California Air Resources Board

Public Comment on SB 253/261 Implementation
Submitted by: Conor Merrigan, Senior Principal, Sustainability at Spirit: A Montrose Environmental Company

Dear CARB Staff,
Spirit/Montrose appreciates the opportunity to comment on the Climate Accountability Package implementation. As a leading verification and assurance provider, we offer two key recommendations surrounding the assurance provisions:

1. Allow Verifiers to Participate Based on Experience and Standards Alignment and
2. Stagger Reporting Deadlines for Enhanced Program Success

Details follow:

We recommend CARB initially allow any assurance provider that has completed a demonstrable number of publicly available assurance engagements and has claimed alignment with one of the referenced standards to participate. This approach recognizes that technical competence and practical experience are paramount, while allowing firms following newer standards or standards without dedicated accreditation programs to contribute their expertise.

Among the standards referenced in slide 43, I’d like to note a few important distinctions and the general relationships amongst them:

Standards with formal accreditation: ISO 14065 provides specific accreditation for GHG validation/verification bodies and works in tandem with ISO 14064-3 for technical requirements. AICPA attestation standards offer established credentialing for CPAs.

Standard with licensed providers: AA1000AS v3 operates through AccountAbility-licensed providers with mandatory Certified Sustainability Assurance Practitioner (CSAP) qualifications, focusing on stakeholder-inclusive sustainability assurance.

Standard with required elements: ISSA 5000, effective December 2026, is an emergent standard for sustainability assurance, incorporating and eventually replacing ISAE 3410 for GHG assurance. This framework-neutral standard is designed for both accountant and non-accountant practitioners. While there is no formal accreditation, practitioners need to be at a firm that meets certain quality and ethics requirements, which may be harder for non accountants

CARB could also request that the companies demonstrate their qualifications and qualify (and re-qualify) them on an annual basis using either an outside accreditation/ licensure/ demonstration of required elements as noted above or some other evidence of having the appropriate systems in place for the fundamental components of assurance.

All of these standards, as well as other potentially applicable standards not identified here, tend to rely on a core set of practices and principles. These include verifying according to the key principles of the GHG protocol (relevance, completeness, consistency, transparency and accuracy) as well as adhering to assurance principles such as independence, impartiality, establishment of materiality, risk assessment, review of controls, internal quality controls, etc. that may vary slightly by standard but generally can be found to some degree in all of the standards.

They also reference each other on occasion and can be thought of as coming from a similar conceptual home of generally applying a similar level of rigor to environmental data that has been applied to financial data. There have been evolutions and changes, and the concept of limited assurance is not recognized in all of these standards, but allowing the covered entities to select from a range of standards with a range of providers seems reasonable to start.

As a provider that most often aligns with ISO 14064-3, we have a preference, and like the international alignment and environmental rigor of that system, but we are also familiar with others and can flex to the engagement to find what is the best fit when looking at the data. If assurance accreditation is determined to be desired, we would recommend allowing time for that to happen, as it is generally a rigorous exercise.

We do feel that ISO 14065 is one of the more rigorous standards for this type of application, and would recommend leaning towards that if a stringent accreditation is deemed critical for credibility or other reasons.

2. Stagger Reporting Deadlines for Enhanced Program Success

We strongly recommend implementing two deadlines for SB 253 in 2026: June 30th for initial unassured reporting and December 31st for assured reporting. This staggered approach would:

• Enable quality baseline establishment: Allow adequate time for thorough initial data collection and reporting while establishing unassured baseline values for comparison

• Demonstrate assurance value: Provide clear evidence of verification benefits through comparison of unassured versus assured data, helping justify program costs

• Ensure adequate provider capacity: Allow sufficient time and capacity within the assurance provider ecosystem to handle engagement volume without market compression

• Enable thorough investigation: Provide adequate time for proper investigation of material findings, resolution of discrepancies, and implementation of corrective actions, especially in the initial year

• Reduce cost pressures: Avoid market compression that drives up assurance costs due to limited provider availability in compressed timeframes

• Support iterative improvement: Allow for learning and refinement between initial and assured reporting phases, improving overall data quality

• Facilitate stakeholder confidence: Build trust through a measured approach that prioritizes accuracy over speed

This phased approach recognizes the complexity of implementing a first-of-its-kind program while ensuring robust, credible results that serve California's climate leadership goals.

Respectfully submitted,
Conor Merrigan