Kentucky is one of 12 states that have joined a lawsuit against the Environmental Protection Agency’s proposed greenhouse gas regulations. The lawsuit asks the court of appeals in Washington, D.C., to overturn a previous settlement that forced the EPA to take action.The EPA has been required to regulate greenhouse gases—like carbon dioxide—since 2007, when the Supreme Court determined the gases posed a danger to human health. And because coal-fired power plants are major sources of carbon dioxide emissions, the coal industry and supporters have become major critics of the proposed regulations.The lawsuit filed on Friday takes issue with the way the EPA has chosen to regulate carbon dioxide emissions: under section 111(d) of the Clean Air Act. Opponents of the regulations argue this is illegal, because the EPA can’t regulate anything under 111(d) that’s regulated somewhere else. And most power plant emissions—like mercury—fall under another section.But the EPA argues that carbon dioxide isn’t regulated anywhere else in the Clean Air Act, so it’s appropriate to put it in that section.Kentucky Attorney General Jack Conway joined the suit without input from the Beshear Administration’s Energy and Environment Cabinet. Conway’s office said the attorney general wouldn’t comment on pending litigation, but Conway referenced the lawsuit in his Fancy Farm speech over the weekend.“In fact, you’re looking at the only Democratic Attorney General in the country who is standing up for our coal and our low electricity rates by suing the EPA over whether they even have the authority to implement these new rules,” he said.The Kentucky Energy and Environment Cabinet issued a white paper last year on the proposed greenhouse gas regulations, and a spokesman said the cabinet wasn’t consulted before Conway joined the lawsuit. The cabinet will release its own comments on the EPA’s regulations before the Oct. 16 deadline.Indiana signed on to the lawsuit, too. Here’s what Indiana Governor Mike Pence had to say: