A New Era Of Carbon Accounting: ISO And GHG Protocol Unite To Harmonize Global Standards

Greenhouse gas reporting took a major step forward on September 9 with the announcement of a strategic partnership between the International Organization for Standardization (ISO) and the Greenhouse Gas Protocol (GHG Protocol). The two organizations will harmonize existing standards and co-develop new ones, including ISO’s 1406X family alongside the GHG Protocol Corporate Accounting and Reporting, Scope 2 and Scope 3 Standards. By aligning these widely used frameworks, the partnership aims to tackle one of the biggest challenges in carbon accounting: fragmentation. For years, businesses, auditors, investors and regulators have navigated overlapping but often incompatible methodologies, leading to duplication, complexity and limited comparability of emissions data across industries and geographies.

A particularly significant element of the collaboration is the development of a joint product carbon footprint (PCF) standard. Suppliers are often doubling their efforts to meet multiple customer PCF requests under different standards (notably ISO 14067 and the GHG Protocol’s Product Life Cycle Accounting and Reporting Standard). Nearly three-quarters of firms surveyed by Verdantix note that inconsistencies across product carbon accounting methodologies are a major challenge. A unified approach will streamline reporting to customers, reduce duplication of effort, facilitate benchmarking and enhance data exchange across value chains. It will also bring greater consistency in defining scopes, boundaries and verification requirements, helping organizations make clearer decarbonization decisions and giving investors more reliable insights for responsible investment.

In the 2025 Verdantix survey, over half of the firms interviewed report using commercial carbon management software for their Scope 1 and 2 calculations, while 35% leverage these platforms for product carbon footprinting. As adoption continues to grow, carbon management software providers will need to align with the forthcoming unified standards, offering flexibility and futureproof functionality. Vendors that implement these changes swiftly will gain a competitive advantage, as organizations increasingly demand solutions that simplify compliance while ensuring accurate, reliable reporting. Harmonization will also improve interoperability, making it easier to integrate supplier data, external databases and audit workflows into a single, seamless system.

What’s next? Many unknowns remain. It will be interesting to see how the new standards accommodate sector-specific differences. Existing initiatives, such as Catena-X for the automotive industry and Together for Sustainability (TfS) in chemicals, are already driving interoperability and more consistent PCF calculations. At the same time, no timelines have been disclosed for drafts of the unified standards, and critical questions remain around balancing open access, given that the GHG Protocol is freely available while ISO standards often require purchase. It is also unclear how verification requirements will be defined and how integration with other reporting frameworks, such as ESRS, IFRS/ISSB and GRI, will be managed. In the meantime, organizations should look to implement software solutions that remain agile in the face of evolving standards, while supporting scalable, accurate carbon accounting – from corporate emissions to product-level footprinting – across their entire operations.

For more information on vendors offering product carbon footprinting capabilities, read Verdantix Smart Innovators: Product Carbon Footprinting.