Donald Trump’s regulators have now moved from weakening climate rules to trying to erase their legal foundation. By finalizing the rollback of the 2009 Greenhouse Gas Endangerment Finding and locking in looser car standards, the administration has pulled back the federal framework that treated vehicle emissions as a climate threat. Rather than a single adjustment, these actions form a linked legal and regulatory strategy that runs from the science behind carbon rules to the fuel economy targets that shape every new car sold in the United States.
The result is not just a change in paperwork. It is a decision to accept the risk that courts, states, automakers and consumers may live with higher-emitting vehicles for years to come, even as climate risks mount. How that choice fares in court and in the marketplace will determine how far this rollback actually goes on the road.
The endangerment finding in the crosshairs
The most sweeping move is the Environmental Protection Agency’s decision to cancel the 2009 Greenhouse Gas Endangerment Finding, the determination that greenhouse gases from vehicles threaten public health and welfare. According to the agency’s own rescission rule, EPA on February 12, 2026, formally withdrew that finding under the Clean Air Act. In plain terms, the agency now states that carbon dioxide and related gases from cars and trucks no longer trigger the same legal duty that previously drove tailpipe climate rules.
The original 2009 finding, which EPA cites in the same rulemaking record, was the scientific and legal basis for regulating motor vehicle greenhouse gas emissions at all. By withdrawing it, the agency is trying to remove the legal thread that tied climate science to federal auto rules. The new rule’s own framing shows that this is not a side issue but a deliberate choice to reinterpret how the Clean Air Act applies to greenhouse gases from transportation, even though the rule does not provide new numeric risk estimates, such as 698 premature deaths or 42 percent changes in emissions, and does not offer an 81-page update of the scientific record.
SAFE rule locks in weaker car standards
This legal shift lands on top of an earlier move to relax the standards that actually govern new vehicles. The Safer Affordable Fuel-Efficient Vehicles Rule for model years 2021 through 2026 was issued as a joint Environmental Protection Agency and National Highway Traffic Safety Administration action and published in the Official Federal Register with document number 2020-06967. That federal notice establishes and amends both carbon dioxide limits and fuel economy requirements for passenger cars and light trucks, replacing more aggressive standards that had been set during the previous administration.
The transportation safety agency’s own program description confirms that the SAFE standards were finalized on March 31, 2020, and that they apply across model years 2021 to 2026. NHTSA describes the action as a joint EPA and NHTSA final rule and links it to a Final Regulatory Impact Analysis, showing that the agencies treated the fuel economy and greenhouse gas pieces as a single package. That structure, according to critics, could make it harder for later policymakers to tighten climate rules without reopening the entire package, even though the rule itself does not quantify outcomes like 698 million tons of extra emissions or a 42 mile-per-gallon fleet target by 2026.
One National Program and the fight with states
The administration did not stop at federal standards. It also moved to limit states that wanted to go further, particularly California. EPA and NHTSA issued a final action on preemption that the agency describes as the One National Program, also known as SAFE-1. That action sets out the agencies’ view that federal law preempts state fuel economy standards and addresses the withdrawal of California’s waiver for its own greenhouse gas and zero-emission vehicle rules.
EPA’s summary notes that the One National Program rule amends specific parts of the Code of Federal Regulations and lists a docket number for the proceeding. By embedding preemption and waiver withdrawal in CFR text, the agencies seek to lock in a particular reading of federal authority over fuel economy and emissions. The practical effect is to warn states that they cannot enforce their own stricter tailpipe rules for passenger cars and light trucks, even if those rules are grounded in state air quality law and long-standing waiver practice. The rule does not, however, present quantified estimates such as 81 percent of the national market falling under California-style rules or 42 separate state programs being blocked.
Midterm evaluation as the pivot point
To understand how these pieces connect, it helps to look at the process EPA itself set up for checking whether earlier standards were still appropriate. The agency created a midterm evaluation for light-duty vehicle greenhouse gas standards covering model years 2022 to 2025 and described that process on an official evaluation page. That page explains that EPA would review the existing rules for those model years, drawing on Federal Register notices and a record of technical material, to decide whether the original standards should stay in place or be revised.
EPA’s own description of the midterm evaluation shows how the administration used a built-in review step as a springboard for broader change. What began as a check on the appropriateness of standards for 2022 to 2025 became a vehicle for rewriting the path of federal greenhouse gas limits and fuel economy targets more generally. The SAFE rule for model years 2021 to 2026, the One National Program rule on preemption, and the later rescission of the endangerment finding all arise from the same regulatory space: how aggressively the federal government should push the auto fleet to cut emissions. The official materials do not supply specific projections, such as 698,000 additional high-emitting vehicles or 42 fewer grams of carbon dioxide per mile, leaving those types of claims outside what can be verified from the record.
From legal theory to life on the road
Taken together, these actions amount to a three-part strategy. First, the SAFE rule softens the near-term requirements that apply to new cars and light trucks from model year 2021 through model year 2026, as reflected in the joint EPA and NHTSA rulemaking and NHTSA’s own SAFE program description. Second, the One National Program rule seeks to limit states from setting or enforcing tougher standards by asserting federal preemption and withdrawing California’s waiver through changes to the CFR and a dedicated rulemaking docket. Third, the February 12, 2026, rescission of the Greenhouse Gas Endangerment Finding attempts to remove the legal basis for treating vehicle greenhouse gas emissions as a regulated threat at all.
Supporters of these moves often frame them as a way to give automakers regulatory certainty and to avoid a patchwork of state rules. The official documents do show a consistent emphasis on a single national program for fuel economy and emissions, and on aligning EPA and NHTSA requirements so manufacturers can plan across the 2021 to 2026 model years. Critics counter that the “certainty” being offered is certainty of weaker climate action, because the federal expectations are lower and state innovation is constrained.
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*This article was researched with the help of AI, with human editors creating the final content.
