Overview

• The EPA has formally initiated rulemaking to revoke its 2009 Endangerment Finding that underpins federal greenhouse gas regulations.
• The proposal launches a 45-day public comment period before the agency finalizes rollbacks on vehicle emission standards and power plant limits.
• EPA chief Lee Zeldin asserts the original finding relied on “intellectual shortcuts” despite broad scientific agreement on climate risks.
• Environmental groups pledge swift legal challenges, forecasting a battle that could reach the Supreme Court and upend its 2007 Massachusetts v. EPA precedent.
• Critics warn the reversal undercuts efforts to rein in emissions from the country’s largest source—transportation—during record heat waves and after withdrawal from the Paris Agreement.