What is GHG Protocol Scope 1, 2 and 3?
GHG Protocol Scope 1, 2 and 3 is the classification of corporate greenhouse gas emissions set by the Greenhouse Gas Protocol. Scope 1 covers direct emissions from owned sources, Scope 2 covers indirect emissions from purchased electricity, steam, heat and cooling, and Scope 3 covers other indirect emissions across the value chain.
What it is
The Greenhouse Gas Protocol was developed by the World Resources Institute and the World Business Council for Sustainable Development. Its Corporate Standard is the most widely used basis for company emissions inventories, and many regulations and frameworks build on it.
Scope 1 includes fuel burned in boilers, generators and vehicles, and refrigerant leaks. Scope 2 is calculated from purchased energy and, under the Scope 2 Guidance, reported two ways: location-based, using grid average factors, and market-based, reflecting contracts and certificates. Scope 3 has fifteen categories, from purchased goods to use of sold products.
Who it applies to / where it is used
The GHG Protocol is used by companies of every size, by public bodies and by the frameworks that ask for emissions data, including CDP, CSRD, ISSB S2, SBTi and many national rules. Property owners, manufacturers, hospitals, universities and data center operators all depend on accurate Scope 1 and 2 inputs.
How it is measured / what evidence it needs
Scope 1 and 2 emissions are activity data multiplied by emission factors. Errors in activity data carry straight into the result.
- Fuel consumption by site and source for Scope 1
- Refrigerant inventories and top-up records
- Purchased electricity, steam, heat and cooling by site for Scope 2
- Emission factors and contractual instruments used
- A documented inventory boundary
How Aqueduct helps
Aqueduct supplies measured energy and water inputs for Scope 1 and 2. Carbon accounting tools calculate the emissions.
- Metered electricity, gas and fuel by site, replacing estimates and bill gaps
- District cooling and steam consumption where metered
- Verified reductions through aQ EnergySmart to show year-over-year change
- Exports through aQ Assurance for carbon accounting platforms and auditors