By Dan Vergano, USA TODAY
An influential 2006 congressional report that raised questions about the validity of global warming research was partly based on material copied from textbooks, Wikipedia and the writings of one of the scientists criticized in the report, plagiarism experts say. Review of the 91-page report by three experts contacted by USA TODAY found repeated instances of passages lifted word for word and what appear to be thinly disguised paraphrases.
The charges of plagiarism don't negate one of the basic premises of the report — that climate scientists used poor statistics in two widely noted papers.
But the allegations come as some in Congress call for more investigations of climate scientists like the one that produced the Wegman report.
Led by George Mason University statistician Edward Wegman, the 2006 report criticized the statistics and scholarship of scientists who found the last century the warmest in 1,000 years.
But in March, climate scientist Raymond Bradley of the University of Massachusetts asked GMU, based in Fairfax, Va., to investigate "clear plagiarism" of one of his textbooks.
Bradley says he learned of the copying from a year-long analysis of the Wegman report made by retired computer scientist John Mashey of Portola Valley, Calif. Mashey's analysis concludes that 35 of the report's 91 pages
Allegations under review
"The matter is under investigation," says GMU spokesman Dan Walsch by e-mail. In a phone interview, Wegman said he could not comment at the university's request. In an earlier e-mail Wegman sent to Joseph Kunc of the University of Southern California, however, he called the plagiarism charges "wild conclusions that have nothing to do with reality."
The plagiarism experts queried by USA TODAY disagree after viewing the Wegman report:
• "Actually fairly shocking," says Cornell physicist Paul Ginsparg by e-mail. "My own preliminary appraisal would be 'guilty as charged.' "
•"The plagiarism is fairly obvious when you compare things side-by-side," says Ohio State's Robert Coleman, who chairs OSU's misconduct committee.
The report was requested in 2005 by Rep. Joe Barton, R-Texas, then the head of the House energy committee. Barton cited the report in an October letter to The Washington Post when he wrote that Penn State climate scientist Michael Mann's work was
The Wegman report criticized 1998 and 1999 reports led by Mann (Bradley was a co-author) that calculated global temperatures over the last dozen centuries. It also contained an analysis of Mann's co-authors that appears partly cribbed from Wikipedia, Garner says.
Lisa Miller, a spokeswoman for Barton, reiterated the congressman's support of the Wegman report on Monday, saying it "found significant statistical issues" with climate studies.
A 2006 report by the National Research Council (NRC), which examines scientific disputes under a congressional charter, largely validated Mann, Bradley and the other climate scientists, according to Texas A&M's Gerald North, the panel's head. The NRC report found the Wegman report's criticism of the type of statistics used in 1998 and 1999 papers reasonable but beside the point, as many subsequent studies had reproduced their finding that the 20th century was likely the warmest one in centuries.
In a 2007 presentation at the university, report co-author Yasmin Said of GMU said that a Barton committee staffer, Peter Spencer, provided the background material for the report.
Information not forthcoming
The Wegman report called for improved "sharing of research materials, data and results" from scientists. But in response to a request for materials related to the report, GMU said it "does not have access to the information." Separately in that response, Wegman said his "email was downloaded to my notebook computer and was erased from the GMU mail server," and he would not disclose any report communications or materials because the "work was done offsite," aside from one meeting with Spencer.
Said did not reply to requests for comments on her role in the report.
"It's nothing personal. I don't want these guys fired or anything," Bradley says. "They should just retract or withdraw the report as you would any scientific publication that has these sort of problems."
Here is an example of passages Bradley believes were plagiarized with "substantially close" wording from his textbook, Paleoclimatology: Reconstructing Climates of the Quaternary. Sentences in bold italic represents sections he believes were paraphrased:
•Bradley text: "A cross section of most temperate forest trees will show an alternation of lighter and darker bands, each of which is usually continuous around the tree circumference. These are seasonal growth increments produced by meristematic tissues in the tree's cambium. When view in detail (Fig. 10.1), it is clear that they are made up of sequences of large, thin-walled cells (earlywood) and more densely packed, thick-walled cells (latewood). Collectively, each couplet of earlywood and latewood comprises an annual growth increment, more commonly called a tree ring. The mean width of a ring in any one tree is a function of many variables, including the tree species, tree age, availability of stored food within the tree and of important nutrients in the soil, and a whole complex of climatic factors (sunshine, precipitation, temperature, wind speed, humidity, and their distribution throughout the year). The problem facing dendroclimatologists is to extract whatever climatic signal is available in the tree ring data and to distinguish from the background noise."
•Wegman report: "A cross section of a temperate forest tree shows variation of lighter and darker bands that are usually continuous around the circumference of the tree. These bands are the so-called tree rings and are due to seasonal effects. Each tree ring is composed of large thin-walled cells called early wood and smaller more densely packed thick walled cells called late wood. The average width of a tree ring is a function of many variables including the tree species, tree age, stored carbohydrates in the tree, nutrients in the soil, and climatic factors including sunlight, precipitation, temperature, wind speed, humidity, and even carbon dioxide availability in the atmosphere. Obviously there are many confounding factors so the problem is to extract the temperature signal and to distinguish the temperature signal from the noise caused by the many confounding factors."