By Tom Harris
Recent climate change has not caused Australian bushfires. Besides the fact that many of the fires are set by people, either intentionally or by accident, a major cause of Australia’s fire problem has been the high ‘fuel loads,’ underbrush that, left to accumulate over years, acts as a tinder box for bushfires. Craig Kelly, Liberal member of the Australian House of Representatives (Hughes, New South Wales), told ITV’s Good Morning Britain on January 6:
“Now, we have record fuel loads on the ground, … and every single royal commission we have had from our past bushfires have said that we have to reduce those fuel loads. And that is the main issue. And yet we have failed to do so.”
Kelly went on to explain that the Royal Commission in 2009 “called for a minimum burning of 5% of that state’s forest in Victoria. That would amount, over the past two years of something like 770,000 hectares that should have been back burned and the actual number was something only about 200,000.”
Surrey, British Columbia-based forest microclimate specialist, Rob Scagel agrees and said, “Fuel load rules. Spending resources and intellectual capital on climate change considerations is as effective at mitigating bushfires as changing the colour of the paper used in reporting them.”
Later in the interview, Kelly pointed out that drought was also an important contributor to the bushfires but explained,
“If you look at … the long-term rainfall records in Australia, there is simply no trend. As CO2 has increased there has been no trend. The first 20 years of this century, we’ve had more rainfall in Australia than the first 20 years of the last century.”
Kelly was correct again. Here is the graph of rainfall from the Australian Bureau of Meteorology (BOM).
Arson apparently also plays a significant role in Australian bushfires. ABC (Australia) News reported in September 2019 that:
Dr Paul Read, co-director of the National Centre for Research in Bushfire and Arson, said the great majority of bushfires are deliberately lit by “cunning, furtive and versatile criminals”.
“About 85 per cent are related to human activity, 13 per cent confirmed arson and 37 per cent suspected arson,” he said.
“The remainder are usually due to reckless fire lighting or even just children playing with fire.”
And, of course, lightning strikes cause many fires. These strikes occur more frequently in areas where fires occur because of the type of clouds that form, cumulonimbus, and the precipitation they produce. Cumulonimbus are the only clouds that produce lightning.
In recent weeks, Australian bushfires have often been blamed on global warming supposedly caused by rising carbon dioxide (CO2) levels. But this is completely backwards.
Rising temperatures and increasing CO2 both act to increase soil moisture and so reduce the potential of fires. When temperatures rise, evaporation increases, causing more precipitation which increases soil moisture and so lessens fire risk. As CO2 rises, stomata, the pores in plant leaves, are open for shorter lengths of time. Plants therefore lose less water to the air and so more of it stays in the soil, again reducing fire potential.
A closer look at the issue reveals that fire has benefits as well as risk. Indeed, it is an essential part of the natural cycle. Fire clears off dead debris as plants go through their lifecycle. There is a special area of botany called Fire Ecology that studies the role and importance of fire in ecosystems. In most ecologies, especially forests, many plants require fire to soften or open the seeds to start life, although the seed shell must survive the fire first.
One example of such a seed occurs in the vegetation of what is called a Mediterranean climate. California is an example of this type. It is a unique climate zone because 70% of the precipitation occurs in the winter. All other climate types have either 70% in summer or an even distribution throughout the year.
A Mediterranean climate results in a unique vegetation called Maquis in Europe and Chaparral in California. The annual climate cycle that makes this an area that requires fire to be healthy has a hot, dry, summer that shrivels the plant but the seeds survive. At the end of the summer, lightning occurs as rain clouds begin to form, and that triggers fires that burn off the plants but leave many of the seeds intact. Mudslides follow as the rainy season progresses. Fortunately, the seeds germinate quickly and stabilize the soil.
The natural cycle of forest fires creates what are called crown fires. They move through quickly, burning off dead debris but leaving most of the plants still alive. When governments decided to stop forest fires, they upset the natural dynamics completely. The bureaucracies, now populated by graduates of the biased environmental education system, willingly allowed the environmental extremists’ demands to end the former sensible practice of cleaning the undergrowth. Activists complained that such forest tending was not ‘natural,’ when it was, in fact, a reasonable facsimile of ‘nature’. So, the debris built up, leaving the forest a tinder box ready to ignite.
Environmentalists have themselves to thank for much of Australia’s bush fire problem.
Tom Harris is Executive Director of the Ottawa, Canada-based International Climate Science Coalition (ICSC).