Supreme Court Unanimous that Clean Air Act Displaces Climate Suits

Today the U.S. Supreme Court held unanimously in American Electric Power v. Connecticut that the Clean Air Act displaces suits alleging global warming constitutes a public nuisance under federal common law. As I’ve discussed before (see posts here, here and here), this conclusion was hard to avoid once the Supreme Court held (erroneously in my view) that greenhouse gases are “pollutants” subject to Clean Air Act regulation in Massachusetts v. EPA.

Another interesting aspect of today’s opinion is that the Court apparently split 4-4 over whether the U.S. Court of Appeals for the Second Circuit had jurisdiction to hear this case in the first place. Justice Alito also wrote a separate concurrence, joined by Justice Thomas, making clear that he agreed with the Court only on the assumption that Massachusetts v. EPA interpreted the Clean Air Act correctly. [Why didn’t Justice Scalia and Chief Justice Roberts join this opinion when they also dissented in Massachusetts? Perhaps because principles of stare decisis are strongest for questions of statutory interpretation and they have no interest in suggesting they would reconsider what constitutes a “pollutant” under the Act.]

I’ll have more to say on this opinion later today, once I’ve had time to digest it.

UPDATE: I’ve posted my initial thoughts here.