Only a few factors combine to create the problem of ozone layer depletion.  The production and emission of CFCs, chlorofluorocarbons, is by far the leading cause.

Many countries have called for the end of CFC production because only a few produce the chemical.  However, those industries that do use CFCs do not want to discontinue usage of this highly valuable industrial chemical.

CFCs are used in industry in a variety of ways and have been amazingly useful in many products.  Discovered in the 1930s by American chemist Thomas Midgley, CFCs came to be used in refrigerators, home insulation, plastic foam, and throwaway food containers.

Only later did people realize the disaster CFCs caused in the stratosphere.  There, the chlorine atom is removed from the CFC and attracts one of the three oxygen atoms in the ozone molecule.  The process continues, and a single chlorine atom can destroy over 100,000 molecules of ozone.

In 1974, Sherwood Rowland and Mario Molina followed the path of CFCs.  Their research proved that CFCs were entering the atmosphere, and they concluded that 99% of all CFC molecules would end up in the stratosphere.

Only in 1984, when the ozone layer hole was discovered over Antarctica, was the proof truly conclusive.  At that point, it was hard to question the destructive capabilities of CFCs.

Even if CFCs were banned, problems would remain.  There would still be no way to remove the CFCs that are now present in the environment.  Clearly though, something must be done to limit this international problem in the future.