In August 2015, the U.S. Environmental Protection Agency issued the Clean Power Plan (CPP), its Clean Air Act regulation to reduce carbon dioxide emissions from existing power plants across the country. Fossil fuel-fired power plants are the nation’s largest single source of carbon pollution, and the CPP is considered the centerpiece of the Obama administration’s efforts to combat climate change. Shortly after the regulation was issued, 27 states and many industry groups brought suit in the D.C. Circuit, arguing that the CPP exceeds EPA’s authority under the Clean Air Act. The lawsuit, now titled West Virginia, et al. v. EPA, is likely to be one of the most important environmental cases in decades. But a series of unexpected twists have rendered the future of the regulation less certain.

First, on Feb. 9, 2016, the Supreme Court decided 5-4 to temporarily stay implementation of the CPP pending the final outcome of the litigation. The stay came as a shock to the regulation’s supporters and opponents alike: for the first time in the court’s history, it issued a stay before a lower court—in this case, the D.C. Circuit—issued a decision on the case. In the immediate wake of the stay, some observers believed the court was merely exercising caution, ensuring that states didn’t expend resources to comply with the regulation until its legality was certain. Others predicted that the 5-4 decision meant the justices would likely overturn the regulation when it ultimately came before them. But, all were left to speculate. The entire decision (actually, a series of five identical decisions in cases brought by five of the petitioners in West Virginia, et al.) was one paragraph long and contained no reasoning or explanation to support the unprecedented issuance.

Then just four days after the stay was issued, Justice Antonin Scalia passed away. Justice Scalia was a noted critic of the EPA and one of the five justices that voted in favor of the stay. With Scalia’s death, the Supreme Court is split 4-4 between traditionally conservative and liberal justices, between justices in favor and against the stay, and—as many have speculated—between justices likely to uphold or overturn the CPP. In the event of a tie in the Supreme Court, the decision of the lower court stands. Perhaps recognizing the significance of this possibility, on May 16, 2016, the D.C. Circuit unexpectedly announced that it would delay oral argument on the CPP until September to allow the case to be heard by the full court sitting en banc. This is only the second time in the D.C. Circuit’s history that it has decided to have the full court hear a case in the first instance, rather than the court’s normal three-judge panel.

So what does all of this mean for the future of the CPP? If history is the best predictor, when it comes to the CPP, we should expect the unexpected. But, here are a few things we can expect: the D.C. Circuit will issue its decision after the 2016 election, probably in winter or early spring. That decision will be appealed to the Supreme Court. And, the CPP’s ultimate fate will be highly politicized. Indeed, the CPP is already a political tool, with hundreds of Republicans in Congress filing a brief opposing the regulation, and hundreds of current and former Democratic legislators filing a brief in support. 

If a new justice isn’t confirmed by the time the CPP reaches the Supreme Court, the court could split 4-4, upholding the D.C. Circuit’s decision (which many believe will be a 5-4 decision to uphold the regulation, falling along party lines). If Scalia’s replacement is in place, the CPP’s fate may rest heavily on whether his seat is filled by a Democratic or Republican nominee. Supreme Court nominee Merrick Garland has recused himself from the D.C. Circuit en banc hearing; if he’s in Scalia’s seat, he may well be the deciding, Democratic, vote.    

Though the CPP’s future is unknown, one thing is certain:  the Supreme Court’s ultimate decision in West Virginia v. EPA will have enormous implications on how we regulate carbon in the U.S. and what tools we, as a country, have to fight climate change. It will also be a reflection of politics in America. 

—Mindy Goldstein, clinical professor of law and director, Turner Environmental Law Clinic 

For a more detailed look at the CPP implementation in the Southeast, see the Turner Environmental Law Clinic’s recently released report.