News
General Interest
UA climate scientists take a stand before the U.S. Supreme Court
October 5, 2006
By Stephanie Doster
Smog from automobiles.
Credit: University Corporation for Atmospheric Research
Three University of Arizona scientists have filed a brief with the U.S. Supreme Court, claiming that the U.S. Environmental Protection Agency mischaracterized climate science in a recent ruling as more uncertain than it really is. The scientists filed the brief in support of the plaintiffs in the case-a group of states, cities, and environmental organizations-that have sued the agency for refusing to limit greenhouse gas emissions from motor vehicles.
The case, Commonwealth of Massachusetts v. U.S. Environmental Protection Agency, is the first climate change case to come before the high court. The case turns on whether the EPA is required to regulate vehicle emissions of carbon dioxide, one of the gases contributing to global warming.
The UA researchers-Jonathan Overpeck, director of the Institute for the Study of Planet Earth (ISPE) and a geosciences professor; Scott Saleska, an assistant professor of ecology and evolutionary biology; and Joellen Russell, an assistant professor of geosciences-were among 15 other researchers to write the brief.
Saleska organized the group of climate scientists, who wrote that evidence of climate change attributable to greenhouse gases is "so compelling that it has crystallized a remarkable consensus within the scientific community: climate warming is happening, and human activities are very likely a significant factor."
Kirsten Engel, a UA professor who specializes in environmental law and policy, is one of four lawyers for the scientists. She will discuss the case during ISPE Fest, an annual event that celebrates the accomplishments of ISPE, on October 5.
The case began in 1999, when a group of environmental organizations petitioned the EPA to regulate, under the federal Clean Air Act, greenhouse gases from cars and trucks in the same way that it regulates other harmful air pollutants. The agency refused in 2003, saying that it has no authority to regulate air pollutants associated with climate change and that greenhouse gases are not pollutants under the Clean Air Act. Even if it did have the authority, the EPA said, it has the discretion not to regulate them based on continuing uncertainties in climate science and other factors. The environmental organizations, together with 12 states, three cities, and American Samoa, filed an appeal. In 2005, the U.S. Court of Appeals in Washington, D.C., upheld the EPA's decision in a 2-1 ruling. The high court agreed to take up the case; arguments will be heard on November 29, but a decision won't be issued until next year.
If the court rules in favor of the environmental groups, the EPA would be required to revisit a question that is fundamental to the case: does climate change science support a finding that greenhouse gas emissions "may reasonably be anticipated to endanger public health or welfare," a provision included in the Clean Air Act that pertains to air pollutants.
The scientists argue that greenhouse gases are air pollutants that pose a threat to human health and the environment the same way that lead, which the EPA regulates, does.
"The best we can hope for is that the Supreme Court will say, 'OK, EPA. You never made a decision on this, so go back and make it'," Engel said. "When the EPA goes back, it has to look at the science."
Engel said the case is one of high stakes: 27 percent of the total greenhouse gas emissions in the United States in 2003 came from vehicles.
Saleska said he hopes the litigation ultimately triggers mandatory emissions reductions.
"A possible optimistic trajectory is one in which Congress is forced to take up the issue and deal with it," Saleska said.
Overpeck said his main motivation in co-authoring the brief "is to make sure that climate science is interpreted correctly, and not spun incorrectly as apparently the EPA has done."
In their August 31 brief in support of the environmental groups, the researchers argued that the EPA selectively pulled information pulled from the 2001 report, Climate Change Science, which the agency used as its source of climate information, thus misrepresenting climate science and making it appear to be more uncertain that it actually is. Six of the climate scientists who signed the brief helped produce the 2001 report.
That report, the scientists countered, "unambiguously concluded that Earth's climate is changing in ways that risk significant adverse impacts on public welfare" and "found strong evidence for anthropogenic causation of recent climate change by emissions of CO2 and other greenhouse gases."
The scientists wrote that they themselves were surprised by the rapid pace of climate change; by the beginning of this decade, they said, they have observed that global temperatures and sea levels are rising, plant and animal ranges are shifting, glaciers and arctic sea ice are retreating, and the oceans are becoming more acidic.
"To the extent that these changes result from human alteration of the atmosphere," they wrote, "we know that they are just the first small increment of climate change yet to come if human societies do not curb emission of greenhouse gases."
In This Section
Related Links
Brief of Amici Curiae [PDF]