Supreme Court Issues Rare—Temporary—Wins for EPA With Methane, Mercury Rulings

The U.S. Supreme Court on Friday rejected two industry-backed petitions to issue injunctions on new Biden administration rules for methane and mercury in a rare, if temporary, victory for the environment at the nation's top court, which normally rules in favor of industry interests.

The two cases deal with rules issued by the U.S. Environmental Protection Agency (EPA)—one to limit methane gas emitted by oil and gas companies, and the other to limit mercury emissions at coal-fired power plants.

Friday's rulings, which emerged from the court's emergency or "shadow" docket, mean the rules remain in place for now and the emergency applications to block them have failed. However, the cases remain active in lower courts, still to be heard in full, and could eventually return to the Supreme Court.

The justices didn't detail their reasoning and there were no noted dissents in either case. The court didn't yet act on a separate petition to block an EPA rule on power plants' carbon dioxide emissions.

"The Supreme Court has sensibly rejected two efforts by industry to halt critical safeguards," David Doniger, a lawyer at the Natural Resources Defense Council, told NBC News. "The court should do the same with the effort to block EPA's power plant carbon pollution standards."

The EPA finalized the methane rule in March, saying it will cut emissions of the gas by up to 80% over 14 years. Methane is a climate "super pollutant"—a greenhouse gas far worse than carbon dioxide in the short run, as it traps heat far more effectively. Methane leaks are common in natural gas production.

A group of more than a dozen Republican-controlled states, led by Oklahoma's attorney general, and fossil fuel industry interests filed suit and then asked for an injunction at the U.S. Court of Appeals for the District of Columbia Circuit while the case was ongoing. The D.C. circuit court rejected the emergency bid in July, leading the group to bring it to the Supreme Court. The group called the rule an "authoritarian national command from the EPA" in a court filing.

The EPA announced the mercury rule—which also deals with other toxic metals—in April as part of a broader package of regulations. Mercury is a neurotoxin especially dangerous to children. Coal has higher mercury concentrations than other fossil fuels. The rule requires coal-fired power plants to reduce toxic metal emissions by 67%, with slightly different rules set for those fired by lignite coal.

A group of similar legal challengers, also led by Oklahoma's attorney general, went through the same effort at the D.C. circuit as with the methane rule—with what for them was the same negative result.

Whether the rules will hold up in court over the long term remains unclear. Right-wing justices hold a 6-3 advantage on the Supreme Court and have an issued numerous significant pro-industry, anti-environment rulings in recent years, cutting away at the power of the EPA.