Green Groups File Amicus Brief in Support of California Clean Car and Truck Standards

(Washington, D.C. - January 21, 2026) Environmental Defense Fund, Natural Resources Defense Council (NRDC), and Sierra Club are moving to help defend California's protective clean vehicle standards in court.

California and 10 other states filed a lawsuit challenging the "unprecedented and unlawful" use of the Congressional Review Act (CRA) in an attempt to revoke waivers for three California vehicle standards that would protect millions of people from dangerous pollution emitted by cars and trucks. EDF, NRDC and Sierra Club have filed an amicus brief (or "friend of the court" brief) in the U.S. District Court for the Northern District of California in support of the California standards.

BACKGROUND

The transportation sector is the largest source of the nation's climate pollution, responsible for about one-third of U.S. emissions, and is also a major source of deadly particle pollution, smog-forming nitrogen oxides (NOx) and other dangerous air pollutants.

California began regulating vehicle pollution long before the federal government did so and has been a leader in creating policies and technologies to limit it. California also has specific geographic and other challenges that cause especially significant air pollution problems.

Under the Clean Air Act, Congress specifically granted California the right to set its own air pollution standards with waivers from the Environmental Protection Agency. EPA has granted dozens of these waivers over more than half a century.

Last year, Congress used CRAs to try to reverse three already-approved waivers for California's vehicle standards in spite of the fact that the CRA's plain language precludes doing so, and that CRA's were only ever applicable to federal laws. The Senate Parliamentarian, the office specially charged with determining which agency actions are subject to Congressional review, the independent Congressional Research Service, and even Congressional opponents, have all consistently agreed that the waivers for California's state vehicle standards are not subject to CRAs.

California and 10 other states immediately sued.

EDF, NRDC and Sierra Club's amicus brief highlights the vitally important public health benefits provided for generations by California's vehicle emissions standards - one of the great success stories in the history of pollution control. EDF analysis finds that California's more than 50 years of emission standards have significantly reduced harmful emissions, leading to substantial improvements in air quality, protecting thousands of lives, and saving billions of dollars - and the programs under the three waivers at issue would continue to do so long into the future. By 2040 they would prevent up to 7,100 Californians from dying prematurely, would prevent thousands of hospitalizations and ER visits, and would save the state up to $55 billion in health care costs.

QUOTES

"California's clean car and truck standards will save thousands of lives, help prevent cancer and serious heart and lung diseases, and help protect people from the more severe wildfires and weather disasters caused by climate change. EPA's preemption waivers for these protective standards are rooted in Congress's specific instructions in the Clean Air Act and in more than half a century of legal precedent. The flagrant misuse of the Congressional Review Act at issue in this case is undermining the rule of law and endangering millions of people." - EDF Attorney Andy Su

"California's tailpipe standards have delivered cleaner air and better health for decades. This is cooperative federalism in action. The state is working to address its unique air pollution problems just as Congress affirmed in law five decades ago." - NRDC Senior AttorneyJulia Forgie

"California's clean car and truck standards have incredible health, environmental, and economic benefits for communities in California and beyond, and are critical to protecting vulnerable populations like children and the elderly. The Trump administration's illegal and unprecedented attack on clean air and clean vehicles was an obvious giveaway to the fossil fuel industry. We won't stop fighting to protect the public from toxic transportation pollution," - Sierra Club Senior Attorney Andrea Issod