The Australian bushfires, Early Summer 2019 - 2020:
starting earlier, season longer, bigger, hotter, faster moving *
* Passenger liner berthed at the Overseas Passenger Terminal 10 December 2019. The Opera House can just be made out dimly in the background. A video panning right around the harbour can is available at https://www.abc.net.au/news/2019-12-10/businesses-close-and-ferries-cancelled-as-hazardous-smoke-/11784578
The bushfire season started early in Australia in 2019 - in September in fact, and arrived with a vengeance in the the first week of November - and once the season moved forward, fires spread relentlessly at speed ranging over distances never hitherto experienced in previous years. The initial focal points were in northern Queensland, then NSW and southern Queensland, quickly spreading over huge distances to create megafires, one of which, the Gospers Mountain fire in central NSW exceeded half a million hectares.
As the fires moved closer to Sydney the smoke preceded them by hundreds of kilometres leaving the capital city in a pall of smoke for weeks on end. As I write in late December, six people have died, including two firefighters and almost 1000 homes have been destroyed. And it is not only NSW and Queensland who is affected. As I continue to write, prolific fires are burning uncontrolled in Victoria and the Adelaide Hills and Kangaroo Island in South Australia, where homes have also been destroyed. Nationwide, the totals stand out at 9 dead and 5 million hectares of bush land destroyed, and counting. [1]
Fast forward to January 2020 and fires are burning largely uncontrolled in all States, laying waste overall about 12 million acres. In NSW alone 5.2 million hectares are burnt out, 20 people are dead, 1870 homes destroyed, 755 damaged and stock losses stand at 3872, and across the land "many, many billions of animals are feared to have died", along with hundreds of billions of insects, an integral part of the natural environment. [2] Hectares burnt in Queensland total 2.2 million in Western Australia, 1. 4 million in Victoria and about half a million in South Australia. The effect on native wildlife has been immense and unprecedented with thousands of dead birds strewn along a ten kilometre stretch of Mallacoota beach in Victoria - lorrikeets, king parrots, owls, rosellas, eastern honeyeaters, magpies and others - a "sorry sight" in the eyes of one observer who has been studying the local bird life in this area for the past 30 years. This is the same beach from which hundreds of residents had to be evacuated from the fires by sea because there was no other way out: "Australia's first climate change refugees".
A warming climate begets bigger, hotter, faster moving fires on a more frequent basis
What has brought about this calamitous state of affairs? The Australian Prime Minister, deflecting blame from the obvious, tells his flock in blatantly simplistic terms that “climate change is one of many factors to blame”, and that he could remember Sydney being ringed by fires as a kid, ergo, nothing particularly unusual about this "single event". Others have sought to lay the blame at the door of arsonists who have been debited with starting some of the fires, but, as a Sydney Morning Herald correspondent has pithily pointed out, there is a world of difference between the immediate cause and the longer term causes of the conflagration. The ignition point, whatever that may happen to be, is only the immediate cause, leaving unexplained the underlying causes for the catastrophe:
The bushfire season started early in Australia in 2019 - in September in fact, and arrived with a vengeance in the the first week of November - and once the season moved forward, fires spread relentlessly at speed ranging over distances never hitherto experienced in previous years. The initial focal points were in northern Queensland, then NSW and southern Queensland, quickly spreading over huge distances to create megafires, one of which, the Gospers Mountain fire in central NSW exceeded half a million hectares.
As the fires moved closer to Sydney the smoke preceded them by hundreds of kilometres leaving the capital city in a pall of smoke for weeks on end. As I write in late December, six people have died, including two firefighters and almost 1000 homes have been destroyed. And it is not only NSW and Queensland who is affected. As I continue to write, prolific fires are burning uncontrolled in Victoria and the Adelaide Hills and Kangaroo Island in South Australia, where homes have also been destroyed. Nationwide, the totals stand out at 9 dead and 5 million hectares of bush land destroyed, and counting. [1]
Fast forward to January 2020 and fires are burning largely uncontrolled in all States, laying waste overall about 12 million acres. In NSW alone 5.2 million hectares are burnt out, 20 people are dead, 1870 homes destroyed, 755 damaged and stock losses stand at 3872, and across the land "many, many billions of animals are feared to have died", along with hundreds of billions of insects, an integral part of the natural environment. [2] Hectares burnt in Queensland total 2.2 million in Western Australia, 1. 4 million in Victoria and about half a million in South Australia. The effect on native wildlife has been immense and unprecedented with thousands of dead birds strewn along a ten kilometre stretch of Mallacoota beach in Victoria - lorrikeets, king parrots, owls, rosellas, eastern honeyeaters, magpies and others - a "sorry sight" in the eyes of one observer who has been studying the local bird life in this area for the past 30 years. This is the same beach from which hundreds of residents had to be evacuated from the fires by sea because there was no other way out: "Australia's first climate change refugees".
A warming climate begets bigger, hotter, faster moving fires on a more frequent basis
What has brought about this calamitous state of affairs? The Australian Prime Minister, deflecting blame from the obvious, tells his flock in blatantly simplistic terms that “climate change is one of many factors to blame”, and that he could remember Sydney being ringed by fires as a kid, ergo, nothing particularly unusual about this "single event". Others have sought to lay the blame at the door of arsonists who have been debited with starting some of the fires, but, as a Sydney Morning Herald correspondent has pithily pointed out, there is a world of difference between the immediate cause and the longer term causes of the conflagration. The ignition point, whatever that may happen to be, is only the immediate cause, leaving unexplained the underlying causes for the catastrophe:
Arson, strong winds, the drought and hot weather were all, no doubt, immediate causes for the fires, just as the assassination of Archduke Francis Ferdinand was one of the causes of World War I, but just as the underlying causes of that war developed over many years and in several countries, so too the underlying cause of the present bushfires is a gradual change in the global climate that needs immediate action. [3]
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As it turns out, only 1% of these fires is attributable to arson, and several of the biggest fires, including the mammoth Gospers Mountain fire in the Hawkesbury region of NSW, mentioned above, have been attributed to lightning strikes. But the actual ignition source, whatever it may happen to be, is irrelevant. As distinguished scientist Devra Davis, who has worked on the IPCC and was part of the team that won the Nobel Peace Prize in 2007, points out the real culprits lie in “a tremendous lack of water at ground level and a powerful amount of wind”.
NASA sums it up in two words: “Hot and dry. These are the watchwords for large fires. While every fire needs a spark to ignite and fuel to burn, it's the hot and dry conditions in the atmosphere that determine the likelihood of a fire starting, its intensity and the speed at which it spreads. Over the past several decades, as the world has increasingly warmed, so has its potential to burn. High temperatures and low humidity are two essential factors behind the rise in fire risk and activity, affecting fire behaviour from its ignition to its spread. Even before a fire starts they set the stage".
Professor Steven Sherwood of the ARC Centre of Excellence for Climate Extremes, UNSW Climate Change Research Centre said much the same thing in a letter co-signed by 80 Australian Research Council laureates and published on 29 January 2020: “While many factors have contributed to the bushfire crisis, the role of exceptional heat and dryness cannot be ignored. Temperatures nearly everywhere on Earth have been rising for decades, a clear result of the build-up of greenhouse gases in the atmosphere from fossil fuel use and other human activities. The increasing variability of rainfall across Australia, bringing more dry years, is a consequence”.
The size and intensity of these fires is shaped by climate.
"The scale and ferocity of the recent fires are unprecedented since European settlement of this country. They arrived at the end of a year with the lowest average rainfall and the highest average temperatures ever recorded across Australia. Climate change has arrived, and without significant action greater impacts on Australia are inevitable".
Australia is a country exceptionally vulnerable to risks from a changing climate. The link between greenhouse gas pollution, rising heat across Australia and declining cool season rainfall in mainland southern Australia, meaning less runoff into rivers and dams, is clear. Less cloud cover and warmer temperatures exacerbate dry spells by increasing evaporation. These trends are contributing to drier soils and vegetation, increasing the probability of bushfires. The Gondwana rainforests in northern NSW and southern Queensland, previously thought too damp to burn, have also been damaged by fires.
This situation has built up over years. First, unprecedented drought drastically weakens rural communities, destroying their stock and livelihood before obliging them to "squabble over remnant puddles of drinking water". Next, late-summer temperatures, months too soon, turn drought into “catastrophic” fire conditions – and no water to fight them.
A warming world also begets warmer nighttime temperature which allow fires to burn through the night and burn more intensely, and that allows fires to spread over multiple days where previously, cooler nighttime temperatures might have weakened or extinguished the fire after only one day.
And the bushfires may also be helping to supercharge climate change itself by providing a feedback loop. Since August 2019, greenhouse gas emissions from bushfires in Australia equate to half of the nation's usual annual emissions. Although trees take up carbon when they regrow, it might take decades for the carbon emitted during fires to be fully sequestered, and for some vegetation types that are ill-adapted to fire, much longer.
Hotter and drier conditions set the stage for human-ignited fires. NASA gives two interesting examples of human intervention starting two major fires. Sparks flying from hammering a concrete stake into the ground in 100-degree Fahrenheit heat, and sparks from a car's tire rim scraping against the asphalt after a flat tire were the causes of California's devastatingly destructive 2018 Ranch and Carr Fires, respectively. In the same context, human land management such as land clearing is as important to consider as any other factor, and conversely, an increased human presence creating new cropland and roads that serve as fire breaks may actually lead to a decline in global burned areas. [4]
The crunch line is that a warming climate leads to an increasing frequency of extreme events, and Australia, with its periodic droughts and heatwaves, is among the nations most exposed to a tipping point cascade, making it a much tougher climate for us to live in: "Taste the ash, see the pink sun: our dead future is here!" This is the legacy. And not only did that seem to be behind us, at least on a temporary basis, than the State was beset by a series of aberrant and extreme weather events, the indicia of climate change, all in a single day: massive dust storms, hailstorms with hail the size of golf balls, severe thunderstorms and lightning strikes.
NASA sums it up in two words: “Hot and dry. These are the watchwords for large fires. While every fire needs a spark to ignite and fuel to burn, it's the hot and dry conditions in the atmosphere that determine the likelihood of a fire starting, its intensity and the speed at which it spreads. Over the past several decades, as the world has increasingly warmed, so has its potential to burn. High temperatures and low humidity are two essential factors behind the rise in fire risk and activity, affecting fire behaviour from its ignition to its spread. Even before a fire starts they set the stage".
Professor Steven Sherwood of the ARC Centre of Excellence for Climate Extremes, UNSW Climate Change Research Centre said much the same thing in a letter co-signed by 80 Australian Research Council laureates and published on 29 January 2020: “While many factors have contributed to the bushfire crisis, the role of exceptional heat and dryness cannot be ignored. Temperatures nearly everywhere on Earth have been rising for decades, a clear result of the build-up of greenhouse gases in the atmosphere from fossil fuel use and other human activities. The increasing variability of rainfall across Australia, bringing more dry years, is a consequence”.
The size and intensity of these fires is shaped by climate.
"The scale and ferocity of the recent fires are unprecedented since European settlement of this country. They arrived at the end of a year with the lowest average rainfall and the highest average temperatures ever recorded across Australia. Climate change has arrived, and without significant action greater impacts on Australia are inevitable".
Australia is a country exceptionally vulnerable to risks from a changing climate. The link between greenhouse gas pollution, rising heat across Australia and declining cool season rainfall in mainland southern Australia, meaning less runoff into rivers and dams, is clear. Less cloud cover and warmer temperatures exacerbate dry spells by increasing evaporation. These trends are contributing to drier soils and vegetation, increasing the probability of bushfires. The Gondwana rainforests in northern NSW and southern Queensland, previously thought too damp to burn, have also been damaged by fires.
This situation has built up over years. First, unprecedented drought drastically weakens rural communities, destroying their stock and livelihood before obliging them to "squabble over remnant puddles of drinking water". Next, late-summer temperatures, months too soon, turn drought into “catastrophic” fire conditions – and no water to fight them.
A warming world also begets warmer nighttime temperature which allow fires to burn through the night and burn more intensely, and that allows fires to spread over multiple days where previously, cooler nighttime temperatures might have weakened or extinguished the fire after only one day.
And the bushfires may also be helping to supercharge climate change itself by providing a feedback loop. Since August 2019, greenhouse gas emissions from bushfires in Australia equate to half of the nation's usual annual emissions. Although trees take up carbon when they regrow, it might take decades for the carbon emitted during fires to be fully sequestered, and for some vegetation types that are ill-adapted to fire, much longer.
Hotter and drier conditions set the stage for human-ignited fires. NASA gives two interesting examples of human intervention starting two major fires. Sparks flying from hammering a concrete stake into the ground in 100-degree Fahrenheit heat, and sparks from a car's tire rim scraping against the asphalt after a flat tire were the causes of California's devastatingly destructive 2018 Ranch and Carr Fires, respectively. In the same context, human land management such as land clearing is as important to consider as any other factor, and conversely, an increased human presence creating new cropland and roads that serve as fire breaks may actually lead to a decline in global burned areas. [4]
The crunch line is that a warming climate leads to an increasing frequency of extreme events, and Australia, with its periodic droughts and heatwaves, is among the nations most exposed to a tipping point cascade, making it a much tougher climate for us to live in: "Taste the ash, see the pink sun: our dead future is here!" This is the legacy. And not only did that seem to be behind us, at least on a temporary basis, than the State was beset by a series of aberrant and extreme weather events, the indicia of climate change, all in a single day: massive dust storms, hailstorms with hail the size of golf balls, severe thunderstorms and lightning strikes.
[1] Sydney Morning Herald 28 December 2019.
[2] Sydney Morning Herald, 11-12 January 2020. Upon RMIT ABC Fact Check "more than a billion" is found to have been "a conservative estimate".
[3] Rob Jackson, Cheltenham, SMH, 24 Dec 2019.
[4] On a global scale, the satellite data tells the tale. The mechanics are explained here.
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