Oregon Takes Legal Action as EPA Repeals Climate Change Endangerment Finding

Oregon has joined two dozen states and more than a dozen cities in fighting the Trump administration’s decision to override a scientific finding to eliminate all greenhouse gas emission standards for cars and trucks.

The appellants believe that the federal government’s decision could result in the wide-ranging undoing of climate regulations on outlets such as oil and gas facilities and power plants.

The Environmental Protection Agency (EPA) has rescinded a 2009 government declaration that carbon dioxide and other greenhouse gases are a threat to public health and welfare.

The EPA’s Revocation Reverses Almost All Existing Climate Change Regulations

The EPA’s revocation of the 2009 Obama-era declaration reverses almost all existing climate change regulations affecting motor vehicles, power plants, and other sources of pollution.

The lawsuit claims that the EPA has abandoned it core responsibility to citizens with its decision. They are the second group to challenge the endangerment repeal, after a similar lawsuit was brought by environmental and public health organizations.

Transportation is responsible for 35% of the State’s Total Greenhouse Gas Emissions

Transportation alone was responsible for 35% for all greenhouse gas emissions recorded in Oregon in 2023.

According to a comparison by Oregon’s Department of Environmental Quality (DEQ), statewide greenhouse gas emissions increased by 5% from 1990 to 2023, with transportation and electricity being the major contributors.

Since 2025, the DEQ has adamantly opposed the EPA’s proposal to rescind the climate change finding. The DEQ believes that abandoning the Endangerment Finding is not only dangerous to human health, but also ditches a cornerstone of U.S. climate policy that provides the scientific and legal foundation for regulating greenhouse gas emissions under the Clean Air Act.

The DEQ believes the Endangerment Finding is the basis on which many greenhouse gas emission standards have been developed, and is integral to Oregon achieving its climate goal. By 2050, the state wants to reduce emissions from transportation to 80% below 1990 levels.

According to a press release by the DEQ in September 2025, the EPA’s decision to rescind previous climate change rules is based on a report from the U.S. Department of Energy’s climate working group.

Climate scientists have criticized the findings for what they believe is a misinterpretation of evidence and a shift from established scientific norms.

The 24 states, 10 cities, and five counties appealing the EPA’s decision are Oregon, Arizona, Colorado, Delaware, Hawaii, Illinois, Maine, Maryland, Michigan, Minnesota, New Jersey, New Mexico, Nevada, North Carolina, Rhode Island, Vermont, Virginia, Washington, Wisconsin, the District of Columbia, and the U.S. Virgin Islands.