Scope 1-2-3 Explained: Where Should You Start Collecting Data?

Corporate carbon accounting divides greenhouse gas emissions into three scopes under the GHG Protocol.

Scope 1 — Direct emissions

Fuel your organization burns itself: company vehicles, machinery and boilers, plus refrigerant leakage, septic systems and chemical fertilisers. Source documents are fuel receipts, refrigerant service invoices and usage logs.

Scope 2 — Purchased energy

Electricity, steam and cooling bought from outside — monthly utility bills are the primary source. If you hold renewable energy certificates (RECs), market-based factors can be applied.

Scope 3 — Other indirect emissions

Fifteen categories, from purchased goods and employee commuting to end-of-life treatment of sold products. This is where the most cross-team coordination is needed.

Where to begin

Start with Scope 1–2, where documents are complete, then extend to Scope 3 category by category based on materiality — and collect data monthly from the start of the year. It is far less painful than reconstructing everything at year-end.

Common first-year mistakes

Many organizations try to capture every category at once and end the year with none complete. The approach that works: make Scope 1-2 complete and verifiable first, since both are backed by financial documents that already exist. Double counting is the other classic error — fuel for a leased vehicle may be Scope 1 or Scope 3 depending on your control approach, so define the organizational boundary clearly from day one.

Where a system helps in each Scope

Scope 1: specialist models (refrigerants, septic tanks) and duplicate protection. Scope 2: paired location/market-based calculation with REC management. Scope 3: commuting surveys, supplier data templates and materiality assessment — every Scope shares one logic and rolls straight into a single report set.