4613.0 - Australia's Environment: Issues and Trends, 2007
ARCHIVED ISSUE Released at 11:30 AM (CANBERRA TIME) 11/01/2008
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Consumption of ozone depleting substances Ozone in the upper atmosphere protects life on the Earth's surface by absorbing most of the sun's harmful ultraviolet B radiation. Certain substances trigger the depletion of atmospheric ozone. Human activity has been responsible for increasing the concentrations of ozone depleting substances in the atmosphere. The main substances responsible for ozone depletion are chlorofluorocarbons (CFCs) traditionally used in refrigeration, foam production and aerosols, and halons used in the fire protection industry. Excessive UV radiation reaching the Earth's surface can cause health problems for people and other organisms, including eye, skin and immune system damage. UV radiation can also affect crop yields and marine plankton (which may have flow-on effects for marine ecosystems). Radiation can degrade wood, paper, cotton, wool and plastics. Estimates of Australia's total consumption of ozone depleting substances, weighted according to the ozone depleting potential of each, are presented in the graph above as ozone depleting potential tonnes (ODPTs). Consumption in 1989 was over 15,000 ODPTs. By 1996 it had fallen to just over 800 ODPTs. Between 1996 and 2006, consumption fell by a further 80% to just over 160 ODPTs, which represents around 1% of Australia’s consumption of ozone depleting substances in 1989. Consumption in 2006 was mostly composed of hydrocholorfluorocarbons (HCFCs) and methyl bromide. Australia stopped the importation and production of CFCs during the 1990s and HCFCs are minor ozone depleting substances used as interim replacements for CFCs. Following two decades of rapid growth, the ozone 'hole' over Antarctica has maintained its current size of 25 million square kilometres since the mid-1990s. However, there are indications that the concentration of ozone in the upper atmosphere over Australia may have started to increase since 2000 (Endnote 1). Consumption of ozone depleting substances Endnotes(a) Ozone depleting potential tonnes are an aggregated scale of measurement which allows the addition of quantities of different gases and then weights them according to the amount of ozone each could potentially deplete. Source: Available from the Department of Environment and Water Resources on request.
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