Pub. date: 2008 | Online Pub. Date: May 28, 2008 | DOI: 10.4135/9781412963930 | Print ISBN: 9781412941655 | Online ISBN: 9781412963930| Publisher:SAGE Publications, Inc.About this encyclopedia
Atmospheric ozone (O 3 ) is found mostly between about 9 and 23 miles above the Earth's surface in a region called the stratosphere. This ozone layer acts as a barrier protecting life on Earth from harmful ultraviolet (UV) radiation from the sun. From 1970 on, scientists expressed concern that human-made chemicals, particularly chlorofluorocarbons (CFCs), were thinning the ozone layer. A 1976 report by the U.S. National Academy of Sciences (NAS) concluded that the ozone depletion hypothesis was supported by scientific observations. Calculations suggested a global ozone loss of 5 to 7 percent by 1995, with attendant increases in skin cancer, probable damage to human and animal As ...