This joint resolution seeks to overturn an Environmental Protection Agency rule that granted California a waiver to set its own greenhouse gas emission standards for cars starting with the 2009 model year. Under the Clean Air Act, states typically cannot set pollution standards stricter than federal rules, but the EPA can grant California a waiver to establish its own standards that other states can then choose to follow. This resolution would eliminate that waiver and prevent California from enforcing its own vehicle emission requirements. If passed by both chambers of Congress and signed by the President, the rule would have no legal effect. The resolution targets a rule that has been in effect since 2009 and affects California's ability to regulate new motor vehicle emissions independently from federal standards.