-- Australia's bushfires have such a long and
destructive history there's almost no day of the week
that hasn't been dubbed "black" or "ash" to mark a
major conflagration.
There was Black Thursday in Victoria in 1851, which
destroyed five million hectares and claimed 12 lives --
the first large-scale bushfire in the history of white
settlement in Australia.
Since then there's been Red Tuesday in 1898 in
Victoria, which consumed 2,000 buildings, Black Friday
in Victoria in 1938 that killed 71 and destroyed 3,700
buildings, and Ash Wednesday in the early 1980s that
left 71 dead in the state of South Australia.
Most recently in 2009, Black Saturday claimed 173 lives
in the state of Victoria in southern Australia -- many of
the victims unable to even get the distance of their own
driveways before they succumbed to the intense radiant
heat generated by a bushfire.
Many argue that Australia's catastrophic bushfires are
simply a fact of life on a continent where its flora,
heavy with combustible eucalyptus oil, constitute
something of a seasonal time bomb.
Others say more sinister man-made
factors are at work.
Changing climate
Australia has had a troubled relationship
with climate change -- its confused policies
on a controversial carbon tax are credited
with felling the Labor Party at the last
election, while the new government
controversially disbanded the country's
Climate Commission -- but scientists say
the latest bushfire season may turn up the
heat on the climate-change skeptics.
While the jury is still out on whether
climate change is making conditions
perfect for large-scale bushfires, scientists
agree that bushfire seasons -- a regular
occurrence on the Australian seasonal
calendar -- are getting longer and the fires
more intense.
According to David Bowman, professor of
forest ecology at the University of
Tasmania , who has studied bushfires for more than 30
years, bushfire behavior is showing signs of change.
"The problem with Australia is that the records are
pretty shallow, which makes it really difficult to talk
conclusively about any of the fire activity. But when
you piece everything together there's some very
convincing evidence.
Aggressive fires
"Even the firefighters are reporting really unusual
behavior," said Bowman, adding that firefighters are
fighting bigger and more aggressive fires.
"Normally at night -- and this is borne out by
firefighters in the United States -- the fire will quell as
the temperature cools. But firefighters are saying that
because of the heat, bushfires are burning just as
fiercely at night. It's all getting pretty worrying."
He said duration was also a factor that was changing in
bushfire behavior.
"It's no big deal to have a fire in October but to have
one that has burned like this for more than a week at
this level of intensity is unprecedented.
"We are now looking at really catastrophic fire weather
-- for October it just doesn't compute."
A nation built on fire
Fire has been part of the Australian landscape since the
dawn of time and its people have used fire as a farming
tool for more than 40,000 years. One of the earliest
colonial watercolors shows an Aboriginal man gently
setting fire to land that now makes up Sydney's most
expensive waterside suburb of Vaucluse.
Known as fire-stick farming, this mosaic
of fire management systems not only
flushed out game such as kangaroos and
possums, it created new growth which in
turn attracted more game.
With indigenous people no longer part of
the forest management equation, some
scientists argue the fuel load that builds
up from Australia's notoriously
combustible vegetation is now one aspect that needs to
be addressed.
Pyrogeography
Meanwhile, the emerging academic discipline of
pyrogeography is looking at bushfires in Australia -- not
just as a one-off catastrophic event -- but as part of an
interconnected whole where forest fires around the
world feed climate change and make conditions ripe
for the propagation of even more fires.
Bowman says that deforestation fires alone -- the fires
that have been used to destroy forests since the
industrial revolution -- account for about one-fifth of all
carbon dioxide committed to the atmosphere.
"That's a very significant component in global
warming," he said.
One thing that is being noticed by scientists is that
black carbon from forest fires is landing on ice sheets
and accelerating ice melt.
Slippery factors
"These are tricky and slippery factors because there are
places where feedback from fires is actually causing
cooling, especially in places where the loss of forest has
caused the snow to lie for longer leading to regional
cooling."
Vegetation and natural conditions may change
dramatically between New South Wales, Sumatra and
California, but one thing these fires all share in
common is that they are becoming more regular
because the climate is becoming warmer.
Bowman said that vegetation in parts of Victoria, which
normally completely regenerates over a 50-year cycle,
is now being burned as often as three times in the
period of one decade.
The particles from forest fires, he said, actually inhibit
rainfall contributing to regional drying and warming,
which creates a weather cycle conducive to fires. The
problem for scientists, he added, was in connecting the
dots with these patterns.
"It's like trying to find needles in haystacks."
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