Last mentioned: Mar 19, 2026
States File Lawsuit
A coalition of states sues to block the repeal, alleging it violates the Clean Air Act.
Repeal Announced
The Trump EPA formally moves to repeal the 2009 finding, citing a need for deregulation.
Public Outcry
Massive influx of public letters and editorials published in regional news outlets across the U.S.
RMP Revisions
EPA proposes rolling back Risk Management Program safety standards for industrial facilities.
Social Cost Revision
New guidelines set the economic value of human life and carbon mitigation to zero in cost-benefit models.
Endangerment Repeal
EPA formally rescinds the 2009 finding that GHGs threaten public health.
Endangerment Finding Issued
EPA officially determines that six greenhouse gases threaten the health of current and future generations.
Massachusetts v. EPA
Supreme Court rules EPA has authority to regulate GHGs if they are found to endanger public health.
A coalition of U.S. states has filed a major lawsuit against the Environmental Protection Agency (EPA) following its decision to repeal the 2009 Endangerment Finding. The legal challenge seeks to preserve the scientific determination that greenhouse gases threaten public health, which serves as the mandatory legal trigger for federal climate regulations.
The Environmental Protection Agency's recent repeal of the 2009 Greenhouse Gas Endangerment Finding has sparked widespread public outcry and a wave of litigation. This move effectively dismantles the legal foundation for federal climate regulation, signaling a radical shift in U.S. environmental policy.
This page surfaces every story mentioning Clean Air Act across our climate coverage. We track each entity's appearance over time so readers can trace how the narrative evolves — which developments are isolated incidents, which build into longer arcs, and which reframe how operators in the space think about the entity. Story selection uses the same multi-source verification gate applied across the rest of our coverage.
Read our editorial methodology for how we identify, deduplicate, and score entity references. Our glossary defines the technical terms used across stories on this page, and our trends index contextualizes individual developments against the longer-running climate beat. Cross-entity comparisons live on our compare view.
| What you see | What it tells you |
|---|---|
| Story count | Number of distinct stories where Clean Air Act was a primary or referenced actor. |
| Recency clustering | Whether mentions are concentrated in a recent window (a news cycle) or distributed (a sustained arc). |
| Sentiment distribution | Aggregate sentiment of the stories mentioning this entity, weighted by impact score. |
| Cross-niche links | When the same entity surfaces in our sibling networks, we link to those views to enrich context. |