California Air Resources Board Previews 2027 GHG Reporting Requirements While 2026 Reporting Deadline Remains Delayed Until Q4

On Tuesday, July 21, 2026, the California Air Resources Board (“CARB”) held a public workshop to discuss development of the regulatory framework for its greenhouse gas reporting program under the Climate Corporate Data Accountability Act (“SB 253”). This is CARB’s first workshop since it delayed the reporting deadline for Scope 1 and Scope 2 greenhouse gas emissions from August 10, 2026, to November 10, 2026 (see CARB’s notice here).

Tuesday’s workshop briefly addressed the 2026 delayed deadline before turning its focus to 2027 and beyond. The majority of CARB’s presentation time previewed CARB’s approach to a 2027 rulemaking that is anticipated to finally bring details on SB 253’s reporting and assurance requirements (see CARB’s Presentation here). CARB also shared initial draft regulatory text which will form the basis for a rulemaking package to be published in the fall.

Takeaways

1. CARB continues to target November 10, 2026, as the anticipated deadline for inaugural SB 253 reporting for Scope 1 and Scope 2 greenhouse gas (“GHG”) emissions. However, finalization of CARB’s initial regulation, adopting this deadline, must still be approved by the California Office of Administrative Law (“OAL”).
2. In response to questions about the methodology for completing 2026 reports, CARB pointed to its December 5, 2024, enforcement notice. In that notice (available here), CARB clarified that inaugural reports will only require reporting of Scope 1 and Scope 2 emissions data in a reporting entity’s possession as of December 5, 2024.
3. CARB intends to release additional SB 253 guidance by September 1, 2026, including: (1) a voluntary online intake platform for emissions reporting and fee-related information, and (2) an accompanying guidance and instructional video for using the intake platform.
4. Beginning in 2027 – the second year of mandated reporting – CARB is required by statute to propose regulations that employ the Greenhouse Gas Protocol (“GHG-P”) as the foundation of the SB 253 reporting framework. CARB’s draft regulatory concepts therefore rely heavily on GHG-P requirements and recommendations.
5. Among other topics, CARB previewed initial drafts of proposed 2027 regulatory text addressing (i) general requirements for GHG emissions reporting, (ii) Scope 2 reporting, (iii) Scope 3 reporting, and (iv) assurance requirements. For example, CARB is exploring the phase in of Scope 3 reporting over multiple years, starting with a subset of the fifteen recognized categories of emissions, to minimize regulatory burden and reduce complications with compliance.
6. Stakeholders will have the opportunity to further engage in CARB’s 2027 rulemaking development via weekly “Listening Sessions,” beginning August 5.
7. In Q4 2026, CARB intends to release a formal proposed rulemaking package addressing the 2027 requirements, including a staff report, regulatory text, and an economic analysis.

Requirements for anticipated November 10, 2026, Scope 1 and 2 reporting deadline

On Wednesday, June 24, CARB issued a notice announcing a three-month delay to the inaugural SB 253 reporting deadline for Scope 1 and Scope 2 GHG emissions, citing a need to give reporting entities more time following formal adoption of CARB’s initial regulation and a need to “clarify” certain requirements in the regulation (see our previous article here).

No update on substance of pending clarifications 

During yesterday’s workshop, CARB reiterated the rationale for the delayed inaugural SB 253 reporting deadline: providing additional time and greater clarity. Unfortunately, and to several commenters’ chagrin, CARB provided no further details on what specific clarifications CARB may incorporate into the inaugural reporting rulemaking. In response to several questions, CARB merely referred to its June 24 notice, stated it cannot provide more information, and indicated it will issue a public notice on the amended initial regulation. Regardless of the clarifications CARB ultimately makes, OAL must still approve the regulation.

Forthcoming guidance for inaugural SB 253 reporting

CARB announced that, by September 1, 2026, it intends to publish additional guidance to assist reporting entities with their inaugural Scope 1 and Scope 2 emissions report ahead of the anticipated November 10, 2026, deadline (see July 21, 2025, Presentation, Slide 7). This guidance will include (1) a voluntary online intake platform for fee contact information and GHG emissions reporting, and (2) accompanying guidance and an instructional video. Staff noted that the voluntary online intake form is intended to streamline reporting entity submissions and submission of fee information.

No change to content of 2026 reports

In response to several questions regarding the inaugural 2026 report, staff repeatedly pointed to CARB’s December 5, 2024, enforcement notice, which provides that, “for the first report due in 2026, reporting entities may submit scope 1 and scope 2 emissions from ‘the reporting entity’s prior fiscal year’ that can be determined from information the reporting entity already possesse[d] or [wa]s already collecting at the time th[e] Notice was issued.” Staff also reiterated that CARB’s previously published reporting template is intended solely as a voluntary resource and is not a required submission format.

2027 reporting: CARB previews draft language and framework 

CARB devoted most of the workshop to previewing the regulatory concepts that staff is developing for anticipated publication as part of a rulemaking package in Q4 2026.

Emphasis on leveraging existing standards and interoperability

SB 253 requires reporting entities to disclose GHG emissions information in conformance with the GHG-P. To minimize the burden on reporting entities, CARB emphasized its intention to leverage existing GHG accounting standards rather than create a California-specific framework.

Staff noted that many stakeholders have requested interoperability with other climate disclosure programs and stated that CARB intends to align its reporting requirements with established reporting practices where possible. To that end, CARB stated that it “does not want to reinvent the wheel with this program and would like to leverage the experience that many reporting entities already have with voluntary or mandatory climate disclosures.”

Proposed regulatory framework for 2027 rulemaking

CARB broadly categorized the regulatory concepts being evaluated for its rulemaking into three buckets: (1) GHG-P requirements, (2) GHG-P recommendations, and (3) California-specific clarifications intended to address issues unique to California’s regulatory context. See CARB’s Presentation at Slides 8 to 40 for a complete breakdown of proposed requirements.

In most cases, CARB proposes language that will implement the required reporting approach prescribed by the GHG-P but, in some cases, proposed language implements GHG-P recommendations (e.g., measurement uncertainty reporting) or is intended to provide clarity for the California regulatory context (e.g., defining key terms with reference to applicable California regulations).

Proposed general requirements for GHG reporting 

CARB reviewed a series of proposed greenhouse gas reporting requirements it intends to address, including:

• Generation of baseline GHG disclosures,
• Proposed emissions quantification methodologies,
• How reporting entities may assess emissions quantification measurement uncertainty,
• Procedures for the identification of missing data and data substitution,
• A proposed disclosure requirement regarding changes to GHG emission quantification or accounting methods, and
• A proposed recalculation of prior year data triggered where a reporting entity experiences a change greater than 5 percent of its total GHG emissions, year over year, due to modifications of its corporate structure or emissions accounting methodologies.

For additional details on CARB’s proposed general requirements, see Slides 11-24 of CARB’s July 21, 2026, Presentation.

Proposed Scope 2 and Scope 3 emissions reporting requirements 

CARB also ran through proposed emissions reporting requirements for Scope 2 and Scope 3 GHG emissions (see July 21, 2025, Presentation, Slides 25-34).

With respect to Scope 2 emissions, CARB is proposing to implement GHG-P requirements verbatim. As for Scope 3 emissions, CARB is proposing a category phase-in. If adopted, this approach would mean that reporting entities would be required to provide data for the five most commonly reported categories of Scope 3 emissions beginning in 2027: (1) purchased goods and services, (2) fuel and energy-related activities, (3) waste generated during operations, (4) business travel, and (5) employee commuting. Staff noted that these categories have some of the most established data sources and quantification methods. In the inaugural year of Scope 3 reporting – 2027 – disclosing data on the remaining (ten) categories would be voluntary. Presumably these remaining Scope 3 categories would be affirmatively phased in for mandatory reporting in future years.

Exemptions

CARB’s initial regulation exempted insurance companies from 2026 reporting in an effort to avoid duplication with reporting required by the California Department of Insurance (“CDI”). Beginning in 2027, CARB is proposing that insurance companies are no longer exempt; rather, insurance companies will need to submit the same report to satisfy both CDI and SB 253. Furthermore, CARB is proposing if a CDI report does not address all of CARB’s requirements, then insurance companies must supplement the CDI report.

Looking forward

CARB has a busy regulatory agenda as we head towards the fourth quarter of 2026:

• By September 1, CARB has committed to issuing additional guidance for SB 253 reporting.
• CARB must issue a revised Initial Regulation for a 15-day public comment period, with its as yet unspecified clarifications, followed by transmission to OAL for review and approval. Finalization of these revised regulations is expected to formally impose the inaugural November 10, 2026, reporting deadline for Scope 1 and Scope 2 emissions.
• CARB is moving forward with the development of its next phase of rulemaking, with the intent of publishing proposed regulations (including a staff report and economic analysis) in Q4.
• CARB will be hosting weekly Listening Sessions to hear from reporting entities and other stakeholders about its forthcoming regulations. These Listening Sessions are expected to target different types of reporting entities, with the first one tentatively scheduled on August 5, 2026, for data users and public interest stakeholders.

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 complying with California’s climate-related financial risk and GHG emissions disclosure requirements and can help you understand interactions with other relevant sustainability-related reporting regimes required globally.