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Commonwealth of Massachusetts v. United States Environmental Protection Agency, 127 S.Ct. 1438 (2007)

In response to a petition from states and environmental groups, the EPA declared that it lacked authority under the Clean Air Act to regulate greenhouse gas emissions from cars, and that even if it had the authority, the EPA would choose not to exercise it. The states and environmental groups sued, challenging both of EPA’s justifications. A major issue in the case was whether any plaintiff could demonstrate that they suffered sufficient concrete harms from global warming to give them standing to bring the case in federal court.

On April 2, 2007, the Supreme Court ruled 5-4 in favor of Massachusetts, holding that EPA must reconsider whether to regulate greenhouse gas emissions from motor vehicles under section 202 of the federal Clean Air Act. The ruling represents a tremendous victory in one of the most important environmental cases ever decided by the Supreme Court on the preeminent environmental challenge of our time.

Below you will find the Supreme Court opinion, CRC's news release and a number of articles and op-eds by CRC staff. To see documents from the merits stage, click here.