Scope 1 2 3 emissions, explained in plain language

The scopes exist to stop double counting inside one company's report while allowing it between companies: your supplier's Scope 1 is your Scope 3, and that is by design. The GHG Protocol Corporate Standard defines Scopes 1 and 2; the separate Corporate Value Chain Standard defines Scope 3 emissions and their 15 categories.

Boundary questions decide most classification arguments. A leased office is Scope 2 if you hold the utility contract, category 8 if your landlord does. A truck is Scope 1 if you own it, category 4 if a carrier runs it and you pay for the freight. A company card flight is category 6; an employee driving their own car to work is category 7. The rule that resolves nearly everything: who owns or controls the emitting asset, and who pays for the energy.

Worked examples for a SaaS company, a manufacturer and a logistics operator are in our post on scope 1 2 3 emissions examples, and the deeper Scope 1 versus Scope 2 distinction has its own guide.

Scopes 1 and 2 are measured from meters and bills: fuel volumes, kWh, refrigerant top-ups. They should be fully activity-based, and an auditor will expect that. Scope 3 starts from spend because that is the only complete record most companies have of their value chain; the biggest categories then graduate to activity and supplier data. Good carbon accounting software holds all three scopes in one ledger, tags every line with its method and factor, and keeps the evidence linked so the number survives an assurance review.