The ozone layer is thinning out because of the air pollutants that we are releasing.

Phenomenon:
Ozone Depletion

A layer of ozone gas (O3) surronds the Earth about 40km above the ground. This ozone absorbs harmful UV radiation from the Sun, preventing it from reaching the ground.

Since 1976, there has been an alarming decrease in the amount of ozone in the upper layer of the atmosphere (stratosphere) over the South Pole.

What is causing the depletion of ozone in the stratosphere?

It is caused by chlorofluorocarbons (CFC). They are compounds containing the elements carbon, fluorine and chlorine.

CFCs are widely used as propellants for aerosols and as coolants in refrigerators and air conditioners. They are also used in the manufacture of packing foam.

They are very unreactive and can remain in the atmosphere for a very long time. Over years, they slowly diffuse through the air and up to the stratosphere, where they react with ozone and destroy the ozone layer.

What are the effects of ozone depletion?

The thinning of the ozone layer results in an increased exposure to UV rays from the Sun.

In humans, this can cause diseases like skin cancer and cataract and may also result in a reduced resistance to diseases. Humans are also indirectly affected. Too much UV rays will damage plant tissues and destroy crops, thus reducing food production.

Also, planktons - basic source of food for marine life - would be killed, and this will affect the entire ecosystem. Strong UV rays have also been known for deforming fish larva. In the end, all these would result in widespread hunger.