Kyoto Gases
The seven greenhouse gases regulated under the Kyoto Protocol and tracked in GHG accounting: carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), sulphur hexafluoride (SF₆), and nitrogen trifluoride (NF₃).
The Kyoto Protocol (1997) established a legal framework for six greenhouse gases — later expanded to seven with the Doha Amendment (2012). GHG Protocol Corporate Standard and IPCC Guidelines require all seven to be tracked in a complete GHG inventory.
The 7 Kyoto Gases
| Gas | Symbol | Key Sources in Manufacturing | GWP (AR6, 100-yr) |
|---|---|---|---|
| Carbon dioxide | CO₂ | Combustion of fossil fuels (diesel, coal, furnace oil) | 1 |
| Methane | CH₄ | Natural gas leaks, wastewater treatment, landfill | 27.9 |
| Nitrous oxide | N₂O | Combustion (especially in boilers), adipic acid production | 273 |
| Hydrofluorocarbons | HFCs | Refrigerants in chillers, cold storage, air conditioning | 100–14,800 (species-dependent) |
| Perfluorocarbons | PFCs | Aluminium smelting, semiconductor manufacturing | 6,630–11,100 (species-dependent) |
| Sulphur hexafluoride | SF₆ | Electrical switchgear in substations | 25,200 |
| Nitrogen trifluoride | NF₃ | Electronics and semiconductor manufacturing | 17,400 |
Why All 7 Matter for Manufacturing
For most textile and general manufacturers in India, CO₂, CH₄, and N₂O account for over 95% of total tCO₂e emissions. CO₂ from stationary combustion (boilers, generators) dominates. CH₄ appears in natural gas fugitive emissions and wastewater treatment. N₂O appears in all combustion sources as a minor fraction.
HFCs are material for operations with significant refrigeration or air conditioning — cold chain logistics, pharmaceutical manufacturing, food processing. SF₆ appears in large electrical substations and switchgear. NF₃ is relevant only for electronics manufacturers.
A complete GHG inventory must account for all seven gases, even if the calculation confirms that six of them are de minimis for a specific operation. The documentation of completeness is part of the inventory methodology.
GWP and Converting to tCO₂e
Each gas is converted to CO₂-equivalent (tCO₂e) using its Global Warming Potential (GWP). The GWP values above come from IPCC AR6 (Sixth Assessment Report), the current reference standard. AR5 values remain in use in some legacy calculations — the version used must be documented and applied consistently throughout the inventory.
Sustaineve tracks all 7 Kyoto gases individually at source, applying the correct AR6 GWP values to produce a complete, documented tCO₂e total.