Senate hearings strengthen calls for US action over climate

Abstract

Winds of change blow through Congress. The scepticism over global warming that has pervaded US politics is showing signs of abating. Two Senate hearings last week saw some of the strongest assertions yet, especially from Republicans, that climate change is a problem. And a congressman who recently launched a personal inquiry into the validity of certain climate studies has drawn fire from members of his own party for what they call his "intimidating" tactics. Senator Pete Domenici (Republican, New Mexico), who chairs the Senate's energy committee, helped to convene a hearing on 21 July to discuss possible solutions to global warming. Leading US scientists, including the new president of the National Academy of Sciences (NAS), Ralph Cicerone (see In defence of data), and Mario Molina, a Nobel laureate at the Massachusetts Institute of Technology, told the assembled politicians that the world is warming at a dangerous rate. "Nearly all" climate scientists believe that the observed warming is caused by increases in atmospheric levels of greenhouse gases, Cicerone told the hearing. This sentiment echoed his testimony the previous day, when he spoke at a hearing organized by a Senate subcommittee on climate change. "Carbon dioxide in the atmosphere is now at its highest level in 400,000 years," he said, "and continues to rise." Several Republicans broke rank at the 21 July hearing to voice their concerns about global warming. "I don't need to be converted on whether or not we have climate change," said Senator Lisa Murkowski (Republican, Alaska), adding that she had seen evidence for global warming in her home state. Domenici backed her view: "I have come to accept that something is happening to the Earth's climate." Senators agreed that direct action should be taken, although they could not agree on specific energy policies that might address the problem of greenhouse gases. Meanwhile, Joe Barton (Republican, Texas), who chairs the House Committee on Energy and Commerce, has been roundly criticized for demanding information from various climate researchers about studies that show Earth's temperature rising dramatically over the past century. Barton originally wrote to three climate scientists on 23 June, as well as to the heads of the Intergovernmental Panel on Climate Change and the National Science Foundation, asking for extensive information about their funding and methodology. The tone of the letter alarmed many climate researchers, who saw it as a bullying tactic (see Nature 436, 1; 2005). Now it seems that politicians agree. On 14 July, Sherwood Boehlert (Republican, New York), chairman of the House science committee, wrote to Barton calling his inquiry a "misguided and illegitimate" investigation that sought to "intimidate the scientists rather than to learn from them". Researchers are continuing their own protests. On 15 July, 20 leading climate scientists sent Barton a letter pointing out that the study in question is just one among thousands of pieces of evidence contributing to the present consensus over climate change. But Cicerone has offered a kind of olive branch, suggesting that the NAS could do an independent survey of climate-change research for Barton. "Science is one of the few human endeavours that's self-correcting and that we can rely on to get to the truth of the matter," he told the 20 July hearing.