Ozone is a gas found throughout the atmosphere, and is most highly concentrated between 10 and 50 km above sea level (Global). This is known as the ozone layer. The ozone layer makes life on earth possible by protecting us from the damaging effects of ultraviolet radiation from the sun. Recent evidence has shown that some parts of the ozone layer are getting thinner, and there is some controversy as to whether this is due to human activity, specifically the use of chemicals known as CFCs and HCFCs. These chlorine-containing compounds are used in aerosols, refrigerants. Solvents and foam insulation and drift up into the stratosphere where small amounts of these chemicals are able to destroy large amounts of ozone.
People talking about the ozone layer are usually referring to the relatively high concentration of ozone in the stratosphere (Mims). However, about 10 percent of the ozone lies in the troposphere, the lowest portion of the atmosphere, which contains 90 percent of the atmosphere and nearly all the atmosphere's water vapor. Although the ozone in the trophosphere is only a fraction of the total ozone, it absorbs UV radiation from the sun much more efficiently than an equal amount of ozone in the stratosphere. This is because scattering by dust particles and aerosols increases the distance rays have to travel from the sun to the surface of the earth, yet it is often referred to as bad ozone because of its adverse in high concentrations effects. Some scientists believe the decline in the ozone layer is primarily a byproduct of natural meteorological cycles, a changing climate, and possibly the solar cycle, and point to fluctuating ozone cycles ovdr the past 50 or more years. Others believe it is due to volcanic activity, and that the effects of human activity are very minor.
"Global Warming, The Ozone Layer and Acid Rain." 2004. 27 Apr. 2005. < HYPERLINK