The Scientist

Scientists and a Republican member of Congress are protesting other members' attempts to investigate three researchers who have produced climate data that support global warming, arguing the investigation is designed to intimidate scientists who don't generate politically favorable data.

In 1998, Michael Mann of the University of Virginia, Raymond Bradley of the University of Massachusetts, and Malcolm Hughes of the University of Arizona published a paper in Nature showing that temperatures in the Northern Hemisphere rose precipitously in the 20^th century. This, along with an additional report, created the so-called "hockey stick" graph of rising temperatures from global warming. The team's results were among the many included in the United Nations Intergovernmental Panel on Climate Change's third assessment report in 2001, which found that the world is, indeed, experiencing global warming. In June 2004, the group published a Corrigendum to their paper.

Last month, Mann, Bradley, and Hughes received a letter from US Congressmen Joe Barton, chair of the House Committee of Energy and Commerce, and Ed Whitfield, chair of the subcommittee on Oversight and Investigations, with a two-page list of requests for material to support their conclusions, such as all financial support for their research, including–but not limited to–honoraria and financial awards.

Bradley told The Scientist that he believed the motivation behind the letter is to "try to intimidate the messengers because they don't like the message." He added that he welcomes scientific debate, but objects to the way this debate is being conducted. Rather than send personal letters, Barton and Whitfield could have asked for an independent review of the research, or hold a hearing, Bradley noted.

Instead, by "overburdening" him and his colleagues with requests, the congressmen are trying to disrupt their work, Bradley noted. "I've been working for 30 years. If they think I'm going to sit down and go through everything I've done, it's impossible. It would shut me down, which is what they want."

Through a spokesperson, Barton told The Scientist that he decided to investigate Mann et al.'s work when he realized there was controversy about the findings. Specifically, the results have been criticized by Canadian researchers Steven McIntyre and Ross McKitrick, who argue that the earlier research contains fundamental flaws, including what they believe is a computer programming error in constructing the "hockey stick" graph.

"When studies were criticized and results seemed hard to replicate by other researchers, asking why seemed like a modest but necessary step," Barton said. "This is not the first time this committee has asked for this type of information, and it won't be the last."

However, some experts noted that this is the first time they have seen individual congressmen question individual scientists. "I have never seen anything quite as egregious as this," Linda Rosenstock, director of the National Institute for Occupational Safety and Health from 1994 through 2000, told The Scientist.

In protest, both the American Association for the Advancement of Science (AAAS) and the National Academies of Science (NAS) have written letters to Congressman Barton. Alan Leshner, the CEO of AAAS and executive publisher of Science told The Scientist that he believes this could set a dangerous precedent of substituting congressional peer review for academic peer review. "We think it's very important to protect the independence and integrity of the scientific process," he said.

Even the Republican party is divided on this issue. On July 14, Congressman Sherwood Boehlert (R-NY), chair of the House Committee on Science, called the investigation "misguided and illegitimate" in a letter to Barton. "The only conceivable explanation for the investigation is to attempt to intimidate," Boehlert notes, which sets a "chilling" precedent.

And on July 15, twenty scientists voiced their own protests against Barton's investigation, noting that there is debate about climate change, but Mann et al.'s work constitutes "only one item among literally thousands of pieces of evidence that have contributed to the present consensus on the serious nature of climate change." Alan Robock, distinguished professor of environmental science at Rutgers University in New Brunswick, NJ, told The Scientist he joined 19 others in signing the letter to protest Barton's "political attack" on the wealth of data that now support climate change. "Even if [Mann et al.] made a mistake, it doesn't invalidate the global warming theory," he said.

Bradley said that he has responded by sending his own letter to Barton, which included his CV, archives for data used in his research, and criticisms of the work of McIntyre and McKitrick. Mann and Hughes have also submitted responses.

Bradley added that he was "surprised" and "depressed" to receive the letter, and warned that this development does not bode well for scientists who receive federal support or work in controversial areas such as evolution or stem cell research. "This is just the tip of the iceberg," he warned.