564 U.S. 410 (2011)
American Electric Power Co. v.
Does the Clean Air Act, and the EPA rulemaking authority it confers over greenhouse-gas emissions, displace federal common-law public nuisance claims seeking abatement of carbon-dioxide emissions from fossil-fuel-fired power plants?
Federal common law may govern limited areas implicating uniquely federal interests, such as interstate pollution, but it is displaced when Congress has spoken directly to the question at issue by enacting a statutory scheme. Displacement does not depend on whether the responsible agency has actually exercised its regulatory authority; it occurs when Congress has delegated to the agency authority to regulate the field. When displacement exists, plaintiffs must pursue their claims through the statutory framework, with judicial review available under that statute and the Administrative Procedure Act.
Yes. The Clean Air Act and the EPA actions it authorizes displace federal common-law public nuisance claims seeking to cap and reduce carbon-dioxide emissions from power plants. The Court affirmed the Second Circuit's exercise of jurisdiction by an equally divided Court and remanded for consideration of any state-law nuisance claims, including issues of preemption.
AEP v. Connecticut is a cornerstone in climate litigation and federal courts doctrine. It forecloses federal common-law nuisance suits seeking to regulate greenhouse-gas emissions from stationary sources, channeling disputes into the Clean Air Act's administrative process and statutory judicial review. The case clarifies the displacement standard—Congress displaces federal common law when it speaks directly to the issue, regardless of the agency's progress—and underscores institutional competence by reserving complex emissions policy to EPA. It also set the stage for subsequent cases, such as Kivalina v. ExxonMobil, which applied AEP to dismiss federal common-law damages claims for climate harms, and it shifted climate plaintiffs toward state-law theories, where preemption and choice-of-law questions loom large.