California's Mandatory Climate Disclosure Regulations Challenged by New Lawsuit

On October 24, 2025, a significant new lawsuit challenging California's mandatory climate disclosure regulations was filed in federal district court (E.D. Cal.) by ExxonMobil.  Many of the legal arguments advanced by ExxonMobil--e.g., that the climate disclosure regulations violate the First Amendment by compelling speech--were previously made, and rejected, in prior legal challenges to the California laws, including the unsuccessful lawsuit brought by the Chamber of Commerce (where the decision by the district court upholding the climate disclosure regulations is currently being appealed to the Ninth Circuit).  Nonetheless, the arguments advanced here do differ in potentially meaningful ways, including whether ExxonMobil can frame a more potent “as-applied” challenge to the First Amendment concerns.  Still, the primary significance of this lawsuit is that it affords opponents of the mandatory climate disclosure regulations an additional opportunity to potentially block California's climate disclosure laws before they enter into effect in January 2026. 

Nonetheless, the prior legal failures in challenging these mandatory climate disclosure regulations--and the fact that the challenge is being heard by a judge recently appointed by President Biden--do not bode well for the ultimate viability of the legal claims advanced here.  Still, this lawsuit likely represents the final legal avenue available that could potentially block California's mandatory climate disclosure laws before companies are forced to comply in January 2026.