Last mentioned: Mar 19, 2026
23-State Lawsuit Filed
States launch legal challenge against the Trump EPA's rescission efforts.
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.
Endangerment Finding Issued
EPA officially determines GHGs pose a threat to public welfare.
Massachusetts v. EPA
Supreme Court rules EPA has authority to regulate GHGs if they endanger health.
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.
A coalition of 23 states has filed a major lawsuit against the Environmental Protection Agency to prevent the rescission of the 2009 Endangerment Finding. The legal challenge argues that the administration's attempts to decouple greenhouse gas emissions from public health threats violate the Clean Air Act and ignore decades of established climate science.
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.