Supreme Court Considers Limiting E.P.A.’s Ability to Address Climate Change

WASHINGTON — Members of the Supreme Court’s conservative majority on Monday questioned the scope of the Environmental Protection Agency’s ability to regulate carbon emissions from power plants, suggesting that the court could deal a sharp blow to the Biden administration’s efforts to address climate change.

The questioning during the two-hour argument was mostly technical, and several conservative justices did not tip their hands. But those who did sounded skeptical that Congress had meant to give the agency what they said was vast power to set national economic policy.

There appeared to be little appetite for an argument pressed by the Biden administration and environmental groups: that the four cases before the justices, including West Virginia v. Environmental Protection Agency, No. 20-1530, were not ripe for decision because there is no regulation in place. They said the court should wait to address concrete questions rather than ruling on hypothetical ones.

Solicitor General Elizabeth B. Prelogar said the administration was at work on a new regulation, which the courts could consider after it was issued.

Chief Justice John G. Roberts Jr. and Justice Stephen G. Breyer indicated that they thought the Supreme Court did not need to wait.

Much of the argument was focused on whether the Clean Air Act allowed the agency to issue sweeping regulations across the power sector and, more broadly, of how clearly Congress should authorize executive agencies to address major political and economic questions.

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 Obama…