Massive Australian blazes will ‘reframe our understanding of bushfire’
Australia is on fire like never before—and this year’s “bushfire” season, which typically peaks in January and February, has barely begun. Driven in part by a severe drought, fires have burned 1.65 million hectares in the state of New South Wales, more than the state’s total in the previous 3 years combined. Six people have died and more than 500 homes have been destroyed. As Science went to press, some 70 uncontrolled fires were burning in adjacent Queensland, and South Australia was bracing for potentially “catastrophic” burns.
David Bowman, a fire ecologist and geographer and director of the Fire Centre at the University of Tasmania in Hobart, spoke with Science about the crisis. The flames have charred even moist ecosystems once thought safe, he says. And the fires have become “white-hot politically,” with Prime Minister Scott Morrison’s Liberal government drawing criticism for refusing to acknowledge any link to climate change.
The interview has been edited for clarity and brevity.
Q: What is unusual about these fires?
A: The geographical scale and intensity—it’s happening all up and down the country. The very early start to the fire season across eastern Australia. The scale of housing loss.
We’re seeing recurrent fires in tall, wet eucalypt forests, which normally only burn very rarely. A swamp dried out near Port Macquarie, and organic sediments in the ground caught on fire. When you drop the water table, the soil is so rich in organic matter it will burn. We’ve seen swamps burning all around.
Even Australia’s fire-adapted forest ecosystems are struggling because they are facing increasingly frequent events. In Tasmania, over the past few years we have seen environments burning that historically see fires very rarely, perhaps every 1000 years. The increasing tempo, spatial scale, and frequency of fires could see ecosystems extinguished.
Q: What is the role of climate change?
A: You have to ask: Has there ever been a fire event of 1.65 million hectares that’s burnt a large area of what is generally considered fire-proof vegetation, and also occurred simultaneously with fires in other regions of Australia and California? What is happening is extraordinary. It would be difficult to say there wasn’t a climate change dimension. We couldn’t have imagined the scale of the current event before it happened. We would have been told it was hyperbole.
This is teaching us what can be true under a climate changed world. The numbers, scale, and diversity of the fires is going to reframe our understanding of bushfire in Australia. This is a major event which will have huge intellectual and policy legacies.
Q: What policy issues has the crisis raised?
A: The fires are white-hot politically. The fact that the government has questioned the appropriateness of talking about the linkage to climate has put scientists in a difficult position. There has been an unexpected alliance between 24 former state fire and emergency chiefs who are advocating an awareness of increasing bushfire risk linked to climate change. They argue the government has ignored their advice because it doesn’t want to talk about climate. What they are saying is harmonizing with the warnings coming from scientists.
Q: How do the Australian fires relate to fires in other parts of the world?
A: Whilst this was unfolding in Australia, there has been a very late fire season in California. So, we had the long-dreaded overlap between the Northern and Southern Hemisphere fire seasons. If this becomes a fixture it’s going to make sharing firefighting resources between nations much harder. The U.S. has a huge, specialized firefighting aviation force. Traditionally, we were able to bring U.S. aircraft and personnel to Australia, but with fire events happening simultaneously there will be strains on resource sharing.
Q: How big of a problem is the smoke?
A: There is a strong epidemiological association between smoke and respiratory and cardiovascular health. A huge fraction of the population along the east coast—maybe a third of the total Australian population of 25 million—has been exposed to dangerous smoke levels. This will be costly to the health and hospital systems and take people’s lives. Smoke pollution is currently killing far more people than the flames, and it’s not over yet.
Q: What research questions do the fires raise?
A: These are overwhelming in number. The priorities include: getting to grip with the human health impacts of the smoke, understanding fire severity and ecological harms, and understanding why the intensity varied between regions and how much it was related to prevailing weather. There will also be more formal government enquiries, which will draw on postfire assessments and the work of climate scientists. They will be very influential on future fire management practices.
Q: How is research on the fires being funded?
A: How do you prepare and fund research that was unimaginable even a few months ago? There is a disconnect between the scale and speed of these events and the availability of funding to study them. We are lucky in that we have some existing projects and databases. I would expect a large cross-section of scientists from Australia will be entangled in the research in one way or another.
Thankfully, the New South Wales government established a Bushfire Risk Management Research Hub, of which I lead the pyrogeographic node. The hub was refunded 18 months ago and is led by Ross Bradstock of the University of Wollongong. Our databases on fire across New South Wales will enable us to figure out what actually burnt, how severely, the linkage to vegetation type, fuel management, other human land uses, and climate and weather factors. We will look at impacts, capturing available satellite imagery and trying to capture operational data, such as from infrared scanners on aircraft which can map the fire front and perimeter. This will take some time. Such pyrogeographic case studies are novel in the literature and yet are critical in understanding what happened and why.
Q: You call yourself a “pyrogeographer.” What is that?
A: Pyrogeography is thinking about landscape, people, and fire. It takes in fire science but also the humanities, law, psychology, epidemiology, meteorology, and disaster management. Fire is part natural disaster and part human caused and modified, so I try to keep the door open to discourse from different disciplines. It’s wonderful that modern research practice can be so transdisciplinary. It’s great to take people’s insights on detailed specialties and bring them to bear on these fire issues. There are very few centers globally that can take this approach, but there’s increasing interest because of the applied nature of the fire disaster problem and the need to understand the intersection of all these different perspectives.
This interview was first published in Science on November 20 2019.