The Greenhouse Gas (GHG) Protocol is the world's most widely used greenhouse gas accounting framework. Developed by the World Resources Institute (WRI) and the World Business Council for Sustainable Development (WBCSD) in 2001, it underpins virtually every major climate disclosure and target-setting framework in use today.
What the GHG Protocol is
A suite of accounting standards and guidance documents:
- Corporate Standard (2004) — the foundational standard for company-level inventories.
- Scope 2 Guidance (2015) — introduced dual reporting (location-based and market-based).
- Corporate Value Chain (Scope 3) Standard (2011) — the 15 Scope 3 categories.
- Product Life Cycle Standard (2011) — for product-level footprints.
- Project Protocol — for project-level accounting of reductions and offsets.
The five accounting principles
Every GHG inventory must satisfy:
- Relevance — reflect the emissions of the company appropriately.
- Completeness — cover all relevant sources within the chosen boundary.
- Consistency — enable meaningful comparisons over time.
- Transparency — enable third parties to assess credibility.
- Accuracy — bias and uncertainty reduced as far as practicable.
These are not aspirations — they are audit criteria under CSRD assurance.
Organisational boundaries
Two approaches:
- Equity share — the company accounts for GHG emissions in proportion to its equity share in an operation.
- Control — the company accounts for 100% of emissions from operations it controls (financial or operational).
Most companies now use operational control, which aligns with financial consolidation. The choice must be disclosed and applied consistently.
The three scopes
- Scope 1 — direct emissions from owned or controlled sources. Full guide.
- Scope 2 — indirect emissions from purchased energy. Full guide.
- Scope 3 — all other indirect emissions across the value chain. Full guide.
Which gases are covered
The seven Kyoto gases:
- Carbon dioxide (CO₂)
- Methane (CH₄)
- Nitrous oxide (N₂O)
- Hydrofluorocarbons (HFCs)
- Perfluorocarbons (PFCs)
- Sulphur hexafluoride (SF₆)
- Nitrogen trifluoride (NF₃)
All are converted to CO₂e using Global Warming Potentials (GWPs) from the latest IPCC Assessment Report (currently AR6).
Base years and recalculation
A base year anchors emission reduction targets. The GHG Protocol requires a base year recalculation policy — a rule for when historical data is restated (e.g. structural changes like acquisitions or divestments above a materiality threshold, typically 5%).
Why the GHG Protocol matters
It is the accounting foundation for:
- CSRD / ESRS E1 climate disclosures
- ISSB IFRS S2 climate-related disclosures
- SEC climate rule
- Science Based Targets initiative (SBTi)
- CDP disclosure and scoring
- PCAF Standard for financed emissions
- The EU Taxonomy
Following the GHG Protocol is a prerequisite for participating in any of these regimes — not an optional add-on.
Frequently asked questions
Is following the GHG Protocol mandatory?+
The GHG Protocol itself is voluntary, but virtually every mandatory framework — CSRD, ISSB, SEC, SBTi, PCAF — requires GHG Protocol-aligned accounting. In practice it is mandatory.
Which GWP values should we use?+
The current IPCC AR6 100-year GWPs. Most jurisdictions have transitioned from AR5 to AR6 over 2024–2026; check the specific reporting regime you are subject to.
What is the difference between the GHG Protocol and ISO 14064?+
Both are consistent with each other. ISO 14064 provides a certifiable specification (Part 1 for organisations, Part 2 for projects), while the GHG Protocol provides more detailed methodological guidance. Many companies use both.
This article follows Redigo Carbon's editorial standards: factual claims reference recognised frameworks — GHG Protocol, CSRD, ESRS, the Sustainability-Linked Loan Principles, the Green Loan Principles — and Redigo's opinions are labelled as such.
What this article is based on.
- GHG Protocol — Corporate Accounting and Reporting Standard — GHG Protocol
- GHG Protocol — Scope 2 Guidance — GHG Protocol
- GHG Protocol — Corporate Value Chain (Scope 3) Standard — GHG Protocol
- ISO 14064-1 — Corporate greenhouse gas inventories — ISO
- IFRS S1 / S2 — ISSB sustainability disclosure standards — ISSB / IFRS Foundation
- TCFD — Recommendations of the Task Force on Climate-related Financial Disclosures — TCFD / FSB
Redigo Carbon distinguishes between regulatory requirements, industry standards, best practice and Redigo's own recommendations. See our editorial standards for how we research, cite and update this content.
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