The states and other plaintiffs sued the companies — which include Xcel Energy and Duke Energy — in hopes that the federal courts would compel the companies to reduce their greenhouse gas emissions.
But the Supreme Court, in an opinion delivered by Justice Ruth Bader Ginsburg, rejected an appeals court decision that would have allowed federal judges to effectively put limits on greenhouse gas emissions.
That responsibility, the Supreme Court said, should be left in the hands of the EPA.
“The critical point is that Congress delegated to EPA the decision whether and how to regulate carbon-dioxide emissions from power plants; the delegation displaces federal common law,” the decision states.
The ruling builds on a 2007 decision in Massachusetts v. EPA in which the Supreme Court said that greenhouse-gas emissions could be regulated under the Clean Air Act if EPA found they endanger public health and welfare. EPA later made such a finding and has begun phasing in a series of rules aimed at ratcheting down the emissions.
The climate regulations have set off a firestorm in Washington, with Republicans and some moderate Democrats pushing legislation to block EPA from implementing the rules. But the Obama administration has stood by its regulations, vowing to veto any bill that seeks to halt them.
The unanimous decision (Justice Sonia Sotomayor recused herself from the case) is not a surprise. In April oral arguments, the justices hinted that the court would reject the suit.
“You want the court to start with the existing sources, to set limits that may be in conflict with what an existing agency is doing,” Ginsburg said in April. “Do we ignore the fact that the EPA is there and that it is regulating in this area?”
The decision comes at a time when climate legislation is politically dead for now on Capitol Hill.
The ruling — by closing off an avenue for climate advocates to seek mandatory greenhouse gas curbs — underscores the stakes of the legal and Capitol Hill battles over EPA rules.
David Doniger, an attorney with the Natural Resources Defense Council, highlighted this dynamic in a statement Monday on the decision.
“Today’s ruling reaffirms the Environmental Protection Agency’s duty under the nation’s 40-year-old Clean Air Act to safeguard public health and welfare from dangerous carbon pollution. Now the EPA must act without delay,” said Doniger, who represented three conservation groups that had joined with states in seeking the court-ordered emissions curbs on the utilities.
American Electric Power, which is a powerful coal-burning utility with plants in several states, cheered the Monday ruling.
“We’re pleased with the court decision,” spokeswoman Melissa McHenry said. “As we’ve said since the day the lawsuit was filed, Congress, and not the courts, should set policies on climate and greenhouse gas regulation.”
More broadly, a major trade group of for-profit power companies also welcomed the ruling. "Today’s decision wisely removes the threat of endless and multiple lawsuits with no environmental benefit," said Tom Kuhn, president of the Edison Electric Institute, in a statement.
The decision, however, doesn’t completely slam the door on using the courts to seek action against power plants. It orders the U.S. Court of Appeals for the Second Circuit to sort out whether parties can take action against utilities under certain state laws, including whether EPA’s climate plans under the Clean Air Act prevent that.
“Because none of the parties have briefed preemption or otherwise addressed the availability of a claim under state nuisance law, the matter is left for consideration on remand,” the decision states.
This post was updated at 11:59 a.m.