Question

Explain the ozone layer, its advantages, and its depletion.

Answer 1

Ozone layer :

1. Ozone is a highly reactive gas that is made of three oxygen atoms and is found in the upper Stratosphere, which is about 15–30 kilometers above the Earth’s surface.
2. Ozone can be formed naturally or through man-made activities, that are discussed as follows:

• Natural: In the upper atmosphere ( stratosphere) the ozone is formed naturally through the interaction of ultraviolet radiation of the sun with molecular oxygen (O₂). The ozone layer protects the earth from harmful Ultraviolet rays emitted from the sun.
• Man-made: The ground-level ozone or Tropospheric ozone is breathed by us, and is formed primarily from photochemical reactions between air pollutants such as volatile organic compounds and Nitrogen oxide.

Advantages of Ozone :

1. The ozone layer surrounding the earth's atmosphere acts as a shield by absorbing the harmful ultraviolet radiations of the sunlight to protect the living organisms from the harmful effects of UV rays.
2. It is a greenhouse gas so helps in maintaining the earth's temperature.

Depletion of ozone layer :

1. The depletion or reduction in the ozone layer is caused due to the use of various ozone-depleting substances by human beings.
2. The industries are the major sources of ozone-depleting substances such as chemical Chlorofluorocarbons (CFCs), carbon tetrachloride, methyl chloroform, methyl bromide, and nitrogen oxides, halogens, etc.
3. These chemicals continuously find a way to reach the ozone and react with it which has led to the depletion of ozone and an ozone hole is formed.
4. Among all the chemicals, the chlorofluorocarbons (group of synthetic chemicals) released from refrigerators and air conditioners, have a major role in the depletion of ozone. The chlorofluorocarbons (CFCs) produce “active Chlorine” (Cl and ClO radicals) in the presence of UV radiations, which react with ozone and destroy ozone catalytically by converting it into oxygen.