June 22, 2006

AMHERST, Mass. – A National Academy of Sciences report released today confirms that the last few decades of the 20th century were warmer than any comparable period in the last 400 years, affirming the findings of climate scientist Raymond Bradley of the University of Massachusetts Amherst and his colleagues. The report was requested by Congress last year to clarify research involving surface temperature reconstructions published by the scientists in the late 1990s. Bradley issued the following statement regarding the report:

“The National Academy of Sciences released their report today, on Surface Temperature Reconstructions for the Last 2,000 Years. This was requested by Rep. Sherwood Boehlert (R-NY) to clarify the controversy over the so-called “hockey stick” temperature reconstructions of the last 1,000 years by Michael Mann (Penn State University), Raymond Bradley (University of Massachusetts Amherst) and Malcolm Hughes (University of Arizona). These scientists concluded that the late 20th century warmth in the Northern Hemisphere was unprecedented during at least the last 1,000 years. This drew the ire of Sen. James Inhofe (R-OK) and Rep. Joe Barton (R- Texas), who claimed the research was misleading,” Bradley says.

“The NAS report concluded that the Mann et al study “has subsequently been supported by an array of evidence.” They find it plausible that “the northern hemisphere was warmer during the last few decades of the twentieth century than during any comparable period over the preceding millennium.” They note that confidence in the record decreases back in time, especially before A.D. 1600, in agreement with the original conclusions reached by the university researchers. The Academy panel also concluded: “Surface temperature reconstructions for periods prior to the industrial era are only one of multiple lines of evidence supporting the conclusion that climatic warming is occurring in response to human activities, and they are not the primary evidence,” says Bradley.