Bushfires in Australia

Bushfires in Australia can occur all year-round, though the severity and the “bushfire season” varies by region.

There is no formal definition for a single bushfire season across the whole of Australia. There is no one terminology used for periods of fire activity. The technical terms used for periods of fire risk and fire activity include fire weather season, fire danger season, bush fire danger period, fire danger period, fire permit period, restricted burning times, and, prohibited burning times, and fire season.

The term “Australian bushfire season”, is a colloquialism broadly defined by common usage, from when the first uncontrolled fires start any time from June onwards, typically shortened to “bushfire season”, and applies mainly to southern and eastern Australia. It can continue through to April. Central and northern Australia have two separately defined fire seasons. The colloquial term is typically used in conjunction with the technical terms when conveying information to the public.

The Australian Bureau of Meteorology defines five “fire danger seasons”, being times of peak bushfire activity, roughly corresponding to broad bands of latitude across the Australian continent including winter and spring, across the most northern parts of Australia; spring; spring and summer; summer; and summer and autumn, across the most southern parts of Australia.

Each Australian state and territory jurisdiction defines periods of peak fire risk or fire activity differently. New South Wales has a default statutory “bush fire danger period” defined in law, from 1 October to 31 March.

The state government can then declare different start and end dates for bush fire danger periods for each local government area within the state. In 2019 these started 1 August.

Victoria declares a “fire danger period” for each local government area. Victorian fire danger periods typically start in October and finish as late as May.

The South Australia Government declares a “fire danger season” for each local government area, potentially starting in October and finishing at the end of April.

The Tasmanian Government declares “fire permit period”s for local government areas. In 2019 this commenced 31 October.

Western Australia requires each local government area to declare its own “restricted burning times” roughly aligned with spring and autumn, and “prohibited burning times” roughly aligned with summer.

The Northern Territory defines two broad “fire season”s, a northern fire season, which can run from April to November, and a central Australian fire season, which can run from October to March.

The Government also refers to these as “fire danger period”s.

Bushfire seasons are commonly grouped into years such as “2019–2020 Australian bushfire season” and typically apply to the season for southern and eastern Australia; from 1 June to 31 May annually.

Fire is one of the most important forces at work in the Australian environment. Some plants have evolved a variety of mechanisms to survive or even require bushfires or even encourage fire as a way to eliminate competition from less fire-tolerant species.

The fires would have been caused by both natural phenomena and human hands. Aborigines in many regions set fire to grasslands in the hope of producing lusher grass to fatten kangaroos and other game and, at certain times of the year, burned fire breaks as a precaution against bushfire.

Fire-stick farming was also used to facilitate hunting and to promote the growth of bush potatoes and other edible ground-level plants. In central Australia, they used fire in this way to manage their country for thousands of years.

The use of fire by Aboriginal people was so widespread and constant that virtually every early explorer in Australia makes mention of it. It was the Aboriginal fire that prompted James Cook to call Australia ‘This continent of smoke’.

When control was wrested from the Aborigines and placed in the hands of Europeans, disaster resulted. Fire suppression became the dominant paradigm in fire management leading to a significant shift away from traditional burning practices.

A 2001 study found that the disruption of traditional burning practices and the introduction of unrestrained logging meant that many areas of Australia were now prone to extensive wildfires especially in the dry season.

A similar study in 2017 found that the removal of mature trees by Europeans since they began to settle in Australia may have triggered extensive shrub regeneration which presents a much greater fire fuel hazard.

Another factor was the introduction of gamba grass imported into Queensland as a pasture grass in 1942, and planted on a large scale from 1983. This can fuel intense bushfires, leading to loss of tree cover and long-term environmental damage.

Colonial-era

Australia’s hot, arid climate and wind-driven bushfires were a new and frightening phenomenon to the European settlers of the colonial era.

The devastating Victorian bushfires of 1851, remembered as the Black Thursday bushfires, burned in a chain from Portland to Gippsland, and sent smoke billowing across the Bass Strait to northwest Tasmania, where terrified settlers huddled around candles in their huts under a blackened afternoon sky.

The fires covered five million hectares (around one-quarter of what is now the state of Victoria). Portland, Plenty Ranges, Westernport, the Wimmera and Dandenong districts were badly hit, and around 12 lives were recorded lost, along with one million sheep and thousands of cattle.

New arrivals from the wetter climes of Britain and Ireland learned painful lessons in fire management and the European farmers slowly began to adapt – growing green crops around their haystacks and burning fire breaks around their pastures, and becoming cautious about burn-offs of wheatfield stubble and ringbarked trees. But major fire events persisted, including South Gippsland’s 1898 Red Tuesday bushfires that burned 260,000 hectares and claimed twelve lives and more than 2,000 buildings.

Since Federation

Large bushfires continued throughout the 20th century. With increasing, population and urban spread into bushland came increasing death tolls and property damage during large fires.

1925–1926: Gippsland fires and Black Sunday

During the 1925–1926 Victorian bushfire season, large areas of Gippsland in Victoria caught fire, leading to the Black Sunday fires on 14 February, when 31 people were killed in Warburton, near Melbourne. These fires remain the fifth most deadly bushfires recorded, with 60 people killed over two months.

1938-1939 season and Black Friday

The 1939 fire season was one of the worst on record for Australia, peaking with Victoria’s devastating Black Friday bushfires of 13 January, but enduring for the full summer, with fires burning the urban fringes of Sydney, Melbourne and Canberra, and ash falling as far away as New Zealand. The Black Friday fires were the third deadliest on record, with some 71 people killed and 650 houses destroyed.

Black Friday followed years of drought and a series of extreme heatwaves that were accompanied by strong northerly winds, after a very dry six months. Melbourne hit 45.6 degrees and Adelaide 46.1. In NSW, Bourke suffered 37 consecutive days above 38 degrees and Menindee hit a record 49.7 degrees on 10 January.

New South Wales also lost hundreds of houses, thousands of head of stock and poultry, and thousands of hectares of grazing land. On 16 January, The Sydney Morning Herald reported that disastrous fires were burning in Victoria, New South Wales and the Australian Capital Territory as the climax to the terrible heatwave: Sydney faced record heat and was ringed to the north, south and west by bushfires from Palm Beach and Port Hacking to the Blue Mountains, with fires blazing at Castle Hill, Sylvania, Cronulla and French’s Forest. Disastrous fires were reported at Penrose, Wollongong, Nowra, Bathurst, Ulludulla, Mittagong, Trunkey and Nelligen.

Canberra faced the “worst bushfires” it had experienced, with thousands of acres burned out and a 45-mile fire front was driven towards the city by a south-westerly gale, destroying pine plantations and many homesteads, and threatening Mount Stromlo Observatory, Government House, and Black Mountain. Large numbers of men were sent to stand by government buildings in the line of fire. Five NSW deaths were reported, while in Victoria, the death toll reached more than sixty.

Black Friday

The state of Victoria was hardest hit, with an area of almost two million hectares burned, 71 people killed, and whole townships wiped out, along with many sawmills and thousands of sheep, cattle and horses around Black Friday. Fires had been burning through December, but linked up with devastating force on Friday 13 January, plunging many areas of the state into midday blackness.

After the bushfires, Victoria convened a Royal Commission. Judge Leonard Stretton was instructed to inquire into the causes of the fires, and consider the measures taken to prevent the fires and to protect life and property. He made seven major recommendations to improve forest and fire management and planned burning became an official fire management practice.

1966-1967 and Black Tuesday

In the summer of 1967, Tasmania suffered its most destructive fire season and Australia’s fourth most deadly on record. A verdant spring had added higher than usual fuel to the state’s forest floors, and strong northerly winds and high temperatures drove at least 80 different fires across the south-east, burning to within 2km of the centre of Hobart, the state capital. The infernos killed 62 people and destroyed almost 1300 homes.

Ignition

In recent times most major bush fires have been started in remote areas by dry lightning or by electric power lines being brought down or arcing in high winds. Many fires are as a result of either deliberate arson or carelessness, however these fires normally happen in readily accessible areas and are rapidly brought under control. Man-made events include arcing from overhead power lines, arson, accidental ignition in the course of agricultural clearing, grinding and welding activities, campfires, cigarettes and dropped matches, sparks from machinery, and controlled burn escapes. They spread based on the type and quantity of fuel that is available. Fuel can include everything from trees, underbrush and dry grassy fields to homes. Wind supplies the fire with additional oxygen pushing the fire across the land at a faster rate.

Large, violent wildfires can generate winds of their own, called fire whirls. Fire whirls are like tornadoes and result from the vortices created by the fire’s heat. When these vortices are tilted from horizontal to vertical, this creates fire whirls. These whirls have been known to hurl flaming logs and burning debris over considerable distances.

Some reports indicate that a changing climate could also be contributing to the ferocity of the 2019–20 fires with hotter, drier conditions making the country’s fire season longer and much more dangerous. Strong winds also promote the rapid spread of fires by lifting burning embers into the air. This is known as spotting and can start a new fire up to 40 km downwind from the fire front.

In the Northern Territory fires can also be spread by black kites, whistling kites and brown falcons. These birds have been spotted picking up burning twigs, flying to areas of unburned grass and dropping them to start new fires there. This exposes their prey attempting to flee the blazes: small mammals, birds, lizards, and insects.

Topography

Bushfires in Australia are generally described as uncontrolled, non-structural fires burning in a grass, scrub, bush, or forested area. The nature of the fire depends somewhat on local topography. Hilly/mountainous fires burn in areas which are usually densely forested. The land is less accessible and not conducive to agriculture, thus many of these densely forested areas have been saved from deforestation and are protected by national, state and other parks. The steep terrain increases the speed and intensity of a firestorm. Where settlements are located in hilly or mountainous areas, bushfires can pose a threat to both life and property. Flat/grassland fires burn along flat plains or areas of small undulation, predominantly covered in grasses or scrubland. These fires can move quickly, fanned by high winds in flat topography, and they quickly consume the small amounts of fuel/vegetation available. These fires pose less of a threat to settlements as they rarely reach the same intensity seen in major firestorms as the land is flat, the fires are easier to map and predict, and the terrain is more accessible for firefighting personnel. Many regions of predominantly flat terrain in Australia have been almost completely deforested for agriculture, reducing the fuel loads which would otherwise facilitate fires in these areas.

Climate change

Australia’s climate has warmed by more than one degree Celsius over the past century, causing an increase in the frequency and intensity of heatwaves and droughts.

Eight of Australia’s ten warmest years on record have occurred since 2005.

A study in 2018 conducted at Melbourne University found that the major droughts of the late 20th century and early 21st century in southern Australia are “likely without precedent over the past 400 years”.

Across the country, the average summer temperatures have increased leading to record-breaking hot weather, with the early summer of 2019 the hottest on record. 2019 was also Australia’s driest ever year since 1900 with rainfall 40% lower than average.

Heatwaves and droughts dry out the undergrowth and create conditions that increase the risk of bushfires. This has become worse in the last 30 years.

Impact on wildlife

Bush fires kill animals directly and also destroy local habitats, leaving the survivors vulnerable even once the fires have passed. Professor Chris Dickman at Sydney University estimates that in the first three months of the 2019–2020 bushfires, over 800 million animals died in NSW, and more than 1 billion nationally.

This figure includes mammals, birds, and reptiles but does not include insects, bats or frogs. Many of these animals were burnt to death in the fires, with many others dying later due to the depletion of food and shelter resources and predation by feral cats and red foxes. Dickman adds that Australia has the highest rate of species lost of any area in the world, with fears that some of Australia’s native species, like the Kangaroo Island dunnart, may even become extinct because of the current fires.

Koalas are perhaps the most vulnerable because they are slow-moving. In extreme fires, koalas tend to climb up to the top of a tree and curl into a ball where they become trapped. In January 2020 it was reported that half of the 50,000 koalas on Kangaroo Island off Australia’s southern coast, which are kept separate to those on the mainland as insurance for the species’ future, are thought to have died in the previous few weeks.

Wildlife ecologist Professor Euan Ritchie from Deakin University says that when fires have passed, frogs and skinks are left vulnerable when their habitats have been destroyed. Loss of habitat also affects already endangered species such as the western ground parrot, the Leadbeater’s possum, the Mallee emu-wren (a bird which cannot fly very far), and Gilbert’s potoroo. Beekeepers have also lost hives in bushfires.

Kangaroos and wallabies can move quickly trying to escape from fires. However, the Guardian reported in January 2020 that dozens, maybe hundreds of kangaroos “perished in their droves” as they tried to outrun the flames near Batlow in NSW.

The most resilient animals are those that can burrow or fly. Possums often get singed, but can sometimes hide in tree hollows. Wombats and snakes tend to go underground.

Goannas can benefit from bushfires. Dickman says: “In central Australia, we’ve seen goannas coming out from their burrows after a fire and picking off injured animals – singed birds, young birds, small mammals, surface-dwelling lizards, and snakes.”

Impact on humans

The most devastating impact on humans is that bushfires have killed over 800 people since 1851.

In addition to the loss of life, homes, properties, and livestock are destroyed potentially leaving people homeless, traumatized, and without access to electricity, telecommunications and, in some cases, to drinking water.

In the last ten years or so, government licenses have been granted to fire-prevention programs on Aboriginal lands in northern Australia. In this area Aboriginal traditions, which reduce the undergrowth that can fuel bigger blazes, revolve around the monsoon. The land is burned patch by patch using “cool” fires in targeted areas during the early dry season, between March and July.

These defensive burning programs began in the 1980s and 1990s when Aboriginal groups moved back onto their native lands. Since this process began, destructive bushfires in northern Australia have burned 57% fewer acres in 2019 than they did on average in the years from 2000 to 2010, the decade before the program started.

In southern Australia, Aboriginal knowledge systems of fire management are less valued than in the north.

In the Kimberley area, the Land council applies local resources and holds community fire planning meetings to ensure the correct people are doing the burning. Burn lines are approved by the group but Indigenous rangers set the fires, backed up by modern technology involving constant weather readings and taking into account the conditions of the day.

Northern Australia has developed a collaborative infrastructure for ‘cultural burning’ but notes that: “There’s no investment really outside of northern Australia Indigenous fire management of any significance.”

Official inquiries

After many major bushfires, state and federal governments in Australia have initiated inquiries to see what could be done to address the problem. A parliamentary report from 2010 says that between 1939 and 2010, there have been at least 18 major bushfire inquiries including state and federal parliamentary committee inquiries, COAG reports, coronial inquiries and Royal Commissions.

Another report published in 2015 says there have been 51 inquiries into wildfires and wildfire management since 1939. The authors note that: “The fact that catastrophic events continue to recur is evidence either that the community is failing to learn the lessons from the past, or the inquiries fail to identify the true learning – that catastrophic events may be inevitable, or that Royal Commissions are not the most effective way to identify relevant lessons from past events”.

In January 2020, in the middle of the 2019–2020 bushfire season, Prime Minister Scott Morrison raised the prospect of establishing another royal commission. Morrison told Australian Broadcasting Corporation (ABC) that any inquiry into the crisis would need to be comprehensive and investigate climate change as well as other possible causes.

Warnings

During the fire season, the Bureau of Meteorology (BOM) provides fire weather forecasts. Fire agencies determine the appropriate Fire Danger Rating by considering the predicted weather including temperature, relative humidity, wind speed and dryness of vegetation. These Fire Danger Ratings are a feature of weather forecasts and alert the community to the actions they should take in preparation for the day. Ratings are broadcast via newspapers, radio, TV, and the internet.

In 2009, a standardized Fire Danger Rating (FDR) was adopted by all Australian states. This included a whole new level – catastrophic fire danger. The first time this level of danger was forecast for Sydney was in November 2019 during the 2019–2020 Australian bushfire season.[98] In 2010, following a national review of the bush fire danger ratings, new trigger points for each rating were introduced for grassland areas in most jurisdictions.

Remote monitoring

Remote monitoring of wildfires is done in Australia. Geoscience Australia developed the (real-time) Sentinel bushfire monitoring system. It uses data from satellites to help fire-fighting agencies assess and manage risks.

There is also MyFireWatch, which is a program based on an existing Department of Fire and Emergency Services (DFES) program, redeveloped by Landgate and Edith Cowan University (ECU) for use by the general public.

Besides the use of satellites, Australian firefighters also make use of UAV’s as a tool for combating fire.