Question

interrelationship between global warming, acid rain, ozone layer depletion, and photochemical smog?

  

Answer 1

Global warming is the increase in earth’s average temperature due to man-made activities. The major man-made activities responsible for global warming is the increase in CO₂ and methane levels due to industrialization, automobile exhaust, etc. Increased levels of CO₂ in the atmosphere increase the temperature of the earth.

Increased industrial activities and automobile exhaust also lead to generation of sulphur oxides and nitrogen oxides, the major ones being sulphur dioxide, nitrogen dioxide and nitric oxide. SO₂ and NO₂ mix with the moisture in the atmosphere and are precipitated on to the surface of earth as acid rain. Acid rain increase the pH of soil. This is harmful for plants. Acid rain also raises the pH of water bodies and hence is dangerous for aquatic organisms.

Photochemical smog can indirectly lead to increased levels of acid rain. Photochemical smog is formed due to the reaction of sunlight with nitrogen oxides and volatile organic compounds. Photochemical smog leads to generation of particles that remain suspended in air over long periods of time. Photochemical smog has adverse effects on human health, particularly on human respiratory system. These tiny particles enter the human body and can cause breathing difficulties and other serious concerns. Visibility is also affected and loss of vision is an adverse effect of smog.

The temperature of the earth is increased to a certain extent by the ozone layer depletion. The ozone gas forms a protective layer around the earth and prevents the earth from harmful ultraviolet radiation. Extensive use of aerosols, particularly chlorofluorocarbons (HCFCs) deplete the ozone layer and create the ozone hole. HCFCs are radical scavengers and induce the free radical breakdown of ozone. The oxygen radicals combine with HCFCs to form organic compounds. In the absence of ozone, ultraviolet radiation can easily reach the earth and increase the surface temperature of earth.