Exxon is suing California to block the state's climate disclosure requirements for corporations, a battle that could determine whether states can mandate transparency on companies' greenhouse gas emissions and climate risks. If Exxon wins, it could block similar state-level disclosure rules nationwide; if California prevails, it may set a template other states follow. The litigation centers on whether California can enforce reporting requirements that investors and regulators increasingly demand, even as federal climate policy remains contested under the Trump administration.