Environmental Defense Fund

Rule Changes

Co-plaintiff in multiple lawsuits challenging revocation

For seventeen years, the Environmental Protection Agency's 2009 endangerment finding—the determination that carbon dioxide and five other greenhouse gases threaten public health—served as the legal foundation for virtually all federal climate regulation. On February 13, 2026, EPA Administrator Lee Zeldin officially revoked it, eliminating the basis for vehicle emissions standards, power plant rules, and regulations on oil and gas facilities in what the administration called 'the largest deregulatory action in American history.'

Updated Feb 21