Attorney General Dan Rayfield and a coalition of 36 other states, counties and cities today challenged the U.S. Environmental Protection Agency’s unlawful attempt to rescind its 2009 Endangerment Finding– the agency’s major determination that greenhouse gas pollution from motor vehicles drives climate change and endangers public health and welfare.
“Oregonians don’t have to look far to see what’s at stake – from wildfire smoke choking our summers to flooding threatening our communities,” said Attorney General Rayfield. “These vehicle emission standards exist because the science is overwhelming and the law is clear. The EPA is trying to roll back rules that protect the air we breathe, preserve our infrastructure and even lower health care costs.”
The 2009 Endangerment Finding was the direct result of the landmark 2007 Supreme Court decision in Massachusetts v. EPA, which confirmed that the Clean Air Act authorizes EPA to regulate greenhouse gas emissions that endanger public health and welfare. Based on years of rigorous scientific analysis and review, in 2009 EPA determined that emissions from motor vehicles contribute to air pollution that harms public health and the environment. EPA then set federal standards to limit those emissions, which have led to significant reductions in greenhouse gas emissions from motor vehicles.
Now, almost two decades later, EPA has rushed a rulemaking process to rescind the Endangerment Finding and repeal all motor vehicles greenhouse gas standards, blatantly disregarding the law and science. EPA’s rescission is based on flawed interpretations of the law — previously rejected by the Supreme Court — that the agency lacks authority to regulate greenhouse gas emissions. The rescission also ignores decades of peer-reviewed scientific evidence confirming the reality and severity of climate change. By eliminating all existing and future federal vehicle greenhouse gas emission standards, the rule violates EPA’s legal obligations, fundamental principles of administrative law, and its mission to protect public health and welfare.
Oregonians from every corner of the state have experienced the devastating impacts of climate change. These impacts include choking wildfire smoke, deadly heat, flooding, landslides, transportation system disruption, drought, damaged fisheries, burnt forests, and the costs to taxpayers of responding to many of these impacts, to name a few. The Oregon Health Authority has determined that additional costs for smoke-related asthma emergency department visits alone—not including other smoke-related impacts or other asthma-related costs—will add an estimated $99.7 million to health care costs in Oregon in the 2050s.
Today’s lawsuit is the latest action taken by Attorney General Rayfield and the coalition in their ongoing effort to fight back against EPA’s unlawful rescission of the 2009 Endangerment Finding. In the fall of 2025, 23 attorneys general and seven counties and cities in submitting two comment letters urging EPA to abandon the proposal, arguing that it would violate settled law, clear Supreme Court precedent, and scientific consensus, endanger hundreds of millions of Americans—particularly communities disproportionately burdened by environmental harms—and cause unprecedented disruption to the regulatory landscape with catastrophic consequences for residents, industries, natural resources, and public investments.
Attorney General Rayfield is joined in filing this challenge by the attorneys general of: Arizona, California, Colorado, Connecticut, Delaware, Hawai‘i, Illinois, Maine, Maryland, Massachusetts, Michigan, Minnesota, New Jersey, New Mexico, New York, Nevada, North Carolina, Rhode Island, Vermont, Virginia, Washington, Wisconsin, the District of Columbia. In addition, this challenge is joined by Pennsylvania Governor Josh Shapiro; City of Boston, Massachusetts; City of Chicago, Illinois; City of Cleveland, Ohio; City of Columbus, Ohio; City and County of Denver, Colorado; City of Los Angeles, California; City of New York, New York; City and County of San Francisco, California; County of Santa Clara, California; and Harris County, Texas.
