From DWT attorney Kerry Shea:
The U.S. Supreme Court ruled today in American Electric Power v. Connecticut, holding that the Clean Air Act displaces federal common law public nuisance actions to force greenhouse gas (GHG) emissions reductions from fossil-based power plants, even though EPA has not yet set standards to limit those emissions. The opinion (an 8-0 decision) reverses a 2009 Second Circuit decision holding that plaintiffs could seek to limit power plant emissions on the theory that contributing to global climate change constitutes a public nuisance under federal common law. The decision leaves open the question of whether the Clean Air Act has displaced state common law nuisance claims, an issue that is likely to be addressed by the Supreme Court soon in upcoming cases.
Bottomline: This is important because it redirects the focus back to EPA to regulate GHG emissions. Courts still have a voice, and there's a split in the Court about who may bring such claims, but trying to fit GHG emission regulations into federal common law trespass claims as had been done by these plaintiffs is no longer so viable.