The Greenhouse Gas Protocol, convened by the World Resources Institute and the World Business Council for Sustainable Development, is the set of accounting and reporting standards that define how companies measure and report emissions. Its Corporate Standard establishes the scope structure and the organizational boundary rules, with the Scope 2 Guidance and the Corporate Value Chain (Scope 3) Standard extending it. The Protocol governs how emissions are counted, not whether a company is required to report them.
Why It Matters for Manufacturers
The Protocol is the common denominator underneath regimes that otherwise have little in common. CSRD and ESRS, IFRS S2, California’s climate laws, CDP and SBTi all reference it, so one Protocol-aligned inventory can serve several obligations instead of becoming several parallel exercises.
That leverage cuts both ways. Because everything downstream inherits the inventory, the setup decisions propagate. An organizational boundary chosen without thinking through joint ventures and leased plants, or a Scope 3 screening that skipped categories, shows up again in every framework the data feeds and in every assurance engagement.
For manufacturers, the Protocol’s demands are operational rather than theoretical. Applying it properly means site-level activity data, documented emission factors and a defensible reason for every methodology choice.
The standards themselves are free to download. The cost is entirely in the data collection, systems and staff time needed to apply them across a plant network.
U.S. and EU Applicability
The Protocol is global and voluntary in its own right, but it is written into mandatory regimes on both sides of the Atlantic. SB 253 requires emissions measured and reported in conformance with the Greenhouse Gas Protocol standards and guidance, naming the Corporate Accounting and Reporting Standard and the Corporate Value Chain (Scope 3) Accounting and Reporting Standard. IFRS S2 requires emissions measured in accordance with the 2004 Corporate Standard. ESRS is built on the same scope architecture.
IFRS S2 permits a different measurement method where a jurisdiction or an exchange requires one, and applies the Corporate Standard only where it does not conflict with IFRS S2. There is no competing U.S. standard, which is why a Protocol-aligned inventory is the practical starting point for a manufacturer facing more than one regime — including in California, where the SB 253 conformance requirement stands while the Ninth Circuit challenge to the state’s climate disclosure laws remains undecided.
Current Status
Last updated: Aug. 31, 2026
- The GHG Protocol is consolidating the Corporate Standard, Scope 2 Guidance, Scope 3 Standard, its Actions and Market Instruments work and ISO 14064-1 into a single Corporate Standard, currently planned in two parts: general requirements and physical GHG inventory, and actions and market instruments. The GHG Protocol’s Standard Development Plan of July 29, 2026 notes that either part may be subdivided.
- A consolidated draft is scheduled for public consultation in an estimated Q2 2027, with final publication estimated for Q4 2028. The standard is expected to be jointly published and co-branded with ISO. Both dates are given as estimates in the July 29, 2026 Standard Development Plan, which states that the workplan and timeline are subject to change. Earlier dates still circulating elsewhere, including a Q3 2027 consultation and a late 2027 publication, predate that plan.
- The existing standards remain in force in the meantime, and the regimes that reference them continue to reference the current versions. IFRS S2 in particular points to the 2004 Corporate Standard by name.
- Workstream milestones so far include the Scope 2 consultation that opened Oct. 20, 2025 and closed Jan. 31, 2026 after an extension, the Corporate Standard Phase 1 update in December 2025 and the Scope 3 and Actions and Market Instruments Phase 1 updates in March 2026.
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