Capital’s future of extremes
Capital’s future of extremes
23 July 2011
published by www.canberratimes.com.au
Australia — Canberra faces a bleak future of fire, flood and drought as the world warms, according to an official ACT Government report on the effects of climate change.
The frightening vision of the next 40 years includes soaring temperatures, increased deaths and injuries from heat stress, heightened risks of catastrophic bushfires, more extreme flood events but decreased overall rainfall.
As the debate over the Federal Government’s plan for a carbon tax continues to rage, the report prepared for the ACT Government sends a stark warning to territory politicians and their planners to start preparing to cope with the worst effects of climate change.
Private consultants Aecom have assessed the effects of global temperature rises of 2 degrees Celsius, expected by most climate change scientists by 2050, its effects on climatic conditions in the territory and the likely impact on the Canberra’s human population.
For the first time, the report mapped, neighbourhood-by-neighbourhood, the vulnerability of Canberra to the expected changes and has urged the Government to take steps to be prepared for the looming crisis.
Aecom’s report says that Canberra can expect a four-fold increase in days when the temperature rises above 35 degrees and can expect to see temperatures of more than 40 degrees, which are now rare, become regular summer occurrences.
Extreme heat and heatwaves, already the biggest natural killer of Australians, are expected to claim more lives in the capital as the ACT warms and the city’s most vulnerable residents, children, the elderly and disabled, are set to be over-represented on the casualty lists.
Areas of Woden, Tuggeranong, Belconnen and Gungahlin were identified as having populations most at risk of higher numbers of deaths and injury from the increased number of extreme heat events. The number of days when fire danger is rated as high to extreme is tipped to soar by 50 per cent, from 23 a year at present to 36 by 2050.
The ability of the authorities to mitigate risk and control hazards are also predicted to be much diminished, with the window of opportunity for controlled burns growing ever smaller.
Although the city’s fire defences and awareness are at a high standard a legacy of the 2003 firestorm the Aecom researchers recommended that the bushfire alert system be fine-tuned to cope with the escalating danger posed by climate change.
The researchers expect damaging flooding to increase as climate change brings more extreme one-day rain events and noted that ACT Government planners have not started to think about the phenomena in their modelling.
”Climate change is not considered in flood modelling in the ACT,” the report’s authors wrote.
Along with the threat of flash flooding comes the fear, ironically, that decreased overall rainfall could threaten Canberra’s water supplies.
With mean rainfall likely to decline under most climate change scenarios, the Aecom researchers identified the city’s rainfall-dependent water supplies as vulnerable, although the Cotter Dam project is recognised as a sensible precaution against drought.
However, the researchers identified many suburbs where residents’ higher-than-average water use made them vulnerable to global warming-induced shortages.
As more areas are being developed, the ”heat island effect,” in which an urban area becomes significantly hotter than the surrounding countryside, is also likely to increase and researchers admit they are not clear on what the consequences might be.