Ozone is a natural gas that exists in two layers: one near the earthâ€™s surface (troposphere) and the other high in the stratosphere between the earth and the sun.
Ozone near the earth causes smog, but the ozone layer between the earth and the sun protects us from the sunâ€™s ultraviolet (UV) rays. Unfiltered, these UV rays harm human beings by causing skin cancer and eye damage.
In the 1980s scientists discovered that human activity was causing the upper ozone layer to break down. The choloroflurocarbons (CFCs) used in such things as air conditioning, soap-making, and aerosol products were being carried to the ozone layer where the UV radiation broke down the CFCs, releasing chlorine atoms. Each chlorine atom destroyed as many as 100,000 ozone molecules as long as it lingered in the stratosphere. Certain pesticides and other chemicals also have a destructive effect on the ozone layer.
In 1985, world leaders met in whatâ€™s called the Vienna Convention and drew up a framework for dealing with the dangers of a depleted ozone layer.
The discovery in the same year by the British Antarctic Survey of an â€œozone holeâ€ over the Antarctic led to the Montreal Protocol which spelled out what countries should do in order to protect the ozone layer. As might be expected, manufacturers using CFCs resisted, but the international community actually moved quickly to ratify the Protocol. The U.S. signed in 1988. By now, just about all the countries in the world have done the same.
Wouldnâ€™t it be great if world leaders could agree in this way on all the other dreadful man-made threats to the planet?