How One EPA Finding Reshaped American Energy Policy

For nearly two decades, the EPA’s 2009 Endangerment Finding has served as a legal foundation for federal regulation of greenhouse gas emissions. Its history begins with the Supreme Court’s 2007 decision in Massachusetts v. EPA, continues through the Obama administration’s Endangerment Finding, and extends through the greenhouse gas regulations adopted under subsequent administrations. In February 2026, the Trump EPA rescinded the Endangerment Finding as it applied to motor vehicles and repeal...