[JURIST] The US Supreme Court [official website, JURIST news archive] ruled [opinion, PDF] Monday in American Electric Power Co. v. Connecticut [Cornell LII backgrounder; JURIST report] that the Environmental Protection Agency (EPA) [official website] and the Clean Air Act [text] displace claims made under the federal common law of nuisance regarding whether electric utilities contributed to global warming [JURIST news archive]. The court ruled that at least one plaintiff had standing by an equally divided court as Justice Sonia Sotomayor did not take part in the decision. On the merits, all eight justices agreed in rejecting the claims by eight states, New York City, and three private land trusts brought invoking the federal common law for public nuisance against four power companies and the Tennessee Valley Authority (TVA) [official website]. The plaintiffs sought to control greenhouse gas emissions by creating a annually declining cap on emissions. The court held that to challenge greenhouse gas emissions the plaintiffs may file petitions for rulemaking with the EPA to set emissions standards. Currently, the EPA is undergoing rulemaking on the issue and is set to issue new standards by May 2012. The court said:

It is altogether fitting that Congress designated an expert agency, here, EPA, as best suited to serve as primary regulator of greenhouse gas emissions. The expert agency is surely better equipped to do the job than individual district judges issuing ad hoc, case-by-case injunctions. Federal judges lack the scientific, economic, and technological resources an agency can utilize in coping with issues of this order. Judges may not commission scientific studies or convene groups of experts for advice, or issue rules under notice-and-comment procedures inviting input by any interested person, or seek the counsel of regulators in the States where the defendants are located. Rather, judges are confined by a record comprising the evidence the parties present. Moreover, federal district judges, sitting as sole adjudicators, lack authority to render precedential decisions binding other judges, even members of the same court.

In Massachusetts v. EPA [Duke Law case backgrounder; JURIST report] the court found that the EPA had the authority to regulate greenhouse gas emissions under the Clean Air Act and its failure to set applicable standards without reason was no in accordance with law.

The US Court of Appeals for the Second Circuit ruled in 2009 that states can sue power companies for emitting carbon dioxide, reversing a district court decision [JURIST reports] that found the plaintiffs’ claim was a non-justiciable political question. The lawsuit was brought by eight states—California, Connecticut, Iowa, New Jersey, New York, Rhode Island, Vermont and Wisconsin—as well as New York City and three land trusts, against coal-burning utilities American Electric Power, Southern Company, Xcel Energy, Cinergy Corporation [corporate websites] and the TVA]. The Obama administration sided with the power companies.