The U.S. Environmental Protection Agency (EPA) announced the release of a new proposal aimed at rescinding the landmark 2009 Greenhouse Gas Endangerment Finding, which would effectively remove the U.S. government’s ability to regulate greenhouse gas (GHG) emissions from carbon-intensive industries including the automotive and energy sectors.

The 2009 Endangerment Finding by the Obama-era EPA found that GHG emissions endangered public health and welfare through impacts including global warming, by contributing to extreme weather events, heat-related mortality, and by reducing air quality.

The finding underpinned the ability of the EPA to issue a series of regulations aimed at reducing greenhouse gas emissions from sectors, with the agency issuing its first GHG standard for light-duty vehicles in 2010, followed by standards for medium and heavy-duty vehicles in 2011. The Agency has also issued GHG standards for sectors such as power generation and the oil and gas sector which could be impacted by the new move.

In its proposal, the EPA said that it has “serious concerns that many of the scientific underpinnings of the Endangerment Finding are materially weaker than previously believed,” and argues that the global warming projections underlying the Endangerment Finding “appear unduly pessimistic.”

The EPA said that repealing the finding would leave the agency without the statutory authority to prescribe standards for GHG emissions, and that if finalized, the proposal would remove all GHG standards for light-, medium- and heavy-duty vehicles and heavy-duty engines.

EPA Administrator Lee Zeldin said:

“With this proposal, the Trump EPA is proposing to end sixteen years of uncertainty for automakers and American consumers. In our work so far, many stakeholders have told me that the Obama and Biden EPAs twisted the law, ignored precedent, and warped science to achieve their preferred ends and stick American families with hundreds of billions of dollars in hidden taxes every single year. We heard loud and clear the concern that EPA’s GHG emissions standards themselves, not carbon dioxide which the Finding never assessed independently, was the real threat to Americans’ livelihoods.”

Zeldin added that if finalized, the proposal would undo regulations with an aggregate cost of $1 trillion.

Environmental groups sharply criticized the EPA’s proposal. Conrad Schneider, Senior Director, U.S. at Clean Air Task Force called the move a “drastic step” that would result in “needlessly putting the health of millions of Americans at risk.” John Noël, Greenpeace USA Climate Campaign Director, called the announcement “just one more handout from Trump to Big Oil,” adding that “there’s nothing reasonable or science-based about it.”

The proposal could face a ling road before it is finalized, with the EPA opening a comment period and to publish a final rule backed by scientific justification, which is likely to face legal challenges from several groups already pledging to fight the EPA’s plan.

In a statement released following the proposal, environmental advocacy group, the Natural Resources Defense Council said:

“Trump’s EPA wants to reverse a long-standing decision that greenhouse gases and climate change threaten public health. It’s served as a legal foundation for pollution restrictions on oil drilling, cars, and more. If needed, we’ll fight this in court.”