On March 23, 2026, the California Air Resources Board (CARB) held a public workshop initiating the next phase of rulemaking under SB 253, California’s Climate Corporate Data Accountability Act. CARB presented preliminary, pre‑rulemaking concepts that would govern greenhouse gas (GHG) emissions reporting beginning in 2027. Because the first reporting year would cover 2026 emissions, potentially regulated entities should consider evaluating these concepts now and may wish to submit comments to CARB’s rulemaking docket before April 13, 2026.
CARB emphasized that its February rulemaking, which we discussed in a March GT Alert, requires regulated entities to submit an initial, first-year-only report covering Scope 1 and Scope 2 emissions no later than Aug. 10, 2026. CARB’s next rulemaking, initiated March 23, is intended to impact emission reporting starting in 2027, with limited assurance required for Scope 1 and Scope 2 disclosures. CARB noted that it expects these disclosures to transition to a reasonable assurance standard by 2030, aligning with the level of assurance commonly applied in financial statement audits.
During the workshop, CARB shared that it is actively considering several regulatory concepts, including (i) how organizational boundaries should be defined; (ii) how emissions scopes should be delineated based on those boundaries; (iii) acceptable calculation methodologies; and (iv) proposed assurance standards.
CARB discussed two alternative frameworks for establishing organizational boundaries — the equity share approach and the control approach — noting that the choice between the two may materially affect emissions classification and assurance obligations. The equity share approach accounts for emissions in proportion to a company’s ownership interest, while the control approach allocates operational emissions to the company in control of those operations without regard to ownership interest. For example, emissions from operating leases may be characterized as Scope 3 under an equity share approach but may instead constitute Scope 1 or Scope 2 emissions under a control approach, potentially triggering third‑party assurance requirements.
CARB seeks feedback on these and several other concepts outlined during the workshop and, although CARB’s concepts remain preliminary, the workshop underscored the importance of early planning. Potentially covered entities should consider assessing organizational boundary options, evaluating Scope 3 data availability, and identifying assurance readiness gaps as CARB moves toward formal rulemaking.