1 Why is it important?

Earth’s surface is warming rapidly, and our global climate is changing, with impacts already discernible to the present generation. Rising air temperatures, increasing severity and frequency of heatwaves, changing rainfall patterns with more extreme and frequent drought and flood, altered ocean temperature and chemistry, and sea level rise all present potential significant risks to our environment, economy, society and way of life.

South Australia is already seeing the effects of climate change (Box 1). South Australia’s future climate challenges include:

  • securing a reliable urban water supply
  • coping with the effects on
    • agricultural productivity of higher temperatures, more frequent extreme weather events, reduced rainfall and greater variability of rainfall distribution
    • biodiversity of higher temperatures, reduced and altered patterns of rainfall, and changes in the severity and frequency of extreme weather and bushfire
    • coastal settlements, infrastructure and coastal ecosystems of sea level rise and storm surge
    • marine ecosystems, fisheries and aquaculture of warmer, more acidic oceans and altered ocean currents
    • human health and infrastructure of an increased number and severity of heatwaves, bushfires and extreme weather events.

Box 1 The critical decade: extreme weather for South Australia

Hot days and heatwaves

  • The summer of 2012–13 was the hottest on record and included the highest sea surface temperatures on record for the Australian region.
  • In Adelaide, from 1993 to 2006, an increase in total hospital admissions of 7% was recorded during heatwave periods compared with non-heatwave periods.
  • The nature of heatwaves has already changed in many parts of Australia. Over 1971–2008, the duration and frequency of heatwaves have increased, and the hottest days during a heatwave have become even hotter.
  • In Adelaide, the long-term average (1961–1990) number of days per year above 35 °C was 17.5, but during 2000–09 the average number of such days rose to 25.1. This increase is more rapid than climate model projections.
  • Research at the Natural Hazards Research Centre has shown that heatwaves are the most significant natural hazard in Australia in terms of loss of life.


  • Over 2010–11, every state and territory had sites that either set all-time rainfall records for a two-year period or were very much above average.
  • Across Australia, it is more likely than not that heavy rainfall events will become more frequent as the temperature increases.


  • During 2002–03, drought is estimated to have reduced Australia’s agricultural output by 26%.
  • During the drought of 1997–2009, the inflows into the Murray–Darling system were the lowest on record.
  • In 2006–07, it is estimated that drought reduced national gross domestic product by almost 1%.
  • For both south-west and south-east Australia, nearly all of the climate models used in a recent analysis project a significant increase in drought by the end of the century.


  • The Forest Fire Danger Index, one of the measures of bushfire threat, increased significantly at 16 of 38 weather stations across Australia between 1973 and 2010, with none of the stations recording a significant decrease.
  • The increase has been most prominent in south-east Australia, and has been manifest as a longer duration fire season, with fire weather extending into November and March.

Sea level rise

  • A sea level rise of 0.5 metres (compared with 1990), which lies near the lower end of the estimates for 2100, leads to surprisingly large impacts.
  • For coastal areas around Australia’s largest cities, a sea level rise of 0.5 metres would lead to very large increases in the incidence of extreme events, typically by a factor of several hundred and, in some places, by as much as one thousand.
  • A multiplying factor of 100 means that a so-called one-in-a-hundred-year event would occur on average every year.

Source: Climate Commission (2013)

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