DTN's headline "New CSIRO Research shows climate change lights fires" highlights the absurdity of some research findings emanating from our leading scientific institutions. CSIRO attributed our increasing fire disasters to industrial warming of 1.40C since 1910 causing increases in severe fire weather and lightning ignitions.
It's no news that lightning (or people) can start fires. Whether or not they can develop into megafires depends upon the state of the landscape, not climate or weather.
In the early 1790s, during the Settlement Drought – the worst in 500 years including the Federation and Millennium Droughts – there were three consecutive summers of extreme weather.
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Masses of flying foxes and lorikeets dropped dead in Parramatta during three straight days of blistering north-westerly gales and mid 40s temperatures in February 1791. Aboriginal fires were burning 24/7 in what is now wilderness. They didn't explode into firestorms and megafires because the country was clean and healthy.
Megafires commenced when Aboriginal burning was disrupted before any industrial warming. The first initiated the Great Scrub of South Gippsland around 1820, after the Yowenjerre People were decimated by the 1789 smallpox epidemic. In 1851, five million hectares of Victoria were incinerated by the Black Thursday megafires.
Following disasters like Black Friday 1939, the 1952 southeast Fires and Dwellingup in 1961, CSIRO fire scientists worked with foresters to reinstate sustainable fire management across the landscape. In the 1960s, they developed burning prescriptions, including aerial ignition techniques, to restore healthy and safe ecosystems.
In 2009, fire scientists in WA reported the results of 50 years of prescribed burning: "When averaged over 6-year periods, the annual extent of prescribed burning explained 71% of the variation in the mean annual extent of unplanned fires."
Also "the annual area treated by prescribed burning had relatively little effect on the extent of unplanned fire in most years, but a relatively strong negative effect on the probability of occurrence of years in which unusually large areas were burnt by unplanned fire".
In other words, prescribed burning can prevent megafires in extreme weather.
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Long-term data show that a minimum of 8% of the landscape must be treated each year and the benefits persist for six years. So, unless at least half the landscape is properly maintained, forests will explode in bad seasons, whether ignited by lightning or accident or arson.
Some of NSW's first aeroburning, in what is now the Brogo Wilderness, saved Bega from disaster in the subsequent extreme fire season of 1968 when 14 people died and 150 buildings were destroyed in other parts of the state.
Unfortunately, starting with the Scientific Committee On Problems of the Environment in 1976, fire ecologists raised concerns that prescribed burning would cause environmental damage. They claimed it would endanger species that thrived under Aboriginal management for tens of thousands of years.
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