California SB 253: Climate Corporate Data Accountability Act

California’s Climate Corporate Data Accountability Act (SB 253) requires large companies operating in California to annually disclose their greenhouse gas (GHG) emissions, consistent with the requirements of the GHG Protocol.

This law was passed alongside SB 261: Climate-Related Financial Risk Act, forming part of California’s broader effort to enhance corporate climate transparency and accountability.

California SB 253 summary

Status: In effect

SB 253 applies to all corporations, partnerships, LLCs, and other business entities with annual revenues over $1 billion that do business in California. Starting in 2026, these companies must publicly report their GHG emissions each year, including both direct (scope 1) and indirect emissions (scopes 2 and 3).

Disclosures must be submitted to a digital platform and will be subject to an annual filing fee to fund oversight by the California Air Resources Board (CARB). Companies that fail to comply may face administrative penalties.

California SB 253 requirements

Covered entities must measure and publicly disclose the following:

  • Scope 1 emissions: Direct GHG emissions from owned or controlled sources
  • Scope 2 emissions: Indirect emissions from purchased electricity, steam, heating, and cooling
  • Scope 3 emissions: All other indirect emissions in the value chain, including supplier activities, transportation, product use, and more

Disclosures must:

  • Be submitted to a designated emissions reporting organization
  • Align with the GHG Protocol, the leading global standard for carbon accounting
  • Use both primary and secondary data for scope 3 emissions
  • Undergo third-party assurance:
    • Scopes 1 and 2: Limited assurance starting in 2026; reasonable assurance by 2030
    • Scope 3: Limited assurance required beginning in 2030

Federal and other legal challenges impacting California SB 253

On February 3, 2025, a U.S. federal court dismissed portions of a lawsuit against SB 253 and SB 261. The court found the claims were premature, as the CARB has not yet finalized implementing regulations. However, certain claims may be refiled once the rules are in place. While CARB is statutorily required to adopt final regulations by July 1, 2025, the agency has since indicated that the timeline will likely extend into 2026.

On April 9, 2025, a U.S. federal executive order titled “Protecting American Energy from State Overreach” was signed, directing the U.S. Attorney General to identify and challenge state-level climate laws and policies that may be unconstitutional or preempted by federal law. As a result, the implementation or enforceability of state regulations such as California’s SB 253 may be subject to legal review or change.

How ClimatePartner supports compliance with California SB 253

ClimatePartner helps companies comply with CA SB 253 by leveraging its expertise in carbon accounting, emissions data management, and transparent reporting:

  • Comprehensive carbon accounting across scopes 1, 2, and 3
  • Data management with the Emission Factor Database, a unique, science-based database providing precise emission factors
  • Reporting and transparency with assurance-ready reports