How companies measure emissions: building a GHG inventory step by step
A step-by-step guide to a company greenhouse gas inventory: boundaries, activity data, emission factors from CEA and IPCC, a worked calculation, base year, data quality, verification under ISO 14064-3, and where an SME can start.
Step 2: Which emissions go in, by scope?
Next, list every source inside that boundary and sort it:
- Scope 1: fuels burnt on site and in owned vehicles, process emissions, refrigerant leaks.
- Scope 2: purchased electricity, steam, heat and cooling.
- Scope 3: value-chain sources, screened across the 15 categories of the Scope 3 Standard (2011).
ISO 14064-1:2018 uses a different grouping (direct emissions plus several indirect categories), but the sources are the same. A walk-through of each site, the asset register and the purchase ledger are the best ways to find sources people forget, such as a small DG set or a canteen LPG cylinder.
Sources: GHG Protocol Corporate Accounting and Reporting Standard (revised edition, 2004); GHG Protocol Corporate Value Chain (Scope 3) Standard (2011); GHG Protocol: key standard development updates FAQ (29 July 2026); ISO 14064-1:2018 Greenhouse gases, Part 1 (ISO catalogue); ISO 14064-3:2019 Greenhouse gases, Part 3 (ISO catalogue); India GHG Program (WRI India, CII, TERI); India GHG Program: Road Transport Emission Factors technical paper, version 1.0 (2015, draft); Central Electricity Authority: CO2 Baseline Database for the Indian Power Sector; IPCC 2006 Guidelines for National Greenhouse Gas Inventories, Volume 2 Energy, Chapter 1 and Chapter 2; IPCC 2019 Refinement to the 2006 IPCC Guidelines; IPCC AR6 Working Group I (2021), Chapter 7, Table 7.15; UK Government: Greenhouse gas reporting conversion factors 2026 (DESNZ); SEBI: Format of BRSR Core, Annexure I (July 2023); SEBI circular SEBI/HO/CFD/CFD-PoD-1/P/CIR/2025/42 (28 March 2025); Central Electricity Authority, CO2 Baseline Database for the Indian Power Sector, User Guide Version 22.0 (August 2026); MoEFCC, India First Biennial Transparency Report (BTR-1) to the UNFCCC
This article was prepared with AI assistance and checked by the GreenEye team against the sources shown in each section.
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