The Trump administration has proposed to repeal a 2009 finding that human-caused climate change endangers human health and safety

The Trump administration on Tuesday proposed rescinding a 2009 scientific finding that has served as the legal foundation for U.S. efforts to regulate greenhouse gas emissions under the Clean Air Act.

The Environmental Protection Agency’s proposed rule would revoke the “endangerment finding,” a determination that carbon dioxide and other greenhouse gases pose a threat to public health and welfare. This finding has enabled federal regulation of emissions from vehicles, power plants, and other major sources contributing to global warming.

EPA Administrator Lee Zeldin called the proposal “the largest deregulatory action in the history of America.” Speaking on the “Ruthless” podcast, Zeldin said the 2009 finding allowed for broad climate-related regulations that, in his view, imposed significant costs on the economy. “There are people who, in the name of climate change, are willing to bankrupt the country,” he said.

The proposed rule will undergo a formal review process, including a public comment period, before it can be finalized, which is expected sometime next year. Environmental advocacy groups have indicated they will likely challenge the proposed repeal in court.

Zeldin had previously announced plans to revise the endangerment finding as part of a broader regulatory rollback. In March, he described the effort as part of “the greatest day of deregulation in American history,” outlining plans to roll back or eliminate 31 federal environmental rules covering clean air, clean water, and climate policy.

At an event in Indiana on Tuesday, Zeldin criticized past EPA leadership under the Obama and Biden administrations, claiming they had “twisted the law, ignored precedent and warped science” to implement regulations he said amounted to “hundreds of billions of dollars in hidden taxes every single year” for American families.