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 values, and where India's emissions come from.
What is CO2 equivalent (CO2e)?
CO2 equivalent is calculated with a simple formula:
CO2e = mass of the gas x its global warming potential (GWP)
Illustrative example 1 (dairy): a dairy cluster's cattle release 1 tonne of methane in a year. Using the AR6 non-fossil methane GWP of 27.0 (GHG Protocol, August 2024), that equals 27 tonnes CO2e. Using the AR5 value of 28, which India uses in its official reports to the UNFCCC, it equals 28 tonnes CO2e.
Illustrative example 2 (air conditioner): 1 kg of the refrigerant HFC-32 leaks from an air conditioner during a faulty repair. Using the AR6 GWP of 771, that equals 771 kg CO2e, roughly the CO2 from burning about 260 kg of LPG, using the IPCC 2006 default factors (about 2.98 kg CO2 per kg of LPG).
These examples show why small amounts of some gases matter a lot.
Sources: IPCC AR6 Working Group I, Summary for Policymakers (2021); IPCC AR6 Working Group I, Chapter 7: The Earth's Energy Budget, Climate Feedbacks and Climate Sensitivity (2021); IPCC AR6 Working Group III, Annex I: Glossary (2022); GHG Protocol, IPCC Global Warming Potential Values, Version 2.0 (August 2024); MoEFCC, India First Biennial Transparency Report (BTR-1) to the UNFCCC; MoEFCC, India Fourth Biennial Update Report (BUR-4), December 2024; UNFCCC Decision 18/CMA.1, Modalities, procedures and guidelines for the transparency framework; UNFCCC Decision 5/CMA.3, Guidance for operationalizing the modalities, procedures and guidelines for the enhanced transparency framework; Press Information Bureau / PM India: Cabinet approves ratification of Kigali Amendment to the Montreal Protocol (August 2021); 2006 IPCC Guidelines for National Greenhouse Gas Inventories, Volume 2, Chapter 1
This article was prepared with AI assistance and checked by the GreenEye team against the sources shown in each section.
Related articles
What is a carbon footprint?
A plain guide to what a carbon footprint is, what it includes, how big the average Indian footprint is, and what the…
How to calculate your carbon footprint (for Indian households)
A step-by-step method for Indian households: multiply what you use (electricity units, LPG, fuel, flights, food) by a…
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