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).

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.

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.

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.

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.

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.”

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).

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.

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.

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.

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.

Authored by Tom Boer, Maia Jorgensen, and Allison Klei.