The GHG Protocol will combine its corporate greenhouse gas accounting standards with ISO’s, creating a single global standard, alongside updates to its Scope 2 and market-instrument rules announced on 29 July 2026.
The Greenhouse Gas Protocol (GHG Protocol) will merge its corporate carbon accounting standards with those of the International Organization for Standardization (ISO), it said in an announcement on 29 July 2026. The move creates a single harmonised global standard for how companies measure and report emissions.
The consolidation brings together the GHG Protocol’s Scope 1, Scope 2, Scope 3 and Actions and Market Instruments standards with ISO’s 14064-1 standard. An integrated public consultation on the future corporate standard is planned for the second quarter of 2027. Publication of the consolidated joint standard is expected in the fourth quarter of 2028.
The GHG Protocol underpins most corporate emissions reporting worldwide and feeds regulatory regimes from the European Union to disclosure rules elsewhere. Merging it with ISO 14064-1 removes a long-standing overlap between two competing frameworks. For heavy industry, which reports across complex supply chains, one standard should cut duplicated accounting work and give investors more comparable data.
Alongside the merger, the GHG Protocol is publishing the results of its public consultation on the Scope 2 standard and preliminary feedback from its request for information on the Actions and Market Instruments standard. A Phase 1 progress update in March 2026 signalled tighter rules on excluding categories as “not relevant”, less reliance on spend-based proxy data, and clearer treatment of investments and financed emissions.
The update also introduces a requirement to disclose verification status, part of what the body describes as strengthening governance, leadership and institutional capacity to meet rising demand for trusted accounting. The changes land as the Carbon Border Adjustment Mechanism (CBAM) and mandatory disclosure rules raise the stakes on emissions data quality for industrial exporters.
Tighter Scope 3 rules matter most for steel, cement and chemicals producers, whose largest emissions often sit in purchased goods and downstream use. Reduced reliance on spend-based proxies pushes firms towards supplier-specific data, which is harder to gather but far more accurate. Buyers and lenders will be able to compare industrial emitters on a firmer footing.
For industrial emitters, the direction is clear. Emissions figures will face tighter rules, more scrutiny and eventually one global rulebook. Companies that improve Scope 3 data and verification now will be better placed when the consolidated standard takes effect after 2028.
