Mechanisms of Ozone Depletion

1.       Natural process: Ultra Violet Solar Radiation; increased solar radiation from sun sports; redistribution of ozone due to upper atmospheric circulation.

2.       Anthropogenic Processes: The chlorofluorocarbons (CFC) and halous released from synthetic chemicals using devices such as refrigerators, spray can dispensers etc reach stratosphere and breakdown the ozone molecule. Similarly sulfur aerosols e.g. HF₆ emitted from factories, nitrous oxides (NO) molecules released from jet places cause destruction of ozone molecules. With rise in worldwide aviation travel NO release into stratosphere is rising causing both ozone depletion and global warming. A large ozone hole was observed to have been formed over Antarctica but measures taken subsequent to Montreal Protocol have substantially helped to recover the hole with ozone again.

Effects of Ozone Depletion

1.       UV rays will reach earth’s surface causing rise of earth’s temperature causing global warming. CFC increases the greenhouse effect of greenhouse effect of CO₂.

2.       Cooling of the stratosphere due to reduced absorption of UV rays in the stratosphere.

3.       Acid Rain – depletion of ozone in stratosphere will lead to increased amount of hydrogen peroxide in the troposphere which would ultimately induce acid rains.

4.       Ozone depletion and increased solar radiation would also increase photochemical processes which in turn would create poisonous urban smog.

5.       Health hazards such as skin cancer, burning of skin, cataract, and side effects of song would be observed.

6.       Ecological effects- Photosynthesis by plants would be affected both on land and sea (phytoplanktons). This in turn would disturb the whole food chains and food webs leading to ecological instability. Besides there will be separate hazards of increased UV radiations on organisms.