CO2 equivalents

Because emission figures are converted to CO2 equivalents, the aggregate effect of the various types of greenhouse gases can be calculated. The conversion is based on the ‘Global Warming Potential’ (GWP) – defined as the degree to which a gas contributes to the global greenhouse effect. One kg of CO2 equivalents is equal to the effect of emission of 1 kg of CO2. Emission of 1 kg of laughing gas (N2O; nitrous oxide) equals 298 kg of CO2 equivalents and emission of 1 kg of methane (CH4) equals 25 kg of CO2 equivalents. The GWPs of fluorinated gases range from rather small to huge, e.g. 1 kg of sulphur hexafluoride (SF6) equals 22,800 kg of CO2 equivalents.