Clean Air – Page 2 – Environmental and Energy Law Program

Regulatory Tracker

Implementation of 2015 Ozone National Ambient Air Quality Standards (NAAQS)

Under the Trump executive order Regulatory Freeze Pending Review, the Biden administration’s final rule setting deadlines for states to submit SIPs for nonattainment areas did not go into effect. On June 3, 2025, EPA announced its plans to reconsider the rule.

March 9, 2026

Regulatory Tracker

National Ambient Air Quality Standards (NAAQS) for Ozone

On March 12, 2025, EPA announced a reconsideration of the NAAQS.

March 9, 2026

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‘The Clean Air Act is the bedrock of U.S. climate regulation, but it cannot do the job alone.’

Jody Freeman in Yale Environment 360: Now is the time to develop climate strategies that can be pursued when the political balance shifts.

March 3, 2026

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Podcast: Unpacking EPA’s Decision to Rescind the Endangerment Finding

Jody Freeman on the history of the Endangerment Finding, EPA’s rescission, and what could happen if it reaches the Supreme Court.

March 2, 2026

Legal Analysis

Eliminating the Foundation: Vulnerabilities in and Implications of EPA’s Endangerment Finding Rescission

Analysis breaking down EPA’s arguments in the final rule and what it could mean for regulating GHG emissions in the future.

March 2, 2026

Regulatory Tracker

Regulating Greenhouse Gases for New and Existing Fossil Fuel-Fired Power Plants

In June 2025 EPA proposed a rule rolling back the 2024 EPA standards for GHG emissions from existing coal-fired power plants and new gas-fired power plants.

February 27, 2026

Regulatory Tracker

EPA VOC and Methane Standards for Oil and Gas Facilities

The Biden EPA finalized three rules regulating methane emissions from the oil and gas sector. One of the rules, the Waste Emission Charge, was repealed using the Congressional Review Act. In Sept. 2025, EPA proposed to delay the GHG reporting rules until 2034. In Nov. 2025, EPA finalized the deadline exemptions for certain provisions regulating methane emissions from new and existing oil and gas sources.

February 24, 2026

Legal Analysis

Climate Brief: The Legal Reasoning Behind the Endangerment Rescission

How the Trump Administration justified eliminating the bedrock finding for federal greenhouse-gas regulation, and what comes next.

February 17, 2026

Regulatory Tracker

Once In Always In Guidance for Major Sources under the Clean Air Act

Congress repealed the 2024 rule using the Congressional Review Act and EPA reinstated the 2020 rule, which allows a major source to reclassify as an area source if the source reduces HAP emissions.

February 11, 2026