California Asserts Authority to Regulate Vehicle Emissions Standards

With Congressional action to overturn California’s clean vehicles program signed into law this week, the state responded swiftly to assert its authority to enforce more stringent, state-level emission standards for cars and trucks. VX News shares the overview of the legal complaint filed against the federal government by CA Attorney General Rob Bonta and a coalition of 10 state attorneys general challenging the legislative procedures used to overturn the state’s Clean Air Act waivers, as well as the Executive Order issued by Governor Newsom affirming the state’s commitment to accelerating zero-emission vehicle technologies and directing CARB to begin developing an Advanced Clean Cars III regulation that continues furthers the state’s clean air objectives. 

“Congress’s unprecedented action attempting to invalidate California’s waivers contradicts the non-partisan Government Accountability Office and Senate Parliamentarian, both of whom determined that the CRA process to disapprove federal regulations does not apply to waivers.”

LOS ANGELES – California Attorney General Rob Bonta, California Governor Gavin Newsom, and the California Air Resources Board today led a coalition of 10 attorneys general in filing a lawsuit against the federal government challenging the unprecedented and unlawful use of the Congressional Review Act (CRA) to upend California’s clean vehicles program, specifically the Advanced Clean Cars II (ACCII), Omnibus, and Advanced Clean Trucks (ACT) standards. Predicated on illegal actions by the Trump Administration, Congress purported to disapprove the Clean Air Act waivers, granted by the Environmental Protection Agency (EPA), that allow California to enforce these more stringent, state-level emission standards. In the 50 years since the Clean Air Act was enacted, waivers have never been subject to the CRA.  Nor have any other agency orders that adjudicate requests for permission—such as oil and gas leases or mining permits. Congress’s unprecedented action attempting to invalidate California’s waivers contradicts the non-partisan Government Accountability Office and Senate Parliamentarian, both of whom determined that the CRA process to disapprove federal regulations does not apply to waivers.

If California is prevented from enforcing these vehicle emission standards, it will result in the loss of significant economic and public health benefits, costing California taxpayers an estimated $45 billion in preventable health care costs. Despite decades of progress, tens of millions of Californians still breathe some of the worst air in the nation—these regulations were specifically designed to change that. Losing these standards would also undermine market certainty for vehicle manufacturers, stifling innovation and job creation, including in the electric vehicle sector, which has been a growing source of high-paying green jobs and investment. 

“The President’s reckless, politically motivated, and illegal attacks on California continue, this time with his attempt to trample on our longstanding authority to maintain more stringent clean vehicle standards,” said Attorney General Bonta. “The President is busy playing partisan games with lives on the line and yanking away good jobs that would bolster the economy – ignoring that these actions have life or death consequences for California communities breathing dirty, toxic air. I’ve said it before, and I’ll say it again: California will not back down. We will continue to fiercely defend ourselves from this lawless federal overreach.”

“Trump’s all-out assault on California continues – and this time he’s destroying our clean air and America’s global competitiveness in the process," said Governor Gavin Newsom. "We are suing to stop this latest illegal action by a President who is a wholly-owned subsidiary of big polluters.”

Motor vehicle emissions contribute to the formation of smog, as well as fine particle pollution and unhealthy levels of air toxics, all of which are linked to premature death, respiratory illness, cardiovascular problems, and cancer, among other serious health impacts. Transportation is also the leading source of greenhouse gas emissions in the country, and cars and trucks account for more than 80% of those transportation emissions. 

The Clean Air Act requires the EPA to set federal emission standards for air pollutants from new motor vehicles or new motor vehicle engines that cause or contribute to air pollution that endangers public health or welfare. The Clean Air Act allows California to adopt more stringent emission requirements independent from EPA’s regulations, and the Act requires EPA to approve preemption waivers for those requirements absent certain, limited circumstances not present here. Historically, EPA – under both Republican and Democratic administration – has granted California more than 75 preemption waivers for updates to the State’s new motor vehicle emissions control program. As Congress intended, these waivers have allowed California to improve on its vehicle emissions program, which pre-existed the federal government’s efforts to regulate vehicle emissions via the Clean Air Act.

Consumers are rapidly embracing clean vehicle options. In California alone, over 2 million zero-emission passenger cars have been sold, with clean vehicles now making up 26% of all new car sales. This momentum extends to the medium-and heavy-duty vehicle market as well, where sales have exceeded targets for two consecutive years – well ahead of timelines set by state regulations.

Since 2023, the EPA granted California three waivers, allowing it to enforce the ACC II, Omnibus and ACT regulations in California. Under ACC II, automakers must continue to sell an increasing number of zero-emission vehicles in California—as they have been for decades. By model year 2035, 80% of the passenger vehicles sold in California must be zero-emission, while the remaining 20% may be plug-in hybrids. Advanced Clean Truck regulations, which aim to accelerate the widespread adoption of zero emission vehicles in the medium and heavy-duty truck sector, are similarly critical for California’s efforts to meet air quality standards and protect public health. By 2040, the Advanced Clean Truck regulations will reduce emissions of NOx by 16.9 tons per day and fine particulate matter emissions by 0.46 tons per day. The Omnibus regulation requires internal combustion heavy-duty trucks sold in California to meet strict standards for oxides of nitrogen (NOx), which are major contributors to smog formation.

Under the direction of President Trump, the EPA transmitted these waivers to Congress as “rules” in an attempt to invoke CRA procedures, even though all three waivers state EPA’s consistent and longstanding position, under both Republican and Democratic administrations, that waiver decisions are not “rules.” Both the Republican-controlled U.S. House of Representatives and the Senate illegally used the CRA to “disapprove” of California’s Clean Air Act waivers.

The complaint filed today alleges that the attempt to invalidate California’s waivers violated constitutional principles of federalism and separation of powers, the Take Care Clause, and multiple federal statutes including the Congressional Review Act and Administrative Procedure Act.  The complaint asks the court to declare the resolutions to be unlawful and to require the Administration to implement the Clean Air Act consistent with the granted waivers. 

Attorney General Bonta led the lawsuit with the attorneys general of Colorado, Delaware, Massachusetts, New Jersey, New Mexico, New York, Oregon, Rhode Island, Vermont, and Washington.

A copy of the complaint is available here.

EXECUTIVE DEPARTMENT STATE OF CALIFORNIA EXECUTIVE ORDER N-27-25

WHEREAS in 1967, Governor Ronald Reagan established the California Air Resources Board, committing California to aggressively address the serious issue of air pollution in the state, including from vehicle tailpipe emissions; and 

WHEREAS for more than 50 years, California has worked closely with the auto industry and other stakeholders to adopt new vehicle standards that are feasible, cost-effective and significantly reduce harmful air pollution; and 

WHEREAS reducing air pollution from transportation, including toxic air pollutants, helps protect the health of Californians, reducing premature death, illness, hospital visits, health care costs, and school and work absenteeism, in addition to addressing a changing climate that is threatening the health and safety of Californians in unprecedented ways, and costing the State more than $16 billion a year from disasters like drought and wildfire; and 

WHEREAS zero-emission vehicle technologies and equipment needed to reduce transportation pollution are experiencing significant global demand, making American manufacturers’ investments in these technologies critical to the nation’s global market competitiveness; and 

WHEREAS on September 23, 2020, I issued Executive Order N-79-20 establishing, among other things, goals for the State to have 100 percent of instate sales of new passenger cars and trucks be zero-emission by 2035, 100 percent of medium-and heavy-duty vehicles in the State to be zero-emission by 2045 for all operations where feasible and by 2035 for drayage trucks; and 

WHEREAS in 2022, I signed into law Assembly Bill 1279 (Chapter 337, Statutes of 2022), which established the policy of the State to achieve carbon neutrality as soon as possible, but no later than 2045; and

WHEREAS California has enacted a suite of policies and standards advancing zero-emission technologies in vehicles to reduce emissions of both smog-forming, toxic pollutants and greenhouse gases; and 

WHEREAS California’s policies and standards have spurred global innovation in zero-emission vehicles and technologies and successfully moved the market in California so that in 2024, 25 percent of sales of new light-duty vehicles were zero-emission and 16 percent of medium- and heavy-duty new vehicles sales were zero-emission; and

WHEREAS California’s Advanced Clean Cars I regulations were the subject of an illegal and ultimately unsuccessful attempt by the first Trump Administration to impede California’s authority to protect public health and welfare; and 

WHEREAS in response to the unprecedented and illegal action by the first Trump Administration, five light-duty vehicle manufacturers elected to make commitments with California to encourage technological innovation and support continued annual greenhouse gas reductions, providing environmental and public health benefits, economic benefits, and regulatory certainty to manufacturers; and

WHEREAS on July 5, 2023, the California Air Resources Board reached an agreement with manufacturers that represent over 90 percent of California’s truck market, establishing the Clean Truck Partnership under which, in exchange for commitments to work collaboratively with manufacturers to provide lead time to meet specific regulatory requirements before imposing new ones, the manufacturers agreed to meet California’s heavy-duty vehicle emission standards that will require the sale and adoption of zero-emissions technology in California, regardless of the outcome of any change in law concerning California’s authority to implement its more stringent emissions standards under the federal Clean Air Act; and

WHEREAS California’s authority was again subject to illegal actions by the current Environmental Protection Agency under the Trump Administration that resulted in the U.S. Congress and President Trump purporting to disapprove the waivers of federal preemption California was granted under the Clean Air Act for California’s Advanced Clean Cars II, Advanced Clean Trucks, and HeavyDuty Omnibus regulations; and 

WHEREAS these regulations have significant benefits for Californians, including over $45 billion in health savings and thousands of avoided premature deaths; and 

WHEREAS these federal government efforts would retreat to century-old outdated and ineffective technology, keeping us bound to a fossil fuel industry and manufacturers that benefit from thwarting progress and polluting our communities; and 

WHEREAS on May 22, 2025, the Attorney General and I announced California’s intent to sue to challenge the federal government’s unlawful actions in court, and that lawsuit was filed today upon the President signing the resolutions purporting to disapprove the waivers of federal preemption; and 

WHEREAS California has wide latitude, in making vehicle purchasing decisions for the State’s vehicle fleet and decisions to offer public incentives and subsidies, to prioritize directing state funds to those manufacturers who choose to align with state priorities; and 

WHEREAS the role of California is more important than ever to promote the currently available zero-emission technologies that our future, our health, our economy, and our pocketbook demand. 

NOW THEREFORE, I, GAVIN NEWSOM, Governor of the State of California by virtue of the power and authority vested in me by the Constitution and the statutes of the State of California, do hereby issue the following Order to become effective immediately. 

IT IS HEREBY ORDERED THAT: 

1. The State of California reaffirms its commitment to accelerate the deployment of zero-emission technologies, including passenger, medium and heavy-duty vehicles, consistent with the deployment targets and other actions directed in Executive Order N-79-20, to the extent consistent with State law and other legal requirements. 

2. The California Air Resources Board shall develop and propose an Advanced Clean Cars III regulation consistent with State and federal law, that reduces greenhouse gas, criteria air pollutant, and toxic emissions from passenger cars and light-duty trucks, medium- and heavy-duty vehicles, to advance progress towards the deployment of clean air California, its agencies, departments, entities, officers, employees, or any other person.