SYDNEY Australia, the driest inhabited continent in the world, will get even hotter and drier due to climate change triggered mainly by greenhouse gases, authorities said on Tuesday in new projections.
Temperatures had already increased, sea levels had risen and the oceans surrounding the country had warmed, said Scott Power, principal research scientist at the Bureau of Meteorology.
"Further warming and further sea level rise seems inevitable," he said, releasing the "Climate Change in Australia" report produced by the Commonwealth Scientific and Industrial Research Organization and the Bureau of Meteorology.
Temperatures were expected to rise by about 1 degree Celsius by 2030 and could rise more, said Penny Whetton, head of climate impact and risk at the government-backed CSIRO.
Rainfall is forecast to decrease by up to 20 percent by 2070 in southern Australia if greenhouse gas emissions are low and by up to 30 percent if gas emissions are high.
Temperatures in Australia have already risen by 0.9 degrees Celsius since 1950, producing the hottest year on record in 2005.
The present year could eclipse that in key areas.
Southern Australia, and the Murray-Darling Basin food bowl in particular, had its hottest year on record between January and September this year, new data shows.
"It's bitterly disappointing ... that the rainfall during the last month in the Murray-Darling Basin, just when we were all hoping for well above average rainfall, turns out to be the lowest on record," Power said.
"We're more confident than ever before that these changes can be largely attributed to human intervention in the climate."
Australia was likely to be hit harder by climate change than other sub-tropical parts of the world, including South Africa, the Mediterranean and parts of South America, because it was already very dry, Whetton said.
Frequently recurring Australian droughts will be more severe because of higher temperatures, while periods of high fire danger are increasing, as is coastal flooding from storms.
Inland parts of Australia, home to vast agricultural enterprises producing wheat and cattle which supply export markets in Asia and the Middle East, would warm faster than coastal areas and receive less rainfall, Whetton said.
Dryland crops such as wheat could possibly increase because of more carbon dioxide in the atmosphere, if rainfall decline was not too large, Whetton said.
But Australia's wheat crop has already been hit hard by drought in 2002, 2006 and 2007. And there will be less water for irrigated crops, which include grapes, cotton and rice.
Higher temperatures increased coral bleaching and could pose a severe risk to the Great Barrier Reef, she said.
City water supplies could decrease significantly. Melbourne and parts of southern Victoria state have already had 10 years of below-average rainfall.
At low emissions of greenhouse gases, warming of between 1 degree Celsius and 2.5 degrees was expected by 2070, with a best estimate of 1.8 degrees, Whetton said.
At high emissions, the best estimate was warming of 3.4 degrees, in a range of 2.2 degrees to 5 degrees.