The Trump administration on Tuesday proposed repealing the federal government’s bedrock scientific declaration on the dangers of greenhouse gases — a move that would run afoul of decades of research and topple most of the Environmental Protection Agency’s climate regulations.
The rollback is the most audacious attempt yet by President Donald Trump to undo federal restrictions on fossil fuels.
The so-called endangerment finding, which the Obama administration issued in 2009, laid out a comprehensive case for how human emissions of carbon dioxide, methane and other greenhouse gases threaten human health and welfare. The finding serves as the legal basis for most of EPA’s climate rules, including limits on power plant and vehicle emissions — and undoing it, agency Administrator Lee Zeldin said in March, would eliminate “the holy grail of the climate change religion.”
“There’s so much about this that was unprecedented, filled with mental leaps not included in the plain text or the precedent at the EPA,” Zeldin said of the 2009 finding at an announcement in Indianapolis on Tuesday.
Energy Secretary Chris Wright, who was also on hand for the announcement, added that he asked five scientists who “have not been cowed by the politics of climate change” to conduct “an honest, credible, data and fact-driven assessment of climate change.”
The assessment went through an internal peer review at DOE and the national laboratories that Wright characterized as “brief.”
“We want to end the cancel culture Orwellian future reality we’ve been in where climate change is not treated as a serious science, is treated as a political force to silence and shame people,” Wright said.
Also on Tuesday, EPA proposed scrapping all limits on carbon dioxide pollution from cars and trucks.
The elimination of the endangerment finding is sure to draw legal challenges from environmental groups and Democratic-controlled states. Environmentalists have long argued that any effort to weaken or undo the finding would face an insurmountable mountain of scientific evidence, including signs that warming temperatures are already wreaking havoc around the globe.
The EPA’s proposal arrives as scientists warn that the world is on the brink of emitting enough greenhouse gases to make it inevitable that global warming will surpass 1.5 degrees Celsius since the preindustrial era, a long-time international goal meant to stave off the worst impacts of climate change.
But the administration’s proposal appears to pair its questions about the Obama administration’s scientific conclusions with criticisms of its rulemaking process, as well as assertions that a key 2007 Supreme Court ruling allows but does not require the agency to regulate greenhouse gases.
During a podcast appearance on Tuesday before the announcement, Zeldin raised a litany of complaints about the finding, including that EPA ignored the benefits of carbon dioxide, refused to consider economic costs of regulation and never took public comment.
However, the Obama administration did consider benefits, did take public comment and said that the economic costs of potential future regulations that stem from the finding would be considered when such rules were adopted.
EPA defended Zeldin’s statements in response to questions, arguing that the finding should be revisited to incorporate developments made in the past 16 years and that the economic cost of potential future regulations should be incorporated at this first stage.
The 2007 Supreme Court ruling, Massachusetts v. EPA, said the agency had violated the Clean Air Act by refusing to even consider whether greenhouse gases cause or worsen climate change. President Barack Obama’s EPA issued its finding two years later, writing that rising amounts of greenhouse gases in the atmosphere “threaten the public health and welfare of current and future generations.”
Courts have since upheld the finding on multiple occasions, including as recently as 2023 when the Supreme Court refused to hear a challenge. EPA also declined to revisit the finding during Trump’s first term. But Trump came roaring into his second term with unbridled plans to boost fossil fuel production.
Undoing the endangerment finding would go a long way toward that goal by shielding the top polluting sectors from regulation, and blocking off any effort to require other industries to reduce their emissions.
Transportation, including cars and trucks, makes up 29 percent of U.S. greenhouse gas emissions, according to EPA’s most recent data. The electric power sector, which has significantly cut its climate pollution during the past two decades, still represents 23 percent of U.S. emissions. Other major industries — including iron and steel, cement and petrochemicals — together make up an additional 23 percent, but likely will not be regulated if EPA undoes the endangerment finding.
Under Trump, EPA has already taken other steps to provide relief to industries facing climate regulation.
A recent EPA proposal to repeal Biden-era standards for coal- and natural-gas fired power plants argued that U.S. power sector emissions, which account for about 3 percent of global emissions, aren’t “significant” enough to regulate under the Clean Air Act. Trump has also nullified several California clean vehicles rules, including one that would have banned new gasoline-powered car sales in the state in 2035.
EPA’s proposal Tuesday to undo carbon dioxide limits for cars and trucks addresses complaints by Trump and other Republicans who said Biden’s rules amounted to a mandate for U.S. consumers to buy electric vehicles. Earlier this month, Republicans also defanged the 50-year-old fuel economy program run by the Transportation Department by ending all penalties for automakers.
Most of EPA’s remaining climate regulations will fall if the endangerment finding goes away, but a few rules may survive.
Most notably, Congress in 2020 passed a bipartisan law signed by Trump requiring EPA to phase down the use of hydrofluorocarbons, a greenhouse gas used as a refrigerant. Hydrofluorocarbons are more potent greenhouse gases than carbon dioxide but do not last as long in the atmosphere. That law does not depend on the endangerment finding being in place.
Zeldin said the proposal will be open for 45 days of public comment once published in the Federal Register.
