Duke climate scholars warn of legal, financial risks following EPA ‘endangerment finding’ repeal

The Environmental Protection Agency rescinded a major rule underpinning the country’s federal climate regulations on Thursday. The move comes amid an ongoing campaign by the Trump administration to reverse U.S. climate change mitigation efforts.

Known as the “endangerment finding,” the principle empowered the EPA to regulate six common greenhouse gases under the Clean Air Act by asserting they pose a risk to “the public health and welfare of current and future generations.” Since it was set in 2009, that finding has served as the basis for a slew of regulations governing the climate impact of cars, power plants and other large emitters.

Now, the government is doing away with that finding in a move it’s celebrating as “the single largest deregulatory action in U.S. history.” But environmental scholars have condemned the change as worrisome, and policy experts have cast doubts on the economic claims predicting trillions of dollars saved.

The Chronicle spoke to environmental scholars at Duke to understand the change and its anticipated effects.

Why was the finding repealed?

The EPA has largely framed the rescission around lessening regulation of the U.S. auto industry, which the Trump administration has long claimed is overly cumbersome.

EPA Administrator Lee Zeldin began discussing the matter with the White House about a year ago although the agency did not make an initial proposal until July 2025. The proposal stated that motor vehicle and engine manufacturers would be released from their obligation to measure, report and control the greenhouse gas emissions of their products. 

Following the EPA’s approval of the rule, the White House has touted the shift as beneficial to both auto manufacturers and consumers, arguing that it “clears the path for lower prices, greater consumer choice and a thriving economy” and that it will save $1.3 trillion.

What do experts at Duke say?

Environmental scholars at Duke maintain that the science behind the original endangerment finding is solid — and that its elimination likely means more adverse health outcomes for Americans.

“Greenhouse gas regulations reduce co-pollutants, like the fine particulate matter, nitrous oxide and ozone precursors … pollutants that are directly linked to asthma, to heart disease, to stroke, to lung disease. And they lead to premature death — absolutely undeniable,” said Toddi Steelman, vice president and vice provost for climate and sustainability. “So weakening federal standards means we’re going to see increased exposure over time.”

According to Steelman, the downstream effects of those higher exposure rates include higher health care costs and lost productivity, undercutting the Trump administration’s argument that eliminating emission regulations will be good for American consumers and the economy.

Even if consumers see short-term benefits in the form of lower vehicle prices — the Trump administration is projecting families will save $2,400 on average — Steelman thinks that pursuit is “short-sighted.” She said it ignores long-term costs to health, safety and economic welfare that would be incurred by failing to take substantial action to mitigate the impacts of climate change.

Still, Jonathan Wiener, William R. Perkins distinguished professor of law, asserted that the actual impact of the regulatory change on U.S. emissions remains a “big question.”

“If electricity from wind and solar is more economically attractive … than electricity from burning fossil fuels, then there’ll still be a long-term incentive for industry to shift to cleaner energy,” he said, pointing out that U.S. emissions have been declining since 2006, in large part thanks to renewable energy sources becoming more cost-effective.

One of the EPA’s primary arguments for dismantling its own finding is that emissions from the various sectors it regulates do not on their own constitute a large enough share of the global total to have a meaningful impact on public health and welfare. Wiener said challengers will likely counter that the EPA’s reasoning “slice[s] up” those sectors and that taken together, they do threaten public health.

What will happen next?

Steelman posited that the ruling is “less about climate science than it is about regulatory power.”

“I think the broad objective is to create a path to the Supreme Court,” she said.

The endangerment finding stems from a 2007 Supreme Court case called Massachusetts v. EPA, which established that the agency could regulate greenhouse gases under the Clean Air Act but didn’t require that it do so. When the endangerment finding was established two years later, the EPA became obligated to exercise that authority.

Elizabeth Albright, Dan and Bunny Gabel associate professor of the practice of environmental ethics and sustainable environmental management, thinks last week’s repeal will draw lawsuits from states and environmental groups around the country that may set the stage for Massachusetts v. EPA to eventually be overturned. She said that could either significantly narrow the agency’s ability to regulate carbon emissions under the Clean Air Act or eliminate it altogether.

But it will likely take years for the case to make it that far. Wiener outlined a lengthy process where opponents must first file a lawsuit, after which the case must pass through the U.S. Court of Appeals for the District of Columbia, another waiting period while the Supreme Court decides if it will hear an appeal and then, if so, to finally hear arguments and render its own decision. Each step of the way brings new delays and chances for the case to be stalled or thrown out.

All in all, the process would likely take two to three years — at which point, Wiener pointed out, a new presidential administration would likely be in place or fast approaching. If the court rules in favor of upholding the case, it would be up to the new EPA to decide how to regulate greenhouse gases. But in the unlikely scenario where Massachusetts v. EPA is overturned, Congress would have to pass a new law for the federal government to be able to regulate greenhouse gases again.

In the meantime, actors in high-emitting industries could be more vulnerable to nuisance lawsuits and face more regulatory uncertainty as the question plays out in the courts.

“There will be very far-reaching consequences, I would say, at a time when we absolutely need to be accelerating our climate action, not backpedaling,” Steelman said.