David Mark reported this story on Wednesday, October 23, 2013 18:22:16

PETER LLOYD: Despite the extreme bushfire conditions in New South Wales today, there have been no deaths or loss of property.



No doubt that's been a combination of good management, planning and some good luck, particularly given the Blue Mountains fires, which are burning close to a string of towns that are surrounded by bushland.



The statistics show that the three-quarters of people who perish in fires die within 30 metres of the bush and the more extreme the fire weather, the more likely it is that people will die in their home.



An expert in fire risk management says those two facts alone and a warming climate, plus our love of the bush, means we face some hard choices about where we build houses in Australia.



David Mark reports.



DAVID MARK: Bushfires are a fact of life in Australia. Given that, surprisingly little is known about how people die in bushfires.



Recently Justin Leonard, the research leader for Bushfire Urban Design at the CSIRO, and his colleagues set about to rectify that gap in our knowledge.



The result is a database that looks at 825 bushfire deaths over the past 110 years. When they finished, some startling facts jumped out.



JUSTIN LEONARD: What really left an impression on us when we started looking at the general statistics was, in fact, how close to the bush the vast majority of people were at the time of death and also how close their own place of residence they were when they died.



DAVID MARK: It turns out most people die within a stone-throw of the bush.



JUSTIN LEONARD: There was something like over 85 per cent of all of those deaths were actually within 100 metres of the forest and, in fact, about 78 per cent of all the fatalities were within 30 metres of the forest. So you can see that interaction of the fire effects coming out of forested areas and that's excluding grassland areas and areas that are less fuel-loaded than forests.



DAVID MARK: The numbers also show most people die from bushfires when they're in the open.



But as the fire weather gets worse, more and more people die in their homes.



JUSTIN LEONARD: So people are sort of retreating under those really, really severe conditions but the houses and the way people attempt to survive in those houses simply isn't effective once things escalate to that level.



DAVID MARK: Today in the Blue Mountains the fire danger was Extreme; that's one step down from Catastrophic, the worst possible category.



More than two thirds of the deaths over the past 110 years occurred on just 10 days when the fire weather was Catastrophic.



Those days are rare, but:



JUSTIN LEONARD: There's a very clear signal that we're going to see the fire events that we've experienced in the past far more often under climate change for any given area across Australia. So that means that a broadening of the fire season and far more frequent number of days within that fire season that can promote the types of fire behaviour that will cause life and house loss.



DAVID MARK: Professor Ross Bradstock is from the Centre for Environmental Risk Management of Bushfires at the University of Wollongong.



ROSS BRADSTOCK: There's now a copious literature on future fire weather coming out of climate projections under global warming so, you know, we know what's down the track.



DAVID MARK: He says the confluence of facts - where people die, their proximity to the bush and the likelihood of more catastrophic days - suggests Australians might have to rethink their decision to build and live near the bush.



ROSS BRADSTOCK: Yeah, well there's a fairly obvious message that if you choose to live in these situations, you do have to accept a high risk of loss of your property and, perhaps, injury and death.



DAVID MARK: Justin Leonard:



JUSTIN LEONARD: Not only do we need to be effective in designing houses that are relatively close to the bush to be effective in a bushfire, but also to provide defendable space or space around those houses that are free from fuel, so that if people have to leave their house they can move onto burnt ground with a minimum sort of distance from the forest that ensures that they won't be sort of fatally exposed if they have to leave a burning house.



DAVID MARK: Professor Ross Bradstock:



ROSS BRADSTOCK: And, I guess, one of the key messages is: education, education and education. I think many people don't really understand the risks they face to live in these beautiful places.



PETER LLOYD: That's Professor Ross Bradstock from the Centre for Environmental Risk Management of Bushfires at the University of Wollongong. David Mark was the reporter.