The government's Commonwealth Scientific and Industrial Research Organisation (CSIRO) predicted in a report that rainfall in parts of eastern Australia were forecast to drop 40 percent by 2070, with a seven degree Celsius rise in temperature.

It said that by 2030 the risk of bushfires will be higher, droughts more severe and rainfall and stream run-off lower.

By 2070, the town of Gunnedah in western New South Wales state will have more than 100 days a year with temperatures over 35 Celsius (95 degrees Fahrenheit) and Walgett may have 83 days a year above 40 Celsius (104 Fahrenheit), said the report.

Such constantly high temperatures could turn normally drought-proof green pastures into brown dustbowls.

"The CSIRO research paints a frightening picture. That's why we need a national approach to climate change," said New South Wales state Premier Morris Iemma.

Howard, although now conceding the existence of climate change, still refuses to sign the Kyoto Protocol aimed at lower greenhouse gas emissions, arguing it is flawed because it does not include big polluters India, China and the United States.

Many scientists say carbon dioxide from burning fossil fuels and methane from agriculture is causing the atmosphere to warm. The Kyoto Protocol obliges about 40 nations to cut emissions by at least 5.2 percent below 1990 levels by 2008-12.

With an Australian election due within a year and the environment emerging as a major political issue, Howard recently announced a number of green projects and called for Asia-wide emissions trading as part of a planned "new-Kyoto".

PERMANENT CHANGE

Professor Mike Young, a water management expert at the University of Adelaide and a member of the Wentworth Group of scientists, said that even when the five-year-long drought breaks Australia will not return to cooler, wetter conditions.

"It is the worst type of drought because after the drought we are not expecting to return back to the old regime," he said.

"The last half of last century was much wetter. What we seem to have done is ... built Australia on the assumption that it was going to be wetter, and we haven't been prepared to make the change back to a much drier regime."

Young said Australia's present water usage, both rural and city, was no longer sustainable. He said water usage must become more efficient and users must pay a realistic price for water.

Sydney's water supply dam is now only at 40 percent of its capacity. With forecasts that dams on the country's main Murray-Darling river system could run out of water within six months, Howard has called for a water summit on Tuesday.

The average inflow of water into the Murray River, which feeds Australia's major growing food belt, is 11,000 gigalitres a year. In the last five months it has received less than 600 gigalitres, with forecasts for the year of 1,000 gigalitres.

Green groups and politicians want irrigators, particularly rice and cotton farmers, to return water to the Murray-Darling.

"Urgent action is needed to address the water crisis," said Greens Senator Rachel Siewert. "There will be no water for some rural towns this summer."