To date, the only circuit courts that have reviewed public nuisance claims related to climate change, the Second Circuit, in American Electric Power, and the Fifth Circuit, in Comer v. Murphy Oil, have ruled that such suits can proceed. However, last week the Court of Appeals for the Fifth Circuit decided to hear Comer v. Murphy Oil en banc, which certainly has to give the plaintiffs pause. While I am not fully versed in this issue, a quick glance at the web indicates that statistical analysis confirms one’s naïve assumption, i.e., that a full appellate court often decides to hear a case en banc because a majority thinks that the panel got it wrong.

As I noted when the original decision was issued, even under liberal standing rules, which suggest that the plaintiffs’ harm can be “traced” to the defendant as long as the defendant’s conduct “contributed” to the harm, it’s going to be very difficult for plaintiffs, particularly under the Supreme Court’s new pleading rules, to argue that, for example, Murphy Oil “contributed” to the harm caused by Katrina. If the Fifth Circuit sitting en banc affirms the District Court dismissal in Murphy v. Comer, we could be headed back to the Supreme Court on climate change, since that would set up a conflict between the Second and Fifth Circuits.