The Trump Administration Moves to Revoke the Scientific Basis of U.S. Climate Policy

U.S. Environmental Protection Agency Administrator Lee Zeldin said Tuesday that the Trump administration intends to revoke the scientific finding that underpins the federal government’s legal authority to combat climate change.

Speaking at a car dealership in Indianapolis, Zeldin announced that the agency plans to rescind the 2009 finding, known as the "endangerment finding," which states that greenhouse gases causing planetary warming pose a threat to public health. It was this determination that allowed the Obama and Biden administrations to impose strict limits on carbon dioxide and other pollutants from cars, power plants, and industry.

"If implemented, this would represent the largest deregulatory move in U.S. history," Zeldin emphasized. He added that it would also eliminate national emissions standards for vehicle pollution.

If the endangerment finding is revoked, the EPA would lose all authority under the Clean Air Act to regulate greenhouse gas emissions resulting from the burning of fossil fuels.

The proposal marks the Trump administration’s most sweeping effort yet to dismantle federal climate policy. It signals a shift from earlier rhetoric that downplayed the threat of global warming to outright rejection of the accumulated scientific evidence on climate change.

This move is not merely about scrapping current environmental rules: if the initiative survives legal challenges, it could significantly hinder future administrations from curbing emissions from coal, oil, and gas.

Without climate action from the U.S., it becomes much harder to meet the global goal of limiting average temperature rise to 1.5 degrees Celsius (2.7 degrees Fahrenheit) above pre-industrial levels. Surpassing that threshold, climate scientists warn, sharply increases the risk of devastating hurricanes, droughts, wildfires, extreme heat, and mass species extinction.

In recent weeks, the Trump administration has taken additional steps in the same direction: lifting emissions limits on power plants, halting key atmospheric greenhouse gas measurements, and delaying approval for wind and solar energy projects on federal land.

"Today’s EPA announcement completely ignores the glaring reality of the climate crisis and sidelines the agency’s own scientists and legal experts in favor of fossil fuel interests and profits," said former Vice President Al Gore in response.

To justify its proposal, the agency cited a report commissioned by the U.S. Department of Energy and prepared by five scientists known for challenging the scientific consensus on climate change—specifically the link between fossil fuel combustion, greenhouse gas emissions, and global warming. Among the authors were physicist and "Unsettled" author Steven Koonin and atmospheric scientist John Christy, a noted skeptic of human-caused warming.

The report criticized climate models, arguing they overstate the extent of warming. It also claimed that carbon dioxide—the primary greenhouse gas—has beneficial effects, such as promoting plant growth and increasing crop yields. Overall, the authors argued that climate regulations have little impact on global temperature trends.

The agency reiterated this point in its proposal, arguing that greenhouse gas emissions from U.S. vehicles have little effect on global climate change because their share of global emissions is relatively small. Even if those emissions were eliminated entirely, the EPA claimed, "there would be no scientifically measurable improvements in climate change or public health and the environment." The agency further stated that climate regulations themselves pose a threat to prosperity by raising the cost of new cars and limiting consumer choice.

Environmental organizations and legal experts sharply criticized these claims, pointing out that transportation is the largest source of greenhouse gas emissions in the U.S. According to the agency’s own data, if the U.S. auto sector were considered a separate country, it would be the world’s fourth-largest emitter.

"If vehicle emissions aren’t considered significant for the climate, then it’s unclear what is," said Dina Adler, a senior attorney at the Institute for Policy Integrity at NYU School of Law.

Dan Becker, who leads transportation policy at the Center for Biological Diversity, called the EPA initiative a "cynical double whammy" that would boost gasoline-powered car production while weakening pollution controls. He noted that the rescinded standards could have prevented 7 billion tons of greenhouse gas emissions and saved each American driver about $6,000 in fuel and maintenance over the lifetime of their vehicle.

"The agency is stripping the U.S. of its most significant measure to cut oil consumption, save consumers money, and fight global warming," he said.

The proposal also has supporters. Daren Bakst, director of the Center for Energy and Environment at the libertarian Competitive Enterprise Institute, stated, "You can’t claim emissions are dangerous when their level is minimal."

Indiana Governor Mike Braun, speaking at the event in Indianapolis, slammed Biden-era environmental rules, saying they have burdened the state’s auto industry. "I’ve spent 37 years in the car business, and I know a thing or two. You can count on Indiana to stand for common sense and limited government," he said.

John Bozzella, head of the lobbying group Alliance for Automotive Innovation, said his organization is still reviewing the EPA’s new proposal. However, he added that the rules adopted under the previous administration are "unrealistic" and should be revised to reflect market conditions and preserve U.S. auto industry competitiveness.

Interestingly, while industry and fuel lobbyists strongly opposed the "endangerment finding" when it was first adopted, calls for its repeal have largely faded in recent years. This year, Marty Durbin, head of the energy division at the U.S. Chamber of Commerce, called the document a "settled matter of law" and noted that the Chamber is not seeking to overturn it.

"I don’t know of a single company that is currently pushing for this," confirmed attorney Jeffrey Holmstead of the firm Bracewell, who previously served at the EPA under both George H. W. Bush and George W. Bush.

The plan to revoke the endangerment finding marks a turning point in the political evolution of Lee Zeldin, who for many years held moderate views on climate and environmental issues.

A native of a coastal Long Island district vulnerable to sea-level rise—one of the key effects of global warming—Zeldin was once part of a bipartisan climate working group. In 2019, he defied his own party line by voting against an amendment that would have barred the EPA from regulating greenhouse gas emissions.

A close ally of Donald Trump who defended him during impeachment proceedings in Congress, Zeldin shifted sharply rightward on energy and environmental policy during his failed 2022 campaign for New York governor. Just weeks after being appointed to lead the EPA, he pledged to "drive a stake through the heart of the religion of climate change"—his words for repealing emissions regulations.

"There are people who are willing to bankrupt this country under the pretense of fighting climate change," Zeldin said Tuesday on the conservative podcast Ruthless. One of the hosts called the endangerment finding "the scaffolding of the left’s entire climate hoax," a statement with which Zeldin readily agreed.

The EPA’s proposal is almost certain to face legal challenges. David Doniger, senior attorney at the Natural Resources Defense Council, expressed confidence that the courts would ultimately reject it. He noted that since the endangerment finding was issued in 2009, climate science has advanced significantly.

Following the proposal’s publication in the Federal Register, the agency will open a 45-day public comment period, Zeldin said. After that, the rule is expected to be finalized sometime next year.