The Endangerment Finding Repeal: What You Need to Know

On February 12, 2026, the United States Environmental Protection Agency (U.S. EPA) signed a rule to finalize the recission of the 2009 Endangerment Finding and greenhouse gas (GHG) vehicle standards. The repeal of the 2009 Endangerment Finding removes the legal basis for regulation of GHG emissions under the Clean Air Act (CAA). This is one of the most significant changes to U.S. EPA air quality regulations in recent years. The final rule was published in the Federal Register on February 18, 2026, and takes effect April 20, 2026.

What is the Endangerment Finding?

In 2009, following the Massachusetts v. U.S. EPA Supreme Court decision made in response to U.S. EPA’s denial of a petition to regulate GHG emissions from new motor vehicles, U.S. EPA issued a formal determination that six greenhouse gases (i.e., carbon dioxide, methane, nitrous oxide, sulfur hexafluoride, hydrofluorocarbons, and perfluorocarbons) endanger public health and welfare. U.S. EPA also determined that emissions from new motor vehicles contributed to GHG pollution that threatened public health and welfare. Once U.S. EPA found that GHG from motor vehicles caused harm, the law required them to regulate those emissions from motor vehicles. The Endangerment Finding was also the basis for regulating other sources of GHG emissions.

Why has U.S. EPA Repealed the Endangerment Finding?

U.S. EPA’s justification for the repeal is primarily legal and procedural, based on their review of the following Supreme Court Decisions:

Utility Air Regulatory Group v. EPA (UARG) (2014): The Supreme Court ruled that U.S. EPA cannot use the CAA to regulate sources solely on their GHG emissions under PSD or Title V permitting. The agency can only regulate GHG emissions if a stationary source is already required to obtain a permit due to other air pollutant emissions.

West Virginia v. U.S. EPA (2022): The Supreme Court ruled that agencies have only those powers given them by Congress and that Congress must clearly authorize agencies to take actions that decide major questions of policy. Congress did not clearly grant U.S. EPA authority to address a global issue, like climate change, through the CAA that was originally designed to regulate local and regional air pollutants.

Loper Bright (2024): With the end of “Chevron deference,” U.S. EPA must follow the “best reading” of the statute. U.S. EPA states that the regulation of GHG emissions under the CAA was an improper expansion of the agency’s authority with the potential for adverse effects on the U.S. economy.

In summary, U.S. EPA argues that the CAA only authorizes the regulation of air pollutants that cause domestic harm and that Congress has not explicitly authorized the agency to adopt regulations that address global climate change. They also note that the complete elimination of GHG emissions from all new and existing motor vehicles in the U.S. would have only de minimis effects on global temperature change and sea level rise.

What happens next?

This repeal, if it stands, will significantly change how GHGs are regulated in the U.S. If Federal regulations are no longer authorized, we are likely to see increased activity in certain states that remain concerned about the impacts of GHG emissions from their sources. We expect the following:

• Lawsuits: Environmental groups and a coalition of states have already indicated that they will challenge this repeal. It will likely be years before we have a final decision.
• Further Clean Air Act GHG regulatory repeals: U.S. EPA already proposed to repeal the following regulations, and we assume these actions will be finalized during 2026:
  • 40 CFR Part 98: Mandatory Greenhouse Gas Reporting (although U.S. EPA’s reasoning for this repeal centered around its Clean Air Act Section 114 information gathering authority, there is no reason to gather this information if they are eliminating Federal GHG standards)
  • 40 CFR Part 60, Subpart TTTT: Standards of Performance for Greenhouse Gas Emissions for Electric Generating Units
  • 40 CFR Part 60, Subpart TTTTa: Standards of Performance for Greenhouse Gas Emissions for Modified Coal-Fired Steam Electric Generating Units and New Construction and Reconstruction Stationary Combustion Turbine Electric Generating Units
  • 40 CFR Part 60, Subpart UUUUb: Emission Guidelines for Greenhouse Gas Emissions for Electric Utility Generating Units
• Reconsideration of the GHG emissions standards for the oil and gas industry at 40 CFR Part 60, Subparts OOOOb/c and the requirements at 40 CFR Part 98, Subpart W.
• State Regulations: Even though Federal GHG regulations are being repealed, they do not currently affect state-level GHG emissions regulations (other than the fact that some states rely on Part 98 as their reporting mechanism). Companies still need to comply with all state-level GHG regulations. Examples currently include California, New York, Oregon, and Washington, and we expect this list to expand absent federal GHG regulations.

We expect GHG regulatory volatility and uncertainty as a result of the Endangerment Finding repeal. We are seeing that some states and the Federal government have conflicting viewpoints when it comes to GHG and climate change regulation. There is some discomfort as the Part 98 regulatory deadline is approaching, U.S. EPA is not clearly signaling their intentions, and state programs have incorporated the Part 98 reporting mechanism into their requirements. To ensure your company remains resilient amid ongoing regulatory uncertainty, it is critical to implement robust GHG data management systems, stay aligned with applicable state-level GHG requirements, and proactively prepare for potential regulatory changes. It’s possible that the Federal GHG regulatory lull is only temporary. ALL4 can support you with strategy, data management, inventory updates, and regulatory compliance. If you have any questions about GHG regulations or how these Federal regulatory actions will affect you, feel free to contact me at lshaffer@all4inc.com or reach out to your ALL4 project manager.