President Donald Trump spent 2025 dismantling EPA’s regulatory architecture in an effort to prevent future administrations from reining in greenhouse gas pollution.
Next year will begin to show if it’s a winning strategy.
The president carried his view that climate change is a make-believe issue of the left into his second term by directing EPA to weaken or erase a slate of rules aimed at reducing warming pollution from cars, power plants and oil fields.
In response, the agency fired off proposals in record time to gut Biden-era regulations while reversing long-held authorities for governing greenhouse gases like the endangerment finding and emissions reporting for industry.
“What they came in with wasn’t a road map, it was a wrecking ball,” said Miles Keogh, executive director of the National Association of Clean Air Agencies. “They got a lot done, but what they got done was taking stuff down, breaking stuff. You can do a lot of that fast.”
Next year will begin to reveal if the rules that rise from Trump’s regulatory demolition in 2025 survive judicial review.
By front-loading proposals in his first year, the president tried to position his administration for an aggressive defense of each new rule — all the way to the Supreme Court. If they’re upheld, it could be very difficult for future presidents to introduce similar standards without new action from Congress.
“Our deregulatory agenda is historic, and will deliver historic results for the American people, unlike the Biden administration’s half-baked rules that strangled the economy and drove up costs while failing to achieve real environmental progress,” said Brigit Hirsch, the EPA press secretary.
The administration set its sights almost immediately on undoing the endangerment finding — a scientific declaration issued under former President Barack Obama that enabled EPA to regulate greenhouse gases under the Clean Air Act. Trump declined to undo the finding during his first term.
It was hours after Trump’s inauguration this year when he gave Lee Zeldin, his future EPA administrator, a single month to decide to revoke the 2009 finding that climate pollution endangers public health. On Feb. 19, Zeldin sent a nine-page memo to the White House saying the endangerment finding no longer reflected the current state of climate science, engineering, economics and law.
The missive to the Office of Management and Budget — which wasn’t made public until five months later — read like a legal brief. It argued that recent decisions by the Supreme Court, including a 2024 ruling that had severely limited agency discretion in translating ambiguous statutory text into regulation, meant the finding was no longer valid.
“The EPA, in collaboration with relevant agencies, recommends to the director of OMB that EPA [r]econsider the 2009 Endangerment Finding and, subsequently, any EPA regulation or action that relies on it,” the memo stated.
The dry language understated the consequences of the move: Zeldin was planning to rewrite the 16-year-old document that gave EPA its power to reduce greenhouse gases from the biggest sources of climate pollution in the country. In other words, he was ripping out climate rules by the roots.
In March, EPA went public with its plans to undo the finding, along with greenhouse gas rules for vehicles and power plants that it underpinned. ItsJune proposal to stop regulating carbon from coal- and gas-fired power plants didn’t reference the endangerment repeal directly, though it advanced a related argument that U.S. energy generation didn’t contribute enough climate pollution globally to make regulations appropriate.
The agency released its draft repeal of the finding in July, together with a proposal for undoing Biden-era climate standards for cars and trucks. Then, in September, it announced a plan to repeal greenhouse gas emissions reporting for big polluters such as fossil fuel and industrial facilities. Last month, the agency suspended compliance requirements under a Biden-era methane rule for oil and gas development.
“They’ve done that all incredibly quickly, notwithstanding the reductions in staff and notwithstanding the shutdown,” said Meghan Greenfield, a former EPA attorney who’s now a partner with Jenner & Block.
Despite the breakneck pace of Trump’s regulatory moves, his administration has actually fallen behind schedule. The administration’s regulatory agenda released in September projected that EPA would finalize repeals for endangerment, motor vehicles, power plant and reporting rules by the end of 2025. None of those final drafts have been submitted to OMB for review, its regulatory dashboard shows.
EPA blamed the delay on Democrats in Congress, whom it said had caused the 43-day government shutdown that ended in November.
“EPA was intentional in establishing a lapse in funding plan that allowed the agency to continue to fulfill our statutory obligations and presidential priorities,” the agency said in an email to POLITICO’s E&E News. “However, ultimately the Democrat shutdown disrupted critical functions of our agency and others across the federal government.”
The endangerment finding repeal, it said, would be finalized “in the near future.”
Final rescission for vehicle climate standards will be packaged with the endangerment rollback early next year. A final repeal of Biden-era standards for coal- and gas-fired power plants is also expected in the early months of 2026, and could be released at the same time.
EPA declined to provide estimates for when the rules would be issued. Justice Department attorneys representing EPA in litigation over the power plant standards filed a status report in that case last month blaming the government shutdown for delaying the final repeal.
“Considering the lapse in appropriations and the press of other obligations, EPA is in the process of revising its expected timeline,” DOJ wrote. “EPA will provide a further update on February 23, 2026, when its next status report is due.”
It’s unclear if the power plant repeal could be finalized before then.
When EPA does issue final repeals on endangerment, power plants and vehicles, the field of play on climate deregulation will shift from the agency to the courts. Litigants have 60 days to file challenges to each of those rules after they’re filed in the Federal Register.
“I’m going to go out on a limb and say that there’ll be a lot of litigation,” said Jeff Holmstead, who served as EPA’s air chief under former President George W. Bush.
The U.S. Court of Appeals for the D.C. Circuit will hear those cases, though the Supreme Court may issue the final decisions in most or all of them. But the rulings may not come next year — especially if EPA issues its final rules months into 2026.
A decision by the Supreme Court could take Clean Air Act climate regulation off the table for good, unless Congress grants EPA new authorities.
For example, if the high court accepts EPA’s argument that the agency lacks authority to regulate greenhouse gases under the Clean Air Act because climate pollution doesn’t endanger the public through direct exposure, that could end carbon regulation under the statute.
“[N]o future EPA would be able to regulate [carbon dioxide] or anything else that does not endanger health or welfare when people or things are exposed to it,” said Holmstead.
Joe Goffman, who served as EPA air chief during the Biden administration, said DOJ might have to seek expedited review by the D.C. Circuit to ensure that the Supreme Court has enough time to hear the cases before the end of Trump’s second term in 2028.
In another scenario, the Supreme Court could take the case before the appeals court weighs in, he said. That would be unusual, but the high court has broken with established practices by using the emergency, or “shadow,” docket to rule quickly on important questions.
“The Supreme Court has unmoored itself from historical standards of deference to lower courts and to the historic sequence of review,” said Goffman. “So I wouldn’t be surprised if somewhere in the administration or among the administration’s allies, somebody wasn’t trying to think of a way to circumvent the D.C. Circuit and get the case to the Supreme Court.”
EPA’s fast pace on the biggest climate regulations — endangerment, power plants, and motor vehicle emissions — could give the agency plenty of time in the second half of Trump’s presidency to reverse lower-priority climate rules. One example: weakening or canceling EPA’s finding that aircraft endanger public health.
“I don’t think that they’ve suffered from a lack of imagination about what’s possible,” said Keogh.
He said EPA might turn its attention to policies that are not squarely climate regulations but that can be framed as such, like efficiency or renewable energy standards.
“I think it’s possible we’ll start seeing more proactive steps taken to expand the market share for fossil fuel resources,” Keogh said.
