There is a hole in the ozone layer. What do you understand by this?

Explanation

1. The Ozone layer is found in the upper layer of the atmosphere, the stratosphere.
2. This layer acts as a shield absorbing UV radiations from the sun.
3. The Ozone gas is formed by the action of UV rays on molecular oxygen and also degraded into molecular oxygen in the stratosphere.
4. For the Ozone layer to be intact there has to be balance between the production and degradation, this has been disturbed by the CFCs (Chlorofloro carbons) used in refrigerators.
5. The CFCs react with UV rays to form Cl atoms. They act as a catalysts that degrade the ozone releasing molecular oxygen.
6. The Cl has a permanent and continuing effect on the ozone levels as it is not consumed thus resulting in the thining out of the ozone layer also known as ozone hole.