Hydrology and Earth System Sciences (Sep 2012)

Changes in Köppen-Geiger climate types under a future climate for Australia: hydrological implications

  • R. S. Crosbie,
  • D. W. Pollock,
  • F. S. Mpelasoka,
  • O. V. Barron,
  • S. P. Charles,
  • M. J. Donn

DOI
https://doi.org/10.5194/hess-16-3341-2012
Journal volume & issue
Vol. 16, no. 9
pp. 3341 – 3349

Abstract

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The Köppen-Geiger climate classification has been used for over a century to delineate climate types across the globe. As it was developed to mimic the distribution of vegetation, it may provide a useful surrogate for making projections of the future distribution of vegetation, and hence resultant hydrological implications, under climate change scenarios. This paper developed projections of the Köppen-Geiger climate types covering the Australian continent for a 2030 and 2050 climate relative to a 1990 historical baseline climate using 17 Global Climate Models (GCMs) and five global warming scenarios. At the highest level of classification for a +2.4 °C future climate (the upper limit projected for 2050) relative to the historical baseline, it was projected that the area of the continent covered by <br><br> &ndash; tropical climate types would increase from 8.8% to 9.1%;<br> &ndash; arid climate types would increase from 76.5% to 81.7%;<br> &ndash; temperate climate types would decrease from 14.7% to 9.2%;<br> &ndash; cold climate types would decrease from 0.016% to 0.001%. <br><br> Previous climate change impact studies on water resources in Australia have assumed a static vegetation distribution. If the change in projected climate types is used as a surrogate for a change in vegetation, then the major transition in climate from temperate to arid in parts of Australia under a drier future climate could cause indirect effects on water resources. A transition from annual cropping to perennial grassland would have a compounding effect on the projected reduction in recharge. In contrast, a transition from forest to grassland would have a mitigating effect on the projected reduction in runoff.