Up in the sky, above the air we breathe, there’s a layer called the stratosphere. Ozone is produced in the stratosphere by the action of ultraviolet light on oxygen. It helps us by blocking out rays from the sun that can harm our skin, and by letting the rays that are good for us from unwanted amounts of radiation.
Now the ozone layers is being diminished at the poles by gases that people have made. The gases are called chloroflurocarbons or CFC’s, and halons. They are used in refrigerators, fire extinguishers, air conditioners, plastic, and other things.
The CFC’s are not easily destroyed in the troposphere and, therefore, make their way up to the stratosphere where the layer of ozone is and react to destroy the ozone. Scientists are concerned about the ozone layer, because a lot of it has gone away in just a few years.
Stability is what makes CFC’s a threat. Chemicals which contain fluorine and chlorine may resist breakdown for decades. Eventually, they drift into the stratosphere, some 10 to 32 kilometers, or 6 to 20 miles above the Earth. There the sun’s unfiltered ultraviolet rays destroy CFC molecules, releasing the chemicals chlorine atoms.
The release of chlorine, in turn, triggers a more threatening reaction. Chlorine atoms can catalyze the destruction of 100,000 molecules of ozone. If uncontrolled, it is predicted that CFC’s could destroy a significant part of the vital ozone layer in a hundred years. For this reason we have virtually stopped production of the persistent CFC’s.
At ground level, ozone is the major pollutant and health threat. But in the stratosphere, it protects us by absorbing the sun’s ultraviolet rays. Unfiltered by ozone, those rays could seriously damage animals and plants. Without the ozone layer, life itself may not be possible.