Attorney General Phil Weiser statement on U.S. EPA revoking a key policy to combat climate change

Feb. 12, 2026 (DENVER) — Attorney General Phil Weiser today issued the following statement in response to the U.S. Environmental Protection Agency’s final rule rescinding the 2009 endangerment finding, which determined that greenhouse gas emissions from motor vehicles contribute to air pollution that drives climate change and endangers public health and welfare:

“In the action announced today, EPA has finalized its misguided proposal to rescind the endangerment finding. As I explained in my testimony to EPA on the proposal, there is no legal or scientific justification to roll back decades of progress in fighting climate change by undoing a finding rooted in well-established research and common sense: greenhouse gas emissions from motor vehicles endanger public health and welfare. We live that reality every day in Colorado, with record drought, catastrophic wildfires, and ever-increasing heatwaves that threaten our residents, economy, and infrastructure. The Supreme Court held nearly 20 years ago that the federal Clean Air Act authorizes EPA to regulate greenhouse gas emissions. I will challenge this illegal action in court.”

The 2009 endangerment finding was the direct result of the landmark 2007 Supreme Court decision in Massachusetts v. EPA, which confirmed EPA’s authority under the Clean Air Act to regulate greenhouse gas emissions that threaten public health and welfare. In response to that opinion and after years of scientific review, EPA confirmed in 2009 that greenhouse gas emissions from motor vehicles contribute to air pollution that harms public health and welfare in numerous ways. The agency then set standards to limit motor vehicle greenhouse gas emissions.

The EPA’s rescission of the endangerment finding rests on the flawed assertion—soundly rejected by the Supreme Court—that it lacks legal authority to regulate greenhouse gas emissions and ignores longstanding scientific evidence that greenhouse gases endanger public health and welfare. The rule eliminates all existing and future federal greenhouse gas standards for vehicles, violating the agency’s legal obligations and fundamental responsibility to protect public health and welfare from environmental harm.

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