Supreme Court Justice Antonin Scalia’s untimely departure has radically changed the outlook on the Clean Power Plan’s future. As Ann Carlson of environmental law blog Legal Planet wrote in a recent blog post, the chance of a Supreme Court decision upholding the rule may have, in the last several days, gone from “less than 25 percent to higher than 75 percent.”
The Environmental Protection Agency’s landmark Clean Power Plan (CPP) rule mandates that states lower CO2 emissions from electric power generation by 32 percent relative to 2005 levels by 2030. In doing so, the CPP encourages states to lessen their dependence on fossil fuels and make greater use of renewable energy. After its introduction, the EPA was sued by 27 states and various industry groups unhappy with the rule. In January, a D.C. Circuit panel denied a stay on the rule that would prevent it from going into effect until the case is decided on the merits. The Supreme Court, however, reversed the D.C. Circuit denial last week in an unprecedented 5-4 decision that, at the time, did not portend well for the CPP’s ultimate fate. The D.C. Circuit will now hear the case on June 2nd.
Even if the D.C. Circuit decides in favor of the rule, as it is expected to, the case will still go to the Supreme Court for a decision on the merits. If President Obama is able to appoint another liberal justice to replace Scalia by that time, it is likely the CPP will be upheld. If Obama cannot appoint a new justice in time, likely because the Senate refuses to confirm the justice, the case could be decided by an eight member Supreme Court, in which case a highly plausible 4-4 decision would let the D.C. Circuit decision stand. The case could also remain undecided until the next president appoints a new Supreme Court justice, in which case the Court will likely rule along party lines. If it is Hillary or Bernie – the CPP will probably survive. If it is Trump or Cruz or someone else – well, good news for coal companies.
A liberal-majority Supreme Court would also bode well for a recently introduced legal theory positing that section 115 of the Clean Air Act could be used by the executive branch to reign in American greenhouse gas emissions. Section 115 allows the executive branch to use market-based programs to reduce air pollution (which, as per the decision of Massachusetts v. EPA, includes greenhouse gases) endangering other countries if those countries provide reciprocal protections to the U.S. The theory – put forward in an excellent paper by legal scholars at Columbia’s Sabin Center for Climate Change Law, NYU’s Institute for Policy Integrity and UCLA’s Emmett Institute on Climate Change and the Environment – suggests that the recent Paris Agreement satisfies this element of reciprocal foreign protection.
A case made on the basis of section 115 would, however, be highly dependent on the willingness of the Court to allow such an obscure provision of an old statute – and such abstract foreign protection commitments, considering the Paris Agreement is currently non-binding – to command such considerable power. Even so, a liberal-majority Supreme Court would make the legality of an EPA-introduced cap-and-trade program, or something of the sort, more conceivable than ever before.
 See Massachussets v. EPA, 549 U.S. 497 (2007).