Problems Associated with CFCs

Monitoring and Management‎ > ‎4. The Atmosphere‎ > ‎

Discuss the problems associated with the use of CFCs and assess the effectiveness of steps taken to alleviate these problems

  • Once in the stratosphere, CFCs cause the destruction of ozone, with one CFC molecule being able to destroy thousands of ozone molecules. (See two below)
  • This causes a decrease in stratospheric ozone concentration, particularly at the poles, and this decrease was first detected in the 1970s and 1980s.
  • Ozone holes: Marked decreases in the concentration of ozone in the ozone layer above the north and south poles.
  • Because the cycle of ozone formation and decomposition absorbs medium and high energy ultraviolet radiation, a decrease in ozone concentration causes more of this radiation to reach the surface of the earth.
  • Medium to high energy ultraviolet radiation can cause:
    • Sunburn.
    • Skin cancers.
    • Eye cataracts.
    • Decreased immune response.
    • Plant damage.
    • Polymer decomposition.
  • The only way to stop ozone destruction by CFCs is to prevent the releasing of the substances.
  • There have been several international agreements aimed at stopping the use of CFCs and other ozone-destroying compounds.
    • The Vienna Convention of 1985 established the framework for the protection of the ozone layer.
    • The Montreal Protocol (The Montreal Protocol on Substances which Deplete the Ozone Layer) was signed in 1987 by 27 nations, and involved:
      • Freezing CFC production at 1986 levels immediately.
      • Reducing CFC production by 50% by the year 2000.
    • A further agreement made in London in 1990 involved:
      • Eliminating the production and use of CFCs, halons, and carbon tetrachloride by 2000, with this date being extended by ten years for developing nations.
      • Eliminating the production and use of 1,1,1-trichloroethane (methyl chloroform) by 2005.
      • Eliminating the production and use of HCFCs by 2040 at the latest, but preferably by 2020.
    • A further agreement made in Copenhagen in 1992 involved:
      • Eliminating the production and use of halons by the end of 1994.
      • Eliminating the production and use of CFCs and 1,1,1-trichloroethane (methyl chloroform) by 1996.
      • Providing financial aid to developing nations for the implementation of the above measures.
  • More developed signatory nations to the above agreements, such as Australia, have been quite successful in adhering to terms and timetables.
  • Recent research shows that these international agreements have been successful in solving the problem of ozone depletion.