On July 29, 2026, the Greenhouse Gas Protocol (GHGP) and the International Organization for Standardization (ISO) announced a landmark update to corporate carbon accounting. The two organizations have committed to consolidating their respective frameworks into a single, harmonized, and co-branded global corporate standard. This move addresses long-standing industry requests for unified reporting methodologies amidst an increasingly complex regulatory landscape.
The GHGP & ISO Partnership Objective
1. Key Drivers for Consolidation
The strategic merger of these standards is driven by several pressing market and regulatory needs:
- Regulatory Interoperability: Ensuring alignment with sweeping mandatory climate disclosure rules such as the European Union's CSRD (ESRS) and California's SB 253.
- Reducing Reporting Fatigue: Eliminating redundancies for companies that previously had to report against multiple, slightly differing frameworks to satisfy diverse stakeholders.
- Methodological Standardization: Creating a unified approach to complex accounting issues like market-based Scope 2 calculations and intricate Scope 3 value-chain mapping.
2. Current vs. Proposed Framework Consolidation
| Current Framework (Pre-2026) | Key Focus | Future Consolidated Standard (Post-2028) |
|---|---|---|
| GHGP Corporate Standard (2004) | Base inventory boundary setting | Unified GHGP-ISO Corporate Standard |
| GHGP Scope 2 Guidance (2015) | Market-based & Location-based electricity | Integrated into the Unified Standard |
| GHGP Scope 3 Standard (2011) | Upstream & Downstream value chain (15 categories) | Integrated into the Unified Standard |
| GHGP Actions & Market Instruments (AMI) | Market interventions and certificates | Integrated into the Unified Standard |
| ISO 14064-1 | Organization-level GHG quantification | Harmonized and co-branded with GHGP |
3. Projected Timeline and Next Steps
The consolidation process will follow a structured, multi-year timeline involving extensive stakeholder engagement and technical drafting:
- Current Status (Q3 2026): GHGP is publishing results from recent public consultations on Scope 2 and releasing preliminary feedback on the Actions and Market Instruments (AMI) workstream.
- Public Consultation (Q2 2027): A single, integrated public consultation for the future consolidated corporate standard will be launched.
- Final Publication (Q4 2028): The finalized, joint GHGP-ISO corporate standard is expected to be published and officially adopted.
4. Strategic Implications for Sustainability Leaders
While the final standard will not be published until 2028, sustainability, finance, and risk leaders must begin preparing their data infrastructure today. Companies should continue using the existing GHGP standards while ensuring their data collection systems are flexible and robust enough to handle heightened audit requirements. Transitioning to granular, primary activity data for Scope 3—rather than relying on spend-based estimates—will be critical as the new standard will likely demand higher data quality and assurance readiness.