The Australian Broadcasting Corporation, ABC, has put together the story of the largest bushfire in the recorded history of the continent. When the spread of the Gospers Mountain Fire finally halted during the 2019-2020 bushfire season, it had merged with four other large blazes to ultimately burn 1,071,740 hectares (2,648,323 acres).
Sometimes in the United States we call a fire that reaches 100,000 acres a “megafire”, but the prefix “mega” means a million (106). Last bushfire season the Aussies had a legitimate megafire.
The article at ABC is well researched and interesting. It includes details that previously were not widely known — such as the fact that firefighters were worried that the fire could burn into the northern suburbs of Sydney, the state capital of New South Wales.
Although Australia is no stranger to wildfires, the 2019-2020 season was one of the worst fire seasons on record. Major bushfires began in spring 2019 (June), and by September were stronger, more intense, and more frequent. The fire situation continued to worsen, and by November, Australia requested international assistance to suppress the thousands of fires on the landscape.
Over a span of four months, the United States responded to Australia’s request for firefighters by providing personnel from the Bureau of Indian Affairs, Bureau of Land Management, U.S. Fish and Wildlife Service, Forest Service, and National Park Service. In total, the U.S. Fish and Wildlife Service (FWS) provided 11 individuals to assist in suppression efforts.
FWS employees filled important roles, including engine captain, situation officer, aircraft officer, task force leader, fire behavior analyst, division supervisor, planning section chief, operations section chief, air support group supervisor, and public information officer.
“Our mission was to support the Australian government in suppressing the bushfires and keeping the Australian people and communities safe,” said Reynaldo Navarro, Assistant Fire Management Officer, South Texas Refuge Complex. “Our tasks included firing operations, engine support, mopping up or blacking out, hand line construction, hazard tree felling, and structure triage and protection.”
“Being in Australia was a great, yet very humbling experience,” said Kyle Bonham, Engine Captain at Klamath Basin National Wildlife Refuge Complex, of his time in Australia.
Although the Australia bushfires brought great destruction and impacts to the country, FWS personnel were welcomed with cheer and open arms.
“What stands out to me are the Australian people,” said Richard Sterry, Fire Management Specialist, Lakewood, Colorado. “I was assigned to a more rural area, and the Australian people were wonderful to work with. They always had smiles on their faces and were constantly going out of their way help us learn their system.”
By mid-February, more than 46 million acres (72,000 square miles) burned since the first fires in June, 2019. Overall, 80 percent of the Blue Mountains World Heritage area in New South Whales, and 53 percent of the Gondwana World Heritage rainforests in Queensland burned.
Fighting bushfires in Australia provided a unique opportunity for FWS firefighters to learn new firefighting skills, as well as hone the skills required to fight fire in the United States. Due to Australia’s location in the southern hemisphere, fire season occurs at a time when much of the U.S. is out of danger of wildfire. Firefighters helping with suppression efforts in Australia were afforded a unique opportunity to polish firefighting skills needed during wildfire season in the U.S.
Kari Cobb is the acting public affairs officer for the U.S. Fish and Wildlife Service at the National Interagency Fire Center.
When a reporter for Bloomberg asked me if she could interview me I said OK, as long as I could have the rights to publish the article on my web site — Mira Rojanasakul said yes. I thought the article, written with Hayley Warren, was going to be primarily about air tankers, and those used in Australia in particular, but now that it has been published today I see that it also covers how climate change is affecting wildfires down under and in the United States.
In addition to being a writer, Ms. Rojanasakul is an accomplished graphics editor for Bloomberg. And that’s why I’m writing about this article and why you should check it out. She takes graphics to a higher level.
Here are some samples.
A very impressive large animated version of the graphic below is on the Bloomberg website.
Data collected in an Australian study could lead to the development of more accurate predictive models for wildfire behavior and spotting, especially for extreme wildfires.
Burning embers driven ahead of a wildfire can dramatically increase the rate of spread and the danger faced by firefighters and the public. Under moderate burning conditions a small number of spot fires might be suppressed if enough firefighting resources are available, but on large plume-dominated fires pushed by strong winds spot fires far from the main fire can burn together making suppression at the head of the fire impossible. In many cases ember showers have been the primary ignition source for the destruction of structures in the wildland urban interface.
During the 2009 Black Saturday bushfires in eucalpyt-dominated forests in Australia the maximum spot fire distances were 30 to 35 km (18 to 22 miles) and during the 1965 wildfires in eastern Victoria were 29 km (18 miles). Spot fires in North America have been documented at distances of up to 19 km (12 miles).
The researchers took advantage of the increasing use of airborne mapping technologies on wildfires in Australia, including infrared and multispectral line scanning, to analyze data from 338 observations. (See map above.) They used ArcGIS to manually draw polygons and determine the size of the actively burning areas of the fire, which they called “source fire area”, and measured the distance to spot fires and the size of each. They also collected fuels, weather, and topography information.
Below is an excerpt from the research:
Maximum spot fire distances ranged from 5.0 m to 13.9 km (mean, 0.9 km; 95th percentile, 3.9 km). The mean number of spot fires per source fire (irrespective of distance) was 13. The distribution of maximum distance values appeared exponential, with a high proportion of shorter distances (Fig. 4a). Very long-distance spotting was rare; only 11 source fires had a maximum spotting distance >5 km.
Eleven of the fires had spotting distances more than 5 km (3.1 miles). The longest distance measured to a spot fire was 13.9 km (8.6 miles).
The analysis of 338 wildfire line scan observations found the size of the active area of the source fire to be the strongest predictor of long-distance spotting. Important secondary effects were fuel, weather, and topography.
Wind speed was important to both Maximum-distance and long-distance Spot-number. Upper-level wind speed had weaker but still significant effects in the models. Wind at different levels can influence many aspects of wildfire behaviour, including plume development, plume turbulence and tilt, fire intensity, vorticity development, firebrand transport and ignition likelihood in receiver fuels.
A steep slope somewhere within the source fire (i.e. source fire max. slope) increased the maximum spot fire distance and the probability of spot fire occurrence >500 m. TRI [Terrain Ruggedness Index] performed similarly but was highly correlated with slope (>0.9), so was not included in the same models. An area of relatively high wind exposure (e.g. exposed ridge) also increased maximum spotting distance. Slope and wind exposure may be important through interactions with wind, changing wind speed, increasing turbulence and potentially enhancing pyroconvection, leading to enhanced firebrand generation and transport.
[W]e did not find a commonly used measure of bark spotting potential to be a significant predictor. Our results suggest that to accurately predict long-distance spotting, models must incorporate a measure of source fire area. Gathering data on spotting and plume development at wildfires over a range of intensities (including measuring intensity and frequent line scans) and improving fuel maps should be prioritised to allow for the development of reliable predictive spotting models.
The fibrous or stringy bark on some eucalyptus species is particularly suited aerodynamically for being lofted in a convection column and traveling for long distances while still burning, and is one of the primary ignition sources for long range spotting in Australia. The bark on North American trees is different, but the methods used by the Australian researchers could be used to collect similar spot fire occurrence data in the United States and Canada which could lead to improved spotting and fire behavior models.
…Global warming boosted the risk of the hot, dry weather that’s likely to cause bushfires by at least 30%, they say.
But the study suggests the figure is likely to be much greater. It says that if global temperatures rise by 2C, as seems likely, such conditions would occur at least four times more often. The analysis has been carried out by the World Weather Attribution consortium.
Co-author Geert Jan van Oldenborgh of the Royal Netherlands Meteorological Institute in De Bilt, The Netherlands, told the BBC even the study’s very conservative estimates were troubling.
“Last year the fire prevention system in Australia, which is extremely well prepared for bushfires, was straining. It was at the limits of what it could handle, with volunteers working for weeks on end,” said Prof van Oldenborgh.
“As the world warms, these events will become more likely and more common. And it’s not something that we are ready for.”
During the 2019-2020 fire season in Australia, record-breaking temperatures and months of severe drought fueled a series of massive bushfires across the country. At least 33 people were killed and more than 11 million hectares (110,000 sq km or 27.2 million acres) of bush, forest and parks across Australia burned.
Although it makes sense that human-induced global warming is likely to have led to more bushfires, assigning a figure to that increased risk is complex. That is because other factors not directly related to climate change may also play a significant role. These include increased water use making the land drier, urban heating effects or unknown local factors.
Nevertheless, Prof Jan van Oldenborgh and 17 fellow climate scientists from six countries gave it their best shot. “It was by far the most complex study we have undertaken,” he told the BBC.
The researchers found the climate models consistently underestimated the observed increase in temperatures in southeast Australia and so could not pinpoint a figure for the increased risk from climate change. They were, however, able to tease out a minimum risk.
“We show that climate change definitely increases the risk of the extreme weather that makes the catastrophic bush fires (that south-east Australia has experienced) in the past few months more likely by at least 30%.
“But we think it could be much more. We don’t know how much more. It could be a lot more.”
Prof van Oldenborgh is among those attempting to find out if the current climate computer models really are underestimating the influence of global warming – and if they are, working out how to correct them.
The Governor-General of Australia has appointed three commissioners to lead a royal commission to look into the bushfires that so far during the 2019-2020 fire season have devastated to an unprecedented extent large areas of Queensland, New South Wales, and Victoria.
From ABC Australia:
Two more commissioners, former Federal Court judge Annabelle Bennett and leading environmental lawyer Andrew Macintosh, will join former Australian Defence Force (ADF) chief Mark Binskin.
The trio are due to deliver their findings to the Federal Government by the end of August.
More than 30 people died across the country during the disaster, and thousands of homes were destroyed.
The ABC revealed earlier this month that hazard reduction would form a key part of the inquiry, after Prime Minister Scott Morrison demanded an investigation into whether controlled burns and land clearing operations had been hampered across the country.
Climate change, and specifically its effect of creating longer, hotter and drier fire seasons, will also be considered by the royal commission.
In January when a royal commission was being proposed, the United Firefighters Union of Australia said there had already been numerous bushfire-related inquiries over the past two decades. One more commission would likely come up with the same issues, they said.
The union believed there should be instead, an audit all of the existing recommendations that haven’t been implemented. They said Royal Commissions are expensive, can take hundreds of days, force witnesses to relive the trauma, and the commission has no binding power to implement recommendations.
Witnesses included two expert panels and 100 “lay” witnesses drawn from bushfire-affected communities. Almost 1,700 written submissions were considered by the Commission, close to 1,000 exhibits tendered and 20,500 pages of written transcripts produced.
Meanwhile, New South Wales is conducting an “independent expert inquiry” into the 2019-2020 bushfire season. Dave Owens APM, former Deputy Commissioner of NSW Police, and Professor Mary O’Kane AC, Independent Planning Commission Chair and former NSW Chief Scientist and Engineer, are leading the six-month inquiry, which is reviewing the causes of, preparation for, and response to the 2019-20 bushfires.