What are the three scopes?
Scope 1 covers direct emissions from sources a business owns or controls. Scope 2 covers emissions associated with purchased electricity, steam, heating or cooling. Scope 3 covers other upstream and downstream value-chain emissions. The exact inventory boundary and accounting approach must be documented.
Start with the boundary
Agree the reporting entity, sites, period and purpose before collecting numbers. A single factory, a group and a customer-specific product request have different boundaries. An organisational inventory is not automatically a product carbon footprint.
Collect activity data before selecting factors
Activity data can include fuel use, purchased electricity and refrigerant records. Keep units, dates and supporting documents. Emission factors should match the geography, activity, reporting purpose and methodology where applicable. Record their source and year rather than copying a number without context.
Screen Scope 3 deliberately
Screen relevant value-chain categories and explain exclusions. Data needs can include purchased goods, transport, waste, travel and product use, depending on the business. Do not assume every category is material or that estimated supplier data is equivalent to independently verified data.
Keep calculations reviewable
Retain the formula, factor source, assumptions, data gaps and quality checks. A credible baseline explains limitations. Reporting emissions does not demonstrate a reduction by itself, and offsets do not remove the need for a clearly defined inventory.
Sources & further reading
GHG Protocol — standards & guidance ↗
Official sources checked 30 October 2026. General educational content; confirm entity-specific requirements with a relevant adviser. No personal practitioner credentials or technical review are claimed.