Richard Wolf

USA TODAY

WASHINGTON — The Supreme Court dealt a blow to President Obama's signature climate change initiative Tuesday by halting the administration's effort to reduce pollution from coal-fired power plants while a legal battle rages on.

The move by the court's five conservative members was a shock to environmentalists, who had hoped the justices would deny -- as a federal appeals court did last month -- a petition filed by 29 mostly Republican-led states and industry leaders.

Now the Environmental Protection Agency must halt enforcement of the so-called "Clean Power Plan" until the U.S. Court of Appeals for the D.C. Circuit decides on the merits of the GOP-industry lawsuit against it. Oral arguments are set for early June.

Even if the plan is upheld at the lower court, it could not be implemented until the Supreme Court has had the final word. That likely would push the battle into 2017 or beyond.

"This stay will remain in place until the challenges have made their way through the Supreme Court, by which time Obama will likely have left office," said Curt Levey, executive director of the conservative FreedomWorks Foundation. "Thus, the stay may well be a fatal blow to the EPA’s attempt to dramatically expand its power and to the administration’s attempt to shove its climate change agenda down the throats of the American people."

All four of the court's more liberal justices said they would have denied the petition filed by opponents of the plan and let implementation continue. That gave the court order an ideological slant.

Another complication: The initiative is a major part of the administration's contribution to a historic climate change agreement reached in Paris in December by 195 nations. With the Supreme Court's hold in place, the United States may have trouble holding up its part of the deal.

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White House press secretary Josh Earnest said the administration "will continue to take aggressive steps to make forward progress to reduce carbon emissions." But he expressed disagreement with the court's order.

"The Clean Power Plan is based on a strong legal and technical foundation," he said. It "will deliver better air quality, improved public health, clean energy investment and jobs across the country, and major progress in our efforts to confront the risks posed by climate change."

Administration officials noted that states have until 2018 to finalize their compliance plans, and until 2022 before enforcement begins, so the Supreme Court setback won't necessarily push back those deadlines.

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The justices' action marks the second time recently that an executive action taken by the Obama administration has been stalled in the courts. Obama's plan to forestall potential deportation for more than 4 million illegal immigrants also has been blocked pending the high court's review. Oral arguments are likely in April and a decision expected by June.

Environmental groups called the high court's latest action highly unusual. "The battle to defend the Clean Power Plan is far from over," said Howard Fox of EarthJustice. "Today's Supreme Court ruling did not rule on the validity of the plan."

The plan is a cornerstone of Obama's climate change initiative, now incorporated into the recently signed United Nations climate agreement. It aims to reduce carbon dioxide emissions from power plants by nearly one-third from 2005 levels over the next 15 years.

The states are seeking to have the regulations overturned in court and had sought to block implementation in the meantime. Their lawsuit, filed in October after the new rule went into effect, says it is "arbitrary, capricious, an abuse of discretion and not in accordance with law."

24 states challenge Obama's Clean Power Plan as rules go into effect

West Virginia Attorney General Patrick Morrisey, one of the leaders of the effort, hailed the ruling. “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.

The appeals court had refused to delay the program, saying the states "have not satisfied the stringent requirements for a stay pending court review."

Federal appeals court: Clean power plan can proceed

In December, Obama vetoed two congressional resolutions of disapproval, aimed at rescinding different sets of regulations on new and existing power plants.

The court's conservatives now have struck blows against two of Obama's environmental initiatives in a row. In June, the court voted 5-4 along the same lines to block federal clean air regulations on coal- and oil-fired power plants that were designed to reduce the amount of mercury and other toxins that pollute the nation's air.

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