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.

Image of blackened, dead trees and bare earth in Kinglake national park following black saturday
The desolate aftermath of the Black Saturday fires in Kinglake National Park. Climate change could mean more fires like these in the future. Image source: CSIRO

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.

A yellow fire fighting helicopter flies against a background of smoke, and living and dead trees, which have not yet been burnt.
Firefighting resources are often shared between the US and Australia, which could become impossible as climate change causes fire seasons to overlap. Source: Lance Cheung, United States Department of Agriculture

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.

 

 

Sources:

 

Bradstock, R., Penman, T., Boer, M., Price, O., & Clarke, H. (2014). Divergent responses of fire to recent warming and drying across south-eastern Australia. Global Change Biology, 20, 1412-1428. doi: 10.1111/gcb.12449

CSIRO & Australian Government Bureau of Meteorology (2018). State of the Climate. Retrieved from CSIRO:  https://www.csiro.au/en/Showcase/state-of-the-climate

Extreme Events. (2016). In The Impacts of Climate Change on Human Health in the United States: A Scientific Assessment (ch. 4). Crimmins, A. J., Balbus, J. L., Gamble, C. B., Beard, J. E., Bell, D., Dodgen, R. J., Eisen, N., Fann, M. D., Hawkins, S. C., Herring, L., Jantarasami, D. M., Mills, S., Saha, M. C., Sarofim, J., Trtanj, & L. Ziska, (Eds.) US Global Change Research Program, Washington, DC. doi: 10.7930/J0R49NQX

Hamilton, S. (2019, February 7). Climate change is poised to deliver more Black Saturdays in decades to come. The Conversation, retrieved from https://theconversation.com

Pitman, A. J., Narisma, G. T. & McAneney, J. (2007). The impact of climate change on the risk of forest and grassland fires in Australia. Climatic Change, 84(3-4), 313-401. Retrieved from https://link-springer-com

Readfearn, G. (2018, November 16). Longer fire seasons threaten to disrupt US-Australia firefighting cooperation. The Guardian, retrieved from https://www.theguardian.com

Ryan, K. C. (2000). Chapter 8: Global Change and Wildland Fire. In J. K. Brown, & J. K. Smith (Eds.), Wildland fire in ecosystems: effects of fire on fauna (175-182). Colorado: United States Department of Agriculture Forest Service.

Stevenson, C. (2010). A literature review on the economic, social and environmental impacts of severe bushfires in south-eastern Australia: Fire and adaptive management report no. 87. Victoria: State Government of Victoria, Department of Sustainability and Environment.

Teague, B. & McLeod, R. & Pascoe, S. (2010). 2009 Victorian Bushfires Royal Commission Final Report Summary. Victoria: Government Printer for the State of Victoria.

Teague, B. & McLeod, R. & Pascoe, S. (2010). 2009 Victorian Bushfires Royal Commission: Fire Preparation, Response and Recovery, Final Report Volume II. Victoria: Parliament of Victoria.

Tollefson, J. (2018). Enormous wildfires spark scramble to improve fire models: Blazes in North America are becoming larger and more powerful. Nature, 561, 16-17. doi: 10.1038/d41586-018-06090-0

Willis, M. (2004). Bushfire arson: a review of the literature. Research and public policy series no. 61. Canberra: Australian Institute of Criminology.

 

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.


12 Responses to “The changing nature of Australia’s bushfires”

  1. fmarshall says:

    I cannot remember off the top of my head, but I believe the statistic included all fire ignitions. The reference for the statistic is included at the end of the blog post, so you are welcome to follow up on that (though I warn you, it’s a long read); it was a submission made to the Black Saturday Royal Commission. If you are interested in reading more about it, this news article is discussing a different study which had much the same findings (slightly different numbers, probably slightly different method and classifications, but the trend is essentially the same): https://www.abc.net.au/news/science/2015-12-11/bushfires-in-south-east-australia-mostly-caused-by-humans/7013914

  2. fmarshall says:

    Thanks for the suggestions, I will keep them in mind for the next blog post!

  3. fmarshall says:

    I believe after the Royal Commission into Black Saturday there were considerable changes made to planning regulations in fire-prone regions, and that a rating system was created to identify how vulnerable/at risk a location may be should there be a major fire. The Royal Commission findings are worth a read, and I will see if I can find an article on the changes to building requirements for structures in the ‘flame zone’ for you.

  4. fmarshall says:

    Yeah, nor had I until I started looking into this, but apparently, it’s causing a few problems as we share a surprising amount of resources (which I guess made sense in the past, as we only really needed them for 6 months of the year), which Australia is now going to have to consider sourcing itself as they may not be available to share in the future.

  5. fmarshall says:

    Thanks! I’ve read a few extracts of that, I keep meaning to get a copy to read the whole book as it sounds really interesting!

  6. fmarshall says:

    Yep! There is a full breakdown of the statistic, which was submitted to the Black Saturday Royal Commission, I’ve added the reference to it to the blog post. Here is also a news article (as the Royal Commission submission is a lot of reading); the statistics in this article are from a different study, which covers a slightly different region of the country and has slightly different methodology, so there are a few differences, but you can see the general trend: https://www.abc.net.au/news/science/2015-12-11/bushfires-in-south-east-australia-mostly-caused-by-humans/7013914

  7. Alex Borowiak says:

    ‘[…]only 6% of bushfire ignitions in Australia are attributed to ‘natural’ causes’ – This is a very scary statistic.

  8. pmchenry says:

    Awesome piece! Dark Emu by Bruce Pascoe has some amazing details about some incredibly effective fire control techniques employed by First Nations Peoples!

  9. Gen says:

    It’s interesting that the fire seasons in the US and SE Aust are overlapping more! I have never considered this. Interesting insight.

  10. Zara Henderson says:

    This was a really interesting and well-written read. I’d be interested to learn how urban planners are designing properties in fire-prone areas to become more resistant/resilient.

  11. Liujun Wang says:

    It’s interested to read about changing bushfires’ patterns and frequency due to human activities. It seems like your writing should be on a scientific journal instead of a blog, which makes me feel having a distance with you (maybe the words choosing?). Some suggestions: make a more exciting title? provide a story or news at the beginning? But, great information on increasing frequency, strength and severity of U.S. and Australian bushfires.

  12. Layal El Wazan says:

    Great article! The fact that only 6% of bushfires are of natural causes is quite alarming. But I was wondering, how extensive does fire have to be to be considered for this statistic? What are the classifications of a bush fire, because if this includes small accidental fires that are easily managed then the statistic becomes less alarming (because I’m sure there are plenty of those).