By Poppy Johnston in Canberra
Australia may not have the infamous Santa Ana winds fanning flames through the suburbs of Los Angeles in the middle of winter, but climate change and urban sprawl make the nation’s cities more vulnerable to fire.
Cities such as Adelaide and Perth share the same Mediterranean climate type as the southern Californian metropolis devastated by wildfires, and that poses a similar risk.
Rising temperatures are causing the tropics to expand like “earth’s bulging waistline”, Central Queensland University professor of environmental geography Steve Turton says, encroaching on areas with Mediterranean climates closer to the poles.
For regions experiencing this transition, the era of long, hot and dry summers and mild, wet autumns and winters is giving way to less cool-season rainfall.
Perth has already had a 20 per cent fall in average rainfall since the 1970s, Professor Turton told AAP, with a more modest decline in Adelaide.
For Los Angeles, dry conditions and water shortages were exacerbated by another side-effect of its fading Mediterranean climate – spells of persistent rainfall, followed by prolonged periods without.
This allowed vegetation to grow madly and then dry out, priming the city for disaster once the gusty Santa Ana winds got going – a cool-season phenomenon unique to the region involving dry air from the desert blowing to the southern Californian coast.
“Nothing could have prevented it,” Prof Turton said.
“All the water in the world would not stop a firestorm like that.”
Australian cities were unlikely to experience blazes of a similar scale in winter without the incredibly strong, dry and hot Santa Ana winds, he said.
But the warming climate is already lengthening Australia’s normal bushfire season into spring and autumn, he added.
Jim Smith, a former deputy commissioner of Fire and Rescue NSW, said longer and more destructive seasons stretch firefighting resources.
He worries states and territories would not be able to share if they are busy fighting their own blazes.
The changing climate had further narrowed the window for hazard reduction burning, with weather over the past few years either too wet or too hot and dry.
Many parts of Australia had endured a similar run of heavy rainfall years as LA, allowing shrubs and other vegetation to build up, Mr Smith warned.
“Once we hit the dry it’s going to be a different kettle of fish,” he told AAP.
While Sydney and Melbourne are classed as cool temperate climates and not experiencing the same changes in rainfall patterns as Adelaide and Perth, Prof Turton said they were still getting drier and hotter.
They are also growing quickly and expanding further into bushland on the urban fringe.
He was confident Australian authorities are better prepared than in LA and regulations for fire-resilient construction and urban planning were more robust, especially in cities at risk such as Canberra.
But the professor worries places with typically wet summer months such as Brisbane may underestimate the risk of a serious fire during a drier El Nino weather pattern.
“More and more people are living in these bush blocks around the city, and a lot of these bush blocks are overgrown,” he said.
City-fringe residents of suburbs close to bushland were prone to “bush blindness”, says fire preparedness expert and La Trobe University adjunct professor Jim McLennan.
“They see the houses on either side of them, but they don’t really see the bush on the other side of the road,” he told AAP.
When it come to fire preparedness, home owners in rural areas or small towns were typically on the front foot.
It was those living on urban bushland fringe who were generally less prepared.
“Many of these people come from inner-city areas where bushfires are something that happens on television, to other people in other places,” he said.
“They don’t come to an urban bushland fringe area with a with a knowledge base or an expectation of bushfires.”
He recommended vigilant vegetation management for anyone living near the bush to protect their homes.
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