SOUTH-EASTERN Australia will have to endure three times as many high-risk bushfire days over the century because of climate change, one of the world's biggest re-insurers says.
Costs to Australia from natural catastrophes have almost quadrupled from 1980 to reach $6.3 billion a year, a figure which will soar to $23 billion by 2050, according to Munich Re's latest Expect the Unexpected report.
Most of the threats, ranging from droughts to heatwaves and sea-level rise, will be worsened by a warming planet caused by rising greenhouse gas levels, Eberhard Faust, head of climate risk research for Munich Re, said.
"All these perils could be affected negatively by climate change. We think the risk will increase over the decades to come."
Bushfire risks will be elevated by a combination of worse droughts and also rising hotter temperatures.
"In terms of the atmospheric conditions which are prone to forest fires, the models project a three-fold increase in frequency by the end of the century for southern and eastern Australia," Dr Faust said.
While north-east Australia can expect the number of tropical cyclones of moderate to medium intensity to drop by as much as 35 per cent, the most powerful storms will likely increase in frequency, climate models indicate.
The region of cyclones' maximum intensity is also shifting poleward in both the northern and southern hemispheres. That means a category 3-strength cyclone hitting Brisbane "is on the cards", Dr Faust said.
"Insurers should really get it on the radar...and think about the huge exposure and what the consequences would be."
Shifting wind patterns that may hamper the formation of cyclones have other consequences, such as triggering more thunderstorms. These already count among Australia's biggest natural disasters, such as the April 1999 Sydney hailstorm that left a $3.8 billion damage bill in today's dollars.
For Melbourne, the number of days a year with atmospheric conditions conducive for thunderstorms will rise by 20 per cent by the end of the century, based on a high global emissions trajectory.
While nations can limit the damage by curbing carbon emissions, constructing more resilient homes, bridges and other buildings would cut Australia's future repair bills. Such spending can also help protect against a threat few Australians have considered - earthquakes.
Melbourne, Sydney, Perth and especially Adelaide are located in areas with an "enhanced level of seismicity", with the South Australian capital rocked by a magnitude-5.4 quake in 1954, Munich Re said.
