CalCPA, in partnership with the AICPA, continues to play a leading role in shaping California’s climate disclosure regulations—an area of growing importance for the profession, markets, and the public.
Following CARB’s March 2026 public workshop, CalCPA and AICPA submitted joint comments providing technical input on the next phase of implementation under California’s climate disclosure laws. This marks the latest step in an ongoing series of engagement with state regulators as the policy continues to take shape.
Moving Into Assurance
This most recent workshop was notable as the first meaningful discussion of the assurance framework that will underpin greenhouse gas (GHG) disclosures. Assurance is critical to the success of the policy—providing investors, regulators, and the public with confidence that reported emissions data is credible and decision-useful.
CARB identified AICPA standards as one of the proposed acceptable frameworks for assurance, and CalCPA and AICPA strongly supported their inclusion. As the standard setter for audit and attestation engagements in the U.S., AICPA standards bring a recognized level of rigor, independence, and professional oversight that markets rely on.
Ensuring Consistency and Confidence
A central theme of the joint comments is the importance of consistent, high-quality assurance across all providers. While CPAs operate under well-established frameworks for independence, ethics, and quality control, not all assurance providers are held to the same standards.
To address this, CalCPA and AICPA recommended that CARB:
Establish minimum requirements for all assurance providers, including independence, competency, and quality management
Require engagements to be performed in accordance with recognized standards, not just referenced
Consider appropriate oversight and monitoring mechanisms to ensure consistency in practice
These recommendations are designed to protect the integrity of the system and ensure that all users of GHG disclosures can rely on the results, regardless of who performs the assurance.
Aligning Reporting and Assurance
The comments also emphasized the importance of aligning California’s requirements with the Greenhouse Gas Protocol, the global baseline for emissions reporting. Maintaining consistency across accounting methodologies, reporting requirements, and assurance is key to:
Avoiding fragmentation and duplicative reporting
Reducing compliance costs for companies
Supporting comparability across jurisdictions
CalCPA and AICPA encouraged CARB to fully incorporate GHG Protocol guidance and ensure that both quantitative and qualitative disclosures are included within the scope of assurance.
Supporting a Global Framework
As companies navigate an increasingly complex global reporting landscape, the comments also highlight the importance of interoperability. CalCPA and AICPA recommended that CARB allow companies to leverage reporting and assurance prepared under other major frameworks, such as international sustainability standards, where appropriate.
Ongoing Engagement
These comments reflect CalCPA and AICPA’s continued leadership and engagement with California regulators on an issue that extends well beyond the state’s borders. California’s climate disclosure framework is being closely watched at both the national and international levels and is likely to influence how other jurisdictions approach reporting and assurance.
As a result, the policies being developed—and the standards that underpin them—have broader implications for the accounting profession, global markets, and the consistency of sustainability reporting worldwide. CalCPA and AICPA will continue to engage to help shape a framework that is practical, aligned with global standards, and grounded in strong professional requirements, while keeping members informed as these developments evolve.
