Carbon dioxide is not normally considered a pollutant because it is a normal constituent of air. However, excess of carbon dioxide is considered a [pollutant because it leads to adverse effects on the environment. The higher concentration of carbon dioxide in the atmosphere is likely to increase the temperature of the atmosphere. As already discussed carbon dioxide permits the short wavelength visible radiations to pass through it but traps the longer wavelength infra-red radiations (heat waves) reflected by the earth’s surface. This trapping of heat waves causes excessive heating of earth’s atmosphere. This heating effect on earth produced in this way is called GREEN HOUSE EFFECT. The excessive heating of earth and its atmosphere ca have adverse effect on our climate, which will affect all the living beings. The climate will become gradually hot.
According to an estimate, the average temperature of the earth has increased by 10 C in the last 50 years. It is predicted that if the global temperature rises by 3.60 C, the polar ice caps and glaciers would melt. This would increase the water level of oceans by about 100 m and hence lead to the flooding of low-lying coastal areas of the earth.