Science, Vol 308, Issue 5721, 482 , 22 April 2005
Global Warming Skeptic Argues U.S. Position in Suit
The U.S. government has enlisted an outspoken skeptic of global warming in a legal fight with environmental groups over U.S. funding for overseas energy projects. The move has angered several prominent climate researchers, however, who say the government's arguments fly in the face of scientific consensus about both the causes and possible consequences of global warming.
On 29 April, a federal district court in San Francisco will hear a case (Friends of the Earth v. Peter Watson) about whether the National Environmental Policy Act (NEPA) should apply to projects supported by the Export-Import Bank and the Overseas Private Investment Corporation. The act requires the government to assess actions that could alter the environment. The plaintiffs in the case, which include several environmental groups and four western U.S. municipalities, argue that the federally supported projects--including oil drilling, pipelines, and commercial power plants--contribute to global warming, which in turn affects U.S. economic interests and its citizens. That connection is essential to establish their legal right, or standing, to bring suit.
To counter that claim, the Justice Department argues that "[t]he basic connection between human induced greenhouse gas emissions and observed climate itself has not been established." It buttresses its case with a 41-page statement from David Legates, head of the Center for Climatic Research at the University of Delaware, Newark.
Legates begins by attacking the evidence for the 0.6°C rise in temperature in the 20th century cited by the Intergovernmental Panel on Climate Change (IPCC) in Geneva, Switzerland, in its 2001 report and by the plaintiffs. The proximity of temperature gauges to cities, he says, has artificially elevated reported temperatures. He also points to natural variability as an important factor, citing a 2004 study that suggested solar variability may have contributed up to 0.25°C of the recent warming. As for future impacts, he says surface temperatures in Greenland are falling, coral bleaching is a beneficial response to stress, and the impact of droughts has been relatively benign in the 20th century. Legates says a Canadian climate model that plaintiffs cite to show potential changes in surface temperatures and moisture across North America is "extreme" and "overstated."
The plaintiffs counter with a 45-page brief from climate researcher Michael MacCracken, former head of the Office of the U.S. Global Change Research Program. In an interview, MacCracken called the Legates document "an attempt to go back and reargue the IPCC." Core findings of the IPCC, he says, have been repeatedly confirmed, including the 0.6°C increase in the last century. The urban heat effect has been discounted and cannot explain the warming oceans, says Thomas Wigley, a climatologist at the National Center for Atmospheric Research (NCAR) in Boulder, Colorado. Legates's arguments on solar variability are "standard skeptic crap" that has been discredited, Wigley declares.
MacCracken says Legates's assertion that Greenland is cooling is "wishful thinking," pointing to vast melting around the landmass documented in the recent Arctic Climate Impact Assessment. Severe droughts are on the increase, says IPCC lead author Kevin Trenberth of NCAR. As for Legates's criticism of the Canadian model, MacCracken notes that relevant government agencies have approved the 2000 U.S. National Assessment in which the model was put to use. "It's a selective use of studies and half-truths," Trenberth says about Legates's arguments.
In an interview with Science, Legates says he's standing his ground. He questions whether the IPCC represents a true consensus, claiming "a lot of dissenting views." He defends the studies he cites and attacks the Arctic assessment, which he says ignores natural Arctic cycles. Connecting emissions overseas to stateside impacts is simply tenuous, he maintains, adding that the plaintiffs are being selective in choosing the most dire projections.
Previous legal attempts to force the government to report carbon dioxide emissions under NEPA, by linking those emissions to climate impacts, have failed. But a 2003 ruling in a suit over natural gas turbines found the failure to disclose CO2 emissions "counter to NEPA." Earlier this month a federal appeals court heard arguments in a suit that would require the Environmental Protection Agency to regulate CO2 emitted by motor vehicles.