SB 253 / SB 261 (CARB)

California climate-reporting laws: what companies should prepare now

Effective California Air Resources Board (CARB)

The California Air Resources Board (CARB) approved the climate-transparency regulation implementing SB 253 (corporate GHG emissions reporting) and SB 261 (climate-related financial risk reporting) on 26 Feb 2026. The first annual Scope 1 and Scope 2 emissions disclosures under SB 253 were due 10 Aug 2026; Scope 3 reporting is expected to begin in 2027. CARB has indicated it will apply enforcement discretion to good-faith initial submissions.

The Scope 1 and Scope 2 reporting obligation under SB 253 is now in effect for the first reporting cycle (deadline 10 Aug 2026, already passed). Scope 3 reporting, SB 261 climate-related financial risk deadlines, and further CARB implementation guidance are still developing — confirm current requirements directly with CARB before concluding an obligation is fully settled for your organization.

Official publication date: 26 Feb 2026
Effective / expected date: 10 Aug 2026; Publication date is CARB's regulation-approval announcement. Effective/reporting date shown is the first-year Scope 1 & 2 disclosure deadline under SB 253 — Scope 3 and SB 261 deadlines differ and are not yet reflected in a single date.
Last reviewed: 31 Aug 2026; OCEANS™ content & research team

What changed?

Who may be affected?

CARB states SB 253 applies to qualifying U.S. entities with more than $1 billion in annual revenue doing business in California; SB 261 applies a lower $500 million revenue threshold for climate-related financial risk reporting. Exact "doing business in California" criteria and covered-entity definitions should be confirmed against CARB's own guidance for your specific structure.

What information may be required?

Revenue and "doing business in California" facts
Legal-entity and organizational-boundary structure
Scope 1 and Scope 2 activity data
Emerging Scope 3 category scope
Calculation methodology and evidence
CARB implementation guidance updates

What should teams do next?

Map potentially covered entities and confirm organizational boundaries
Establish Scope 1 and Scope 2 calculations with supporting evidence
Assess likely-relevant Scope 3 categories ahead of the 2027 timeline
Preserve calculation evidence and methodology documentation
Monitor CARB's further implementation guidance and enforcement approach

What remains uncertain?

Later-year Scope 3 requirements, SB 261 financial-risk reporting specifics, and CARB's ongoing implementation guidance (including enforcement posture) remain subject to change. This summary does not resolve whether SB 253/261 applies to any specific organization.

Value-chain impact

Large reporting companies may request Scope 1, 2, and eventually Scope 3 data from California-connected suppliers as part of their own inventory even if those suppliers are not directly covered by SB 253/261.

Data to prepare, by workflow

Organizational boundary

Legal entities, facilities, and control structure potentially covered by SB 253/261.

Connect Data

Scope 1 and Scope 2 emissions

Fuel, purchased electricity, and other direct/indirect activity data for the first reporting cycle.

Calculate Emissions

Scope 3 emissions (future cycle)

Procurement, travel, logistics, and supplier data ahead of the 2027 Scope 3 timeline.

Scope 3 & Supplier Data

Methodology disclosure

Emission factors, boundaries, and calculation methods used to produce reported figures.

Calculation Methodology

Supporting documentation

Source records, assumptions, and review history behind each calculation.

Verify Evidence

Official sources

California Air Resources Board
California Corporate Greenhouse Gas Reporting and Climate-Related Financial Risk program overview (opens in a new tab)
California Air Resources Board
CARB approves climate transparency regulation for entities doing business in California (opens in a new tab)
Published 26 Feb 2026

General information — not legal, accounting, regulatory, or assurance advice. Confirm applicability with qualified advisers. OCEANS™ Sustainability supports preparation, not a compliance or applicability determination.