https://www.cbc.ca/news/technology/australia-bushfires-1.5414325
[images and links in online article]
'It's unprecedented': What is behind Australia's devastating fires?
Much of the country has been in a persistent drought but there are other
reasons
Nicole Mortillaro · CBC News · Posted: Jan 04, 2020
Australia continues to burn after more than a month of raging bushfires,
and it doesn't appear the smoke-filled skies will be clearing any time soon.
As of Friday, more than five million hectares have burned, 19 people
have died and 21 people are missing. Tens of thousands of people were
forced to flee their homes. More than eight million more were under an
emergency order.
While Australia is no stranger to bushfires, this one has captured the
world's attention. Images of burnt-out cars, people fleeing homes, a
parched koala desperately drinking from a cyclist's water bottle and
angry townspeople screaming at Prime Minister Scott Morrison for more
action are making global headlines.
And there's a good reason for the attention.
"In my experience of doing this fire monitoring, in some places you see
intense fires over quite large areas maybe for a week or a few weeks,
but to see them for four months in one particular place … it is quite
surprising," said Mark Parrington, a senior scientist at the European
Centre for Medium-Range Weather Forecasts (ECMWF).
"We only have 17 years of [CO2 emissions] data," said Parrington, who
works in the Copernicus Atmosphere Monitoring Service Development
Section at ECMWF analyzing wildfire emissions, among other sources. "But
in that context then, yeah, absolutely, it's unprecedented."
Australia has been experiencing warmer, drier conditions lately — a
result in part to something called a Positive Indian Ocean Dipole, a
phenomenon similar to El Niño.
As a result of westerly winds in the equatorial region weakening, warm
water from the deep ocean shifts towards Africa from the Indian Ocean
and cool water rises up in the east. For Australia, this temperature
difference means drier and hotter weather for much of the continent.
However, that's not the only factor. The country has been experiencing
long-term drought conditions, even when there isn't a positive dipole.
In Eastern Australia, which includes New South Wales, Queensland and
Victoria where the fires are the worst, rainfall has been the lowest on
record.
New South Wales alone has been the driest on record with rainfall 36 per
cent below the 1961–1990 average, according to Australia's weather and
climate agency.
The Murray-Darling Basin that stretches from Queensland southwest to
South Australia, has experienced the driest 34 months on record,
compared to other 34-month records starting in January. Victoria, where
a state of disaster was declared, has also had its driest 34 months on
record.
The fear is that the fingerprints of climate change are all over this.
Like the rest of the world, Australia is dealing with the consequences
of a warming planet. Since 1910, the average temperature for the country
has warmed by 1 C. Preliminary data from Australia's Bureau of
Meteorology (BoM), suggests that in 2019 the annual temperature in that
country was 1.52 C above average. (The official report is set to be
released on Jan. 9.)
If the data holds, it will blow out the record high set in 2013 when the
annual temperature was 1.33 C above average.
"The duration, frequency and intensity of heat waves have increased
across large parts of Australia since 1950," the Australian government
reported. "There has been an increase in extreme fire weather, and a
longer fire season, across large parts of Australia since the 1970s."
Renowned climatologist Michael Mann, a professor of atmospheric sciences
at Penn State University, was in Australia during the fires. In a recent
opinion piece in the Guardian, he described "smoke-filled valleys" and
"brown haze."
"What is happening in Australia is a harbinger for other countries — a
taste of what our future will look like if we don't act now," Mann told
CBC News.
Of particular concern to him is the planned Adani coal mine in
Queensland (also known as the Carmichael mine) that would be one of the
biggest in the world. And that mine could release more than 4.49
gigatonnes annually of CO2 — the leading contributor to the climate
crisis. The carbon dioxide emissions would be among the "highest in the
world for any individual project," according to a 2011 joint report to
the Land Court of Queensland.
Far-reaching consequences
Parrington recalls one of Australia's worst fires, known as Black
Saturday, which in 2009 killed 173 people in Victoria, injured 414 and
killed more than a million animals, both wild and domesticated.
The human death toll pales in comparison thus far, but Parrington says
the peak of the fires lasted just a few days.
"But the fact that this has been going on for several weeks, is really
concerning, particularly as a lot of [fires] are occurring upwind of
large population centres," he said.
It's particularly the scale of the current fires and number of people
impacted, including those in New Zealand, where smoke from the fires has
drifted, that concerns him. And that smoke can produce toxic chemicals
like benzene and hydrogen cyanide, Parrington said.
Then there's the effect on glaciers.
The reflectivity of an object is referred to as the albedo. In the case
of ice, its white surface reflects solar radiation, and it stays cool.
But if the ice darkens for some reason — say, if black soot falls on it
— that warms it up.
"Once it gets into the upper troposphere [lowest layer of Earth's
atmosphere], it can get picked up by the jet stream there and be
transported thousands more kilometres," Parrington said. "If there is
transport to Antarctica … any deposition of soot or black carbon to the
ice would mean a change to the albedo and potential acceleration of the
melting, local to where that deposition took place."
Already, the Australian fires have changed the albedo on glaciers in New
Zealand.
And the world's glaciers are already threatened with climate change.
So, is this a sign of things to come?
"What the future holds is much worse in the absence of concerted action
on climate," Mann said.
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