Question

The major cause for depletion of ozone layer in stratosphere can be attributed to:

• A. Increase in the level of greenhouse gases.
• B. Increased usage of CFCs.
• C. Decreased use of CFCs.
• D. Increase in sulphur dioxide and carbon monoxide.

Answer 1

The correct option is B

Increased usage of CFCs.

The ozone depletion process begins when CFCs and other ozone-depleting substances (ODS) are emitted into the atmosphere. CFCs are extremely stable, and they do not dissolve in rain. After a period of time, CFC molecules reach the stratosphere. Due to the action of UV rays, CFCs release chlorine atoms.These chlorine atoms react with ozone molecules and destroy the ozone layer.
It is estimated that one chlorine atom can destroy over 1,00,000 ozone molecules before it is removed from the stratosphere.