The U. S. Supreme Court, in an 8-0 decision, reversed a lower court’s ruling permitting states and environmental groups to bring common law nuisance actions against utilities due to their greenhouse gas (GHG) emissions. American Electric Power Co. v. Connecticut, No. 10-174, June 20, 2011.
In an opinion authored by Justice Ginsburg, the court held that Clean Air Act’s (CAA) delegation of authority to the Environmental Protection Agency (EPA) to regulate GHGs from utilities under section 111 effectively displaced the federal common law cause of action. NMA participated in the litigation as amicus curiae in support of the utilities.
On the issue of displacement, the court found that “[t]he critical point is that Congress delegated to EPA the decision whether and how to regulate carbon-dioxide emissions from power plants; the delegation is what displaces federal common law. Indeed, were EPA to decline to regulate carbon-dioxide emissions altogether at the conclusion of its ongoing § 7411 rulemaking, the federal courts would have no warrant to employ the federal common law of nuisance to upset the agency’s expert determination.” The court expressly declined to decide whether, even assuming no regulation under the CAA and therefore no displacement, a federal common law nuisance action actually exists against utilities due to their GHG emissions. Similarly, the court declined to answer this question for common law nuisance claims brought in state courts.
The important remaining issue is to what extent future congressional legislation divesting EPA’s authority under section 111 to regulate GHGs from utilities would impact the decision. More than likely, such congressional action would bar displacement as an effective defense and a judicial determination would have to be made whether a federal common law cause of action is viable. Currently, the EPA is scheduled by consent decree to propose GHG standards of performance for new and existing coal-fired utilities by Sept. 30, 2011.