Does EPA Have the Authority to Regulate Greenhouse Gas Emissions from New Cars?

May 16, 2008
Client Alert Newsletter May 2008

One year after the Supreme Court held in Massachusetts v. EPA that the Clean Air Act granted the U.S. Environmental Protection Agency ("EPA") authority to regulate greenhouse gas emissions from new motor vehicles, a group of 18 states and several environmental organizations petitioned the D.C. Circuit Court of Appeals to force EPA to decide whether to do so. The petitioners, which include the New Jersey and Delaware attorneys general and the Pennsylvania Department of Environmental Protection, seek a writ of mandamus ordering the EPA to determine within 60 days whether carbon dioxide ("CO2") emissions from new motor vehicles endanger public health and welfare. An "endangerment" finding by EPA would be the first step in regulating CO2 emissions from mobile sources, and could also affect the regulation of greenhouse gas emissions from stationary sources.

The states' petition followed EPA Administrator Stephen Johnson's announcement in a letter to Congress that the agency's first formal step towards federal regulation of greenhouse gases under existing Clean Air Act authority would be to issue an advance notice of public rulemaking ("ANPR") that requests public comment on a number of issues related to greenhouse gas regulation generally. The letter indicated that the ANPR would be issued sometime in the spring and would request comment on, among other things, the best available science related to the effects of greenhouse gases relevant to making an endangerment finding, and the implications of making such a finding on the regulation of both mobile and stationary sources. Congressional Democrats and the state petitioners criticized EPA's current approach as a means to delay any EPA action on climate change regulation during the Bush administration. EPA has responded that the Massachusetts v. EPA decision does not set any deadlines for EPA action and that the complexity of the issues and ramifications require additional time for comment and analysis.