CLIMATEWIRE | EPA Administrator Lee Zeldin has one week to tell President Donald Trump whether the agency could abandon its authority to regulate climate pollution under the Clean Air Act.
His decision stands to cast EPA into a monumental fight over its ability to reduce carbon emissions, potentially reverberating beyond Trump’s presidency.
If Zeldin attempts to upend the 2009 scientific finding that underpins all greenhouse gas rules — known as the endangerment finding — he would risk being rebuked by the courts. But if judges upheld EPA’s move to reverse the finding, it would accelerate Trump’s efforts to dismantle a host of climate rules enacted under President Joe Biden, while erecting legal hurdles for future administrations that want to curb climate pollution.
On supporting science journalism
If you’re enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.
“I think they can do it, and I, and I just hope the administrator is well briefed so that he can make the right decision,” said Myron Ebell, who led Trump’s EPA transition team in 2017, in a recent interview.
EPA did not respond to a request for comment.
Trump issued a Day 1 executive order directing Zeldin and other agency heads to brief the White House by Feb. 19 on “the legality and continuing applicability” of the endangerment finding.
The finding, issued during President Barack Obama’s first term, holds that greenhouse gas emissions “may reasonably be anticipated to endanger public health or welfare.” It’s the prerequisite for Clean Air Act rules targeting heat-trapping pollutants such as carbon dioxide and methane. The finding originally pertained to climate pollution from vehicles, but it opened the door for regulations on power plants and oil and gas infrastructure. And it could support future regulation on additional sources of climate pollution, such as landfills, refineries and industrial plants.
Getting rid of the finding would make scrapping EPA climate rules a matter of routine paperwork, an expert said. Regulations could be undone through simple, swift rulemakings. No replacement rules would be needed.
“Taking away the 2009 endangerment finding would really make it almost a virtual formality to take down all the greenhouse rules for CO2 and methane,” said Joe Goffman, EPA’s air chief under Biden.
EPA would still need to strip out sector-specific findings from rules written under a key section of the Clean Air Act — known as Section 111 — he said. But when the dust settled, EPA could regulate oil and gas facilities for ozone-forming pollutants alone, and not for methane — greatly reducing requirements for industry. And power plants that burn fossil fuels wouldn’t be regulated for carbon.
The first Trump administration decided against challenging the endangerment finding, despite being urged to by conservative critics of climate regulation such as Ebell, who at the time cast doubt on the underpinnings of climate science from his perch at the Competitive Enterprise Institute.
It’s not clear whether EPA will choose differently this time.
As a congressman, Zeldin voted against an appropriations rider that targeted the endangerment finding. David Fotouhi, Trump’s pick to be Zeldin’s deputy at EPA, had a hand in the first-term decision to avoid challenging the finding. And many industry groups oppose removing the finding — because it would strip EPA of its regulatory authority on climate change.
Edison Electric Institute, the trade association for investor-owned utilities, filed an amicus brief supporting EPA in a Supreme Court case in 2022, warning that undermining EPA’s authority could lead to “a multiplicity of tort suits” against industry that would seek to “dictate” policy by shuttering facilities and through court-ordered emissions limits.
Trying to scrap the endangerment finding could also drain EPA of valuable time and resources if it’s defeated in court. It takes the agency two or three years to pull back a prior administration’s rules — like Biden’s power and methane rules — and to finalize replacement standards. Those new rules will be litigated. If court battles over the endangerment finding delays any part of that process, the Trump administration may not have the opportunity to defend its own standards.
Daren Bakst, director of the energy and environment program at the conservative Competitive Enterprise Institute, a think tank that has long advocated getting rid of the endangerment finding, agreed that it would “present legal challenges.”
But he said the risk was worth taking.
“If the EPA finds there is no endangerment, and this survives in court, it would have the important effect of stopping the EPA from regulating greenhouse gases,” he said.
Regarding next week’s deadline, he said Zeldin might submit only preliminary recommendations to the Office of Management and Budget, rather than a full-blown decision to challenge the finding, or pass on it.
Ebell, who previously led the same CEI program, told POLITICO’s E&E News last month that Trump’s Day 1 executive order hinted that the administration might be ready to challenge the endangerment finding. Besides directing Zeldin to make “recommendations” on the finding by next Wednesday, the order also asked him to take the lead in deciding whether EPA and other agencies should continue to use a social cost of greenhouse gases metric in regulations and other decisions that might have consequences for the climate.
EPA’s decision on the social cost of greenhouse gases is due March 21, according to the order.
Ebell said if the finding remained intact and rulemakings or permitting decisions didn’t grapple with climate change by applying the social cost of greenhouse gases, that omission would create legal headaches for the Trump administration.
“The D.C. Circuit [Court of Appeals] is going to tell them, ‘Well, you’re required to consider the effects of climate change because of the endangerment finding. And you have to include that in this rulemaking, and you’ve taken off the table the principal tool for measuring it,’” he said, referring to the social cost metric.
Undoing the 2009 finding wouldn’t necessarily require EPA to challenge scientific findings on climate change, Ebell said. Instead, the agency could argue that the Clean Air Act wasn’t “fit for purpose” as a tool to address climate emissions. EPA could point to three defunct power plant carbon rules — including Trump’s first-term standards — to make that case.
But environmental lawyers noted that courts have rejected past claims by EPA that it can choose to not issue an endangerment finding based on factors other than the science — as when the agency argued that the Clean Air Act is ill-suited to tackle climate pollution.
David Doniger, senior attorney and strategist at the Natural Resources Defense Council, said the George W. Bush administration made similar arguments to defend its decision to not issue a finding that would support greenhouse gases regulations on vehicles.
But the Supreme Court in 2007 rejected that view in Massachusetts vs. EPA, said Doniger.
“The only question the statute makes relevant is the science question of endangerment to health or welfare,” he said.
The scientific consensus linking carbon emissions to climate-related disasters has strengthened in the 18 years since the high court decided Massachusetts vs. EPA. Those dangers are reflected in successive editions of the National Climate Assessment — a comprehensive report Trump has hinted he might try to influence.
EPA has also reaffirmed the endangerment finding in rulemakings since 2009 — something Goffman said could make it harder for the agency to now argue that warming isn’t dangerous.
“The litigation history is a weight around one ankle, and the agency’s own science and own vast record is a weight around the other ankle,” Goffman said.
Reprinted from E&E News with permission from POLITICO, LLC. Copyright 2025. E&E News provides essential news for energy and environment professionals.
