Ozone Depletion and Deforestation

Ozone Depletion

Ø The ozone layer is found in the upper part of the stratosphere.

Ø It protects the earth from the harmful UV rays of the Sun. High energy UV rays break the bonds within the molecules such as DNA and proteins.

Ø Ozone is formed by the action of UV rays on oxygen molecule and its thickness is measured in Dobson units (DU).

Ø The ozone layer is getting depleted by the action of chlorofluorocarbons (CFCs) found in refrigerants and perfumes.

Ø The CFCs are acted upon by UV rays in the stratosphere, liberating the Cl atoms, which act as catalysts to degrade ozone into molecular oxygen.

Ø The ozone depletion is particularly greater in Antarctica, resulting in the formation of a large thinned ozone layer commonly known as ozone hole.

Ø The UV rays of shorter wavelength cause skin cancers, mutations in the cellular DNA, snow-blindness, cataract, etc.

Ø To check this ozone depletion, Montreal Protocol was passed in 1987 to control the use of substances that cause ozone depletion.

Deforestation

Ø It is the unlimited cutting of trees and conversion of forests into cultivable land.

Ø In the beginning of 20th century, India had 30% of its area under forests, which was reduced to just 19.4% by the end of 20th century.

Ø Deforestation is a result of a number of human activities such as increased population and the demand for land.

Ø Trees are cut for timber, fuel, and also for Slash and burn agriculture, also called Jhum cultivation. In this, trees are cut and plant remains in the forest are burned since the ash acts as a fertilizer.

Ø Some of the major effects of deforestation are the increase in carbon-dioxide levels, loss of habitat for wild animals, soil erosion, and consequent desertification.

Ø Deforestation can be controlled by reforestation and afforestation.

In 1980s, the concept of Joint Forest Management was introduced by the government of India. In this, support of local communities was taken for conservation of forests and in return, the local people were free to use the products obtained from the forests.