Question

Describe how the use of CFC products created a hole in the ozone layer?

Answer 1

(3) What causes this phenomenon?

Scientists have reached consensus that ozone depletion in the stratosphere is caused by ozone depleting chemicals. These chemicals contain chlorine or bromine atom with inherent chemical stability and have long lifetime in the atmosphere, in the range of 40 to 150 years. These chemicals and other trace gases drift up into the stratosphere and become involved in chlorine-releasing reactions. The chlorine atoms then react with the ozone molecules in the presence of sunlight and destroy the ozone molecules. Just one chlorofluorocarbon molecule can destroy tens of thousands of ozone molecules.

These ozone-depleting chemicals are extensively used man-made chemicals including the followings: -

chlorofluorocarbons (CFCs);

halons;

1,1,1-trichloroethane (methyl chloroform);

carbon tetrachloride;

methyl bromide;

hydrobromofluorocarbons (HBFCs);

hydrochlorofluorocarbons (HCFCs); and

bromochloromethane (BCM).