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http://www.sciencedaily.com/releases/2007/10/071027180556.htm
Land Clearing Triggers Hotter Droughts, Australian Research Shows
ScienceDaily (Oct. 31, 2007) – A University of Queensland scientist
has led groundbreaking research which shows that clearing of native
vegetation has made recent Australian droughts hotter.
In an Australian first, they applied the CSIRO Mark 3 climate model,
satellite data and the DNRW supercomputer, and showed that 150 years
of land clearing added significantly to the warming and drying of
eastern Australia.
“Our work shows that the 2002-03 El Nino drought in eastern Australia
was on average two degrees Centigrade hotter because of vegetation
clearing,” said Dr Clive McAlpine of the University of Queensland.
“Based on this research, it would be fair to say that the current
drought has been made worse by past clearing of native vegetation.
Our findings highlight that it is too simplistic to attribute climate
change purely to greenhouse gases,” he continued. “Protection and
restoration of Australia’s native vegetation needs to be a critical
consideration in mitigating climate change.”
Dr McAlpine of UQ’s Centre for Remote Sensing and Spatial Information
Science and Mr Jozef Syktus, principal scientist in the Queensland
Natural Resources and Water Department (DNRW), headed a study which
will be published later this year in Geophysical Research Letters,
the journal of the American Geophysical Union. Co-authors are Dr
Hamish McGowan, Associate Professor Stuart Phinn and Dr Ravinesh Deo
– all of UQ – Dr Peter Lawrence of the University of Colorado and Dr
Ian Watterson of CSIRO.
The researchers found that mean summer rainfall decreased by between
four percent and 12 percent in eastern Australia, and by four percent
and eight percent in southwest Western Australia. These were the
regions of most extensive historical clearing.
“Consistent with actual climate trends, eastern Australia was between
0.4 degrees Centigrade and two degrees Centigrade warmer, and
southwest Western Australia was between 0.4 degrees and 0.8 degrees
warmer.
“Native vegetation moderates climate fluctuations, and this has
important, largely unrecognised consequences for agriculture and
stressed land and water resources,” Dr McAlpine said.
Australian native vegetation holds more moisture that subsequently
evaporates and recycles back as rainfall. It also reflects into space
less shortwave solar radiation than broadacre crops and improved
pastures, and this process keeps the surface temperature cooler and
aids cloud formation.
The project, Modeling Impacts of Vegetation Cover Change on Regional
Climate, was funded by Land and Water Australia Research and
Development Corporation (Canberra) as part of their Innovation
Research Program.
Adapted from materials provided by University Of Queensland.
University Of Queensland (2007, October 31). Land Clearing Triggers
Hotter Droughts, Australian Research Shows. ScienceDaily. Retrieved
February 15, 2008, from
http://www.sciencedaily.com-/releases/2007/10/071027180556.htm
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