House Science Committee Chairman Sherwood L. Boehlert (R-N.Y.) has demanded that another senior Republican, Energy and Commerce Committee Chairman Joe Barton (Tex.), call off his investigation of three scientists who have charted Earth's rapid warming in recent decades.
The unusual public tiff between two powerful GOP lawmakers highlights the sharp divide that drives the nation's climate change debate. Barton, along with President Bush and many other House Republicans, opposes mandatory curbs on greenhouse gas emissions and questions the science underlying such efforts. Boehlert, who backs limits on carbon dioxide pollution, said he fears such attacks could chill future scientific inquiry.
In a sharply worded letter sent last week, Boehlert called Barton's probe into the findings of Michael E. Mann, Raymond S. Bradley and Malcolm K. Hughes a "misguided and illegitimate investigation." Mann will direct the Earth System Science Center at Pennsylvania State University as of next month, Bradley is a geosciences professor at the University of Massachusetts at Amherst and Hughes is a professor at the University of Arizona's Laboratory of Tree-Ring Research.
Using climate records culled from tree rings, glacial-ice layers and coral-growth layers, the three professors -- whose research was funded in part by the federal government -- determined in 1998 that temperatures have skyrocketed in the past century compared with the 500 years preceding it. The three men put the figures in a graph now known as the "hockey stick," and their work helped prompt the U.N. Intergovernmental Panel on Climate Change in 2001 to declare the 1990s as the warmest decade in the past 1,000 years.
Barton began investigating Mann and his colleagues late last month, asking them to justify their work with documents from hundreds of studies. Noting that two Canadian researchers had questioned their findings, Barton wrote that he had opened "this review because this dispute surrounding your studies bears directly on important questions about the federally funded work upon which climate studies rely."
In a letter Boehlert publicly released yesterday, the veteran GOP moderate asserted that his panel has jurisdiction over climate change and that Barton is targeting these scientists because he disagrees with their conclusions.
"My primary concern about your investigation is that its purpose seems to be to intimidate scientists rather than to learn from them, and to substitute congressional political review for scientific review," Boehlert wrote.
Barton, however, said he plans to proceed with the probe. He also dismissed a July 1 protest by Rep. Henry A. Waxman (Calif.), a senior Democrat on the Energy and Commerce Committee, who wrote Barton that some might interpret the probe "as a transparent effort to bully and harass climate change experts who have reached conclusions with which you disagree."
"Chairman Barton appreciates heated lectures from Representatives Boehlert and Waxman, two men who share a passion for global warming," committee spokesman Larry Neal said. "We regret that our little request for data has given them a chill. Seeking scientific truth is, indeed, too important to be imperiled by politics, and so we'll just continue to ask fair questions of honest people and see what they tell us. That's our job."
Although senior House Republicans often duel behind the scenes, they rarely issue public rebukes of each other. Boehlert's blunt language, coupled with Barton's harsh response, reveals the extent to which global warming has fostered a rift within the GOP on Capitol Hill.
"It's unusual for a chairman to write this kind of letter, but we feel the situation's unusual," said Science Committee staff director David Goldston, adding that the fight was about the need for independent scientific research, not climate change. "We are surprised at the level of sarcasm Mr. Barton's spokesman has used to respond to our serious concerns."
Several members of the scientific community have protested the probe -- 20 prominent climatologists sent Barton a letter Friday questioning why he has focused on just one of the many studies that underpin current thinking on global warming -- and the president of the National Academy of Sciences (NAS) offered to appoint an independent panel to assess the scientific consensus on climate change.
"A congressional investigation, based on the authority of the House Commerce Committee, is probably not the best way to resolve a scientific issue, and a focus on individual scientists can be intimidating," NAS President Ralph J. Cicerone wrote in a letter to Barton.
Barton dismissed the idea as well. "We can't evaluate the idea without having seen it, and maybe it's a darned fine one, but an offer that says, 'Please just go away and leave the science to us, ahem, very intelligent professionals,' is likely to get the reception it deserves," Neal said. "We get a lot of offers to butt out from folks who would rather avoid public scrutiny, and reputable scientists wouldn't feel comfortable in the company of most of them."
In the meantime, the three scientists are assembling documents in response to Barton's inquiry. Mann on Friday defended his work in a letter to Barton, saying he had exposed his research to public scrutiny and shared much of his data with other scientists.
"My research findings, which support the conclusion that the earth's surface is warming, and that recent warming is due in large part to human influences, are consistent with the overwhelming scientific consensus on climate change," Mann wrote. "Other scientists have replicated all facets of my research and found it accurate and reliable."
Staff researcher Alice Crites contributed to this report.
Rep. Joe Barton (R-Tex.) heads Energy and Commerce.