Trump is killing climate rules. It will be a disaster for Washington | Opinion

The Trump administration has proposed repeal of the 2009 EPA Endangerment Finding. That would be a huge mistake for two big reasons.

The endangerment finding was issued by the Environmental Protection Agency (EPA) in 2009 in response to a Supreme Court decision determining that greenhouse gases — the climate pollution emitted when fossil fuels are burned for energy — should be considered a form of pollution governed by the Clean Air Act, our nation’s bedrock clean air policy.

The EPA found that global concentrations of greenhouse gases from all foreign and domestic sources “constitute the largest anthropogenic driver of climate change” and attributed climate change impacts to increasing global greenhouse gas concentrations;” that “climate change can increase the risk of morbidity and mortality” directly through increased global temperature, air quality effects and changes in extreme weather events; and that climate change can impact welfare indirectly through net impacts on food production, forestry, water resources, sea level rise, energy infrastructure and ecosystems. It concluded that “greenhouse gases constitute air pollution that endangers public health and welfare.”

The endangerment finding serves as the foundation for all U.S. climate policy.

The Trump Administration’s Reconsideration of 2009 Endangerment Finding and Greenhouse Gas Vehicle Standards proposes “to repeal all greenhouse gas emission standards for light-duty, medium-duty and heavy-duty vehicles and engines” with the argument that “the Clean Air Act does not authorize the EPA to prescribe emission standards to address global climate change concerns”.

This argument fails for several reasons. The reconsideration’s interpretation of the Clean Air Act Section 202(a) is inconsistent with both the statute’s text and congressional intent.

First, the statutory language in the act does not limit Section 202(a) to local or regional pollution. On the contrary, Section 302(h) specifies: “All language referring to effects on welfare includes, but is not limited to, effects on soils, water, crops, vegetation, manmade materials, animals, wildlife, weather, visibility, and climate.”

Second, Congress’ actions over decades confirm that it intended for EPA to regulate greenhouse gases from motor vehicles. Congress has repeatedly affirmed EPA’s authority to regulate greenhouse gas emissions from motor vehicles. In the 15 years since the 2009 endangerment finding, Congress has never acted to limit this authority, underscoring its consistent legislative intent.

Moreover, repealing the endangerment finding would be foolish, costly and shortsighted.

The links between greenhouse gases and climate change are well established in 800,000 years of ice core records from Antarctica and in the rapid global warming of the last five decades. Our civilization is based on the relatively steady climate of the past 10,000 years, not a world with rising seas, more violent storms, depleted mountain snowpack, and expanding wildfires.

While we can partially adapt to some of these changes, the costs of adaptation rise fast as sea level rise exceeds one meter. It is noteworthy that the last time the carbon dioxide concentration was as high as it is now, sea level was about 20 meters (65 feet) higher than now.

While such sea level rise will take centuries, my own research estimated a 70% reduction in mountain snowpack in the Western U.S. by the end of this century for an emissions scenario like the path we are on now. Given our heavy reliance on snowmelt for summer irrigation, such a loss of mountain snowpack has severe implications for agriculture in the western U.S.

Furthermore, the reconsideration fails to provide rigorous analysis to support its assertion that, “Complying with our GHG emission standards often requires manufacturers to design and install new and more expensive technologies ... EPA has serious concerns that its GHG standards may be harming air quality by raising prices and reducing fleet turnover.”

EPA did actually conduct such an analysis when it published its 2024 motor vehicle emissions standards, concluding that they would yield approximately $1 trillion in net benefits over the next three decades while resulting in improved air quality nationwide.

I therefore conclude that the endangerment finding must be upheld.

Sadly, by attempting to repeal the endangerment finding, shut down the monitoring of carbon dioxide concentration at the surface and from satellite, and by canceling the publication of the latest National Climate Assessment, the Trump Administration is acting as if ignoring the threat of climate change will somehow eliminate the threat.

No, it would only eliminate the responsible response to the threat. Future generations would pay a very high price for such shortsighted action.

To help uphold the endangerment finding, prepare and submit your comments to the EPA by Sept. 22.

Retired climate scientist Steve Ghan leads the Tri-Cities Washington Chapter of Citizens Climate Lobby, guides crews that remove logs from the Pacific Crest Trail and serves as Treasurer for the Three Rivers Folklife Society.

This story was originally published September 4, 2025 at 5:00 AM.