocaine” addiction.
The “climate change skeptic” right-wing think tank Heartland Institute has been quietly updating its list of almost 60 speakers for the second annual International Conference on Climate Change to be held in New York this March – and Canadian skeptics are front and centre. And in at least two cases, the official affiliations listed for speakers appear unlikely to be bona fide.
Last year’s inaugural event was derided by climate scientists as a PR sham masquerading as a scientific conference. Conference speakers, most of whom are not practicing climate scientists, are paid a generous honorarium and all travel expenses. Funding sources are not disclosed, but the Heartland Institute has received $676,000 from ExxonMobil since 1998.
This year’s meeting will feature first time invitee Stephen McIntyre, founder of the popular ClimateAudit blog, as one of six headliners. McIntyre is described by Heartland as a “devastating critic of the temperature record of the past 1,000 years”, but has published only one peer-reviewed article in a recognized science journal.
Interestingly, McIntyre’s listed affiliation is with the University of Toronto. McIntyre’s connection to the University is unclear, although he does apparently have a University email address.
Among the other five confirmed Canadian speakers, undoubtedly the most controversial is Lawrence Solomon, listed as affiliated with the National Post, a national Canadian daily newspaper. Solomon is the author of The Deniers, a book based on a long series of individual profiles written for the Post. He has recently launched attacks in the Post on Michael Mann, director of the Earth System Science Center at Penn State University, as seen here and here. Solomon is executive director of Energy Probe, a non-profit group that “works for environmental sustainability by promoting property rights.” (Closer scrutiny of this group is clearly warranted, but will have to wait for a future post).