Scope 1, 2, and 3 Emissions: The GHG Protocol Accounting Boundaries
The Greenhouse Gas Protocol divides corporate emissions into Scope 1 (direct, on-site fuel and process emissions), Scope 2 (purchased electricity and heat), and Scope 3 (everything else in the value chain). Scope 3 typically dwarfs the other two for technology and consumer brands.
The Greenhouse Gas Protocol, maintained by the WRI and WBCSD, is the dominant international accounting standard for corporate greenhouse-gas inventories. It splits emissions into three scopes based on who controls the activity that releases them. **Scope 1** covers direct emissions from sources owned or controlled by the reporting company: on-site fuel combustion, process emissions (such as fluorinated gases used in semiconductor fabrication), fleet vehicles, and refrigerant leaks. **Scope 2** covers indirect emissions from purchased electricity, steam, heating, and cooling. It is usually reported under two methods: location-based (using grid-average factors for the region where the electricity was consumed) and market-based (reflecting contractual instruments like renewable energy certificates and PPAs). **Scope 3** covers all other indirect emissions across the value chain, divided into 15 sub-categories including purchased goods and services, capital goods, upstream transportation, business travel, use of sold products, and end-of-life treatment. For most technology and consumer companies, Scope 3 dwarfs Scope 1 and 2 combined and captures the embodied carbon of purchased hardware. It is also the hardest to measure: most large reporters concede major data gaps in supplier emissions, often falling back on spend-based estimates rather than activity-based ones.