Signed into law as part of California’s landmark Climate Accountability Package, Senate Bill 253 (SB 253)—the Climate Corporate Data Accountability Act—establishes the nation’s first legally binding corporate greenhouse gas disclosure mandate encompassing Scope 1, Scope 2, and full upstream/downstream Scope 3 emissions.

Core Mandate & Timelines

SB 253 applies to all public and private US corporations with annual total revenues exceeding $1 billion that do business in California. Reporting entities must quantify Scope 1 and Scope 2 emissions starting in 2026, with mandatory Scope 3 disclosures phased in by 2027. Disclosures must follow the GHG Protocol Corporate Accounting Standard and obtain independent third-party assurance.

1. Scope of Application: The “Doing Business in California” Test

Unlike federal regulations that apply exclusively to SEC-registered public filers, SB 253 applies equally to privately held enterprises, private equity portfolio companies, and international corporations.

  • Maintaining commercial facilities, distribution warehouses, or corporate offices within California.
  • Employing personnel or independent contractors operating in California.
  • Exceeding California sales thresholds under Cal. Rev. & Tax Code § 23101.
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2. Third-Party Assurance & Attestation Standards

Corporate filings under SB 253 cannot be self-certified. Reporting entities must retain an independent verification provider:

  • Scope 1 & 2 Assurance: Limited assurance required beginning with 2026 filings, stepping up to reasonable assurance by 2030.
  • Scope 3 Assurance: Limited assurance required beginning in 2030, following an initial grace period.
  • California Health and Safety Code § 38532 (enacted via SB 253).
  • California Air Resources Board (CARB): Climate Data Accountability Program Implementation Framework.
  • World Resources Institute (WRI) & WBCSD: The Greenhouse Gas Protocol Corporate Standard.

US REGULATORY COMPLIANCE SUITE:

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Peer-Reviewed Scientific Authority

Dr. Ahmad Mahmood, Ph.D.

Assistant Professor & Environmental Systems Specialist. PhD in Integrated Environmental Systems (University of Yamanashi, Japan), MS in Sustainable Resource Management (Technical University of Munich / TUM, Germany).

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