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 1: How do you set the organisational boundary?
First decide which companies, plants and offices are "yours". The GHG Protocol Corporate Standard (2004) offers three approaches:
| Approach | You count | Suits |
|---|---|---|
| Equity share | Your percentage share of each operation's emissions, in line with your economic interest | Groups with many joint ventures |
| Financial control | 100% of operations whose financial and operating policies you direct for economic benefit | Groups that want the inventory to match financial accounts |
| Operational control | 100% of operations where you have full authority to introduce operating policies | Most single companies and MSMEs |
Pick one approach, apply it to all sites and state it in the report. Operational control is usually the simplest for a company that runs its own plants.
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.
Related articles
Scope 1, 2 and 3 emissions explained: a guide for Indian companies
What Scope 1, 2 and 3 emissions mean under the GHG Protocol, how location-based and market-based Scope 2 differ, the…
Product carbon footprint (PCF) and life cycle assessment (LCA) explained
What a product carbon footprint is, how life cycle assessment works under ISO 14040, 14044 and 14067, cradle-to-gate…
BRSR and ESG climate reporting in India: what companies must disclose
A plain guide to SEBI's BRSR and BRSR Core: who must file, the Principle 6 climate indicators including Scope 1 and 2…
What are greenhouse gases and CO2 equivalent (CO2e)?
Which gases warm the planet, how CO2 equivalent and global warming potential work, why reports use different GWP…
How to reduce your carbon footprint: for homes, offices and companies
A practical avoid-reduce-replace guide for Indian households and businesses: BEE star-rated appliances, rooftop solar…
Carbon and Climate Glossary: Key Terms Explained Simply
An A-Z guide to 59 carbon and climate terms people and companies meet, from additionality and BRSR to CBAM, CCTS,…
Want to understand this for your home or company?
Talk to us. We are happy to explain what this means for you in plain words. We do not sell carbon credits and we cannot promise any result, but we can help you think it through.
Talk to usShare this article