GHG verification

July 29, 2026

Key Takeaways: CARB’s July 21 Workshop

The California Air Resources Board (CARB) held a virtual public workshop to support the development of the California Corporate Greenhouse Gas Reporting (GHG) Program authorized by Senate Bill (SB) 253 as amended by SB 219. Below is a summary of the update provided, including CARB’s regulatory concepts for Scope 1 and 2 GHG emissions reporting requirements for 2027 and beyond. Also, CARB discussed its proposed approach for Scope 3 emissions reporting to begin in 2027.

• 2026 Reporting Guidance: By September 1, CARB will provide additional guidance to support Scope 1 and 2 GHG emissions reporting for 2026.
• Current and Future Due Dates: CARB confirmed its extension from the August 10 deadline until November 10 for 2026. CARB also announced November 10 as the deadline for future reporting periods to be added to its next rulemaking in 2027.

Proposed Future Requirements for Corporate GHG Reporting

Most of the workshop addressed CARB’s proposed regulatory language, to be included in a 2027 rulemaking proposal.

• Proposed Basis: CARB will align with the Greenhouse Gas Protocol (GHG-P) standards, add clarifications for California, and seek to promote interoperability with other climate disclosure programs to streamline implementation.
• Methodology and data transparency: For all Scopes and including biogenic emissions, CARB is expecting companies to disclose their organizational boundary, Global Warming Potential values, emission-factor sources, calculation methods, measurement uncertainty, missing data/substitution, data exclusions, assumptions, and uncertainty assessments. Changes in methodology and recalculations would also need to be explained.
• Biogenic emissions: CARB proposed that biogenic emissions from the combustion, consumption, or biodegradation of biomass and biomethane must be included in GHG emissions reports, and are to be reported separately from Scope 1, 2, and 3 emissions totals.
• Reporting Emissions Reductions or Removals. Reporting entities may report separately voluntary investments (e.g., carbon credits, offsets), management activities (e.g., land management practices resulting in biological GHG sequestration), or other activities that result in fossil or biogenic emissions reductions or removals.
• Scope 2 reporting: Companies are to report both location-based and market-based Scope 2 emissions, to be identified by energy source type, such as purchased electricity, steam, heating, and cooling.
• Base-year recalculations: CARB proposed a 5% threshold for determining whether structural or methodological changes require recalculation of previously reported emissions.
• Phased Scope 3 reporting: To reduce the initial reporting burden, CARB proposed requiring the five most commonly reported Scope 3 categories beginning in 2027:
  • Category 1 – Purchased Goods and Services
  • Category 3 – Fuel- and Energy-Related Activities
  • Category 5 – Waste Generated in Operations
  • Category 6 – Business Travel
  • Category 7 – Employee Commuting

• For each required category, reporters are to disclose the calculation methodology, data types used, total emissions, excluded activities or emissions, and the percentage calculated using primary supplier or value-chain data. The calculation methods are to be consistent with the GHG-P Scope 3 Standard and identified in reporting.

• Reiterated 3^rd party Assurance Standards: CARB listed the 5 standards discussed at their March 2026 workshop.
  • AA1000AS v3, AICPA AT-C Section 210, ISAE 3410 with ISAE 3000, ISSA 5000, and ISO 14064-3:2019, subject to applicable qualification and accreditation requirements.
  • CARB specified that Assurance applies to reporting Scopes 1 and 2 plus biogenic emissions, for quantitative as well as qualitative elements in 2027.
• Six listening sessions are planned in August and September, with one for data users/ stakeholders and five sessions by corporate sectors. These are an important opportunity to provide feedback to CARB about the draft proposed language for the 2027 regulation, provided in the Workshop slides. Use the links below to register for each session.

Register Session 1 – Data Users & Public Interest Stakeholders
Date: Wednesday, August 5, 2026
Time: 10 a.m.-12 p.m. PT
Data users and public interest stakeholders, including universities, research institutions, Non-Governmental Organizations (NGOs), Environmental, Social, and Governance (ESG) software providers, consultants, assurance providers, and organizations that analyze or apply climate data to support public accountability, environmental justice, consumer interests, assess community impacts, and share data for public understanding.

Register Session 2 – Manufacturing, Industrial, Fuel & Life Sciences
Date: Wednesday, August 12, 2026
Time: 10 a.m.-12 p.m. PT
Companies engaged in oil and gas, refining, chemicals, metals, construction materials, mineral processing, automotive, aerospace, pharmaceuticals, biotechnology, and medical devices.

Register Session 3 – Agriculture, Food, Beverage & Forestry
Date: Wednesday, August 19, 2026
Time: 10 a.m.-12 p.m. PT
Companies involved in farming, livestock, forestry, food processing, beverages, agricultural products, tobacco, and related processing with significant land sector emissions.

Register Session 4 – Energy, Utilities, Transportation, Logistics & Waste Management
Date: Wednesday, August 26, 2026
Time: 10 a.m.-12 p.m. PT
Companies involved in generating electricity, renewable energy, water and gas utilities, transportation, freight, airlines, rail, shipping, and waste management.

Register Session 5 – Retail, Consumer Goods, Technology & Commercial Services
Date: Wednesday, September 2, 2026
Time: 10 a.m.-12 p.m. PT
Companies engaged in retail, apparel, wholesale, e-commerce, software, semiconductors, telecommunications, media, entertainment and gaming, real estate, hospitality, construction services, and professional services.

Register Session 6 – Banking, Finance & Insurance
Date: Wednesday, September 9, 2026
Time: 10 a.m.-12 p.m. PT
Companies involved in banking, insurance, asset management, investment, fintech, credit union services, asset management and private equity, capital markets, non-bank financial institutions, and other investors.

Need support? Feel free to reach out to us. We are happy to have a chat with you!

• Aicha Slassi Sassou, PhD, Project Manager, Climate Practice at 

January 28, 2026

The Washington Department of Ecology has designated SCS Engineers as an Accredited Offset Verification Body within the Washington State Cap-and-Invest program. WAC 173-446-540(1)(c) dictates separate, specialized accreditation for offset verifiers under the Climate Commitment Act (CCA). While WAC 173-441 provides the data foundation, 173-446-540 reporting requires distinct, stricter verification accreditation for carbon offset projects.

The Washington Department of Ecology designated SCS professionals earlier in January, and the team is already working even as the Department of Ecology prepares to update its website. SCS Engineers is one of a handful of firms throughout North America to have this series of accreditations.

Washington State’s greenhouse gas (GHG) offset program is part of the state’s Cap-and-Invest Program, established under the Climate Commitment Act. The Cap-and-Invest program aims to reduce carbon pollution and achieve the GHG limits set in state law. Offset projects are designed to reduce, remove, or avoid greenhouse gas emissions and must provide direct environmental benefits to the state. Offset projects must meet strict criteria to ensure they are real, permanent, quantifiable, and verifiable.

“SCS Engineers has been an active verification body in the California Air Resources Board compliance offset program for years,” said Ray Huff, VP and National Expert on GHG. “We are pleased to offer this opportunity to Washington’s program and assist businesses in successfully navigating offset protocols and regulatory requirements.”

The GHG verification scopes include entity-wide disclosures, single facilities, compliance offsets, and renewable fuel pathways. SCS Engineers also conducts independent audits of environmental data, including electricity and water usage, waste, and energy, to support accuracy, compliance, and efficiencies across all operations. In addition to the WA ECY Mandatory Reporting and Offsets, SCS Engineers verifies for the following programs:

• California CARB: Mandatory Reporting, Low Carbon Fuels Standard, Offsets
• California Dept. of Energy: High Hazard Fuels
• California Senate Bills 261 and 253 Requirements
• Oregon: Clean Fuels Program and Mandatory Reporting
• M-RET: Renewable Natural Gas Production Measurement, Reporting, and Verification, referred to as MRV in GHG management, to ensure accuracy, completeness, and consistency with standards like ISO 14064-3.
• IRS: 45Z and Y Program

Contact SCS Engineers for a GHG and  Accredited Offset Verification Expert near your facility.