Trump Suit Against California Evokes High Court Emissions Debate

The Trump administration’s lawsuit against California over the state’s vehicle emissions limits recalls a Supreme Court case that was monumental in interpreting how federal policy could regulate greenhouse gas emissions, attorneys say.

The lawsuit, which alleges California violated the Energy Policy and Conservation Act by instating its own vehicle emissions standards, raises parallels from Massachusetts v. EPA, according to legal analysts, in part related to the arguments raised by the federal government in the previous case.

The Trump administration’s argument is “a close analog” to a stance the Bush administration took in arguing the case, according to Ann Carlson, the faculty director at University of California, Los Angeles’ Emmett Institute on Climate Change & the Environment. It alleged the federal government already was responsible for issuing fuel economy standards under EPCA and that regulating greenhouse gases under the Clean Air Act would “overlap,” Carlson said.

“Here they’re trying to argue if you’re trying to regulate greenhouse gases, California, you can’t because that’s related to fuel economy,” said Carlson, who previously worked for the Biden administration when it repealed a Trump-era rule on the issue. “The Supreme Court basically rejected that argument.”

The Supreme Court would have to reverse that decision for the Trump administration’s EPCA preemption argument to hold up in court, said David Pettit, a California-based attorney for the Center for Biological Diversity.

“In that case, the Supreme Court said specifically, and particularly, that EPA does have the power to regulate GHGs under the Clean Air Act. Period,” Pettit said. “You can’t have that stand and have EPA be able to say, ‘Well, actually we don’t, and you don’t either.’”

Endangerment Finding ‘Trial Balloon’

The Center for Biological Diversity is one of several environmental and public health groups suing the administration over its repeal of the endangerment finding, or the scientific idea that greenhouse gas emissions are harmful to human health. States have also expressed interest in filing similar legal challenges.

The finding’s repeal could determine how the administration’s latest suit against California plays out.

“Once you yank the endangerment finding, EPA is essentially saying greenhouse gases aren’t supposed to be regulated under the mobile source provisions of the Clean Air Act,” UCLA’s Carlson said.

“I’m guessing they’re going to say, ‘Well, ACC1 was issued with a waiver from the federal government, and that waiver was dependent upon greenhouse gases being a pollutant that the state could regulate under the Clean Air Act as extended by Mass vs. EPA,’” she added, referring to California’s first iteration of its Advanced Clean Cars program that imposes vehicle emissions limits.

CBD’s Pettit pointed out that the administration doesn’t want every state to have its own greenhouse gas emissions regulations. He said this latest legal challenge is a test to see what argument sticks.

“This is a trial balloon, if you will, for EPA’s argument about why if the endangerment finding repeal stands, that all 50 states can’t go ahead then and enact their own motor vehicle GHG emission regulations,” he said.

This isn’t the first time the administration has zeroed in on state preemption under EPCA. The first Trump administration finalized a rule in 2019 to give the National Highway Traffic Safety Administration the power to set up fuel economy standards for the entire country and make it clear that EPCA preempts states from instating their own, according to the administration’s lawsuit. NHTSA rolled back that regulation in 2021 during the Biden administration when UCLA’s Carlson was working as the agency’s general counsel.

The Trump administration, in its suit, said in rolling back the regulation, “NHTSA did not disclaim or otherwise change its longstanding position on EPCA pre-emption.”

In 2022, the agency reversed a Trump administration decision made under the old rule to revoke California’s waiver to implement its own vehicle emissions standards, which the state—according to the administration’s lawsuit—thinks “is currently in effect, such that its” regulations “are not preempted by the Clean Air Act.”

While the administration’s top-line argument is that California’s regulations violate EPCA, the lawsuit still delves into the Clean Air Act and California’s power to request preemption waivers, arguing “such a waiver has no effect on EPCA preemption.”

Definition Debate

One question the case poses is whether carbon dioxide regulations are considered fuel economy regulations or restrictions governing greenhouse gases, said Maya Lopez Grasse, an environmental lawyer for Alston & Bird in Los Angeles. Grasse said the administration might not have brought its suit under the Clean Air Act because of the states’ lawsuit challenging California’s waivers being rescinded under the Congressional Review Act.

“It may be that they want to keep that issue clean because it’s clear EPCA, in their view, of course, would preempt if it’s tied to a fuel economy,” she said. “If that’s the determination, then EPCA would preempt it regardless of the Clean Air Act.”

The administration alleges California’s limitations “are related to fuel economy standards because reducing or eliminating tailpipe CO2 emissions from internal combustion automobiles effectively increases fuel economy” and “fuel economy is determined by measuring the amount of CO2 emitted from a vehicle’s tailpipe.”

“Fuel economy standards and CO2 standards are two sides of the same coin,” the administration argues.

If a judge doesn’t see it that way, the repeal of the endangerment finding could leave an opening for the state, Grasse surmised.

“The absence of the finding that GHGs are a pollutant under the Clean Air Act, we still have California’s ability to set its own emission standards,” she said. “I think there could be potential opportunity, in the absence of federal regulation of GHGs, for California to find a way to advance its own regulation so long as I guess it’s not tied to fuel economy, of course.”