Scope 1, 2 and 3 emissions

The GHG Protocol Corporate Standard splits an organization's greenhouse gas emissions into three scopes. Scope 1 covers direct emissions from sources it owns or controls, such as fuel burned in company vehicles or boilers. Scope 2 covers indirect emissions from purchased electricity, steam, heat or cooling. Scope 3 covers all other indirect emissions across the value chain, split into upstream categories like purchased goods and business travel and downstream categories like the use of sold products.

Scope 1 and 2 are usually calculated as activity data multiplied by an emissions factor: fuel volume or kilowatt-hours times a factor gives tonnes of CO2-equivalent. Scope 3 is harder to measure directly and is often estimated from spend data, industry averages or supplier disclosures rather than metered, which makes it the least precise and, for most companies, the largest of the three.

The scopes matter because they are the backbone of carbon accounting and most ESG reporting frameworks, including CSRD and ISSB climate disclosures, and because carbon credit claims are typically judged against a company's scope 1-3 baseline. A common pitfall: choosing an operational-control versus equity-share boundary changes what counts as scope 1 versus scope 3 for joint ventures, and one company's scope 3 is another's scope 1 or 2, so value-chain totals cannot simply be added across companies without double counting.