What Is the GHG Protocol? Scopes, Standards and How to Use It
In brief
- The GHG Protocol is the world’s most widely used standard for measuring and reporting greenhouse gas emissions.
- It was created by the World Resources Institute (WRI) and the World Business Council for Sustainable Development (WBCSD).
- It defines Scope 1 (direct), Scope 2 (purchased energy) and Scope 3 (value chain) emissions, and covers the seven Kyoto Protocol gases.
- Its standards underpin SBTi targets, CDP disclosures and many national and EU reporting rules.
If your company has been asked for its carbon footprint, the request almost certainly assumes the GHG Protocol, even if nobody named it. This guide explains what the GHG Protocol is, its main standards, the three scopes, and how a small business can use it without hiring a large consultancy.
What is the GHG Protocol?
The Greenhouse Gas Protocol is a set of free, public accounting standards for measuring emissions. It began in 1998 as a partnership between the World Resources Institute and the World Business Council for Sustainable Development, and today it is used by most large companies that report emissions, and by governments, cities and banks.
The main GHG Protocol standards
| Standard | What it covers |
|---|---|
| Corporate Standard | How a company measures and reports its total emissions (Scopes 1 and 2, with Scope 3 optional) |
| Scope 2 Guidance | How to report electricity emissions both location-based and market-based |
| Corporate Value Chain (Scope 3) Standard | How to measure the 15 categories of value-chain emissions |
| Product Standard | The life-cycle footprint of a single product |
| Other standards | Cities, countries, projects and land-sector emissions |
Scope 1, Scope 2 and Scope 3
Scope 1: direct emissions from sources you own or control, such as fuel in boilers, generators and company vehicles, and refrigerant leaks. Scope 2: indirect emissions from electricity, heat, steam or cooling you buy. Scope 3: all other indirect emissions in your value chain, split into 15 categories; see our full guide to Scope 3 emissions with examples.
Scope 2: location-based vs market-based
Location-based Scope 2 uses the average emission factor of the grid where you use electricity. Market-based Scope 2 reflects the electricity you have chosen to buy, such as a green tariff or renewable energy certificates. The GHG Protocol’s Scope 2 Guidance asks companies to report both, so readers can see the physical grid impact and the effect of purchasing choices.
Which gases does the GHG Protocol cover?
The seven gases of the Kyoto Protocol: carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), sulphur hexafluoride (SF₆) and nitrogen trifluoride (NF₃). Each is converted to carbon dioxide equivalent (CO₂e) using global warming potentials, so they can be added together.
The five accounting principles
Relevance (the inventory reflects the company’s real emissions and serves its users), completeness (all relevant sources are included, and exclusions are explained), consistency (methods allow comparison over time), transparency (assumptions and sources are documented) and accuracy (numbers are neither systematically over nor under, and uncertainty is reduced where practical).
How a small business uses the GHG Protocol
Set your boundary (which sites and activities count), choose a base year, collect a year of fuel, electricity and refrigerant data for Scopes 1 and 2, screen your Scope 3 categories, apply emission factors from a recognised source, and document everything. You can see what this looks like in practice in a sample GHG inventory. Companies with SBTi targets then repeat the exercise every year to report progress.
GHG Protocol vs ISO 14064
ISO 14064 is an international standard family closely aligned with the GHG Protocol. ISO 14064-1 sets requirements for an organisation’s greenhouse gas inventory, ISO 14064-2 covers emission-reduction projects, and ISO 14064-3 covers verification and validation. Many companies build their inventory using GHG Protocol methods and then have it verified against ISO 14064-3. The two are compatible rather than competing: the GHG Protocol gives detailed calculation guidance, while ISO provides a certifiable framework.
Updates to the GHG Protocol
The GHG Protocol is being revised, with updates under way to the Corporate Standard, Scope 2 guidance (especially rules on renewable electricity claims) and Scope 3. If you report emissions, check the GHG Protocol website for the current versions and transition dates, and keep a clear record of which version and emission factors you used each year so your numbers stay comparable.
You can estimate your Scope 1 and 2 emissions in two minutes with our free business carbon footprint calculator.
To build your own inventory, download our free GHG inventory template for Excel, with Scope 1, Scope 2 and a Scope 3 screening ready to fill in.
Frequently asked questions
What is the GHG Protocol?
The most widely used global standard for measuring and reporting greenhouse gas emissions, created by WRI and WBCSD.
Who created the GHG Protocol?
The World Resources Institute (WRI) and the World Business Council for Sustainable Development (WBCSD), starting in 1998.
What are the three scopes of the GHG Protocol?
Scope 1 (direct emissions), Scope 2 (purchased energy) and Scope 3 (other value-chain emissions).
What is the GHG Protocol Corporate Standard?
The standard that explains how a company sets its boundaries and measures and reports Scope 1 and 2 emissions, with Scope 3 reported under a companion standard.
Is the GHG Protocol mandatory?
It is voluntary in itself, but many mandatory rules and initiatives, including SBTi and CDP, are built on it.
Get the climate stories that matter, explained, every Sunday.
One email a week: new explainers, data and free tools. No spam, unsubscribe any time.
More from climaRevolt
B Corp Climate Action Requirements: What Small Businesses Really Need
What Is Net Zero? Net Zero vs Carbon Neutral, Explained
Scope 3 Emissions Explained: The 15 Categories, Examples and How to Calculate Them