The sun sets behind wildfire smoke as drought conditions worsen on July 12, 2021 near Glennville, Calif. David McNew/Getty
On Tuesday, Environmental Protection Agency Administrator Lee Zeldin announced a proposal to rescind the agency’s 2009 “endangerment finding,” a critical Obama-era scientific decision about the human health costs of greenhouse gases that allows the EPA to regulate emissions.
As I reported last week:
On paper, the endangerment finding states that greenhouse gases like methane and carbon dioxide pose a risk to the public’s health and well-being. That may sound obvious enough. But in practice, it’s one of the agency’s most important decisions.
That’s thanks to the landmark 2007 Supreme Court ruling in Massachusetts v. EPA, which found that the agency not only has the authority to regulate greenhouse gases under the Clean Air Act, but the obligation to do so, if it determines the pollutants pose a health hazard. In 2009, backed by an overwhelming body of science, the endangerment finding did just that.
Now, the Trump administration reportedly plans to throw out the finding, stripping the EPA of its central role in regulating emissions from vehicle tailpipes, power plants, and more. If the administration succeeds in court (a big if), experts say it would put the United States’—and the world’s—ability to fight climate change at risk.
In its press release on Tuesday, the EPA said that rolling back the endangerment finding would “undo the underpinning of $1 trillion in costly regulations” and “save more than $54 billion annually” by repealing rules like the Biden administration’s tailpipe emission limits. “With this proposal,” Zeldin said in a statement, “the Trump EPA is proposing to end sixteen years of uncertainty for automakers and American consumers.”
It’s not clear where the agency got these numbers. In 2023, as CNN reported, researchers estimated that climate-driven extreme weather events—which are only expected to get worse—cost the US $150 billion per year.
The agency called the 2009 endangerment finding an “unprecedented move,” arguing that the Obama administration overstepped its congressional authority under the Clean Air Act with a series of “mental leaps.”
In reality, scientific evidence that climate change poses extensive risks to humanity is long-established and overwhelming. “Scientists are the most skeptical people on Earth,” James Milkey, a former environmental attorney who argued Massachusetts v. EPA before the Supreme Court, told me. “And there was a scientific consensus that the accumulation of greenhouse gases in the atmosphere posed dire threats.”
The administration’s proposal isn’t yet in effect, and will be available for public comment until late September, according to the EPA.