Which gas is added to the atmosphere in the process of combustion?

During the process of combustion, carbon dioxide (CO2) is the primary gas added to the atmosphere. This occurs when carbon-containing fuels, such as fossil fuels and biomass, are burned in the presence of oxygen, resulting in the release of energy and the formation of CO2 as a byproduct. Additionally, combustion can also produce other gases, such as water vapor (H2O) and various pollutants, depending on the fuel and combustion conditions.