Part 1 of Essay
CFCs are a family of man-made gases used for various industrial purposes. First developed in the 1920's in the United States, CFCs have been used in large quantaties since 1950. The industrialized countries can account for over 80% of CFCs use. CFC-11 is used primarily as a propellant in aerosol cans, although its use h ....

Part 2 of Essay
.... In addition over the last two decades the percentage increase of CFCs in the atmosphere has been higher than any other greenhouse gas. By 1990 the increase was 4-12% a year. CFCs also destroy ozone - itself a greenhouse gas - their net effect on climate is unclear. The strength of the indirect effect of ozone depletion depends on variables such as temperature of the upper atmosphere and cannot yet be measured with any confidence. According to new research, however, it is possible that the indirect eff ....