MY bird.

The beginning of the CFC(chlorofluorocarbons) era started in 1928, when CFC' were invented by a Du Pont chemist. CFC' were best known as "freons" and became famous as a safe, nonflammable refrigerant. It's invention became a great triumph when Freon took the place of sulfur dioxide or ammonia which was used as the working liquid in refrigerators. It eventually became widely used in automobile air conditioners and nontoxic propellants in aerosol cans. It's insulating properties also was used for blowing agents for plastics and foam cups.
Thus CFCs became used all over the world and its business got bigger and bigger until late in 1973. Sherwood Rowland and Mario Molina, two distinguished chemists, came up with a surprising result in his calculations concerning the CFCs and ozone layer. CFCs are basically inactive in the troposphere(around the altitude of 50,000 feet) so it would gradually drift upward until they reached the mid-stratosphere.(about 100,000 feet) At this point CFCs woul...