Scope 1-2-3 Explained: Where Should You Start Collecting Data?
Scope 1-2-3 is the shared language of carbon accounting worldwide — get these three terms straight and planning your organization's data collection becomes immediately easier.
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.
“Start from documents your organization already has — utility bills and fuel receipts are the best teachers in year one”
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.
GCarbon Team
Carbon accounting specialists
