For centuries, the ozone layers have protected our world from the sun’s ultraviolet radiation and years ago the earth could withstand the heat before humans developed harmful chemicals. As humans developed technology, the ozone layer will get broken down, by such chemicals as chlorofluorocarbons (CFCs). In1985, scientists discovered that a hole has appeared in the ozone layer above Antarctica. Without the ozone layer, humans would absorb UV radiation, which can cause dangerous illnesses.
In September 1985 the hole in the ozone layer was 4.6 million square miles wide. In September 1998 it has increased to 10.5 million square miles, and it was 11 million square miles wide in September 2000.
The earth’s atmosphere is made up of four separate layers. The layer closest to the earth is troposphere, then the stratosphere, the mesosphere, and the thermosphere. The sun’s heat is absorbed by land, air, and oceans, which takes about 30 to 40 percent of the heat then the rest of it is given off back to space.
Source: Dolan, Edward J. Our Poisoned Sky. Dutton: Cobblehill Books, 1991.