President Donald Trump on Thursday revoked a landmark Environmental Protection Agency finding that serves as the legal basis for U.S. climate rules.

He eliminated the EPA’s so-called endangerment finding from 2009 that concluded that six gases in the atmosphere—including carbon dioxide and methane—threaten public health and welfare. He called it an overreach by the Obama administration to tighten tailpipe emissions standards and attack components that make factories “rock and roll.”

Trump said the move would save consumers $1.3 trillion in costs, reverse what he called the “Green New Scam,” and reduce car prices by nearly $3,000.

EPA Administrator Lee Zeldin, who has argued the EPA lacks authority to regulate greenhouse gases under the Clean Air Act, lauded the reversal of what he said came out of “an ideological crusade within the Obama administration.”

The endangerment finding came after the Supreme Court ruled in 2007 that greenhouse gases are pollutants subject to the Clean Air Act.

Scientists have determined that the gases contribute to poorer air quality, rising temperatures, extreme weather events, and risks to public health, agriculture, and infrastructure.

The endangerment finding has underpinned U.S. greenhouse gas regulations for 15 years. Repealing the finding means the EPA will no longer regulate greenhouse gas emissions from U.S. vehicles. It also guts regulations in other areas, such as fuel-fired power plants and oil and gas facilities, according to the Environmental & Energy Law Program at Harvard Law School.

Zeldin called the reversal the largest act of deregulation in U.S. history.

Companies and investors have been bracing for the Trump administration’s rescission since the EPA first proposed it last July, but the move could still have major implications for car makers.

Spurred by environmental regulations, many companies launched electric-vehicle product lines and collected EV tax credits over the past several years. Scrapping those greenhouse gas regulations would mean near-term losses for companies heavily invested in EVs.

In a January regulatory filing, General Motors estimated that $1.1 billion of its total $1.4 billion in acquired credits would be subject to impairment if the EPA removes greenhouse gas rules.

On the other hand, the move could mean a renewed focus on less energy-efficient but more profitable business lines. That is especially true for GM, Ford Motor, and Stellantis, which aremajor sellersof trucks and SUVs, said Morningstar analyst David Whiston.

“If you have less government regulation in selling less fuel-efficient, bigger vehicles, that means you have more freedom to market and sell those vehicles without having to also then run as large of a money-losing EV business,” Whiston told Barron’s.

The impact may be more straightforward for pure-play EV companies. Tesla has long collected emissions credits from its EVs and then sold them on the secondary market, creating a high-margin business stream. Automotive regulatory credits—some of which are not greenhouse-gas credits—contributed about $2 billion to Tesla’s $94.8 billion in revenue in 2025.

Perhaps the bigger challenge for auto makers, whether they are selling EVs or gas-guzzlers, is that no environmental regulation ever seems to last very long in Washington.

“There’s potential for a lot of see-sawing in Washington on environmental policy in respect to the auto industry,” Whiston said. “It’s likely a Democrat will take over as president at some point, and it’s unlikely they would keep the current Trump environmental policies in place.”

The energy and utilities industries could also see an impact.

Coal and gas will face fewer federal legal restrictions and compliance costs, said Tim Winter, a portfolio manager at Gabelli Funds. That means utilities companies will be able to keep existing plants operating as a bridge until replacement capacity is built, Winter added.

“It is important to recognize that state policy remains a major factor,” Winter said. “State-level mandates limit how much utilities can revert to long-term fossil dependence, even if federal authority is reduced.”