This action strips the federal government of its primary existing legal mandate to directly regulate greenhouse-gas emissions unless Congress passes new authorizing legislation. Rules that relied on the endangerment finding (including power-sector emissions standards) face higher legal vulnerability and a likely enforcement/implementation reset. For emitters, the compliance center of gravity shifts toward state-level regimes and sector-specific permitting rather than a unified federal GHG framework, changing planning assumptions for multi-state operations and long-lived capital projects.