On June 20, 2011, the U.S. Supreme Court issued its much-anticipated decision in American Electric Power Co. v. Connecticut, reviewing whether federal common law would support a claim that greenhouse gas emissions could give rise to a public nuisance claim that would warrant injunctive relief against future emissions. The Court concluded that the federal common law cannot support such a claim.
The plaintiffs, including eight states, New York City, and three nonprofit land trusts, brought suit in the Southern District of New York against five electric power companies alleged to be the largest emitters of carbon dioxide in the United States. The complaint alleged that carbon dioxide emissions contributed to global warming and thereBy constituted a nuisance under federal common law. The plaintiffs requested an injunction limiting emissions in the future. No monetary damages were sought. The district court dismissed the case, finding that the complaint presented a nonjusticiable political question. The Second Circuit reinstated the case, holding that the plaintiffs were not barred By the political-question doctrine and had stated a federal common law nuisance claim.