The U.S. Court of Appeals for the Fifth Circuit this week affirmed dismissal of the plaintiffs’ common law tort claims in the case Comer v. Murphy Oil USA, Inc.,[1] one of the first cases seeking to impose common law tort liability on emitters of greenhouse gasses for their alleged contribution to global climate change, and a key case demonstrating the preemptive scope of the Clean Air Act.

Originally filed in 2005, the Comer case was brought by a group of Gulf Coast residents in Mississippi seeking compensation for property damage caused by Hurricane Katrina.  The plaintiffs brought suit against numerous chemical, oil, and power companies alleging that greenhouse gas emissions from their operations had contributed to the ferocity and duration of Hurricane Katrina, allegedly making the defendants liable under common law theories of negligence, nuisance, and trespass, among others.

The federal district court for the Southern District of Mississippi dismissed the case on justiciability, political question, and standing grounds.  The Fifth Circuit reversed in part; however, the district court’s decision was ultimately reinstated due to an unusual procedural quirk when the Fifth Circuit lost its quorum during en banc review.[2]  The plaintiffs sought a mandamus order requiring the Fifth Circuit to hear the case, and when that petition was unsuccessful, refilled their claims in the Southern District of Mississippi.  Again, the district court dismissed, but this time adding res judicata as a basis for dismissal as well as preemption, noting that the plaintiffs’ common law claims fell within the scope of the Supreme Court’s recent American Electric decision [3] and were therefore preempted by the Clean Air Act.  The plaintiffs had sought in the refiled case  to distinguish their claims from those at issue in American Electric.  They argued that their were claims for damages, not injunctive relief like those brought in American Electric, and were premised on state common law, unlike the federal common law claims brought in American Electric.  Chief Judge Guirola found the distinctions did not change the analysis, however, and again dismissed the plaintiffs’ claims.

On appeal the the Fifth Circuit, the Comer plaintiffs asserted that res judicata would not apply because their original claim had never been properly reviewed on its merits.  The Fifth Circuit rejected this argument, however, stating that “’a federal court may not abrogate principles of res judicata out of equitable concerns.’”  Opinion at 9 (quoting IRS v. Teal (In re Teal), 16 F.3d 619, 622 n.6 (5th Cir. 1994) (per curiam)).  Even if its original decision not to hear the appeal had been error, the Fifth Circuit found, there would be no basis for equitably avoiding res judicata.  Opinion at 6-7.  The Fifth Circuit’s opinion notes that the district court also dismissed on preemption grounds, but given the Fifth Circuit’s determination that the appeal was barred on res judicata grounds, the court did not discuss this issue further.

Accordingly, the Fifth Circuit’s decision leaves intact a key decision on the preemptive effect of the Clean Air Act.  Moreover, since the affirmance was on res judicata grounds, an opinion from the U.S. Supreme Court is unlikely to result in any further discussion of preemption even if certiorari is granted, leaving the district court’s opinion as the last word on the issue in the Southern District of Mississippi .  For those following the development of greenhouse gas tort law, the focus will now turn to the currently-pending petition for certiorari in Native Village of Kivalina v. Exxon Mobil Corp., [4] which seeks review of the Ninth Circuit’s affirmance of the dismissal of federal tort claims brought for alleged contributions to rising temperatures and increased storm activity in the Chuckchi Sea.

[1] Case No. 12-60291.

[2] Thanks to proposed amendment to 5th Cir. R. 41.3, the loophole giving rise to this dismissal may soon be closed.

[3] Amer. Elec. Power Co. v. Connecticut, ___ U.S. ___, 131 S.Ct. 2527 (2011).

[4] Case No. 12-1072.