Nov 21, 2019

Massive Australian blazes will ‘reframe our understanding of bushfire’

Australia
by
John Pickrell
,
Science

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.

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.

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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.