GHG Protocol and ISO to Merge Carbon Accounting Standards Into One

The Greenhouse Gas Protocol and the International Organization for Standardization will combine their corporate carbon accounting standards into a single, harmonised global accounting standard, with an integrated public consultation on the future corporate standard planned for the second quarter of 2027. The consolidation brings together GHGP's Scope 1, Scope 2, Scope 3 and Actions and Market Instruments standards with ISO's 14064-1 standard, the two most widely used carbon accounting frameworks globally. Alongside the consolidation announcement, GHGP published results from its public consultation on the Scope 2 standard, which drew nearly 1,100 responses from 56 countries, and preliminary feedback from its Request for Information on the AMI standard.

 

Why Merging Two Major Standards Matters for Companies

 

Companies reporting greenhouse gas emissions across multiple jurisdictions have historically had to navigate the fact that GHGP and ISO 14064-1 are both widely used but not identical, sometimes requiring companies operating internationally to reconcile differences between the two frameworks or maintain separate reporting processes to satisfy different regulators or stakeholders who reference one standard over the other. Consolidating them into a single co-branded standard removes that duplication, giving companies one methodology to follow regardless of which regulatory or market context is requesting the disclosure.

GHG Protocol chief executive Tim Mohin framed the consolidation as simplifying reporting, reducing duplication and providing greater consistency across markets and jurisdictions, arguing this would ultimately free companies to spend more time reducing emissions rather than reconciling competing accounting frameworks. That argument reflects a broader pattern in sustainability reporting standard-setting, where fragmentation across multiple frameworks has repeatedly been identified as a genuine administrative burden diverting corporate resources away from substantive climate action and toward compliance overhead.

This consolidation is also positioned as a specific milestone under the COP30 Action Agenda, the framework through which GHG Protocol and ISO committed to advancing harmonisation of global greenhouse gas accounting standards, tying this technical standards merger directly to broader international climate governance commitments made at the UN climate conference.

 

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What the Scope 2 Consultation Revealed

 

The Scope 2 standard governs how companies account for emissions from purchased electricity, and the consultation's near-1,100 responses from 56 countries surfaced what GHGP describes as a range of opinions on how companies should account for renewable energy purchases, alongside broad support for improving the accuracy, comparability and integrity of electricity emissions accounting. That combination, wide participation plus divergent opinions on the substantive question, indicates this is a genuinely contested area of carbon accounting methodology rather than a straightforward technical update.

The underlying debate touches an issue that has surfaced elsewhere in corporate climate reporting this year: how companies should treat renewable energy certificates and similar market instruments that let a company claim renewable electricity use without necessarily consuming physically renewable power at the specific time and location of consumption. In response to the consultation feedback, GHGP says multiple reporting approaches are being explored reflecting different theories of change, with any further proposals following the standard development process through the Technical Working Group and review by the Independent Standards Board, a multi-stage governance process intended to ensure changes reflect rigorous technical assessment rather than being adopted unilaterally.

 

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Why the "Multi-Statement" Approach Could Change Corporate Reporting

 

The AMI workstream's proposed "multi-statement" reporting approach would require companies to report three distinct components separately: physical emissions from their own operations and value chain, market-based emissions tied to instruments such as commodity certificates and mitigation-related contractual agreements, and a GHG impact statement using consequential methods to assess the emissions impact of a company's actions and investment decisions.

That three-way split addresses a criticism that has followed corporate carbon accounting for years, that blending physical emissions with market-based instruments into a single reported figure can obscure whether a company's reported improvements reflect genuine operational change or simply purchased offsetting instruments. Separating these components lets stakeholders see each dimension independently rather than relying on a single blended number that conflates fundamentally different types of climate action. Tim Mohin described the AMI standard as helping organisations tell a clearer and more credible story of overall climate performance, one reflecting both the emissions a company generates and the actions it takes to reduce them alongside its contribution to real-world decarbonisation.

 

What Happens Next

 

The AMI standard development is being synchronised with the Scope 2 revision process, and both will feed into the broader GHGP-ISO consolidation ahead of the integrated public consultation planned for the second quarter of 2027. Whether the eventual consolidated standard successfully resolves the divergent views the Scope 2 consultation surfaced on renewable energy accounting, and whether the multi-statement AMI approach gains sufficient corporate adoption to genuinely improve transparency around market-based climate claims, will determine how much this consolidation effort actually improves the credibility and comparability of corporate carbon accounting globally, rather than simply merging two frameworks' branding without resolving their underlying methodological disagreements.

 

Source: The Greenhouse Gas Protocol (GHGP)