CO2 is generated by the combustion of heating oil or natural gas and contributes to the greenhouse effect. The calculation of the CO2 emissions includes not just the fuel itself, but also the chain from raw materials recovery to heat transfer from the radiator.
CO2 emissions in kg/kWh for energy sources
heating oil, light 0.260 kg CO2/kWh
natural gas 0.200 kg CO2/kWh