This case alleges that the emissions of greenhouse gases from various energy and manufacturing companies led to a stronger Hurricane Katrina than might have otherwise occurred, and the companies should pay the damages. It was dismissed in litigation in 2010 summarized here.
The plaintiffs filed a new suit, and the trial court dismissed it. On appeal to the Fifth Circuit, the NAM and other groups filed an amicus brief opposing any common law cause of action for harms caused by weather events allegedly caused by climate change. The courts are not the place to make policy judgments about emissions policies for individual defendants, becoming a kind of super EPA. All the most recent Supreme Court and appellate court decisions reject this kind of liability, since EPA is already regulating greenhouse gases.
On May 14, 2013 the Fifth Circuit affirmed the district court’s rejection of plaintiffs’ claims based on the doctrine of res judicata, which holds that once a valid judgment decides a case, that decision shall stand. The case followed a complicated procedural history. The trial court decision rejecting the plaintiffs’ claims was up for an en banc rehearing by the Fifth Circuit. However, without a majority of the Circuit’s judges available to hear the case, quorum was not met and the case was not reheard. Plaintiffs then sought a writ of mandamus from the Supreme Court, which was denied. Then the plaintiffs asserted that there was not a final decision on the merits, and therefore that their claim was not barred by res judicata. The Fifth Circuit disagreed and upheld the trial court’s decision to bar the claims. At no point was the trial court’s final judgment disturbed nor was there was a decision on the merits.