During Tuesday’s oral arguments in American Electric Power v. Connecticut—the global warming lawsuit that Walter Olson recently discussed here and Ilya Shapiro here, and in which Cato filed amicus briefs at both the certiorari stage and the merits stage—the justices concentrated their inquiries on a few technical legal doctrines in order to answer one question: should states even be allowed to sue power companies for the damage that global warming has allegedly done to their lands and citizens?


There are multiple ways this question could be answered, and how it is answered in the final opinion could have important ramifications for future environmental litigation.


Connecticut and five other states, plus New York City and three land trusts, brought the suit against five power companies. Their claim is based on the age‐​old tort of nuisance, the same ground that lets you sue your neighbor if his contaminated water seeps onto your land. Essentially, the states argued that if courts can solve that kind of dispute, then a dispute over global warming is only slightly different—bigger in scope, certainly, but not different in kind.


But at oral argument, the justices did not seem persuaded. Arguing against the states, Acting Solicitor General Neal Katyal opened by pointing out that “[i]n the 222 years that this Court has been sitting, it has never heard a case with so many potential perpetrators and so many potential victims…[T]he very name of the alleged nuisance, ‘global warming,’ itself tells you much of what you need to know.” Chief Justice John Roberts later asked the states’ attorney, New York solicitor general Barbara Underwood, if she had any rebuttal to Katyal’s claim—if there was “any case where it has been as broad as it is here?” Her answer? “Well, of course it depends on what you call broad.”


Indeed.


But how much broader could it be? Taking the scientists at their word, we’d have to include at least every car owner, every coal power plant, every natural gas power plant, every cement producer, every forester, and the fabled effects of bovine flatulence. And not just every one of these in America, but every one in the world. The scope of this case and the numerous trade‐​offs involved make it utterly inappropriate for judicial resolution.


The supposed link between the power companies’ emissions and the alleged global warming harms resembles a Rube Goldberg device of conjectures that stretches back millions of years. In our brief we analogized this to the famous “butterfly effect”: a butterfly flaps its wings in Brazil and causes a tornado in Texas.


A few theories were offered as to why the case should not go any further. The most far reaching of these theories, the political question doctrine, is one we advanced in our amicus briefs. The political question doctrine directs courts to stay out of disputes that are better left to the other branches of government. A decision along those lines would go far in the future toward keeping such suits out of courts.


But many environmental lawyers are hoping, and predicting, that the states will “lose well”—that is, the suit will be dismissed because it has been “displaced” by the “regulatory cas­cade” underway at the EPA, not because it is a fundamentally impossible and illegitimate lawsuit. Dismissing the suit on these grounds would leave the door open for large‐​scale suits to be brought whenever an agency is thought to be shirking its regulatory duties. Such suits are already a problem for administrative agencies, particularly those brought by environmental advocacy groups trying to force agencies to live up to the groups’ idea of sound environmental policy. The NY Times, for example, reported recently on the “barrage [that] has paralyzed the listing process” for the Endangered Species Act.


Not wanting to totally foreclose the possibility of large‐​scale suits being brought in the future, at least three justices, Kagan, Breyer, and Ginsburg, seemed partial to the displacement theory. One hopes that the other five justices will rule, on either prudential standing or political question grounds, that no amount of regulatory action or inaction can make these suits justiciable. If regulation is called for here — a dubious proposition — it should be undertaken by the political branches, not the courts.