In May, the latest chapters in the two remaining global warming tort litigation suits closed, bringing the lengthy saga of these cases closer to a final resolution. In one case, the U.S. Supreme Court declined to hear a final appeal, and in the other, a federal appeals court upheld the lower court's dismissal.

Native Village of Kivalina v. Exxon Mobil Corp.

As reported in The Climate Report, on September 21, 2012, the Ninth Circuit upheld a decision by the U.S. District Court for the Northern District of California dismissing federal common law nuisance and civil conspiracy damage claims by the Native Village of Kivalina and the City of Kivalina against a group of U.S. oil, energy, and utility companies. The plaintiffs alleged that the companies' greenhouse gas emissions were contributing to global climate change, causing severe erosion of the Alaskan island where Kivalina is located and threatening the island with imminent destruction. Native Village of Kivalina v. ExxonMobil Corp., 696 F.3d 849 (9th Cir. 2012). The Ninth Circuit held that, based on the Supreme Court's decision in American Electric Power Co., Inc. v. Connecticut, 131 S. Ct. 2527 (2011), the claims must be dismissed because the Clean Air Act displaces all federal common law claims related to federal regulation of greenhouse gases. The Ninth Circuit denied the plaintiffs' petition for rehearing en banc in November 2012.

On March 20, the Supreme Court denied the plaintiffs' petition for writ of certiorari, finally closing the book on Kivalina's claims.

Comer, et al. v. Murphy Oil USA, et al.

As reported in The Climate Report, on March 10, 2012, the U.S. District Court for the Southern District of Mississippi dismissed an action filed by Mississippi residents alleging that a group of companies were liable in tort for contributing to climate change, which purportedly contributed to strengthening Hurricane Katrina, and in turn damaged plaintiffs' properties. Comer, et al. v. Murphy Oil USA, et al., No. 1:11-cv-00220 (S.D. Miss.) ("Comer II"). The plaintiffs had admittedly filed a nearly identical action in 2005 that was dismissed by the same court in 2007 on standing and political question grounds. Comer, et al. v. Murphy Oil USA, et al., No. 1:05-cv-00436-LG-RHW ("Comer I"). Comer I was also dismissed by the Fifth Circuit when the court lost a quorum to hear the case en banc, see, Comer, et al. v. Murphy Oil USA, et al., 607 F.3d 1049 (5th Cir. 2010), and then the Supreme Court denied the plaintiffs' petition for writ of mandamus. In re Comer, U.S. No. 10-294 (Jan. 10, 2011). The district court's dismissal of Comer II was based in part on a finding that the doctrine of res judicata barred the plaintiffs' claims. Under the doctrine of res judicata, a party is precluded from relitigating issues that could have been raised in a prior action when the prior action resulted in a final judgment on the merits.

On May 14, the Fifth Circuit again upheld dismissal of the plaintiffs' claims, holding they were barred by the doctrine of res judicata, because Comer I was a final judgment on the merits. Comer, et al. v. Murphy Oil USA, Inc., et al., No. 12-60291 (5th Cir. May 14, 2013). The Fifth Circuit held that the Comer I district court judgment was final for purposes of res judicata, because the district court properly entered final judgment and, since no mandate was issued by the Fifth Circuit before it lost a quorum to hear the appeal en banc, the district court's judgment was never modified or disturbed on appeal.

In addition, the Fifth Circuit panel found the plaintiffs' argument for an equitable exception—on the basis that they had not received meaningful appellate review of the Comer I decision—unavailing, because the Supreme Court does not recognize a general equitable exception to the doctrine of res judicata. The court of appeals further held that the Comer I judgment was on the merits, even though the decision was based on the jurisdictional issues of standing and justiciability, because it has been a long-standing rule that principles of res judicata apply to jurisdictional issues.

The plaintiffs may still petition the Supreme Court for a writ of certiorari to review the case. However, based on the Supreme Court's denial of the petition for a writ of certiorari in Native Village of Kivalina v. Exxon Mobil Corp., 185 L. Ed. 2d 1116 (U.S. 2013), it is at best questionable whether the Supreme Court would entertain such a petition.