Why is the ozone layer in the atmosphere important and How does Ozone layer depletion occur?

Why is the ozone layer in the atmosphere important?

The ozone layer is the invisible umbrella that absorbs harmful ultraviolet rays from the sun. Ultraviolet radiation can cause skin cancer in Man. The ozone layer is a natural concentration of ozone. It occurs at a height which varies between 10 to 50 km above the Earth's surface.

Did you know that there is a hole in the ozone layer which is situated over the Antarctic? It was first detected in 1985 by the British Antarctic survey.Since very few people live in the Antarctic, the health risk is minimal. If pollution levels rise, the hole will widen, and South America, Australia and Africa will be affected.

How does Ozone layer depletion occur?

Chemicals such as CFC's, or Chlorofluorocarbons,  Chiefly used in refrigerators, disturb the delicate balance in the ozone layer. Ozone, a colorless toxic gas, forms and decays in the ozone layer. CFC's as well as halons, the chemicals used in fire extinguishers, speed up the rate of decay. So, the rate at which ozone is formed cannot keep up with the rate of decay. The ozone layer is very thin, like a film of oil on water, and holes appear in it. Harmful ultraviolet rays fall on our Earth through these holes.

A rapid, swirling, circular- movements of air called a vortex occurs above each pole. This vortex of air is caused by wind currents, and the rotation of the Earth. During the winter months, in the absence of sunlight, these vortices become very cold. Stratospheric clouds form in these conditions. The presence of these clouds favor chemical reactions, that enable pollutants to reduce the level of ozone.