Sunday, July 6, 2008

Victoria after 2010: heatwaves in 3 out of 4 years

Chris Hammer 
The Age, July 7, 2008

VICTORIA could soon be hit by heatwaves in three out of every four years, as Australia becomes hotter, drier and increasingly drought ravaged.

Drought will occur twice as often and be twice as severe within 20 to 30 years, a joint report by the Bureau of Meteorology and CSIRO examining the extent of drought in Australia has warned.

"While this is a scientific report, parts of these high-level projections read more like a disaster novel than a scientific report," Federal Agriculture Minister Tony Burke said yesterday.

Mr Burke said the sobering analysis had completely rewritten the rules for drought assistance and Australia's agriculture generally.

Victoria has already started warming up and the new weather patterns could start taking hold as soon as 2010, according to the assessment.

"The historical assumption that (exceptionally hot years) occurred once every 20 years has now been revised down to between every one and two years," Prime Minister Kevin Rudd told the ABC.

Mr Burke said: "The thing we know for certain from today is that the ground rules, because of climate change, have themselves changed."

The risk of exceptionally low-rainfall years in Victoria is estimated to rise threefold, and to be exacerbated by a reduction in offsetting exceptionally wet years.

This will trigger exceptionally low-soil moisture levels once in every nine years on average.

The report's findings have serious implications for how governments support farmers through times of drought.

It recommends throwing away the current trigger for drought relief, concluding that the one-in-20-to-25 year definition for exceptional circumstance relief has already been made redundant by climate change. "We need government policy to catch up with what the climate's delivering for our farmers," Mr Burke said.

"If we failed to review drought policy, if we were to continue the neglect and pretend that the climate wasn't changing, we would be leaving our farmers out to dry, well and truly."

The minister said farmers receiving drought assistance would continue to do so while the Government redesigned future policy.

Australiawide, the report concludes that Australians will have heatwaves 10 times more often than in the past.

Before 1968, exceptionally hot years occurred one year in 20.

During the last 40 years that has increased to one year in 10. They are likely to occur every one or two years between 2010 and 2040.

The area of farmland affected by extremely hot years is predicted to grow from about 5% before 1968 to between 40% and 95% over the next three decades.

Southern Australia will be the worst affected, including Victoria, Tasmania, southern parts of Western Australia and South Australia.

The Murray-Darling basin will experience exceptionally hot years two years out of three.

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