The Gases and CO₂e
Seven gases, very different potencies, one common unit.
12 min
Greenhouse gas accounting covers several gases, each with a different warming effect per unit mass. They are converted to a common unit — carbon dioxide equivalent, CO₂e — by multiplying by the gas's global warming potential.
| Gas | Typical GWP (100 year) | Common sources |
|---|---|---|
| Carbon dioxide | 1 | Fuel combustion, some processes |
| Methane | ~28 | Gas leakage, landfill, agriculture, wastewater |
| Nitrous oxide | ~265 | Combustion, fertiliser, some processes |
| Hydrofluorocarbons | Hundreds to ~14,800 | Refrigeration, air conditioning, foam blowing |
| Perfluorocarbons | Thousands | Aluminium and semiconductor manufacture |
| Sulphur hexafluoride | ~23,500 | Electrical switchgear insulation |
| Nitrogen trifluoride | ~16,100 | Electronics manufacture |
Why the high-GWP gases matter disproportionately
A leak of a few kilograms of a high-GWP refrigerant can equal the annual emissions of a delivery vehicle. Organisations that account only for fuel and electricity frequently miss a significant part of their footprint sitting in refrigeration systems and switchgear — and those emissions are usually reducible through maintenance rather than capital investment.