The Supreme Court Closes The Door On Federal Common Law Nuisance Claims Regarding Greenhouse Gas Emissions

On June 20, 2011, the US Supreme Court unanimously held in American Electric Power Co., Inc. et al. v. Connecticut et al., No. 10-174 (AEP), that the federal Clean Air Act displaces any federal common law right to seek abatement of carbon dioxide and other greenhouse gas (GHG) emissions from fossil fuel-fired power plants. In so doing, the Court clearly established limits on the scope of federal common law in areas in which Congress has authorized an expert agency to act, regardless of whether that agency has in fact exercised the authority. This opinion should close the door on attempts by litigants to establish liability for major emitters of GHGs—and conventional pollutants—under federal common law, but it does leave open the question of whether such claims can be successful under state tort law.

Background

The original complainants in AEP—several states, the City of New York and private land trusts—filed claims against four private utilities and the Tennessee Valley Authority (TVA), claimed to be the largest emitters of GHGs in the US and responsible for 2.5 percent of global human-caused emissions. The complainants alleged that these GHG emissions caused them harm by contributing to the risk of climate change. They sought an injunction under the federal common law of interstate nuisance or, in the alternative, state tort law directing each of the defendants to cap its emissions and reduce those emissions annually by a specified percentage for at least a decade. The defendants responded that the complainants lacked standing to bring the case; that federal common law was not applicable, was preempted or was displaced by the Clean Air Act; and that the claims were barred by the "political question" doctrine, which reserves these types of policy issues for the legislative and executive branches.

The district court dismissed the claims as presenting non-justiciable political questions, but the Second Circuit reversed. The appellate panel held that there was standing and that the claims were justiciable and not blocked by the federal question doctrine. The Second Circuit also found that there was cognizable federal common law relating to such interstate pollution claims and that the Clean Air Act did not displace the claims because, at the time, the Environmental Protection Agency (EPA) had not yet acted to regulate GHGs. The Second Circuit did not rule on the alternative state law claims because it found that federal common law applied.

Main Elements of Opinion

Once the matter reached the Supreme Court, only eight justices participated in the opinion because Justice Sotomayor, who was on the original Second Circuit panel that heard the AEP case (although she did not sign the opinion), recused herself from further consideration. All eight justices agreed that the Clean Air Act displaced federal common law of nuisance claims with regard to GHG regulation. They differed only on the justiciabilty of the claims.

Justiciability

The defendants had argued...