Scope 1, 2 and 3 emissions
The three categories of corporate emissions: direct, purchased energy, and value chain.
Scope 1 covers emissions from sources an organisation owns or controls — combustion on site, company vehicles, industrial processes. Scope 2 covers emissions associated with purchased electricity, heat or steam. Scope 3 covers everything else in the value chain, upstream and downstream.
The categories carry very different data quality. Scope 1 is usually metered and reliable. Scope 2 depends on which electricity grid factors are used and whether a market-based or location-based method is applied. Scope 3 typically dwarfs the others in size and is estimated from spend or supplier averages, making it the weakest link statistically.
This hierarchy matters when credits are used. A credit that funds a reduction inside someone else's boundary logically belongs to Scope 3 or to a beyond-value-chain claim, never to Scope 1. Misclassifying it is a recognised form of double counting.
Frequently asked questions
Why is Scope 3 so hard?
Because it spans suppliers and product use the reporting company does not control, so data must be estimated or requested rather than measured.
Can offsets reduce Scope 1?
No. Scope 1 reflects emissions the company physically produces. Credits support reductions elsewhere and are reported separately.