U.S. Supreme Court Deliberates Monumental Global Warming Case

Should the U.S. Clean Air Act limit carbon dioxide emissions from vehicles?

The first substantive discussion between U.S. states and the federal government over federal climate change policy took place in the U.S. Supreme Court on November 29. The country’s top justices heard oral arguments in the case of Massachusetts vs. Environmental Protection Agency (EPA), concerning the federal environment agency’s refusal to regulate carbon dioxide (CO2), a leading greenhouse gas, under the U.S. Clean Air Act. The questions presented to the court centered on (1) whether CO2 is a pollutant, which would allow the agency to regulate CO2 emissions, and (2) whether, if the gas is considered a pollutant, the EPA has the authority to choose not to regulate it.

The path of this important case to the Supreme Court began in 1999, when the International Center for Technology Assessment led a coalition of environmental organizations in petitioning the EPA to set CO2 emissions standards. The Clean Air Act states that the EPA administrator shall regulate any air pollutant emitted from new motor vehicles that, in his or her judgment, “may reasonably be anticipated to endanger public health or welfare.” In August of 2003, the EPA decided it would not regulate CO2 emissions because, according to its interpretation of the Act, it did not have the proper authority to do so—adding that even if it did, the agency would still choose not to regulate, favoring policy over regulation. The Massachusetts Attorney General and 29 other parties challenged the decision in a lower court and lost. The current petitioners, which include New York and California, appealed, and in March 2006 the U.S. Supreme Court agreed to review the case.

According to Lisa Heinzerling, law professor at Georgetown University and former Assistant Attorney General of Massachusetts, the plaintiffs are asking only that the EPA do its job as outlined in the Clean Air Act: that is, look seriously at the science and regulate CO2 and other greenhouse gases as pollutants. Heinzerling believes that because the EPA defendants and their supporters have paid little attention to the language of the statute in question, the plaintiffs are correct in their request for review.

To EPA officials in the current Bush administration, however, the case is not that simple. Moreover, the agency has the support of several key remaining global warming skeptics. A brief filed by the Competitive Enterprise Institute (CEI), with input from climatologists and scientists, states that the detrimental effect of greenhouse gases on human health and welfare is an “unsupported notion.” Since 1998, CEI has received more than $2 million in funding from ExxonMobil, which continues to fight federal action on climate change, and the scientists listed on the report are connected to 21 organizations that have received over $9 million from the oil giant. Their brief does not present any new evidence but quotes selectively from three National Academy of Sciences reports as proof of the uncertainty surrounding global warming.

Many top scientists, however, including several that contributed to those reports, say the EPA and its supporters were wrong to cite them and that the evidence of warming is “so compelling that it has crystallized a remarkable consensus within the scientific community.” Carol Browner, former head of the EPA under the Clinton administration, and a team of scientists led by two Nobel laureates also agree with the compelling nature of the evidence.

In addition, the EPA defendants contest whether a favorable ruling by the Supreme Court would adequately redress the climate issue. Edward Warren, a partner at the law firm Kirkland & Ellis specializing in environmental litigation, believes regulating emissions from U.S. motor vehicles is an inefficient way of combating a global problem. Limiting emissions from developing countries or stationary sources would provide more “bang for the buck,” Warren says. However, with U.S. automobiles accounting for 6 percent of global carbon emissions, Kert Davies, director of research with Greenpeace in Washington, D.C., is confident that “mandating cleaner cars in the U.S. will promote development of cleaner cars worldwide.”

Ultimately, the most important issue at stake may be how—and if—the Supreme Court rules on whether carbon dioxide is an air pollutant. If CO2 and other greenhouse gases are deemed pollutants, this could conceivably pave the way for national air quality standards in the United States. With the new Congress convening in January, however, new climate legislation proposals are likely to precede the justices’ decision, which is expected in early summer. “The zeitgeist around the climate change issue has changed significantly since 1999 and the weight of evidence now can't be avoided,” says Greenpeace’s Davies.

This story was produced by Eye on Earth, a joint project of the Worldwatch Institute and the blue moon fund. View the complete archive of Eye on Earth stories, or contact Staff Writer Alana Herro at aherro [AT] worldwatch [DOT] org with your questions, comments, and story ideas.