What fossil fuels produce a gas when that are burned that adds to the greenhouse effect

Carbon dioxide (CO2)

Explanation:

Carbon dioxide (CO2) makes up the vast majority of greenhouse gas emissions from the sector, but smaller amounts of methane (CH4) and nitrous oxide (N2O) are also emitted. These gases are released during the combustion of fossil fuels, such as coal, oil, and natural gas, to produce electricity.