The court's decision throws into doubt whether President Barrack Obama's signature climate change initiative will survive a legal battle before the high court. | Getty Supreme Court threatens Obama's climate agenda

President Barack Obama will leave office next January with the fate of one of his biggest environmental achievements hanging in the balance.

The Supreme Court on Tuesday took the unusual step of blocking the Environmental Protection Agency’s landmark carbon rule for power plants, throwing into doubt whether Obama's signature climate change initiative will survive a legal battle before the high court.


The decision to grant the stay is no guarantee the justices ultimately will strike down the rule, but the development is a bad sign for EPA’s chances, and the agency's foes quickly cheered the news, with West Virginia Attorney General Patrick Morrisey calling it a “great victory.”

“We are thrilled that the Supreme Court realized the rule’s immediate impact and froze its implementation, protecting workers and saving countless dollars as our fight against its legality continues,” he said in a statement.

The White House vowed that the rule, known as the Clean Power Plan, will survive, saying it “is based on a strong legal and technical foundation."

“We remain confident that we will prevail on the merits,” press secretary Josh Earnest said in a statement late Tuesday night, adding that "the administration will continue to take aggressive steps to make forward progress to reduce carbon emissions.”

"We're disappointed the rule has been stayed, but you can't stay climate change and you can't stay climate action," EPA spokeswoman Melissa Harrison said in a separate statement. "Millions of people are demanding we confront the risks posed by climate change. And we will do just that."

The Supreme Court issued its short order putting the rule on hold at the request of states and companies that had asked the high court to intercede early — even though a lower court had already declined to do so.

The ruling was on a 5-4 vote, with Justices Ruth Bader Ginsburg, Stephen Breyer, Sonia Sotomayor and Elena Kagan — the court's liberal wing — lining up against staying the rule.

Environmentalists quickly downplayed the stay, noting that it did not come to any conclusions about the legality of the rule itself.

"The Clean Power Plan has a firm anchor in our nation’s clean air laws and a strong scientific record, and we look forward to presenting our case on the merits in the courts," said Vickie Patton, the Environmental Defense Fund's general counsel.

The justices did not explain their decision, but the order indicates they believe the rule threatens imminent and irreparable harm. The states and groups challenging the rule noted that the Supreme Court last year identified a major flaw with an EPA regulation limiting mercury emissions from power plants only after that rule had started to take effect, and they urged the justices not to allow something similar to happen with the carbon rule.

The D.C. Circuit Court of Appeals has put the case on a fast track, with oral arguments scheduled for June 2. That indicates a ruling from that court in late summer or fall, and tees up a Supreme Court appeal for as early as 2017.

"The stay is a signal the Supreme Court has serious concerns with the Power Plan," said Mike Duncan, head of the coal-supported advocacy group American Coalition for Clean Coal Electricity.

Coal-heavy utilities, mining companies and 27 states are among those suing to reverse the rule, which opponents say exceeds EPA’s authority under the Clean Air Act.

The stay may only delay implementation of the rule by two or three years if EPA eventually triumphs at the Supreme Court. But it will keep the rule on hold into the next administration, increasing the chances that it could be undone if a Republican is elected to the White House this year.

At the very least, some efforts to replace power plants’ coal with cleaner-burning natural gas and carbon-free wind and solar power are likely to be delayed. And the stay could foreshadow an eventual court decision tossing out the rule altogether, which may severely limit how far the government can go in curbing greenhouse gas emissions.

This is not the first big Obama environmental rule to be stayed during litigation. In late 2011, just two days before it was to take effect, the D.C. Circuit put a stay on EPA’s Cross-State Air Pollution Rule, which targets pollutants like nitrogen oxide and sulfur dioxide that float downwind across state lines.

The circuit later struck down the rule — but the Obama administration appealed to the Supreme Court and ultimately won the case 6-2, and the rule took effect three years after its original start date.

With the rule’s legal defense stretching into the next administration, the possibility of a Republican president casts a thick fog over the regulation’s future. All of the GOP candidates have repudiated the rule as a threat to the economy and vowed to overturn it, and a Republican president would have several avenues for kneecapping the Clean Power Plan, including simply accepting a possible circuit decision to strike down the rule without filing an appeal — a more likely outcome after Tuesday’s stay.

Environmental groups have quietly prepared for that possibility by preserving their own right to defend the rule in court.

A combination of Supreme Court rulings and scientific findings is likely to eventually compel EPA to regulate power plants’ greenhouse gas emissions in some manner, though the extent of such regulations is up in the air.

In the meantime, EPA’s foes will double down on their efforts to get the Clean Power Plan tossed out for good. Critics argue that the Clean Air Act does not allow EPA to require tools such as renewable energy mandates to control pollution, and they say the agency’s authority is limited to cutting emissions from coal plants themselves.

EPA counters that the law allows it to choose the best path forward, and that the agency should receive deference to interpret conflicting statutes that were passed by Congress and signed into law.

Coal producer Peabody Energy, represented by liberal law icon Laurence Tribe, has also raised several constitutional concerns over the Clean Power Plan, though it remains unclear whether the courts will be receptive.