The suit was brought by six states, New York City and several land trusts. Its central contention was that carbon dioxide emissions from power plants belonging to four private companies and the Tennessee Valley Authority amounted to a public nuisance under federal common law. The suit asked a federal court in New York to order the defendants to reduce their emissions.
Justice Ruth Bader Ginsburg, writing for the court, said the plaintiffs were making their case in the wrong forum. Under the Clean Air Act, she wrote, the matter must be addressed by the Environmental Protection Agency rather than by the courts.
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 copingwith 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.