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Fire man
27 March 2004
From New Scientist Print Edition.
Rachel Nowak

Phil Cheney grew up in a fishing village on Phillip Island, off the southern coast of Australia. He moved inland to become a forester, taking a diploma in forestry at the Australian School of Forestry in Canberra, and a BSc in forestry at Melbourne University. He has studied wildfires over four decades, and headed the bushfire behaviour and management group at the Commonwealth Scientific and Industrial Research Organisation for 25 years. Cheney has also won an award for his poetry

Are you a pyromaniac who has found a healthy outlet for your impulses?

People by and large like lighting fires. It's fascinating to watch flames, you get a lot of comfort from it.

But you grew up in a fishing village - how did you end up in forestry?

Forestry seemed an easier life than fishing - which is what my poem [see page 46] is about.

But it wasn't - at least not once you moved into studying forest fires. What's it like being close to one?

It makes you feel very small, and quite inadequate. The day is always hot, 30 °C to 40 °C. It's very dark. It's the middle of the day and it's like night. The first thing you are likely to see is the reflection of flames on the smoke above you. Suddenly it lights up, it's bright red and it gives the illusion that the flames are exceedingly high, even when they are relatively low. You cannot hear yourself talk because of all the noise: the wind noise, the roar of the fire, and this low-frequency thumping that is going on behind it - that's pockets of gas burning very quickly.

How intense are these fires?

A fire with flames around a metre high releases about 1000 kilowatts of energy per metre of fire perimeter. Depending on the fuel load and the rate of spread, a fire with a flame height of 2 to 3 metres that is starting to run up into the upper canopy releases about 2000 to 2500 kilowatts per metre. That's the largest fire you can suppress by any means. In the heart of the Canberra fire last year, in the hills where fuel was heavy, it was around 250,000 kilowatts per metre. That's like having 250,000 1-kilowatt bar radiators stacked up on each other on every metre of the fire perimeter. This massive energy release created a tornado-like vortex that cut a swathe 200 metres wide over 15 kilometres. When it ran into Canberra there was nothing they could do except try to defend individual properties.

What was the aftermath like?

For about a month there was a stench of rotten meat in the forests. The only things moving were carrion eaters, eagles circling around, but even they were few. There has been recolonisation. But we have no idea what was lost, absolutely no idea. It's emotionally draining reconstructing events where people have been severely affected. Very often we might only want a very small snippet of information, but in all fairness you have to relive the story with them and try and help them understand what happened.

Sounds like a stressful life. Did that get you into writing poetry?

You have to have a certain level of stress to write poetry, and bushfire research is very stressful. You're pushing the upper limits of safety. You go through all these arrangements to run a fire. There's 70 people in the field ready, and you look at the wind direction and it's 30 °C out. Everyone is thinking: "For Christ's sake burn this, so we can all go home". I don't have that stress now so my poetry has dropped off - I think the correlation is proved.

In Australia you are encouraged to stay and fight wildfires rather than evacuate - as you are in most countries. Why?

It comes out of our history. In rural areas, if people stayed in their homesteads even when everything else burnt, the homestead would protect them as the flames went over. In the 1983 Ash Wednesday fires, for example, more people were killed being overrun by the fire as they fled in their cars at the last moment. Under extreme conditions things are chaotic, and by the time it's obvious that you are under threat it may be too late to evacuate. Places designated as safe areas may no longer be safe.

So what do you tell people? Are they prepared enough?

Our policy is that if you are going to evacuate we advise you to evacuate early, but it would be better to prepare to stay and protect your property. But I don't know how long we can sustain that. You have to be physically and mentally capable of staying. There are always people who turn up in shorts and sandals without socks and with that level of protection you cannot approach flames even a few centimetres high.

I don't think we have been very successful in preparing people. In the old days, people would have cleared around the homestead and converted it to grass, the flames would have passed by in a few seconds with little smouldering debris persisting. But nowadays there is a tendency to build houses in the forest without much clearing around it - and those suburban properties are indefensible. In a forest fire, tall flames last about 20 seconds, lower flames a couple of minutes, and then it's another 45 minutes before you can go out because of the heat from the smouldering branches and logs. People need to maintain their gardens in such a way that there is little flammable material in them.

Why aren't people more aware about fire?

Fire has been removed from our consciousness. We have electric heaters. We got rid of garden incinerators for air pollution reasons. The rotary mower has replaced the need to burn off the grass. Very few people have an open hearth or light a fire. Generations of Australians have never had to light a wood fire for any reason.

What would you do to prevent fires like the one that devastated Canberra?

You need deliberate prescribed burns, where you burn off to reduce fuel on the forest floor. If we'd done that the Canberra fire would have been out in a day, and the people in Canberra would never have noticed what had gone on in the bush. When it comes to changing the behaviour of fires, managing the fuel is the only thing we can do - we cannot affect the weather - and prescribed burning is the most ecologically sound way of doing that. The fact is that if you let the fuel build up, then sooner or later you end up with catastrophic fires like Canberra. In Europe in the past 50 years, the amount of rural burning has declined and the fire problem has increased along with it. Western Australia is the one state that has really developed prescribed burning and they have had no major fires in their forest areas in the past 40 years.

But in Canberra, the fire carried on burning in the suburbs where there was no forest to burn...

There were a number of reasons for that. People increasingly prefer native plants and mulch instead of tended gardens with lawns. At the same time people object to smoke, so instead of burning off old stuff, it gets left in gardens. That meant it took longer for the fires to run out of fuel, and for people to put out individual spot fires. The level of fire within the suburban landscape in Australia was unprecedented. But it was even worse in the Oakland-Berkeley Hills area in California in 1991. That was the most devastating suburban fire in recent history. It destroyed 2449 family dwellings and 437 apartment buildings and killed 27 people.

Why do people object so strongly to prescribed burning?

Unless you have had recent exposure to what fire can do at the extreme end, it's very difficult for people to comprehend why we do it. The autumn smoke goes up, and they are asking, what are they doing out there? Why are they burning the bush?

People also think of fire as something foreign that humans brought in. But fire from lightning is part of our ecology. Our Aboriginals arrived maybe 80,000 years ago into a flammable continent and they set about using fire, I believe, to protect themselves. At the start of the dry season, they burnt a series of patches that acted as refuges so that subsequent fires didn't remove all the animals and habitat. When Europeans arrived, they stopped the Aboriginals burning. Unless we apply fire at certain times, as would have happened by chance in the past, we have the real potential for extensive high-intensity fires that wipe out whole species. It's also essential to use fire to manage areas for particular plants or animals.

You have lamented the demise of the forester. Why does it matter?

I believe trees are a resource that we should use. I was brought up on the idea that if you harvested the forest you had to ensure that it would be regenerated. It's part of a cycle - there are plants and animals associated with every age and stage of the forest. Today, lots of forests have been converted into national parks or reserves but without the manpower you used to have when the forests were used for wood production. The people who surveyed the trees and did all the jobs associated with forestry, as well as the contractors who did the logging, provided a significant part of the trained firefighting workforce. Firefighting is a part-time summer job - we can't afford full-time specialist firefighters.

So who should be doing what?

Building a fire trail - clearing an area about a foot wide that follows the edge of the fire so that it has no fuel and goes out - requires really fit young men and women. We measured the energy they expend, and it's the same as a marathon runner, and they will do it for 5 or 6 hours. I haven't fought fires directly for a long time, I'm too busted up. You also have to know the forest, and learn the intricacies of fire behaviour. It is a bit of a nerve to expect volunteers to train to that level.

You plan to retire soon. What will you do?

I want a fire-free year - other than those that I light myself for my own enjoyment. Then I'll see what comes up. One of the things I've been wanting to do is look back at some of the history within forestry. We haven't been able to gain an insight into the Aboriginal understanding of fire, and I suspect that in 20 or 30 years, if forestry continues contracting the way it is, we'll have lost the foresters' understanding of fires too. I'd like to try and pick up as much of that before we all go.

How do you feel now when you wake up and hear it's another "extreme fire danger" day?

A little cold trickle of sweat goes down your back, and you think, oh no, not again.

From issue 2440 of New Scientist magazine, 27 March 2004, page 44

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