The amount of polluted gases is increasing continuously due to rapid industrialization and pollution from vehicles. The amount of carbon – dioxide in the atmosphere is increasing due to the burning of coal, wood, mineral oil, etc., and breathing process of creatures, volcanic eruption, decaying of vegetation, etc. The causes for the origin of methane include paddy farming, natural swampy lands, mining, termite, burning of organic substances, etc.
Nitrous oxide is produced mainly by the use of nitrogenous fertilizers, burning of organic substances and fossil fuels. Its amount is also increasing due to the industrial production of nylon. Chloro – fluoro – carbons are formed by certain chemical processes. According to the studies conducted by scientists, carbon dioxide contributes 57% in the greenhouse effect, and methane contributes 18%, nitrous oxide contributes 6% and chloro – fluoro – carbons contribute 17% in it.