The ozone layer is a part of the earth's stratosphere, laying between 15 and 30 kilometers above the earth's surface. It serves the absolutely vital function of shielding the earth from much of the Sun's ultraviolet rays. Without the ozone layer, the earth's temperature would rise to levels unsupportive of human life. Many scientists believe that global climate change, with the increasing incidences of severe weather patterns, has been caused in least in part by the depletion of the ozone layer.
During the 1970s, scientists discovered the ozone layer was shrinking over the Antarctic region. The cause of that shrinkage was traced to the use of man-made chemicals called chlorofluorocarbons (CFCs), which manufacturers used in aerosal spray cans for items like hair sprays, furniture polish and underarm antipersperants. One of the main applications of CFSs was in refrigerants like Freon used in automobile air conditioning systems. Once the linkage between human use of CFCs and ozone depletion was confirmed, governments began to pass laws restricting their use.