Clean Air – Page 2 – Environmental and Energy Law Program

Legal Analysis

EPA’s Final Rule Rescinding 2024 MATS Rule and Reinstating 2012 Standards

The legal foundations, regulatory history, and contested cost-benefit rationale behind EPA’s repeal of the 2024 MATS rule.

March 18, 2026

Quick Takes

EPA Rejects Colorado’s Regional Haze Plan Over Disputed Coal Plant Closure

A quick take on the disapproval, including a look at some of the legal arguments raised by commenters.

March 18, 2026

Regulatory Tracker

Ethylene Oxide (EtO) Emissions Standards for Commercial Sterilizers

In March 2026, EPA proposed rolling back many of the 2024 rule’s more stringent emissions limits.

March 17, 2026

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