Which gas makes up the majority of air pollutants

carbon dioxide makes up the majority of air pollutants.

Explanation:

carbon dioxide is released in the atmosphere  through combustion of natural gases, fossil fuels and petroleum. It is also released when trash is burned and when factories let out smoke. Human activities like deforestation also causes increase in the amount of carbon dioxide in the air as plants need carbon dioxide for photosynthesis and cutting trees and result in less absorption of carbon dioxide by the trees. It is a harmful greenhouse gas that traps heat in the atmosphere which increases the greenhouse effect and thus it leads to global warming.