The Supreme Court could again block action on climate change as it considers whether to suspend new regulations on coal-fired power plants.

The Environmental Protection Agency (EPA) finalized rules this year aimed at limiting greenhouse gas emissions from coal-fired power plants. But red states and industry groups are taking the EPA to court, asking SCOTUS to step in and halt implementation of the rules while they fight it out.

The request is now in the Supreme Court’s so-called “shadow file,” meaning SCOTUS can essentially issue a stay of the rule at its discretion. The court has already made it much harder for federal agencies to regulate industry since Donald Trump packed it with conservative-leaning judges. This is another opportunity to undermine the EPA’s efforts to curb the pollution that’s driving climate change.

“A few years ago, I would have found these kinds of requests ridiculous, but given the way this court operates, nothing makes me laugh anymore,” said Sambhav Sankar, senior vice president for programs at the nonprofit environmental law organization Earthjustice.

The rules are a cornerstone of the Biden administration’s efforts to meet climate goals set in the Paris Agreement. They require coal-fired power plants to remain in operation for at least 15 years to reduce their climate pollution by 90 percent. Coal happens to be the dirtiest fossil fuel, creating more planet-warming carbon dioxide when burned than oil or gas.

When the EPA finalized the plan in April, it was likely only a partial victory for environmental and health activists. The rules had to comply with the Supreme Court’s 2022 decision on West Virginia vs. Environmental Protection Agency. It was a landmark opinion that reinforced the “big questions” doctrine, the idea that federal agencies should not have the authority to make decisions on issues of great national importance without Congress passing legislation explicitly allowing the agency to do so. The decision meant that the EPA would not be allowed to determine whether the U.S. gets its electricity from fossil fuels or cleaner energy sources like wind and solar.

As a result, the EPA’s plans to curb greenhouse gas emissions allow fossil fuel plants to continue operating as long as they install technologies that capture carbon dioxide emissions. Fossil fuel companies have advocated carbon capture and storage as a way to combat climate change without giving up coal, oil or gas. But reliance on carbon capture has disappointed health and environmental advocates who had hoped that a transition to renewable energy would combat climate change. And encouraging utilities to phase out fossil fuel plants that emit soot and other pollutants into nearby neighborhoods.

Now, the industry is arguing that carbon capture and storage (CCS) technologies aren’t even ready to combat climate change — at least not to the extent the EPA says they are achievable in its power plant rules. Since July, trade groups representing utilities and mining companies and a handful of red states, led by West Virginia and Ohio, have filed petitions with the Supreme Court seeking a stay of the EPA’s new rules on carbon emissions (and separate rules for hazardous pollutants including mercury). The U.S. Court of Appeals for the District of Columbia Circuit previously declined to grant a stay.

The plaintiffs argue that capturing 90 percent of the CO2 is not yet a feasible goal. The technology has not yet been demonstrated at that scale, and there are no pipelines to safely transport and store the greenhouse gas after it is captured.

“Because there is no way to meet the 90 percent CCS system, the rule requires operators to relocate electricity generation,” the National Rural Electric Cooperative Association says in its application for the stay. “EPA is once again attempting to transform the energy sector by forcing a shift in electricity generation to its preferred sources.” They are essentially invoking the big questions doctrine once again to challenge the new rules.

The Biden administration defended the EPA’s rules in a response filed with the Supreme Court this week, arguing that the agency has vetted the technology and set achievable carbon capture goals. The case “does not involve the type of fundamental question of statutory interpretation that could justify this Court’s intervention,” the EPA argues. And it points out that a federal appeals court last month declined to grant a stay in the case, in a decision that said the plaintiffs had not shown that they would be able to successfully challenge the rule’s merits or that the case raised an “important issue.” Moreover, the deadlines to comply with the rules don’t begin until 2030 or 2032, making it difficult for plaintiffs to show that they would suffer “irreparable harm” without a stay.

Nevertheless, the groups have since asked the Supreme Court to grant a stay through its emergency, or shadow, filing system. The emergency filing system, once reserved for extremely time-sensitive issues like staying executions, is now filled with requests to pause environmental regulations. It is an expedited process, allowing the court to make decisions without much briefing on the issue or hearing oral arguments on the case.

“A lot of lawyers and others find it deeply troubling,” said Michael Gerrard, founder and faculty director of the Sabin Center for Climate Change Law at Columbia University. “The Supreme Court can do something enormously important without the full information that it has at its disposal.”

It’s a trend that has been growing since 2016, when the Supreme Court issued a surprise halt to the Obama administration’s attempt to regulate greenhouse gas emissions from power plants. The Obama-era rules never went into effect and were eventually rolled back by the Trump administration.

Now history could repeat itself. Donald Trump has promised to scrap emissions rules for power plants again during the presidential campaign. And the Supreme Court could decide at any moment whether to grant the stay. Their decision could potentially affect the case The U.S. Court of Appeals for the DC Circuit is still considering whether to strike down the rules altogether.

The SCOTUS decision on the delay could also potentially affect new rules the EPA is still drafting for existing gas-fired power plants, which are a bigger source of electricity than coal in the U.S. Those rules aren’t expected until after the November election, giving Trump another chance to change course.

“I think the outcome of the upcoming election will be more relevant,” Sankar says. On the other hand, the Supreme Court has recently shocked the legal community with landmark decisions that have limited the EPA’s ability to write regulations. In June, it struck down a legal doctrine called the Chevron deference, which previously allowed federal courts to refer the EPA and other federal agencies to court cases over the interpretation of ambiguous language in legislation.

“If the untrained, unscientific Supreme Court justices are once again willing to question the EPA’s scientists, then it is understandable that those scientists would become a little more cautious,” Sankar said.