The Supreme Court just ruled that regulating greenhouse gases is the Feds' job, as spelled out in the Clean Air Act. Good thing the Federal government is all over that one. (Sarcasm!)
The decision was as unambiguous as they come: All eight justices on the case agreed that states cannot sue utility companies or other polluters for their greenhouse gas emissions under federal common law. (Sonia Sotomayor recused herself on this one.) Specifically, the states were arguing that these emissions were "nuisances" — in the legal sense that they harm others, not in the sense that they’re merely annoying.
This is actually probably just as well. Legal scholars have been arguing for some time that attempts to sue for emissions under nuisance law are doomed to go nowhere. By confirming that regulation of greenhouse gases belongs to the Federal government under the Clean Air Act, the justices sent an unambiguous message to litigants that this is not the way to go about trying to put the screws to climate villains.