Monash University - Paul Read
Paul Read is Senior Lecturer, School of Psychological Sciences, Monash University.
His focus is on global sustainability, natural disasters, and intergenerational equity based on global UN/WHO data linked to policy and the UN Sustainable Development Goals
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In preparing for a lecture on an early spring day in the
hills of Victoria, I noticed that male cicadas, usually prompted by
summer temperatures, began their mating song months earlier than I could
ever remember since childhood.
A week later, Queensland was on fire,
and many of the blazes were attributed to arson. Despite many being
deliberately lit, what followed suggested climate change. The question
remained as to how much.
On further investigation, I
was further shocked to find that the 2019 fires began in late August,
before the usual Queensland bushfire season would start blazing its way
down the east coast, six months ahead of the February peak for
Australia’s deadliest fires for 200 years.
As well as
seasonality, the reach and speed of its journey was “unprecedented”, a
word right-leaning commentators immediately attacked.
Misinformation and politics
Andrew
Bolt pointed out that the fires were small compared to Australian
records since 1851. He ignored the main point about seasonal timing and
speed, and went quiet as the fires grew and surpassed historical
records. A few little-known grassfires in the Northern Territory were
larger in terms of hectares burnt, but even they dwindled into
insignificance when height was added to cover three-dimensional biomass.
Alan
Jones saved the day for climate sceptics by blaming the fires on arson,
using a version of the following logic: If arsonists caused the fires,
then climate change didn’t.
This was based on
misrepresenting fire investigations and satellite data converging on
about 85 per cent of Australia’s 60,000 fires being due to human sources
(yet he never mentioned that only 13 per cent were confirmed arson).
After being promoted by Breitbart News and an army of right-wing bots
spreading misinformation, the same argument was adopted by the Trump
administration’s affiliates.
Experts were forced to
state the obvious – even after human ignition, the size and ferocity of
fires still depends on fuel and prevailing weather. Every cub Scout the
world over knew this, but it still took weeks for the arson argument to
subside.
In fact, the 2019 fires would have needed a
sudden 60-fold increase in arson to account for Australia’s megafires –
an impossibility given tiny 5 per cent increases in arson per year for
decades.
The arson argument was rapidly smothered as
fires grew, because the later, larger southern fires started to create
their own weather – burning hotter than a Bunsen burner, pyro-cumulus
clouds sparked their own dry lightning, and embers started fires more
than 30 kilometres ahead of the front. This was consistent with past
studies that massive fires fed their own growth, with diminishing
contributions from arson and other human causes.
At
this point, and at another level, the only remaining human cause was
climate change. In response, Barnaby Joyce started arguing that the
Greens’ policies prevented controlled burning, causing megafires due to
higher fuel loads.
Determined conspiracy theorists
combined this with the dwindling arson theme, claiming that Greens
activists themselves lit the fires to push their own climate agenda.
Madness. No activist would consider this, much less risk the species
extinction that resulted after more than 1.5 billion animals died in
these fires.
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| Indigenous burning: more funding required. |
In response to the fuel load argument
raised by Barnaby Joyce and others, past fire commissioners pointed to
research and fire management experience showing that reduced fuel loads
from hazard-reduction burns were inconsistent in decreasing seasonal
wildfires. Sometimes it works, sometimes not, often in different areas.
This is because the issue is extremely complex.
Hazard
reduction isn’t just burning, but bulldozing, pesticides, grazing and
deforestation. Using contractors with big machinery smashes
biodiversity, whereas more careful but labour-intensive approaches
include small-scale burning for fire-adapted species.
This
level of sensitivity can only be carried out by dedicated groups of
local volunteers following similar approaches to Aboriginal firestick
burning, because it remains small-scale per participant (compared to
modern machinery), so is more focused and sensitive to patches of
ecological fragility.
This probably needs more
government funding, because the approach is complex at all levels. It
first needs to split state areas into much smaller patches that
recognise the mix of species, their age, growth rates and fire
resilience – all of which go into calculating what’s called the
Tolerable Fire Interval (TFI), a measure now much more sophisticated
than simple hectares burned. Adopted since 2017 in some states, the TFI
pixelates satellite imagery to adjust and apply hazard strategies at
granular levels. Despite the cost, Victoria managed to achieve this
level of management and was still vulnerable to wildfires in Gippsland,
demonstrating just how hard it is to manage bushfire overlays.
Apart
from climate change, the last remaining argument, and one that has some
merit, is that the fires emerged from a confluence of natural cycles.
Australia
was hit by three of its main climate drivers in 2019: the El Nino
Southern Oscillation (ENSO); the positive Indian Ocean Dipole (IOD); and
the negative Southern Annular Mode (SAM).
The natural cycles that fanned the flames
El
Nino is the hotter phase of the Southern Oscillation Index, measured by
air pressure differences between Tahiti and Darwin. The IOD takes a
similar approach, but is based on the sea surface temperature anomalies
in the
Indian Ocean’s tropical west against its southeast. Positive IOD values resemble El Nino, reducing rainfall in Australia’s southeast, and
correlating with every Australian drought since 1889. Sometimes they coincide to form a “super El Nino”, which happened in 2019.
The
third major driver is SAM, vast westerlies that spin around Antarctica,
rising upwards towards Australia in cycles. In 2019 they rose towards
Australia in August, causing
less rain above Sydney and heatwaves in the southeast. As they rise, they blow across the hot Australian interior, explaining the
red dust storms presaging the fires.
There’s
no doubt these climate drivers affected drought and fires in Australia;
no doubt again that some fires were lit by humans or caused by human
activity; again, fuel load would have had a major impact even when
properly managed. All converged on Australia’s biggest fires in recorded
history, and some part is likely due to climate change as well.
There’s
no excuse to remain one of the world’s highest emitters per capita – if
developing nations point to Australia as a standard for their own
rights to emissions, we would now need almost eight planets to
accommodate them.
Here’s a crude estimate of how much climate change might have contributed:
Ignoring
fuel and assuming arson followed its usual trajectory, we can presume
the remainder of the fires emerged from a combination of natural cycles
and climate change. The recently updated McArthur Forest Fire Wildfire
Index (FWI) includes temperature, humidity and rainfall, whereas annual
data is also available for the three main climate drivers back to 1957 –
60 years of data, all accessible to anyone with an internet connection
to BOM.
When the years suffering major fires are
compared with all others, all were affected by El Nino, followed by IOD,
then rainfall (in other words, drought), followed by SAM. The three
natural cycles were involved in 63 per cent of the fires since 1957,
whereas rainfall was involved in 20 per cent.
As the
single measure of climate change, national temperature anomalies had
already risen by one degree in 2020 compared to the average from 1960 to
1990; it transitioned from negative to positive in 1985, and its maxima
was linear, suggesting a rise of 1.5 degrees since 1950.
Using
this metric alone, the effect of climate change on Australia’s
megafires, outside of natural cycles and arson, amounts to 16 per cent.
It’s likely much higher, though, as the natural cycles (except in the
case of ENSO) are themselves affected by climate change, as can be seen
in Figure 1.This simple approach can be calculated by anyone, but is
likely a vast underestimate, as the next section demonstrates.
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| Figure 1. The fingerprint of climate change in the Indian Ocean Dipole, Southern Annular Mode and average annual temperature anomalies for Australia since 1957 (compared to 1960-90). |
So, what did cause the Australian megafires?
At the start of February, the world’s leading science journal,
Nature,
announced that a global team of scientists, including Australia’s own
Dr Sophie Lewis, were working on a complex attribution study to test
whether and how much climate change was to blame for the Australian
megafires.
This study came out last week, buried under news of coronavirus and mass panic relating to toilet paper sales.
The
authors of this eight-week attribution, led by Geert Jan van Oldenborgh
from the Royal Netherlands Meteorological Institute, have now carried
out 231 such studies on natural disasters worldwide – storms, heatwaves,
floods and now fires.
Four of 11 datasets offered
enough Australian data to reach back much further, to 1900. Not all were
appropriate due to missing data in temperature, rainfall, humidity or
wind speed – the types of factors used to predict catastrophic fires by
emergency services. The entire analysis took three steps:
-
Temperature using a seven-day moving average for the fire weather (across available years)
-
Drought using annual precipitation and driest month (again across available years as above)
-
Attribution models on the Fire Weather Index (FWI) and the Monthly Severity Rating (MSR).
They
also checked the results against the amount of area burnt in each month
of the 2019 fires between the Great Dividing Range and the coast. The
models across time and area validated one another, although they didn’t
use actual burned area per year.
Final analyses
demonstrated that fully 30 per cent of the increase in the FWI was due
to anthropogenic climate change alone. Two models converged on a
temperature increase of 1.5°C to 1.7°C from 1900 to 2019, plus a massive
change in the return rate – the number of years that should elapse
between catastrophic events. This fell dramatically from 85 years in
1900, to eight years in 2019.
For Australia, this means more catastrophic fires more frequently.
Outside
of climate change, the more natural cycles of the Indian Ocean Dipole
(IOD) and the Southern Annular Mode (SAM) caused more than half of the
2019 drought – around one third each – with little impact from the El
Nino Southern Oscillation (ENSO). The probability of catastrophe rose by
a factor of 11, mostly due to trends in temperature.
Implications for political arguments and misinformation campaigns
These
results should put a host of political issues to rest, and also pave
the way for adaptation and mitigation strategies – things such as the
Australia Institute’s climate disaster levy, reanalysis of our
obligations under the Paris Agreement, and a long-overdue
reconsideration of Ross Garnaut’s efforts on behalf of the nation.
It
should inform what the federal government aims to handle over the next
six months – a re-evaluation of our approaches to bushfire, and our
commitments under the Paris Agreement.
The Paris
Agreement, even if fulfilled, still leaves the world on track for +3°C
of warming – and even below this, +2°C would be enough to quadruple the
frequency of catastrophic megafires.
The equally important issue of the coronavirus shouldn’t distract us from what the government chooses to do about fires.
As
well as the royal commission into the Black Saturday fires, the
Deloitte analysis of intangible costs, and many other factors, the
government should also take into account two seemingly unrelated reports
– the
2019 mass extinction report led by Professor Sandra Diaz, and the 2020
A Future for the World’s Children? report by the World Health Organization and UNICEF, in which Australia fails miserably to protect its own children.
If
our children are to avoid ecological catastrophes, the world will have
to adapt very rapidly to zero emissions – so rapidly that it would
likely lead to resource wars and economic collapse. This means we need
to act now if we mean to ease their adoption up to 2050 – to prevent
them walking a razor’s edge between natural disaster and war.
For
Australia, an interim aim would be to constrain, by 2025, Australia’s
emissions to eight tonnes per capita of emissions. There’s no excuse to
remain one of the world’s highest emitters per capita – if developing
nations point to Australia as a standard for their own rights to
emissions, we would now need almost eight planets to accommodate them.
Apart
from Australia, the US and a clutch of OPEC nations, the world average
is only 2.2 tonnes per capita. Even those who successfully optimised the
health of their citizens over the past 60 years needed no more than
eight tonnes, and this without any access to renewable technologies.
So
why not Australia? If the value of our coal exports ends up less than
the rising costs of bushfires, then why not apply a disaster levy,
reintroduce Professor Garnaut’s solution, and aim for eight tonnes per
person by 2025? At the very least, drop the ingenuous appeal for special
consideration based on a confection of carbon credits.
And
isn’t it also time to drop the ubiquitous argument of conservative
commentators that we also need special consideration because we only
emit 1.1 per cent of the world’s emissions. Just wait until China and
India claim the same consideration based on our emissions per person –
then see Australia furiously back-pedalling as its backyard burns.
If we act now, the cicadas will keep singing, and so will Australia’s children.
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