A layer of gas called ozone sits up around 25-30 kms above the earth’s surface. Ozone is made up of oxygen and is produced naturally in the atmosphere. As the presence of ozone gets reduced in the atmosphere, it causes the ozone layer to get thinner and thinner. The more ozone layer gets thin, the more big gets the size of ozone hole.
Ozone layer is important because it prevents too many harmful ultra violet rays from reaching earth. Ultra violet rays have the capability to destroy plants and animals and can cause skin cancer, cataracts to human beings. Existence of life on earth is possible only because of the presence of ozone layer around the earth.
This ozone depletion was worrisome, because it was taking place at an unprecedented rate.