The changing nature of Australia’s bushfires
An inherent component of Australia’s environment, bushfires come with significant risks
Human history is intertwined with fire; the friendly warmth of a campfire connects us through the ages to our early hominid ancestors, offering succour from the darkest nights. Yet our campfires fiercer cousin, bushfires, are an innate element of the Australian landscape which can be a destructive force and a source of fear for many communities.
The horrors of major fires such as Ash Wednesday and Black Saturday are well remembered by the Australian community. Not only do bushfires pose an immediate risk to life and property, they leave behind countless challenges for the communities and individuals affected. Bushfires are associated with significant physical and mental health risks and cause enormous economic losses. Black Saturday alone cost an estimated $4 billion and 173 lives, and while its ongoing impact on communities in the region is challenging to quantify, it is clear communities are still dealing with the consequences, more than10 years later.
This image was captured by a NASA satellite on February 14th 2009, showing the extent of the bushfire damage to the Kinglake area and the Great Dividing Range. The image was taken in ‘false-colour’ by NASA to make the smoke more transparent. Un-burned vegetation is red, naturally bare ground tan, and the darker regions are burned areas.
Credit: NASA image created by Jesse Allen, using data provided courtesy of NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team.
Given the significant consequences of bushfires and the costs associated with them, it is important to address the fact that bushfires in Australia are becoming increasingly frequent, intense and severe. Bushfire patterns are affected by human activity in several interconnected ways, which poses challenges when addressing the increasing risk.
Climate change is changing fire patterns in Australia
According to a study by the Australian Institute of Criminology, only 6% of bushfire ignitions in Australia are attributed to ‘natural’ causes; the rest involve humans, through a combination of arson, accidental ignitions and faulty infrastructure. Furthermore, the increasing rural-urban interface, as cities sprawl out into the surrounding bushland, heightens the risk of fires caused by human activities; fires in these areas also pose a greater risk to life and property than those in more sparsely populated regions.
Additionally, researchers have found that climate change is increasing the frequency of severe fire weather events and extending the fire season. This means it is likely we will see conditions like those of Black Saturday more frequently in the future.
Climate change-induced warming and drying of some regions is making it more likely fuel will be ignited by a spark and results in more intense fires, which behave unpredictably, spread rapidly, and pose significant challenges for fire services combatting them.
Other areas are seeing greater rainfall, which, although it seems contradictory, can also increase bushfire risk, as it promotes vegetation growth and increases the amount of small (<6mm diameter) fuel. This increased fuel loading causes fires to spread faster and burn more intensely.
Where does the future take us?
Other regions of the globe, particularly the US, are seeing similar changes, including lengthened fire seasons and increasing fire intensity; the fire season in many regions of the US is beginning to overlap with that of South-Eastern Australia. Australia currently shares resources with the US, including fire-fighting aircraft and helicopters, and personnel. This may not be possible in the future as major fires become a year-round threat.
An essential part of ensuring a secure future in the face of a changing climate is understanding these changing fire patterns and the impact of human activity on bushfires. This is a multidisciplinary issue, requiring cooperative efforts from climate scientists, policy-makers, urban planners, land management services and fire services, to reduce the risk of a disaster like Black Saturday occurring in the future.
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This blog post was inspired by background research done for a reflective essay and an analysis of the current media portrayal of an environmental issue, which were produced for the University of Melbourne subject An Ecological History of Humanity.