The Supreme Court presently has before it the question whether state attorneys general or environmental groups may sue owners of fossil-fuel-fired power plants under the federal common law of public nuisance for the plants' alleged contribution to climate change. Plaintiffs in the case seek to recover an injunction requiring the defendant power companies to reduce the power plants' emissions of carbon dioxide, the principal greenhouse gas. American Electric Power Co. Inc. v. Connecticut, No. 10-174.

The petitioner power companies and the Tennesee Valley Authority -- all defendants in the trial court -- filed their merits briefs on January 28. Amici in support of their position, filed on February 4. The Respondents' (that is, the plaintiffs') briefs are due on March 11.