The main purpose of this legislative text is to express Congress's disapproval of a specific rule set by the Environmental Protection Agency (EPA). This rule allows California to implement its own stricter greenhouse gas emission standards for new motor vehicles, which are different from federal standards. The resolution aims to block this rule, effectively preventing California from enforcing these standards. The key provisions of this resolution state that Congress officially disapproves of the EPA's decision to grant California a waiver under the Clean Air Act.