It's like planting a tree in a forest. On Wednesday, police in New South Wales said they were investigating at least seven "suspicious" fires, and on Thursday a year-old boy was charged with arson in Queensland. But what does "broken" mean?
A review of decades of bushfire studies by Matthew Willis found revenge - against an employer or ex-partner - was a "primary" motive. One man told ABC that he started a bushfire after finding out his girlfriend was sleeping with someone else. At the same time, arsonists are often "odd", marginalised, and angry at society - " weird Pete down the road ", as Dr Read puts it. That begins to explain why things get worse when there are already bushfires.
People who are angry - and irrational - are happy to make things worse for people already suffering. There is also a "small proportion" of arsonists, Dr Read says, who simply like fire the term pyromaniac is no longer used. In February there were bushfires across the state of Victoria, eventually killing people.
At least ten of those deaths, in the town of Churchill, were down to Sokaluk. When the fire raged, Sokaluk "sat on his roof and watched them with great glee", says Dr Read. Sokaluk perfectly fit the profile of the older bushfire arsonist - he was 39, bullied at school, and struggled to read and write.
But he didn't just watch - at one point, he took his dog and went to help a man dampen fires around his house. Mountain Ash can only regenerate from seeds, and fire is essential to provide the right conditions for their germination. However, if fires occur before the young trees reach maturity and produce seed at 50 years old , the species may be completely wiped out.
It may then be replaced by other species better adapted to that fire regime. Some plant species, such as eucalypts, regenerate from lignotubers, which are stimulated by fire to develop shoots. Also, smoke from plant material promotes seed germination in more than species of Australian plants. Researchers at the University of Melbourne are exploring the effects of bushfires on water supply.
Bushfires can have important consequences for water supply, by increasing erosion and dirtying water, making it unsafe to drink. Following some bushfires, townships have been forced to boil water to make it safe to drink. Along with a degradation of water quality, in some forests, particularly the Mountain Ash forests of Victoria, bushfires can reduce the amount of water available for drinking. This is because the forests use more water as they grow back after fire.
Between and , people in Australia were killed by bushfires. The most destructive of these occurred fairly recently. The Ash Wednesday bushfires of 16 February that swept through southern Victoria and South Australia were devastating. Seventy-five people lost their lives—47 in Victoria and 28 in South Australia. More than , hectares of land were burnt and 3, houses and other buildings were lost. Ten months of dry weather and a hot summer produced a dry landscape, primed for fire.
Temperatures were in the high 30s to mids, the air was dry and there were gale-force winds. There were already fires burning that Wednesday, but by the afternoon several more were burning throughout southern Victoria. Some were deliberately lit. Once again, there were hot, dry conditions, with extremely high temperatures and strong winds.
On 7 February , around fires started in Victoria. Around Most fire activity occurred during the afternoon and early evening of Black Saturday. One hundred and seventy-three people were killed in the Black Saturday fires. More than people were injured and 2, homes were lost. The amount of energy released by the fires was estimated to be equivalent to around 1, Hiroshima atomic bombs.
In some situations, the fires produced sufficient radiant heat to kill people metres away. A Royal Commission was established to examine the causes and consequences of the Black Saturday fires. Its final and interim reports are a valuable source of information on the impact of bushfires in Australia.
As described above, four things need to be in place for a bushfire to occur: fuel must be available; the fuel must be dry; weather conditions need to be hot, dry and windy; and there needs to be a source of ignition.
So, is climate change likely to affect any of these? This is known as the CO 2 fertilisation effect, and it will ultimately create more fuel for a potential fire. However, this effect only improves plant growth when there are sufficient amounts of other nutrients and water. Warmer temperatures at night and during winters will also increase the growing season of many plants. The drier the fuel, the more likely it is to burn.
Increased average temperatures caused by climate change will contribute to fuel dryness. Rainfall will also influence how dry or wet the fuel is. While the predictions for changes in rainfall are not as definitive as those for temperature, it is expected that there will be less rainfall in much of Australia in the future, particularly in the south-eastern and south-western regions. The weather conditions are part of the criteria used to assess the degree of fire risk on any given day.
An increase in warmer and drier weather means a higher number of days of high or extreme fire risk. Along with more days of higher risk, climate change will also bring an extension of the fire season. It is inevitable that Australia will always have large fires but, with better land management and improved understanding of bushfire behaviour, hopefully the catastrophic loss of life that has occurred in the past can be avoided.
More on bushfires: Managing landscapes. Bushfires 1: Understanding bushfires Expert reviewers. A bushfire approaching properties in Coonabarabran. Used with permission. Mr Morrison has repeatedly defended his government's stance. Do you have any questions about the Australia fires?
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If you are reading this page and can't see the form you will need to visit the mobile version of the BBC website to submit your question or send them via email to YourQuestions bbc. Please include your name, age and location with any question you send in. A visual guide to Australia's bushfire crisis. What is Australia doing to tackle climate change? Which animals fare best and worst in fires? Is climate change to blame for Australia's fires?
How do you fight extreme wildfires? Image source, AFP. Where are the fires? This includes areas around Sydney and Adelaide. How big are the Australia fires? Image source, EPA. A visual guide to Australia's bushfire crisis The beach town where fires turned day to night.
Wildfires thin forest canopies and undergrowth, allowing sunlight to reach the forest floor and a new generation of seedlings to grow. In fact, some species of trees, like sequoias , rely on fire for their seeds to even open. Wildfires devastate anything in their path. While they are difficult to stop, there are many steps people can take before, during, and after wildfires to limit their damage. All rights reserved. Climate Wildfires. How wildfires start Though they are classified by the Environmental Protection Agency as natural disasters , only 10 to 15 percent of wildfires occur on their own in nature.
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