Understanding Scope 1, 2, and 3 Emissions: A Practical Guide
A clear breakdown of what Scope 1, 2, and 3 emissions are, where they come from, and why the distinction matters for accurate carbon accounting.
The GHG Protocol defines three scopes that form the foundation of how organizations classify greenhouse gas emissions.
Scope 1: What You Burn
Direct emissions from sources your organization owns or controls — natural gas in boilers, fuel in fleet vehicles, on-site industrial processes, and fugitive emissions from refrigeration.
Scope 2: What You Buy
Indirect emissions from purchased energy. Can be calculated location-based (grid average) or market-based (your energy contracts).
Scope 3: Everything Else
All other indirect emissions in your value chain. The GHG Protocol defines 15 categories — 8 upstream (purchased goods, capital goods, business travel, commuting, etc.) and 7 downstream (product use, end-of-life, etc.). Category 1 (purchased goods and services) alone often accounts for more than half of total Scope 3.
Why the Distinction Matters
- Avoids double counting — your Scope 2 is your supplier's Scope 1
- Targets action — each scope requires different reduction strategies
- Meets regulations — CSRD/ESRS requires all three scopes
Practical Approach
Start with Scope 1 and 2 (most accessible data), then progressively improve Scope 3. Begin with spend-based estimates, then upgrade to supplier-specific data for your highest-emitting categories.