In a unanimous 8-0 decision this morning, the United States Supreme Court found that the EPA’s authority to regulate greenhouse gases under the Clean Air Act, 42 U.S.C. § 7401 et seq., displaces alleged common law nuisance claims against greenhouse gas emitters. The Court’s ruling, in American Electric Power Co., Inc., et al. v. Connecticut, et al., 564 U.S. ____ (2011), essentially ends the federal nuisance action brought by several states, the city of New York and private land trusts against four private electric utility companies and the Tennessee Valley Authority. Plaintiffs had sought injunctive relief requiring each defendant to cap their carbon dioxide emissions and then reduce those emissions over time

In the time period between when the nuisance actions were brought and today’s decision, the Supreme Court ruled in Massachusetts v. EPA, 549 U.S. 497 (2007), that EPA had the authority to regulate greenhouse gas emissions under the Clean Air Act. In 2009, EPA issued an endangerment finding that greenhouse gas emissions cause or contribute to air pollution that could endanger the public health. Since the endangerment finding, EPA has issued rules regulating greenhouse gas emissions from light duty vehicles as well as from other major greenhouse emission sources

The Court relied on its prior ruling in Massachusetts to conclude that the Clean Air Act and EPA’s regulations completely displace any federal common law of nuisance relating to greenhouse gas emissions. The Court found that the enforcement options available to EPA and to citizens and States are sufficient to ensure that the alleged harms that plaintiffs sought to remedy were addressed. Finally, the Court concluded that EPA, as an expert agency, was in a far better position to effectively regulate greenhouse gases than the federal judiciary

Click here to see a copy of the decision.