American Electric Power Co. v. Connecticut

Background

Several States, the city of New York, and three private land trusts sued four large private power companies and the federally owned Tennessee Valley Authority, alleging those defendants are major carbon-dioxide emitters whose pollution contributes to global warming. The plaintiffs asked federal courts to order each defendant to cap and then steadily reduce its carbon-dioxide emissions. The suits began years before EPA completed greenhouse-gas rulemakings; the Second Circuit allowed the federal common-law nuisance claims to proceed and found the plaintiffs had standing.

Reasoning

The Court addressed whether federal common-law public-nuisance claims can be used to force emission limits on fossil-fuel powerplants. Relying on this Court’s earlier decision that greenhouse gases qualify as air pollutants under the Clean Air Act, the majority held that Congress gave EPA the authority to regulate carbon dioxide and related emissions. Because the Clean Air Act and the actions it authorizes