Wal-Mart v. Dukes was not the only important Supreme Court decision issued today. The Court also handed down it’s decision in American Electric Power v. Connecticut, in which the Court unanimously rejected state efforts to sue power companies for contributing to the “public nuisance” of global warming. This is a significant holding, and a setback for environmentalist plaintiffs and activist state AGs, though some climate suits may continue.
In AEP the U.S. Court of Appeals for the Second Circuit had held that a suit by several states and environmentalist groups against some of the nation’s largest power companies could proceed, despite the EPA’s ongoing efforts to regulate greenhouse gases. (Then-judge Sonia Sotomayor was on the panel that heard the case, although she did not participate in the final decision, or in the Supreme Court’s review of the case.) The Second Circuit’s opinion clearly misread applicable precedent, so it was relatively easy for the Justices to agree on reversal. Under the Court’s prior holdings, legislative action entering a field displaces relevant federal common law causes of action. So, if the Clean Air Act applies to greenhouse gases — which the Supreme Court so held a few years back — federal common law nuisance suits are displaced. It’s that simple, as Justice Ginsburg’s opinion for the Court made quite clear.
While the Court was unanimous on displacement, it split 4-4 on another question: Whethr the plaintiffs had standing to bring their claims in the first place. The Court’s four conservative justices thought not. The three participating liberals and Justice Kennedy thought otherwise. So the Court left in place the Second Circuit’s conclusion that it had jurisdiction to hear the case. For all practical purposes, this is a loss for those who would like to restrict Article III standing, as there’s little doubt Justice Sotomayor would have provided the fifth vote on this question had she not been recused.
Though the Court rejected the federal common law claims, this decision does not put an end to climate change nuisance suits. State AGs and activist groups may still bring state law claims, as the Court did not consider whether such suits are preempted. Justice Ginsburg’s opinion did, however, provide a nice discussion of how courts are not particularly well suited to settle climate change claims. We’ll see if lower and state court judges listen.