Carbon accounting
Scope 1 is what you burn yourself — fuel in your vehicles, gas in your kitchen. Scope 2 is the electricity you buy, burned at someone else’s power station. Scope 3 is everything else that happens because of your business, upstream and downstream: what you buy, how staff commute, how customers use what you sell.
The split exists to stop double counting. If everyone counted all emissions everywhere, the world total would be several times its real size. So each emission has one owner in Scope 1, and everyone else who touches it counts it in Scope 3.
| Scope | The rule of thumb | Typical for a small business |
|---|---|---|
| 1 | You burned it | Cooking gas, generator diesel, company vans, refrigerant leaks |
| 2 | You bought the electricity | Grid electricity, purchased steam or chilled water |
| 3 | Everything else | Purchased goods, water, waste, business travel, commuting |
Scope 3 is usually the largest of the three by a wide margin — CDP puts the supply-chain emissions reported by large companies at 11.4 times their operational emissions on average, and at 26 times in its 2023 data. It is also the hardest to measure, which is why so many first inventories cover Scope 1 and 2 and say so. Within those two, Scope 2 is normally the biggest line and the easiest to get right, because the electricity bill is already a meter reading. Scope 1 is usually small but simple.
Sources checked 30 September 2026