Supreme Court Decides that Clean Air Act Displaces Federal Common Law Claims for Climate Change

On June 20, 2011, the U.S. Supreme Court decided the closely watched case of American Electric Power Co. v. Connecticut, 131 S. Ct. 2527 (2011) (AEP), in which eight states, the City of New York, and several land trust organizations sued the nation’s five largest fossil-fuel-burning electric utility companies to reduce their emissions of greenhouse gases, arguing that these emissions constitute a public nuisance under federal common law. The Supreme Court rejected this claim, reasoning that the Clean Air Act (CAA), when coupled with the Environmental Protection Agency’s (EPA’s) authority and the actions EPA has taken in the last two years to regulate greenhouse gas (GHG) emissions, displaces federal common law nuisance causes of action for injunctive action addressing climate change.