Republicans Deal A Blow to White House Efforts to Address Climate Change, Dooming the Planet.

The Supreme Court on Thursday limited the Environmental Protection Agency’s ability to regulate carbon emissions from power plants, dealing a blow to the Biden administration’s efforts to address climate change.

The vote was 6 to 3, with the court’s three liberal justices in dissent, saying that the majority had stripped the E.P.A. of “the power to respond to the most pressing environmental challenge of our time.”

The ruling appeared to curtail the agency’s ability to regulate the energy sector, limiting it to measures like emission controls at individual power plants and, unless Congress acts, ruling out more ambitious approaches like a cap-and-trade system at a time when experts are issuing increasingly dire warnings about the quickening pace of global warming.

The implications of the ruling could extend well beyond environmental policy and further signal that the court’s newly expanded conservative majority is deeply skeptical of the power of administrative agencies to address major issues facing the nation and the planet.

That skepticism has been evident in recent decisions arising from the coronavirus pandemic. The court ruled, for instance, that the Centers for Disease Control and Prevention was not authorized to impose a moratorium on evictions and that the Occupational Safety and Health Administration was powerless to tell large employers to have their workers be vaccinated or undergo frequent testing.

The question before the justices in the new case, West Virginia v. Environmental Protection Agency, No. 20-1530, was whether the Clean Air Act allowed the E.P.A. to issue sweeping regulations across the power sector. More broadly, the court was asked to address whether Congress must “speak with particular clarity when it authorizes executive agencies to address major political and economic questions.

The court has called this inquiry the “major questions doctrine.”

Last year, on the last full day of Donald J. Trump’s presidency, a federal appeals court in Washington struck down his administration’s plan to relax restrictions on greenhouse gas emissions from power plants. The Trump administration said the Clean Air Act unambiguously limited the measures the agency could use to those “that can be put into operation at a building, structure, facility or installation.”

A divided three-judge panel of the court, the U.S. Court of Appeals for the District of Columbia Circuit, ruled that the Trump administration’s plan, called the Affordable Clean Energy Rule, was based on a “fundamental misconstruction” of the relevant law, prompted by a “tortured series of misreadings.”

“The E.P.A. has ample discretion in carrying out its mandate,” the decision concluded. “But it may not shirk its responsibility by imagining new limitations that the plain language of the statute does not clearly require.”

The panel did not reinstate a 2015 Obama-era regulation, the Clean Power Plan, which would have forced utilities to move away from coal and toward renewable energy to reduce emissions. But it rejected the Trump administration’s attempt to replace that rule with what critics said was a toothless one.

The appeals court’s ruling also cleared the way for the Biden administration to issue stronger restrictions.

The Obama-era plan had aimed to cut emissions from the power sector by 32 percent by 2030 compared with 2005 levels. To do so, it instructed every state to draft plans to eliminate carbon emissions from power plants by phasing out coal and increasing the generation of renewable energy.

The Clean Power Plan never came into effect. The Supreme Court blocked it in 2016, effectively ruling that states did not have to comply with the measure until a barrage of lawsuits from conservative states and the coal industry had been resolved. That ruling, followed by changes in the court’s membership that have moved it to the right, has made environmental groups wary of what the court might do in cases on climate change.