On February 9, 2016 a divided United States Supreme Court issued an emergency stay of the Obama Administration’s Clean Power Plan, blocking enforcement of the power plant rules by the Environmental Protection Agency (EPA) until the resolution of pending litigation regarding their legality, which is anticipated later this year.

After EPA announced the final Clean Power Plan in August 2015, a group of states, coal and utility companies and industry groups filed the litigation challenging the rules, which call for a 32 percent reduction in power plant emissions of greenhouse gases (GHGs) nationwide by 2030. The challengers’ central argument is that the required reductions will force states to transition from coal-fired power generation to renewable sources such as wind and solar energy, which is regulation “outside the fenceline” of power plants that the Clean Air Act does not permit. They requested a stay of EPA’s implementation of the rules on the basis that beginning to plan the transition to cut GHG emissions, before the courts had ruled on this argument, would irreparably harm their economic interests.

By granting the request, the Supreme Court overturned the ruling of the United States Court of Appeals for the District of Columbia Circuit, which had unanimously turned down the stay request and held that the challengers’ interests were not sufficiently threatened. The Supreme Court did not, however, issue any judgment as to the ultimate legality of the Plan, which is scheduled for oral argument before the Court of Appeals in June 2016. A subsequent appeal of that decision to the Supreme Court, regardless of outcome, is certain. While the Plan does not require states to begin reducing emissions until 2022, their implementation programs are due in 2017. Thus, despite issuance of the stay, it is likely that many states and industry participants will continue to prepare for compliance with the Plan until the litigation is concluded.