California’s landmark climate disclosure laws are under legal siege, and the outcomes will shape corporate reporting for thousands of companies. The SB 253 and SB 261 lawsuit, filed by the U.S. Chamber of Commerce and allied business groups, challenges both laws on First Amendment grounds. Here’s what makes this complicated: one law survived the legal challenge so far, while the other didn’t.

SB 253, which requires greenhouse gas emissions reporting, is proceeding toward its August 10, 2026 deadline (CARB, 2026). SB 261, which mandates climate risk disclosures, has been enjoined by the Ninth Circuit since November 2025 (Jones Day, 2025). ~4,160 entities sit on CARB’s preliminary list across both SB 253 and SB 261 (Harvard Law School Forum on Corporate Governance, 2025). If you’re one of them, the status of this litigation directly affects your next twelve months of compliance planning.

Source: CARB (2026), Jones Day (2025), Harvard Law School Forum (2025)

What Is the Current Status of the SB 253 and SB 261 Lawsuit?

As of April 2026, SB 253 is proceeding toward enforcement while SB 261 remains frozen. CARB adopted final SB 253 regulations on February 26, 2026 (National Law Review, 2026), confirming the first reporting deadline of August 10, 2026 for ~4,160 entities on CARB’s preliminary list across both SB 253 and SB 261 (Harvard Law Forum, 2025). The litigation hasn’t slowed the regulatory machinery.

Both cases had oral argument before the Ninth Circuit on January 9, 2026 (Akin Gump, 2026). No final ruling has been issued. The critical difference is that SB 261 was enjoined by the Ninth Circuit in November 2025, suspending its reporting requirements. SB 253 was not enjoined. That distinction matters enormously for compliance planning.

What about the federal angle? The SEC abandoned its defense of its own climate disclosure rule on March 27, 2025 (SEC.gov, 2025). That retreat left California’s laws as the primary climate disclosure mandates in the U.S., and other states are now introducing copycat legislation. It also means there’s no federal backstop if California’s laws get struck down. For context on how SB 253 fits within the broader global framework landscape including CSRD and IFRS standards, see our full comparison.

Who Filed the SB 253 and SB 261 Lawsuit?

The U.S. Chamber of Commerce, along with allied business associations, filed the challenge against both bills shortly after Governor Newsom signed them into law. The lawsuit names the California Air Resources Board as a defendant, with penalties of up to $500,000 per year for SB 253 non-compliance (California Legislature, 2023) providing the financial stakes.

The challengers’ core argument is constitutional, not procedural. They claim that forcing companies to report emissions data, particularly Scope 3 estimates, amounts to compelled speech under the First Amendment. This isn’t a technical dispute about data quality. It’s a fundamental challenge to whether the government can mandate these disclosures at all.

The choice of legal strategy is telling. By framing this as a First Amendment case rather than a Commerce Clause or preemption challenge, the plaintiffs elevated the stakes. A ruling on compelled speech could affect climate disclosure mandates far beyond California, including future federal rules.

What Are the Legal Arguments in the California Climate Disclosure Lawsuit?

The case centers on the First Amendment’s compelled speech doctrine. The challengers argue that SB 253 and SB 261 force companies to make statements about their climate impact that go beyond factual commercial disclosures. The pivotal legal test is Zauderer v. Office of Disciplinary Counsel, which permits compelled commercial speech only when it’s “purely factual and uncontroversial.”

Based on court filings: Chamber of Commerce v. CARB, Ninth Circuit (2024–2026)

The challengers’ arguments

Business groups contend that emissions reporting, especially Scope 3, isn’t “purely factual.” Scope 3 data relies on estimates, assumptions, and modeling across entire value chains. They argue this makes it inherently speculative, not a verifiable fact the government can compel. The SB 261 climate risk reporting, they say, is even more subjective because it requires forward-looking risk assessments.

The defenders’ arguments

California and environmental groups counter that emissions data is factual commercial information, calculated using established GHG Protocol methodology. They argue the government has a substantial interest in climate transparency and that the Zauderer test supports compelled disclosures in the commercial context. Standard industry methodologies, they contend, make this no different from requiring financial statements.

The legal distinction between SB 253 and SB 261 reveals how courts treat different types of climate data. Emissions quantities are closer to financial numbers. Climate risk assessments are closer to opinion. This distinction will likely define the boundary of mandatory climate disclosure for years.

SB 253 Litigation Timeline: Where Does It Stand?

SB 253’s litigation journey has been more favorable for the law than many expected. The district court denied the preliminary injunction, a critical early win for California, and the Ninth Circuit has not overturned that decision. With CARB regulations adopted on February 26, 2026 (National Law Review, 2026), enforcement is proceeding on schedule.

The key takeaway? SB 253 has not been blocked at any stage. Businesses on CARB’s list of ~4,160 entities should not assume the lawsuit will provide relief before the August 2026 deadline.

SB 261 Litigation Timeline: Why Is It Suspended?

SB 261 took a very different path through the courts. The Ninth Circuit granted a preliminary injunction in November 2025 (Jones Day, 2025), suspending the law’s climate risk reporting requirements. That’s a significant win for the challengers and a signal that the court sees merit in the First Amendment argument, at least as it applies to SB 261.

The injunction means no company is currently required to comply with SB 261. But the law isn’t dead. A full trial is set for October 2026. If SB 261 survives trial and subsequent appeals, reporting obligations could snap back into effect. Companies that assumed the law was finished could find themselves scrambling.

Why does this timeline matter? Because the gap between the October 2026 trial and a potential compliance restart could be narrow. Building TCFD-aligned climate risk capabilities takes months, not weeks.

Why Did SB 261 Get Enjoined But Not SB 253?

This is the most important legal distinction in the entire case. Courts treat factual data differently from subjective analysis under the First Amendment. SB 253 requires quantitative emissions data using GHG Protocol methodology, information the court views as closer to verifiable commercial fact. SB 261 requires forward-looking climate risk assessments, which involve judgment, assumptions, and speculation.

Think of it this way: requiring a company to report “we emitted 50,000 metric tons of CO2” is closer to requiring a nutrition label on food. Requiring a company to report “we believe climate change poses a material risk to our coastal supply chain over the next 20 years” is closer to compelling an opinion. Courts are far more comfortable with the former.

What Does This Mean for Your Compliance Strategy?

The split between SB 253 and SB 261 demands a split compliance strategy. For SB 253, there’s no ambiguity: proceed with full compliance. CARB adopted regulations on February 26, 2026 (National Law Review, 2026), and the August 10, 2026 deadline is firm. Penalties can reach $500,000 per year (California Legislature, 2023).

SB 253: Full speed ahead

If your company is on CARB’s list of ~4,160 entities, you should already be collecting Scope 1, 2, and 3 emissions data. Our comparison of 8 SB 253 reporting solutions can help you choose the right platform. The court didn’t block this law, and CARB isn’t waiting for the court to decide before enforcing it. Hoping the lawsuit will save you from the deadline is not a compliance strategy.

SB 261: Prepare, don’t panic

SB 261 is paused, so there’s no immediate reporting obligation. But don’t stop building your climate risk assessment capabilities. The October 2026 trial could go either way. If SB 261 survives and the injunction is lifted, you’ll want TCFD-aligned data ready. Besides, the EU’s CSRD and ISSB standards require similar disclosures. The work isn’t wasted.

We’ve found that companies treating the SB 261 injunction as a permanent reprieve are making a mistake. The smarter approach is to use this window to build climate risk assessment processes at a manageable pace rather than rushing under a deadline later.

What Are the Possible Outcomes of the SB 253 SB 261 Litigation?

Four main scenarios could unfold from the Ninth Circuit’s pending decision. Each carries different compliance implications. The oral arguments on January 9, 2026 (Akin Gump, 2026) gave some signals about the court’s thinking, but predicting appellate outcomes is always uncertain.

Assessment based on Ninth Circuit oral arguments (Jan 9, 2026) and current injunction status

What should you plan for? Scenario 1 is the most likely near-term outcome based on the current trajectory. But smart compliance teams plan for Scenario 2 as well, especially since TCFD-aligned data is increasingly required by other frameworks.

Building Compliance Readiness for Both Scenarios

Regardless of how the courts rule, companies need infrastructure for GHG reporting now and climate risk assessment capability in reserve. Credibl ESG’s platform supports both: automated Scope 1, 2, and 3 data collection aligned with GHG Protocol methodology for SB 253, and TCFD-aligned climate risk reporting frameworks for SB 261.

The platform maps your data to multiple frameworks simultaneously. That means work done for SB 253 compliance also feeds into CSRD, ISSB, and SEC readiness. If SB 261’s injunction is lifted after the October 2026 trial, the climate risk module activates without starting from scratch. One data pipeline, multiple regulatory outputs.

Conclusion: Don’t Let the Lawsuit Become an Excuse

The SB 253 and SB 261 lawsuit is creating uncertainty, but it shouldn’t create paralysis. SB 253 is active, CARB’s regulations are adopted, and the August 10, 2026 deadline is real. SB 261 is paused, but October 2026 could change everything. The companies that come out ahead will be those that prepared for compliance while their competitors waited for a court ruling that may never come.

The broader trend is unmistakable. Climate disclosure is moving from voluntary to mandatory across multiple jurisdictions. Whether it’s California’s SB 253, the EU’s CSRD, or ISSB standards, the reporting infrastructure you build now will serve you for years. Don’t wait for legal certainty to start building.