32 Australian Geographic
A
S WE WENT to press, bushfires
had ripped across a huge area of
the country’s south-east, making
it our worst-ever summer bushfi re season.
It was exceptional also for razing large
parts of typically moist northern New
South Wales and many Australian habitats
that rarely experience fi re and have little
tolerance for it, such as rainforests, tall wet eucalypt forests,
swamps and marshes. What link did climate change have
to the scale and severity of this season’s fi res?
The short answer is that, according to Australian Bureau
of Meteorology data released in January, 2019 was both
the hottest and driest year this country has experienced in
120 years of records (see p44). Rainfall was 40 per cent lower
than average and many environments were tinder-dry after
three consecutive years of drought. Most of the south-east
was kindling waiting to be ignited – via lighting strike or,
to a lesser extent, deliberately or accidentally by people.
For a more nuanced explanation, we have to look to cli-
mate patterns. One weather system called the Indian Ocean
Dipole leads to moisture being drawn away from Australia
when it is in a positive phase, as we experienced particu-
larly strongly in 2019. Positive phases – when the eastern
part of the Indian Ocean off northern Western Australia is
cooler than the western part of the ocean – are becoming
increasingly common with climate change.
The El Niño–Southern Oscillation is another driver
of our country’s climate. So called El Niño conditions
occur when warming in the eastern tropical Pacific
Ocean reduces the trade winds carrying rain towards
Australia. This can make things signifi cantly drier in east-
ern Australia and occurs about every eight years.
W hat is pa r t icu la rly wor r y ing is that 2019’s record d roug ht
wasn’t experienced during an El Niño year, which many
previous years with bad droughts and bushfi res have been.
This hints that in future conditions could get even drier.
Another reason the fi res were able to spread so far this
year and cause so much damage was because warmer con-
ditions, caused by climate change, are allowing the bushfi re
season to begin earlier each spring and linger longer into
autumn. In 2019, for the fi rst time, fi re seasons overlapped in
Northern Hemisphere California and Southern Hemisphere
Australia. That could mean Australia may no longer be able
to rely on vital fi refi ghting resources, such as aeroplanes,
shared with the USA.
Published in January, a review of 57 studies by academ-
ics at the UK’s Met Offi ce and several British universities,Record-breaking heat and drought in 2019 set up the perfect storm for bushfi res to explode
across eastern Australia, but major weather systems also played their part.showed fi re seasons have been lengthening in many parts of
the world, including Australia, since 1979, resulting in an
increase in duration of about 20 per cent. In south-eastern
Australia the bushfi re season usually peaks about January,
but catastrophic fi res had already started in south-eastern
Queensland and northern NSW by September in 2019.
The review by UK scientists also confirmed a link
between climate change and an increase in severity and
frequency of fi re weather. This usually means a combination
of high temperatures, low humidity and rainfall, and high
winds. In fact, there was another weather system at play
this year – the Southern Annular Mode. This caused strong
winds to blow from the west across the continent, carrying
hot air from Central Australia to fan the fl ames.
The environmental damage to Australia has been stagger-
ing this season, and the scale of animals, plants and habitats
wiped out likely makes this our single biggest ecological
disaster. Frighteningly, the scale of what we witnessed was
not predicted to happen until global temperatures had risen
further. Many imagined a bushfi re crisis such as this to be a
theoretical worst-case scenario likely to still be decades away.
But now is not the time to despair. It’s time to push for
action. We can prevent this or worse from becoming the
new normal. Action to limit greenhouse gases and mitigate
catastrophic climate change isn’t that hard. We just need
leaders with the political will to get on with it, and do so
fast. For now all I can hope is that by the time you read
this, drought-stricken regions have been drenched with
long sought-after rains.HOW CLIMATE CHANGE
IGNITED A MONSTER
JOHN PICKRELL
is a former editor of
AUSTRALIAN GEOGRAPHIC.
Follow him on
Twitter: @john_pickrell2019/2020 BUSHFIRE CRISIS