Emissions related to energy use include emissions of CO₂, CH₄, N₂O, NO_x, CO, and NMVOCs. They also include emissions of sulfur dioxide (SO₂).

1. CO₂ Emissions

Carbon dioxide (CO₂) emissions result from the oxidation of the carbon in fuels during combustion. In perfect combustion conditions, the total carbon content of fuels would be converted to CO₂. However, real combustion processes are not perfect and result in small amounts of partially oxidized and unoxidized carbon.