Massachusetts v. EPA

Massachusetts v. Environmental Protection Agency, 549 U.S. 497 (2007), is a 5–4 U.S. Supreme Court case in which Massachusetts, along with eleven other states and several cities of the United States, represented by James Milkey, brought suit against the Environmental Protection Agency (EPA) represented by Gregory G. Garre to force the federal agency to regulate the emissions of carbon dioxide and other greenhouse gases (GHGs) that pollute the environment and contribute to climate change. Under the Clean Air Act, Massachusetts argued that the Environmental Protection Agency was required by law to regulate "any air pollutant" which could "endanger public health or welfare." The EPA denied the petition, claiming that federal law does not authorize the agency to regulate greenhouse gas emissions. Section 202(a)(1) of the Clean Air Act (CAA), 42 U.S.C. § 7521(a)(1), requires the Administrator of the Environmental Protection Agency to set emission standards for "any air pollutant" from motor vehicles or motor vehicle engines "which in his judgment cause[s], or contribute[s] to, air pollution which may reasonably be anticipated to endanger public health or welfare." In 2003, the EPA made two determinations: The EPA lacked authority under the CAA to regulate carbon dioxide and other GHGs for climate change purposes. Even if the EPA did have such authority, it would decline to set GHG emissions standards for vehicles. The petitioners were the states of California, Connecticut, Illinois, Maine, Massachusetts, New Jersey, New Mexico, New York, Oregon, Rhode Island, Vermont and Washington, the cities of New York, Baltimore, and Washington, D.C., the territory of American Samoa, and the organizations Center for Biological Diversity, Center for Food Safety, Conservation Law Foundation, Environmental Advocates, Environmental Defense, Friends of the Earth, Greenpeace, International Center for Technology Assessment, National Environmental Trust, Natural Resources Defense Council, Sierra Club, Union of Concerned Scientists, and the U.