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 3: What activity data do you need?
Activity data is the measured or recorded quantity of the activity that causes emissions.
| Source | Activity data | Where to find it |
|---|---|---|
| Grid electricity | kWh or MWh | Electricity bills, sub-meters |
| Diesel, petrol, LPG, furnace oil | Litres or kg | Purchase invoices, stock registers, DG logbooks |
| Coal, biomass | Tonnes, with calorific value if tested | Weighbridge slips, lab reports |
| Refrigerants | kg topped up | AC and chiller service records |
| Business travel | Trips, distance or spend | Travel agent reports, expense claims |
| Purchased materials | Tonnes or spend | Purchase ledger, ERP |
Use physical units (litres, kWh, tonnes) wherever possible. Spend-based data (rupees) is a rough fallback, mostly for Scope 3.
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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