DEFORESTATION by European settlers may be to blame for making Australia's drought longer, hotter and dryer than it would be otherwise.
The "big dry", Australia's 11-year drought, has been blamed on greenhouse gases and natural variability. To see if deforestation played a part, Clive McAlpine of the University of Queensland in Brisbane and colleagues used a climate model to simulate Australian conditions from the 1950s to 2003. They then compared the impact of today's fragmented vegetation, obtained from satellite images, with that of 1788, prior to European settlement.
Over much of south-east Australia, where the drought has hit hardest, less that 10 per cent of the original vegetation remains. The team's model showed that this land clearance has increased the length of droughts in the area by one to two weeks per year. In years of extreme drought, the loss of vegetation caused the number of days above 35 °C to increase by six to 18 days, and the number ...