U.S. President Donald Trump is set to repeal a key Obama-era regulation underpinning federal climate policies, WSJ reports, citing administration officials. The move targets the Environmental Protection Agency’s 2009 endangerment finding, which established that greenhouse gases endanger public health, forming the legal basis for Clean Air Act vehicle emissions rules. EPA Administrator Lee Zeldin called the repeal “the largest act of deregulation in U.S. history,” eliminating requirements for industries to measure, report, and comply with federal emissions standards for motor vehicles. The rollback excludes power plant regulations but could pave the way for broader regulatory changes, the report notes.