The Yale Law Journal‘s new “Summary Judgment” online series features a set of essays on the Supreme Court’s decision in American Electric Power v. Connecticut, in which the Court held unanimously that suits against utilities alleging their emissions of greenhouse gases contribute to the “public nuisance” of global warming under federal common law were displaced by the Clean Air Act. Contributors to the online symposium include Hari Osofsky, Daniel Farber, James May, Maxine Burkett, Michael Gerrard, and yours truly. My contribution, “A Tale of Two Cases” (PDF), discusses how the outcome in AEP was predetermined by the Court’s prior holding in Massachusetts v. EPA that greenhouse gases were pollutants subject to regulation under the Clean Air Act. The essay is based on a longer article forthcoming in the Cato Supreme Court Review that I will discuss at the Cato Constitution Day event on Thursday.