Ninth Circuit Will Not Enjoin California Climate Disclosure Regulations Before They Enter Into Force

On October 29, 2025, the Ninth Circuit scheduled oral argument on the Chamber of Commerce's appeal of the district court decision denying the sought injunction to block California's mandatory climate disclosure laws--and the oral argument was scheduled for January 9, after the laws enter into effect on January 1, 2026.  In other words, companies will be compelled to comply with at least one of the mandatory climate disclosure regulations--that companies with more than $500 million in revenue disclose climate-related financial risks and measures taken to address them--before the Chamber of Commerce's appeal is even heard by the Ninth Circuit, let alone decided.  (The mandatory disclosures of Scope 1 and Scope 2 greenhouse gas emissions by companies with more than $1 billion in revenue will likely not be required before mid-2026.)

Although a new legal challenge to the mandatory climate disclosure laws was recently filed, and it remains possible that this new lawsuit could block the regulation from entering into effect, it is more than likely that California's mandatory climate disclosures will be operational and enforceable before another court has the opportunity to evaluate their validity.  (And, to be clear, these mandatory climate disclosure regulations have already survived multiple rounds of judicial scrutiny, so it is not probable that any of the new legal theories advanced or previously-rejected arguments will fare any better before a new judge.)

So, companies should be prepared to comply with California's mandatory climate disclosure regulation.  The Ninth Circuit will not act in time--irrespective of whether it ultimately upholds the laws--to relieve impacted companies of their regulatory obligations.