Ozone is concentrated in a layer in the stratosphere, about 15-30 kilometres above the earth’s surface. Ozone is a molecule containing three oxygen atoms. It is blue in colour and has a strong odour.
Significance of ozone layer :
Even the small amount of ozone plays a key role in the atmosphere. The ozone layer absorbs a portion of the radiation from the sun, preventing it from reaching the planets. Most important of all it absorbs the portion of ultra violet light which causes many harmful effects including various types of skin cancer and harm to some crops, certain materials and some forms of marine life.
Ozone depletion :
Certain industrial processes and consumer products results in the emission of ozone depleting substances to the atmosphere. Chlorofluoro carbons used in almost all refrigeration and air conditioning systems destroy ozone layer. The ozone hole is not really a hole, but it was observed that there is less ozone in Antarctica than in arctic region.
Conservation of ozone layer :
The discovery of an ozone hole over Antarctica prompted action to control the use of gases which have a destructive effect on the ozone layer. From this concern emerged the Montreal protocol on substances that deplete the ozone layer signed by 24 countries in 1987.
