Existing authority  under the Clean Air Act--particularly § 115 on "International Air Pollution"--could provide for the establishment of a cap-and-trade program without further Congressional action.

In the fall of 2009, the Second Circuit issued its long-awaited decision in Connecticut v. American Electric Power Company, a case alleging a federal common law nuisance claim based on the effects of greenhouse gases.  The Second Circuit Court of Appeals reversed a lower court dismissal of the case.  In a lengthy opinion, the Second Circuit held that plaintiffs-eight states, the City of New York, and three nonprofit entities-had standing to seek an injunction against six electrical utility companies to restrict their greenhouse gas emissions based on a public nuisance claim.  The Court also held that the claims were not barred by the political question doctrine, which forecloses courts from deciding questions that have been committed for decision to the executive and legislative branches.  Finally, the Court held that plaintiffs had stated a viable federal common law nuisance claim, which had not been displaced by congressional or regulatory action.