Supreme Court Upholds California’s Authority to Set Stricter Emissions Standards

The court declined to hear a constitutional challenge from 17 states, preserving California’s EPA waiver for stricter vehicle pollution rules.

The Supreme Court rejected an appeal by Ohio and 16 other Republican-led states challenging California’s unique authority under the Clean Air Act to implement stricter emissions standards.
California’s EPA waiver, first granted in 1967, allows the state to address its severe air pollution issues with rules stricter than federal standards, a policy followed by over a dozen other states.
The decision leaves in place a lower court ruling affirming California’s right to set its own emissions standards, which have significantly reduced pollution over the past decades.
The court will still hear a separate case next year on whether fuel producers have standing to challenge California’s zero-emission vehicle mandates.
California’s clean air rules face potential challenges from the incoming Trump administration, which has stated intentions to revoke the state’s EPA waiver.