Massachusetts v. EPA

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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 no.	05-1120
Citations	549 U.S. 497 (more) 127 S. Ct. 1438; 167 L. Ed. 2d 248; 2007 U.S. LEXIS 3785
Argument	Oral argument
Case history
Prior	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); cert. granted, 549 U.S. 1029 (2006).
Subsequent	249 F. App'x 829 (D.C. Cir. 2007)
Holding
Greenhouse gases are air pollutants, and the States may sue the United States Environmental Protection Agency if it fails to properly regulate these pollutants.
Court membership
Chief Justice John Roberts Associate Justices John P. Stevens · Antonin Scalia Anthony Kennedy · David Souter Clarence Thomas · Ruth Bader Ginsburg Stephen Breyer · Samuel Alito
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 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.