The Supreme Court has thrown a curve ball straight at the Clean Power Plan, the new federal regulations designed to fight climate change by limiting GHG emissions from U.S. power plants.

When we last reported on the status of the Plan, twenty-four states had filed a lawsuit in federal court, claiming that the Plan exceeds EPA‘s legal authority. They have since been joined by three more states and a coalition of utility and coal companies, trade associations, and the U.S. Chamber of Commerce.  We noted that the legal battle would likely be long and complex. Oral argument on the challenge is scheduled for June 2, and the losing side will certainly appeal the decision to the Supreme Court.

In most cases, when a legal challenge to a federal regulation (like the Clean Power Plan) is pending, the regulation remains in effect, unless and until a court determines that it is invalid. In this case, the challengers asked that the Plan be stayed – put on a temporary hold. Last week, in an unprecedented decision, the Supreme Court granted the request for a stay. The Court has never granted such a request before the regulation has even been reviewed by a federal court.

What this means is that the Plan cannot go into effect until the legal battle has fully played out. And that might not happen until the summer of 2017.

While the Plan can withstand the effect of the lengthy delay (the first deadlines have built-in extension mechanisms that take them beyond 2017), the Supreme Court’s 5-4 decision made the future of the Clean Power Plan look dim in terms of how the Court will treat if and when the case it arrives back there. But with the death this past weekend of Justice Scalia (one of the five), the fate of the Clean Power Plan has perhaps taken another twist. If the Plan survives the challenge in the lower courts, a tie at the Supreme Court would mean that the regulations stand.

The “temporary” obstacle is not by itself a big deal.  A permanent block could completely derail the commitment the U.S. made in the Paris Agreement to ambitious GHG reduction targets.  Stay tuned for more developments. We will continue to follow and post updates about this important case.