The states and industry groups tried to argue that the EPA’s greenhouse gas regulations went against the Clean Air Act in multiple ways. But the DC appeals court strongly disagreed, finding in every instance that the EPA was “unambiguously correct.”
Historical context behind the court ruling that the EPA may regulate greenhouse gases
When the DC appeals court ruled that the EPA had the authority to regulate greenhouse gases on June 26, 2012, it brought to a close a process of regulation and court challenges that started in 1999.