Massachusetts v. Environmental Protection Agency

Massachusetts v. Environmental Protection Agency
Supreme Court of the United States
Argued November 29, 2006 Decided April 2, 2007
Full case name	Massachusetts, et al., Petitioners v. Environmental Protection Agency, et al.
Docket nos.	05-1120
Citations	549 U.S. 497 (more) 127 S. Ct. 1438, 167 L. Ed. 2d 248
Prior history	415 F.3d 50, 367 U.S. App. D.C. 282 (D.C. Cir. 2005); rehearing denied, 433 F.3d 66, 369 U.S. App. D.C. 56 (D.C. Cir. 2005); certiorari granted, 549 U.S. 1029, 127 S.Ct. 617, 166 L.Ed.2d 427 (2006)
Subsequent history	249 Fed. Appx. 829 (D.C. Cir. 2007)
Holding
Greenhouse gases are air pollutants, and the United States Environmental Protection Agency may regulate their emission.
Court membership
Case opinions
Majority	Stevens, joined by Kennedy, Souter, Ginsburg, Breyer
Dissent	Roberts, joined by Scalia, Thomas, Alito
Dissent	Scalia, joined by Roberts, Thomas, Alito
Laws applied
U.S. Const. art. III; Clean Air Act

Massachusetts v. Environmental Protection Agency, 549 U.S. 497 (2007), is a 5-4 U.S. Supreme Court case in which twelve states and several cities of the United States brought suit against the Environmental Protection Agency (EPA) to force that federal agency to regulate carbon dioxide and other greenhouse gases (GHGs) as pollutants.

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 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.S. Public Interest Research Group. James Milkey of the Massachusetts Attorney General's Office represented the petitioners in oral arguments before the U.S. Supreme Court.