CARB further delays rulemaking to implement greenhouse gas emission reporting pursuant to SB 253

Regulatory timeline

SB 253 – as amended by SB 219 – mandates that public disclosure of a reporting entity’s scope 1 and 2 emissions shall be made starting in 2026 “on or by a date to be determined by the state board.” When SB 253 was signed by Governor Newsom in 2023, the statute directed CARB to adopt implementing regulations by January 1, 2025. Recognizing the complexity of this endeavor, in late June of 2024 the Governor proposed legislation that would have delayed the deadline for CARB rulemaking to implement SB 253 by two years (until January 1, 2027). The legislature failed to vote on the Governor’s proposal before the end of the 2024 legislative session and, in adopting SB 219 on September 27, 2024, only provided CARB six additional months – through July 1, 2025 – to adopt implementing regulations. CARB failed to meet this deadline and, until last week, had repeatedly assured the regulated community that it intended to finalize the implementing regulations by December 2025. Now CARB has signaled that the December deadline will not be met either.

Last week, CARB notified the public that it is now aiming to finalize implementing regulations during the first quarter of 2026.  The effort is a complex process because of the breadth of SB 253’s applicability and limited direction in the statute itself; in addition to specifying a 2026 reporting deadline, the regulations are expected to address a host of other critical issues, including defining what it means to “do business in California” and providing instructions for calculation of Scope 1, 2, and 3 emissions.  CARB has cited the large volume of public input Staff has already received as driving the delay. 

Because SB 253 is not self-executing, this further delay will likely impact the deadline for reporting entities to file their first Scope 1 and 2 emission reports. As of its August 21, 2025, public workshop CARB was contemplating a June 30, 2026, implementation deadline for SB 253 Scope 1 and Scope 2 reporting. That timing may be infeasible if regulations are not finalized until the Spring of 2026.

Draft scope 1 and scope 2 emissions reporting template

On October 10, 2025, CARB published its Draft Template and an accompanying guidance memorandum.  The Template is intended to streamline reporting, particularly for entities disclosing greenhouse gas emissions for the first time.  These materials are available for download from CARB’s website, here.  Key points from the memorandum include the following:

• Template Use: Significantly, use of the Draft Template is voluntary for the 2026 reporting cycle. CARB clarifies that the Template is not intended to supersede or modify the statute or impose new requirements and notes that it will “provide guidance on later reporting cycles as part of its regulatory process.”

• Template Structure and Key Metrics: The Draft Template is organized into the following eight sections: (1) Organization Information, (2) Third-Party Verification, (3) Inventory Boundary, (4) Scope 1 and Scope 2 Disclosure, (5) Methodology, (6) De Minimis / Minor Source, and, if applicable, (7) California Mandatory Reporting Regulation (MRR) Fields and (8) Emission Reductions.
• Other Data Fields: The Draft Template also includes optional fields, such as base year emissions, and “decision-useful” fields intended to facilitate “intraorganizational comparison,” align reported data with other CARB regulatory databases, and provide more transparency to investors and other stakeholders.

CARB is seeking public comments on the Draft Template via its public docket until October 27, 2025.  CARB has specifically requested input on the following key elements that could impact how corporate emissions data is structured and compared:

1. Disclosure by Source vs. by Gas: The Draft Template proposes disclosure of Scope 1 and Scope 2 emissions primarily by emission source (e.g., electricity, fuel use, refrigerants), while providing optional fields for disclosure by specific emission type (e.g., carbon dioxide, methane, etc.), where data is available.
2. Organizational Boundaries: The Draft Template asks reporting entities to specify whether they define organizational boundaries using the equity share, financial control, or operational control approach, consistent with Greenhouse Gas Protocol guidance. CARB is evaluating whether to select a single approach to defining organizational boundaries or retain the current, more flexible, approach.
3. Emissions Reduction Initiatives: CARB is seeking public input on a proposed field for emissions reductions associated with direct contracts for renewable electricity and renewable gas, as well as input on other types of reduction targets or initiatives that could be included in the Scope 1 and 2 reporting template.

Key takeaways:

• CARB will not finalize its implementing regulations for SB 253 until Q1 2026. Given the further delay in developing regulations, there is considerable uncertainty about the deadline by which reporting of Scope 1 and 2 emissions will be required in 2026.
• Given the shift in the final rulemaking timeline, reporting entities have an additional opportunity to refine internal data collection processes and provide strategic input on the Draft Template and its related guidance.
• The public comment period for feedback on the Draft Template and associated guidance memo closes on October 27, 2025.
• CARB previously made available a preliminary list of potentially covered entities under SB 253 and the California Climate Related Financial Risk Act (SB 261)—see our article, here. That list is not legally determinative. Entities should continue to independently assess their disclosure and reporting obligations, particularly once CARB promulgates implementing regulations for SB 253.

The broad range of expertise at Hogan Lovells US LLP – including the Environment and Natural Resources, Litigation/Consumer Products, Sustainable Finance and Investment, Corporate and Finance, and Infrastructure, Energy, Resources and Projects teams – are available to assist clients with submitting feedback to CARB during its rulemaking process and complying with GHG emissions disclosures pursuant to SB 253, and can help you understand interactions with other relevant sustainability-related reporting regimes required globally.

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This note is intended to be a general guide to the latest climate transition developments. It does not constitute legal advice.

Authored by Tom Boer and Maia Jorgensen.