Source: Sitthixay Ditthavong © The Canberra Times/ACM


Bushfires in the ACT

The 2019–20 bushfire season, also known as Black Summer, was one of the worst on record for the ACT and across much of Southeast Australia (Figure 1). The fires were connected to climate change, which is contributing to more severe fire seasons that are starting earlier and lasting longer (see Climate change).

Figure 1. Area of Southeast Australia burnt in the 2019-20 bushfire season.

Data sourced from: Environment, Planning and Sustainable Development Directorate.

Over Black Summer, 24.3 million hectares were burnt across Australia. This resulted in the loss of lives, property and cultural heritage sites, as well as severely impacting the health and wellbeing of human communities across the country. The fires have had a devastating impact on Australia’s environment, with large-scale impacts on vegetation and ecosystems and the death or displacement of billions of animals. Recovery from the 2019–20 bushfire season will take decades.

The information presented in this section comes from the Environment, Planning and Sustainable Development Directorate unless otherwise stated. This includes: ACT Bushfire and Flood Recovery Plan; Orroral Valley Fire Rapid Risk Assessment Namadgi National Park; ACT Government website Recovering from the 2020 bushfires; and ACT Parks and Conservation, 2023, 2020 Orroral Valley Bushfire: Reconstruction and analysis of fire spread, collation of fire weather and indices, photographical records, and imagery, prepared by Owen Salkin (Natural Systems Analytics), Unpublished report.

The 2019–20 bushfire season significantly impacted the ACT, most notably through the burning of native ecosystems and biodiversity, extreme levels of air pollution from bushfire smoke, and damage and destruction of cultural heritage sites.

In January and February 2020, nearly 90,000 hectares — around 40% of the ACT — were burnt by the Beard and Orroral Valley bushfires (see Fire). These bushfires were the largest and most severe since the devastating fires of 2003 burnt 164,000 hectares (70% of the ACT).

The severity and size of the ACT’s bushfires were influenced by the extreme temperatures over the 2019–20 summer (see Climate change). On 4 January 2020, the ACT experienced its hottest day on record at 44°C. The mean maximum and minimum temperatures over the summer were the third warmest on record. In addition, the ACT, along with much of NSW, was experiencing the lowest rainfall on record for much of 2019. The combination of extreme temperatures and low rainfall provided optimal conditions for the bushfires.

Weather conditions also led to concerning fire severity risk conditions for the ACT prior to the fires (see Fire). The risk conditions were particularly elevated in the month leading up to the Orroral Valley fire and for the first days of the fire. The Fire Danger Rating included two catastrophic and two extreme risk days, seven severe days, ten very high and nine high risk days. Such conditions significantly increased the severity and spread of the Orroral Valley fire.

The ACT’s first fire of concern for the 2019–20 bushfire season was the Beard bushfire, which burnt around 424 hectares. The fire started on Wednesday 22 January in Pialligo Redwood Park and threatened properties in Beard, Oaks Estate and West Queanbeyan. The fire was brought under control on Thursday 23 January and declared out on Tuesday 28 January. The fire led to the closure of Canberra Airport for a day.

The most significant 2020 bushfire in the ACT was the Orroral Valley fire (Figure 2). The fire and its ignition are the subject of a coronial inquiry which commenced in June 2023. 

Figure 2. Orroral Valley bushfire spread, 27 January to 6 February.

Data sourced from: Environment, Planning and Sustainable Development Directorate.

Key dates in the Orroral Valley fire were:

27 January 2020

The fire started in the afternoon, ignited by the landing light of an Australian Army helicopter which had set down in grassland in Namadgi National Park.

27 January 2020

28 January 2020

Driven by hot and dry weather conditions, topography and exceptionally dry fuel loads, the fire had grown to 2,575 hectares by the morning of 28 January. The fire was just 9 kilometres from Tharwa which prompted an emergency warning for the Tharwa community and the southern suburbs of Canberra, including Banks, Gordon and Condor.

28 January 2020

28 to 31 January 2020

The Orroral Valley bushfire grew approximately 4,500 to 8,000 hectares per day, extending to remote and inaccessible wilderness within Namadgi National Park.

28 to 31 January 2020

31 January 2020

At midday the ACT’s Chief Minister declared a state of emergency for the ACT, the first time such action had occurred since the 2003 fires.

31 January 2020

1 February 2020

This day was the largest increase in fire spread for the Orroral Valley bushfire. The fire more than doubled in size within the ACT, growing by approximately 27,000 hectares to around 49,000 hectares (Figure 3). The fire moved predominantly southeast, and crossed into NSW at Clear Range in the form of multiple spot fires. On what is considered to be the worst day of the Orroral Valley bushfire, there were also converging fire fronts that increased fire intensity, pyrocumulonimbus cloud and storm development, and strong fire-generated winds. Such conditions cause unpredictable fire behaviour, increase the spread of fire, and make it more difficult and hazardous to control. The increase in fire spread and intensity caused multiple property losses and damage in NSW.

1 February 2020

5 February 2020

As the threat to residential areas abated, the Orroral Valley fire was downgraded to ‘advice’ status on 5 February. Fortunately, there was no loss of human life or residential buildings.

5 February 2020

27 February 2020

The fire was finally contained at around 88,000 hectares and declared extinguished.

27 February 2020

Figure 3. Orroral Valley bushfire spread, 27 January to 10 February.

Data sourced from: Environment, Planning and Sustainable Development Directorate.

Much of the information presented in this section comes from the impact assessments of the Orroral Valley bushfire undertaken soon after the fire, or within the first year of the post-fire period. Consequently, the discussions presented may not reflect the current status of impact severity, ecosystem health, and biodiversity recovery. As monitoring and assessments continue, a clearer picture of the fire impacts and environmental recovery will become available.

The Orroral Valley bushfire caused devastating impacts on the ACT’s natural environment. The fires burnt around 80% (82,700 hectares) of Namadgi National Park, and 22% (1,450 hectares) of Tidbinbilla Nature Reserve, which are home to critical ecosystems and habitats for many species, including endangered plants and animals. Namadgi National Park and Tidbinbilla Nature Reserve contain habitats ranging from grassy plains through to snow gum forests and alpine meadows. There have been more than 700 species of plants, 222 species of vertebrate animals, 15 threatened species and over 40 rare or uncommon species recorded to date in Namadgi and Tidbinbilla. The burnt area also included significant areas of the High Country Bogs and Associated Fens threatened ecological community. Approximately 90% of the Orroral Valley fire footprint had also burnt in the 2003 bushfires just 17 years earlier.

The impact of fire is greater as fire intensity increases. Whilst fire intensity varied during the Orroral Valley bushfire, there were significant areas burnt at high severity. Over 20% of the burn area was estimated to be at a high to very high fire intensity. Such burns consume all ground vegetation and tree crowns, and increase the likelihood of post-fire impacts such as debris flows and soil erosion. These impacts lengthen the recovery time for some vegetation species and, in extreme cases, may decrease the chances of recovery for species with lower fire tolerances.

The environmental impacts of the Orroral Valley bushfire have been magnified by the prolonged and severe drought conditions that preceded the fire. The hot and dry conditions had already placed a significant amount of stress on flora and fauna populations, and ecological communities. This may have consequences for post-fire recovery in some areas.

The recovery of native ecosystems and biodiversity will take many decades. In addition to the loss of millions of plants and animals, many of those that survived the fire are greatly threatened by post-fire conditions. The destruction of vegetation reduces the availability of habitat and food resources, increases the risk of weed invasions, increases the risk of predation by invasive animals, and increases grazing competition from invasive herbivores. These all reduce the ability of native ecosystems and biodiversity to recover from severe fires and, in extreme cases, can lead to significantly altered native plant and animal communities.

The Orroral Valley bushfire has also significantly impacted aquatic ecosystems. After the fire, high intensity drought-breaking rains fell on recently burnt areas, leading to sedimentation from increased erosion, the deposit of ash and other burnt materials into waters, and the loss of riparian vegetation.

Fire suppression impacts

Fire suppression activities are necessary to prevent the unchecked spread of fire and for the protection of important assets such as water supply catchments, critical ecosystems, rural lands and buildings, infrastructure, and cultural sites. However, they are also a source of post-fire environmental impacts.

Fire suppression activities for the Orroral Valley bushfire included approximately 577 kms of control lines associated with the fire operations (the majority of these were along existing fire trails), 20 kms of control lines in agricultural lands for infrastructure protection, and 2.17 million litres of fire retardant dropped across 46 kms of the burn area. These suppression activities will all impact on biodiversity and ecosystem health through the loss of native vegetation, erosion, increased opportunities for invasive plants, the introduction of toxic chemicals (from fire retardants), and water quality impacts.

It is important that fire suppression areas are subject to rehabilitation works and ongoing monitoring to determine any long-term impacts.

Overview of biodiversity recovery

It is important that post-fire threats are managed to improve the recovery of native ecosystems and biodiversity. The ACT is undertaking a range of activities to assist natural recovery processes. These include:

Many of these activities will be ongoing as recovery from the fires continue. For example, biodiversity and ecosystem impact assessments and restoration works are likely to take decades.

For more, see Landcare and Bushfire Recovery.

Climate change and bushfire recovery

Climate change will be a significant challenge to the post-fire recovery of native ecosystems and biodiversity. The hotter and drier conditions will magnify post-fire pressures, reducing the ability of native animals to increase their populations and preventing the regeneration of native vegetation species. This may have significant consequences for the distribution and abundance, as well as the long-term viability, of some native species in post-fire landscapes. In areas severely impacted by fire, the added pressure of climate change may mean that some species and ecological communities will not be able to recover at all.

The greater occurrence of severe storms associated with climate change will also increase erosion in fire impacted areas. This will impact on aquatic ecosystems, reduce the presence of native vegetation and increase the spread of invasive plants.

One of the most significant impacts of climate change on post-fire recovery will be the increased risk of more frequent and more severe fires in the future (see Climate change). Even if ecosystems and biodiversity start to recover from one fire event, cumulative future fires are very likely to prevent recovery in the long term.

The impact of the Orroral Valley bushfire on the ACT’s flora species has been immense. The fire burnt significant areas of vegetation including threatened flora species and ecological communities, as well as non-threatened floral biodiversity. Some of the burnt flora species and communities are sensitive to fire, which is concerning for their ability to recover in the future, especially as many of these areas had also burnt in 2003, just 17 years earlier.

Threatened floral species and communities burnt by the fire include two ecological communities and five species listed under the Environment Protection and Biodiversity Conservation Act 1999. Two of these species and two communities are also listed as threatened under the ACT Nature Conservation Act 2014. In addition, 17 nationally significant flora species are also known to be impacted by the fire. There is concern that threatened flora populations and extents will decline. Some populations may have been lost.

Five ecological communities within the Orroral Valley bushfire area have been identified as requiring post-fire monitoring and management. These include Snow Gum (Eucalyptus pauciflora), Alpine Ash (Eucalyptus delegatensis), Cypress Pine (Callitris spp.), Black Sallee (Eucalyptus stellulata), and Mountain Tea Tree (Leptospermum grandifolium) dominant grass and woodlands. Research has been undertaken on the impacts of the Orroral Valley bushfire on these and other communities in the Namadgi National Park and Tidbinbilla Nature Reserve. The research included six fire-sensitive and two threatened vegetation communities, and also assessed the recovery of those communities in the first 12–18 months after the fire. Selected main findings of the research are presented below.

Alpine Ash forest

Black Sallee woodland 

Jounama Snow Gum woodland

Mountain Tea-tree heathland

Natural Temperate Grassland (threatened)

Other monitoring programs have also found a strong response to the Orroral Valley bushfire, with some flora species appearing to benefit from the post-fire conditions. For example, over 256 individual records of orchids were recorded across 18 sites by volunteers from Canberra Orchid Society, including a new record for the Critically Endangered Brindabella Midge Orchid (Corunastylis ectopa).

These results show that whilst the response of flora communities varies, the vegetation of Namadgi National Park is generally recovering well. Monitoring observations show the prolific and spectacular post-fire growth of grasses and herbs, and vigorous basal and epicormic resprouting of most fire-impacted tree species. This has no doubt been facilitated by wetter-than-average conditions in the ACT since the fires.

It is also apparent that Namadgi National Park is undergoing a period of major ecological change in response to a changing climate and more frequent fire, with some flora communities likely to further diminish in the future. It is unknown at this stage what the long-term effects of these changes will be on the composition of native species and ecosystem structure and function within the park. As is generally the case with ecological change, it is likely that some species will benefit while others will be unable to survive in altered post-fire habitats.

Approx. 19 days post fire
Three months post fire
One year post fire
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Source: Environment, Planning and Sustainable Development Directorate

Monitoring in the burnt areas of Namadgi National Park has shown the resilience of some native species to recover from significant bushfire events. About a month after the fire, vegetation appeared to be dead and the ground devoid of plant life. But within a few weeks, epicormic growth (leaves sprouting from the bark of trees) appeared as the trees began their recovery. Months later, saplings produced new red leaves as they began to grow again. Ten months after the fire, lush grass covered the ground, providing food for animals. The high rainfall in the years since the fires have resulted in prolific regrowth in some areas of the Namadgi National Park.

Not all plant species are showing signs of recovery. The post-fire recovery of Alpine Ash is particularly concerning. These trees are killed by intense fire and must regenerate from seed. However, it is uncertain how well Alpine Ash will recover after being burnt by two intense fires in 2003 and 2020, only 17 years apart. This short duration between fires is unlikely to be long enough for Alpine Ash to mature and produce the seeds required for recovery after severe bushfires. In Namadgi, monitoring confirms that many young Alpine Ash trees which germinated after the 2003 fires were killed by the Orroral Valley bushfire. Fortunately, some important stands of Alpine Ash were not affected by the 2020 bushfires with 33% (around 2,415 hectares) of Namadgi National Park’s Alpine Ash forest unburnt by the fires.

Conversely, some species appear to have benefited from the fires. The removal of vegetation by fire can create ideal conditions for the germination of short-lived herbs and grasses. Species such as Pink Trigger-plants (Stylidium montanum), Blue-purple Bluebells (Wahlenbergia spp.), White Stellaria (Stellaria pungens), Billy Buttons (Craspedia sp.) and several species of white or yellow daisy, have all flourished post-fire.

More information on the post-fire vegetation recovery in the Namadgi National Park can be found here.

Recovery from the Orroral Valley bushfire will take decades for many fauna species. The fires caused the death or displacement of countless native fauna including mammals, birds, reptiles, amphibians, aquatic species and invertebrates. For those animals that escaped the fire, the large-scale disturbance of vegetation and ecosystems, combined with post-fire pressures, will result in ongoing survival pressures. These include:

These all reduce the ability of native fauna to persist and recover from severe fire events, leading to significantly altered fauna populations and distributions in some areas.

Impacts on some species of high importance due to their already threatened status are discussed below. However, there are many threatened fauna species that lack identified population locations and are only known to occupy the burn area from opportunistic sightings or historical records. This makes it difficult to assess the fire impacts on these species, as well as their post-fire recovery. It should also be noted that regardless of a species’ status, there will be many fauna populations severely impacted by the Orroral Valley bushfire. The recovery of both threatened and non-threatened species is critical to future ecosystem health and biodiversity in the ACT.

For more, see Bushfire Recovery of the Gang-Gang Cockatoo.

The Broad-toothed Rat

The Broad-toothed Rat is an endangered animal and a species of national concern. They are often found in Alpine Bogs and Fens – a threatened ecological community also impacted by bushfires. Of the 13 monitored locations of Broad-toothed Ratin Namadgi National Park, seven have been impacted by severe intensity fire, three by moderate intensity fire, and three remain unburnt. It is important that remnant populations and those impacted by moderate intensity fire are protected from increased predation to enable recolonisation of severely burnt sites as the ecosystem recovers.


Two species of large gliders, the Greater Glider (Petauroides volans) and the Yellow-bellied Glider (Petaurus australis) are found within the Orroral Valley bushfire area. Both these species are listed as species of national concern due to fire impacting a large extent of their range across the country.

Recent surveys in Namadgi National Park identified three main areas where large gliders occur. The largest of these areas, which has the highest density of gliders, is in an unburnt region of the park (Bendora area of the Brindabella Range). The second area is in the Upper Cotter area of the Bimberi Wilderness and has been impacted by fire of moderate to low severity and retains much of its canopy cover. This means that most sites where Greater Gliders have been previously recorded did not burn in the Orroral Valley bushfire, and the northern part of Namadgi continues to support good populations of Greater Gliders.

The third area, around Booroomba Rocks and Honeysuckle Creek, has been impacted by moderate to high fire severity with extensive canopy destruction, and is the area of most concern for glider populations. If gliders survived the initial fire impacts they were likely highly susceptible to starvation during the weeks following the fire due to the loss of canopy leaves.

For more, see Greater Gliders in the ACT.

Reiks Crayfish

Reiks Crayfish (Euastacus reiki) is a poorly known species of mountain spiny crayfish that inhabits the tributaries and bogs in the upper Cotter catchment, upper Naas, Orroral and Gudgenby Valleys. It is estimated that 95% of its habitat in the ACT is within the burn area. The species is extremely vulnerable post-fire as poor water quality encourages them to emerge from their burrows, exposing them to increased risk of predation.

Two-spined Blackfish

The Two-spined Blackfish (Gadopsis bispinosus) is a threatened fish species found in the Upper Cotter catchment. Three of the five areas identified as important habitat in the ACT have been impacted by the Orroral Valley bushfire. The fire burnt at least the 40% of the Blackfish range in the ACT, particularly above Corin Dam. 

Following the fire, runoff from heavy rain caused significant impacts to water quality. Erosion from the burn area delivered sediment and ash into the river, smothering the spaces between the cobbles that Blackfish need to breed, find food, and shelter from predators and high flows. The sediment also made the river shallower and filled deep, cooler holes and runs that Blackfish depend on for refuges.

Monitoring of Blackfish populations has shown that the Orroral Valley bushfire reduced the Blackfish population by around 80% in a large proportion of their range. There was no significant recovery evident in 2021 mainly due to the large amount of sediment that is still impacting waterways in the burnt area. However, there are now signs of recovery with young Blackfish being recorded.

For more, see Two-spined Blackfish After the Orroral Valley Bushfire.

Macquarie Perch 

The Macquarie Perch (Macquaria australasica) is a threatened fish species also found in the Upper Cotter catchment. It is a species of national concern, with a significant proportion of its range burnt nationally during the 2019-20 Black Summer. The population of Macquarie Perch that extends from Corin Reservoir upstream in the Cotter River is an important insurance population and one of only two populations in the ACT. This area has been subject to high severity fire. Like the Two-spined Blackfish, the biggest threat to Macquarie Perch comes from post-fire conditions that can degrade water quality.

For more, see Post-Fire Recovery of Mountain Galaxias.

The Orroral Valley bushfire burn area includes the southern region of the Cotter River catchment, an area of high value for aquatic ecosystems and biodiversity, including listed threatened species. The Cotter River catchment is also a vital source for approximately 85% of the ACT’s water supply. The network of wetlands and waterways in the catchment flow into the Cotter River and the Corin, Bendora and Cotter storage dams.

Within the Upper Cotter catchment, the Orroral Valley bushfire burnt 99% of the Corin dam catchment and 29% of the Bendora dam catchment. The Lower Cotter catchment was unaffected by the fires. The severity of the fires was highly variable in both water storage catchments, but extensive areas of the Upper Cotter burnt at very high severity. Fires that burn with high severity are known to considerably increase the likelihood of degraded water quality.

Post-fire rain, erosion and sedimentation

The impacts of the Orroral Valley bushfire on aquatic ecosystems was compounded by severe storms on 7-8 February 2020 and high rainfall between 10 and 14 February 2020 (around 158 mm). In areas where fire had removed most of the vegetation and ground cover, the high rainfall mobilised large amounts of sediment and ash which entered waterways in Namadgi National Park and Tidbinbilla Nature Reserve. This resulted in greatly degraded water quality and aquatic ecosystem health, including the smothering of habitat required for many aquatic species. In extreme cases, post-fire runoff can degrade water quality to the point where fish kills occur.

High rainfall continued in the ACT with 2020 to 2022 experiencing above average rainfall. Whilst beneficial to the recovery of vegetation, the increased rainfall has meant that waterways within and downstream of the burn area have suffered ongoing high rates of sedimentation. This is having an ongoing impact on aquatic ecosystem health and biodiversity as evidenced by the population decline of species such as the Two-spined Blackfish (see Impacts on Fauna).

Post-fire erosion was found to be significant in the Upper Cotter River Catchment. In some areas gullies over two metres deep were formed, and debris from these was transported by heavy rain into reaches of the Cotter River. Deposition of boulders, stones, sand, silt, and ash in the river channel led to the alteration of the watercourse in some areas, and caused the erosion of banks which deposited more sediment downstream. River pools that were previously several metres deep, providing important refuges for native fish and other aquatic species, were particularly affected and many have filled with sand and silt.

Months after the fire, flushes of sediment continued to move downstream in the Cotter River, covering rocky sections. The sediment also led to the loss of instream aquatic flora in many areas with plants such as water milfoil (Myriophyllum sp.) now absent.

Recovery to pre-fire levels is expected to be slow. After the 2003 fires, pool habitats in the lower Cotter had not recovered 10 years later. Over two years post-fire, aquatic habitats are still severely impacted in the Upper Cotter River Catchment.

Post-fire impacts on drinking water catchments

Following the Orroral Valley bushfire, there was much concern over water quality impacts. Icon Water is responsible for the management of drinking water catchments in the ACT. Ongoing monitoring of water quality in the Cotter Catchment water storages showed that water quality in these storage reservoirs was not immediately impacted by the fire but this changed with the post-fire rainfall events that followed. To minimise the post-fire rainfall impacts on the ACT’s water supply, sediment traps were installed to reduce sediment movement in drainage lines and silt curtains deployed on Corin and Bendora reservoirs to contain ash and suspended material.

In the years since the Orroral Valley bushfire, it is apparent that the immediate severe impact to water quality caused by the post-fire rainfall has since improved. However, the water quality in the Corin and Bendora storage reservoirs is likely to vary in response to post-fire sediment inputs. The steep slopes within severely fire impacted areas have remained relatively stable post-fire and have continued to develop good ground coverage of vegetation re-growth which is helping to stabilise the soils and mitigate erosion. This will help maintain water quality in the future.

Post-fire management

It is important that post-fire impacts on waterways are mitigated to improve the health of aquatic ecosystems and to protect biodiversity. The ACT Government is undertaking a range of activities with key partners such as Icon Water to protect water quality and restore riparian zones. These include:

Sedimentation control and restoration of riparian areas will greatly benefit the recovery of threatened aquatic species such as fish, amphibians, and platypus.

Source: Icon Water

The Orroral Valley bushfire and post-fire rainfall resulted in extensive erosion and high sediment loads in some reaches of the Upper Cotter Catchment. This is especially the case for areas with steep slopes where most vegetation and ground cover were removed by severe burning.

The increased sediment loads were found to be degrading aquatic habitat by smothering riverbeds and filling the deeper pools that are vital to many aquatic species, including the Two-spined Blackfish.

Icon Water experimented with variations in environmental water releases to try and assist with removal of the sediment build-up in shallow sections of the river. Flushing flows (more than 550ML/day for two consecutive days) were released over selected weekends in conjunction with lower flows during the week. This approach proved effective, and was sufficient to re-establish deeper channels and pools within the Cotter River, particularly in areas associated with high sedimentation like White Sands Creek below Corin Dam.

The success of the environmental flow releases has improved the aquatic ecosystem health for some of the Cotter River reaches which were at risk of significant degradation from post-bushfire sedimentation. It is likely that this will greatly assist the recovery of aquatic fauna in the Upper Cotter Catchment.

Source: Environment, Planning and Sustainable Development Directorate

Alpine Sphagnum Bogs and Associated Fens ecological communities are high-altitude wetlands that are waterlogged, acidic and have low nutrients and temperatures. The ACT High Country Bogs and Associated Fens community is listed as endangered under the Australian Government’s Environment Protection and Biodiversity Conservation Act 1999. They are home to threatened species including the Broad-toothed Rat and the Northern Corroboree Frog (Pseudophryne pengilleyi).

Most of the ACT’s bogs and fens were burnt in the Orroral Valley bushfire, resulting in the loss of nearly all vegetation. Although the Ginini Flats wetland was not burned, other important bogs and fens were impacted by the fires such as Snowy Flats, Hanging Flats, Rotten Swamp, Cotter Source and Bimberi.

To help restore the bogs and fens, post-fire rehabilitation works were carried out in the spring of 2020. The hard work and long days required for the rehabilitation works were undertaken by rangers, researchers and volunteers, all dedicated to the recovery of these delicate habitats.

Rehabilitation works included the installation of 128 leaky weirs and 260 shade cloths across 10 priority bog sites. Leaky weirs were created using coir logs with the aim of preventing and reducing erosion; increasing the wetness of the peat; and increasing vegetation cover and recovery speeds by creating moist surface areas in which Sphagnum mossand other peatland species could recover. Shade cloths were installed with the aim of increasing the survival, condition and growth rates of Sphagnum hummocks by mimicking the physical conditions underneath shrubs found in unburnt bogs.

Initial results suggest that shade cloths significantlyimproved the recovery of live Sphagnum and reduced ongoing mortality after the fire. However, leaky weirs have not had a clear effect on vegetation recovery. Although the amount of bare ground decreased and vegetation cover increased significantly over time, leaky weirs did not improve Sphagnum recovery rates. This may be due to the high rainfall experienced in the ACT since the fires which provided high moisture availability regardless of the presence of weirs. The weirs may become more beneficial in drier years.

This section draws on published literature, government reports and data, and analysis of research data to describe the effects of fire and bushfire smoke on humans. Common views are illustrated by quotes from community members sharing their lived experience, and that of their friends’ and family’s, during this time. Details in this section are drawn from a report on the bushfire impacts led by Dr Rachael Rodney-Harris.

During Black Summer, bushfire smoke from both the ACT and NSW fires severely impacted Canberra’s air quality (see Air). Over the 91 days of summer, air pollution monitored at the Monash Station in Tuggeranong exceeded the national standards for health on 56 days, with 42 of these days above the hazardous rating (Figure 4). On 1 January, PM2.5 pollution levels were at around 25 times the threshold to be considered hazardous. During days of severe air pollution, Canberrans were advised to stay indoors whenever possible.

Figure 4: Air Quality Index ratings from the Monash station in Tuggeranong over summer 2019-20.

Data sourced from: ACT Health Directorate.

Bushfire and bushfire smoke can severely disrupt daily life and have considerable effects on physical health, mental health, and medical services. These effects of bushfire can persist well beyond the fire being extinguished or the smoke having cleared. 

Exposure to bushfires and bushfire smoke related air pollution can have considerable short- and long-term adverse health outcomes including burns, heat exhaustion, dehydration and psychological trauma. High levels of bushfire smoke related air pollution can impair respiratory and cardiovascular functioning, exacerbate respiratory disease (including asthma and chronic obstructive pulmonary disease), and alter immune function.

Depending on the level of pollution and exposure, many people will experience subclinical, limited or short-term symptoms; whereas others will have more severe symptoms requiring medical intervention. High levels of fine particulate matter present in smoke have been associated with elevated rates of hospital presentations and admissions, especially for cardiovascular and respiratory conditions including asthma.

Across Australia, hospital presentations generally increased on or immediately following days of more intense air pollution. Bushfire smoke has also been associated with increased mortality, and an estimated 340,000 deaths can be attributed to bushfire smoke globally each year. The total smoke-related physical health costs of the 2019–20 bushfire period have been estimated to be AU$1.95 billion.

The effects of smoke can be more severe in vulnerable populations such as the very young, older adults, pregnant people and those with pre-existing medical conditions including cardiovascular disease or respiratory conditions. Urban exposure to bushfire smoke is generally brief (a matter of days at most). However, the prolonged exposure to poor air quality experienced in Canberra and other urban centres throughout the 2019-20 bushfire season may be more hazardous. The long-term health impacts of such exposure are not well understood.

Bushfire smoke had acute negative impacts on the physical health of almost all (97%) people surveyed living in and around the ACT during the 2019-20 bushfire season. People experienced eye and throat irritation, coughing and respiratory symptoms such as wheezing and breathlessness, and headaches. Almost a third of Canberrans (31%) reported worsening of an existing physical health problem and 16% had difficulty managing an existing health condition as a result of smoke and/or fires. 

Source: Dr Rachael Rodney-Harris

It was estimated that during the 2019-20 bushfire season within the ACT, bushfire smoke was responsible for 31 excess deaths, over 200 excess hospitalisations for cardiovascular and respiratory problems, and 89 presentations to emergency departments with asthma.

Analyses of hospital data identified emergency department (ED) presentations and hospitalisations for asthma and respiratory conditions increased throughout most of December and January compared with previous years (see Figure 5). Increases in presentations and hospitalisations coincided with days of, or immediately following, higher fire activity or air pollution.

Figure 5. Increases in emergency department presentations for asthma (top) and respiratory conditions (bottom) in the ACT, weekly between 1 September 2019 and 29 February 2020, compared with the same period in 2018-19.

Source: AIHW analysis of NNAPEDCD data, 2018-19 and 2019-20, Supplementary table S3.

At the peak, weekly emergency department presentations increased by about 230% for asthma, 58% for respiratory conditions, and 155% for breathing difficulties. Hospitalisations for respiratory conditions increased by 52% compared to the same period in previous year/s (see Figure 5). Hospitalisation for select heart conditions and cerebrovascular conditions also increased throughout some of the 2019-20 bushfire period.

Concern about long-term health effects

In addition to the acute effects experienced, people are concerned about the potential long-term health effects of prolonged exposure to hazardous levels of bushfire smoke. Community members reported developing enduring adverse conditions following the fires that have persisted beyond the period affected by smoke. They are worried about the potential impact of these on their ongoing health, including susceptibility to other conditions such as COVID-19.

“Still feeling effects of bushfire smoke, with respiratory symptoms, cough and sinus irritation.  Quite a few of my friends experienced this too, and it is not severe enough to seek medical advice.  I am worried that the bushfire exposure makes people more vulnerable to corona virus lung damage” 

Groups that were particularly concerned about the long-term health effects of smoke exposure included parents and pregnant people. 60% of parents and carers said their choice of behaviours was influenced by their children or dependants, particularly parents of younger children. This was likely due to a combination of concern for health and the challenges of keeping children entertained indoors for long periods.

“My primary concern and the anxiety I felt during this time was/is for the short- and long-term health impacts on my children…, rather than myself. … The secondary issue to this was the strain of being confined/confining my children (toddler in particular) over an extended period of time. I felt trapped in our house as there didn’t seem to be many alternative indoor options…”

Pregnant people were exceptionally concerned about the effects of fire on their pregnancy and baby, but found information hard to find, further heightening anxiety and stress. 83% of pregnant people surveyed in the ACT said their pregnancy influenced their health protection decisions, with all but one indicating they were more responsive to smoke because of their pregnancy.

There is limited information about the effects of bushfire smoke on maternal and child health. Possible associations have been identified between exposure to bushfire smoke and adverse outcomes such as decreased birth weights, premature birth, and increased risk of gestational diabetes. However, more robust research is needed on the effects of fire and smoke on pregnant people and their babies.

“Being pregnant, I was highly concerned about my health and the impacts on my baby. Information seemed scarce and restricting myself indoors so frequently was concerning and disruptive to my wellbeing.”

Bushfires, smoke, and other natural disasters can affect the mental health and wellbeing of community members and those on the frontline. During the event, feelings of anxiety and distress may be driven by the unpredictability of the situation, as well as the perceived and actual threat to life and wellbeing. After the event, individuals may continue to experience distress because of personal, material, and/or environmental loss, as well as post-traumatic stress.

In the months following the 2019—20 bushfire season (March—April 2020), the Bushfire Health Study led by the Australian National University identified 55% of respondents self-reporting symptoms of anxiety (45.3%) and/or feeling depressed (21.4%) as a result of the smoke and its effects on daily life. As well, 31.9% of people reported elevated levels of psychological distress, while 10.5% of people reported clinical levels of depression and 14.3% of people reported clinical levels of anxiety. Mental health impacts were consistently higher for women than men.

Significant self-reported rates of anxiety and depression were revealed in the Living well in the ACT region: Exploring the wellbeing of ACT residents in 2019-20 study conducted by the University of Canberra. This study was conducted in April-May 2020, finding that 36% of ACT residents often felt anxious or worried during the fires, and a further 52% reported feeling anxious occasionally. Additionally:

The majority of ACT residents also reported that they had access to emotional support (63%). However, younger people were more likely than older people to report fires triggering psychological distress, consistent with what has been seen in NSW. Following the bushfire, few ACT residents (10%) reported persistent mental health challenges because of, or worsened by, the fires. A much larger proportion of participants reported experiencing concern about the environmental impacts of the fires (78%) and the prospect of there being future bushfire seasons like Black Summer (71%).

Consistent findings were also reported in the Impact of the 2019/2020 bushfires on a cohort of older adults report conducted as part of thePATH Through Life Study. In this study of a longitudinal cohort of ACT residents, people aged 59-65 reported worsened mental health during the period of the bushfires but that symptoms returned to pre-bushfire levels following the bushfires.

Participants also reported feelings of distress associated with being on alert and having to pack up and prepare for evacuation, particularly people with prior exposure to major bushfires, such as the 2003 Canberra bushfires. These participants reported feeling fearful, not being able to relax, or not knowing when it would end. Feelings of helplessness were common, in terms of being able to assist and support friends or contribute to efforts to fight the fires. Participants also expressed fears for friends and family, including for those on the frontline, and fears about the possible negative health effects of prolonged bushfire smoke exposure.

“Felt anxious but took steps to manage it. Turned off news shows, mindfulness practice. Undertook activities to distract myself.  Looking out the window allowed me to see the smoke coming with the easterly, complete outdoor tasks and get inside before the worst of the smoke arrived.”

“I felt extremely low during the period – I was so unwell and felt incredibly depressed at the thought that perhaps this is how all summers will be from now on. I didn’t get to celebrate Christmas or travel to see my family, and I felt robbed of what should’ve been a really happy time. I also felt so powerless to stop the destruction all around me, and hopeless at the thought that things could be like this forever.”

“I felt more anxious about the fires specifically and the climate more generally than I did about the smoke.  I also care for my …mother with dementia, but she lives in her own home alone …, a lot of my anxiety was about her safety and evacuation.”

For more, see Life in the Haze.

Source: Dr Rachael Rodney-Harris

The significant mental health effects of the bushfires and smoke on ACT residents is reflected in hospital presentations and admissions data. During periods of significant distress, some people need to attend the emergency department, or be admitted to hospital, to help manage their mental health needs.

In general, emergency department presentations in the ACT during the 2019—20 bushfire period were higher compared to the same period in 2018—19. There was a 35% increase in emergency department presentations for mental health in the week beginning 26 January 2020 (an extra 30, or 6 per 100,000 people) than in the previous bushfire season. A similarly elevated general increase in mental health hospitalisations in the ACT during the bushfire period was also observed (Figure 6), compared to the previous five-year average. It should be noted that it is difficult to establish if this observed increase was solely due to bushfires and bushfire smoke.

Figure 6. Admitted patient hospitalisation rate for mental health related conditions in the ACT from 1 Sep 2019 to 23 Feb 2020.

Source: AIHW analysis of NHMD data, 2014-15 to 2019-20. Supplementary table S1.

In response to the 2019-20 bushfires, several additional Medicare Benefits Schedule (MBS) subsidised mental health items were introduced. The ACT had the highest weekly rate of bushfire-specific MBS claims per capita for much of the period explored between January 2020 and February 2021.

Source: Dr Rachael Rodney-Harris

Aboriginal and Torres Strait Islander people experience bushfire differently to non-Indigenous Australians due to their spiritual and cultural connection to Country, cultural heritage, legal rights and interests as Traditional Custodians, and the ongoing impacts of colonisation. Bushfire is recognised as essential to the health and healing of Country, while also posing a threat when too intense or frequent.

Aboriginal and Torres Strait Islander people comprise 3.2% of Australia’s population but 5.4% of the population living in areas of NSW and Victoria that were affected by fires in 2019—20. This means they are more highly represented in fire-affected populations, particularly as a proportion of the number of children. This was also recognised in a nation-wide survey following the 2019-20 bushfires, in which Aboriginal and Torres Strait Islander people were over-represented in bushfire affected areas, and bushfires appeared to exacerbate existing inequities and vulnerabilities. Aboriginal and Torres Strait Islander people experienced higher rates of depression, anxiety, and PTSD, but also higher rates of post-traumatic growth and resilience following fire, compared to non-Indigenous participants.

Despite bushfires impacting Aboriginal and Torres Strait Islander people to a greater extent than non-Indigenous Australians, because of their numerical minority and sustained discrimination stemming from colonisation they are at risk of being overlooked in design and implementation of disaster response efforts. Aboriginal and Torres Strait Islander people and communities may have distinctive strengths in recovery and resilience following bushfire events including close community connection, as shown by their propensity for resilience following bushfire. It is also likely that Aboriginal and Torres Strait Islander people will have specific vulnerabilities that may be intensified as a result of bushfire. These specific strengths and vulnerabilities need to be considered in fire recovery and response. The destructive 2019—20 bushfire season has increased discussion about Indigenous fire knowledge and practice, providing an opportunity to enhance representation and involvement in bushfire prevention, management, response and recovery.

Note: Because of the population size, little of the population-level work done in the ACT has collected identifying data on Aboriginality or Torres Strait Islander Status, and as such is not able to detect specific impacts of bushfire on these community members. This enhances the risk of being overlooked in local bushfire responses. Culturally competent research should be conducted within the ACT community to identify the distinctive experiences, strengths and needs of Aboriginal and/or Torres Strait Islander people living or connected to this region in response to fire and smoke.

Expert Comment

Dr Arnagretta Hunter, cardiologist & physician, Human Futures Fellow, Australian National University

The state of our environment and the state of our health are connected and entwined. The last few years have reminded us of just how much human health is influenced by the world around us. Biodiversity, plants, animals, air, soil and water quality are not just factors for the health of the environment and our city, but are of importance to the people who live, work, and play here.

It’s almost like we forgot to pay attention to the important building blocks of our health and wellbeing over the past decades: the air we breathe, the food we eat and the water we need to survive, the places in which we live and the way we live there.

During Black Summer, air pollution from bushfire smoke bathed our city for weeks and to extreme levels. Air, always thought to be reliable, was now a source of anxiety and concern. And after the smoke, as the fires went out, air remained a source of anxiety for our communities as the coronavirus pandemic began to unfold.

There is so much to learn from these experiences including considering how our health and wellbeing intersects with the places we live and how we protect and preserve the essential ingredients of health: air, food, and water.

Our population generally has good health. Life expectancy continues to improve with medicine and healthcare advances, offering ongoing improvements for the quality and quantity of the lives we lead.  However, in 2021 more than one in five Australian adults contended with an active mental health condition in the preceding 12 months. Similarly sobering statistics are readily available for other chronic diseases such as type II diabetes, hypertension, and cancer. While our healthcare system works to provide acute supports for those in need, when rates of chronic disease are high, a population focused approach is needed. This means moving our healthcare system from a narrow model of acute care targeted at the individual patient, to one that focuses on health and overall wellness of the broader population.

The balance between disaster response and proactive prevention is a valuable lens to apply in both healthcare and in approaching the environment and our changing climate. Much of our healthcare system is focused on treating diseases that may have been preventable with better overall population health, which is influenced by essential elements of health such as air quality, the food we eat, how active we are, our education and work. Similarly, Australia is rightly proud of its emergency response to natural disasters. However, interventions to reduce the risks of these disasters, such as decreasing our greenhouse gas emissions, are much more complex to carry out.

Climate science informs our understanding of future risks, offering a horizon in which extreme weather events occur with increasing frequency and severity, devastating our environment and our health. Unprecedented weather events are likely to define decades ahead, in ways sometimes difficult to imagine. With the growing risks of an extraordinary future come opportunities for change, to approach challenges from new or different perspectives.

It is remarkable how often interventions to improve our environment also carry advantages for our health and wellbeing. One well understood example is transitioning from burning fossil fuels for transportation, heating and cooking, which doesn’t just lower our greenhouse gas emissions but also improves air pollution and our health.

Engaging our population in environmental protection work, in preparation for the challenges ahead, fosters community engagement and improves mental (and sometimes physical) health. Joining these dots between policy silos might be one of the biggest opportunities of the years ahead.

Sometimes I reflect on the changes in our understanding of the world that have taken place just in the past five years. The conceptual future risk of climate change is now a lived experience, with the fires and smoke bringing a sense of the apocalypse to our beautiful town.

Our future seems more uncertain than the era from which we have just emerged. Yet, within an increasingly challenging environment, our future can be one that fosters combining science and understanding with care, connection, creativity and imagination, tools that see our future even brighter than our past.

Fire management aims to reduce the risk of fires to human and environmental assets. Fuel management is the primary means for land and fire managers to reduce the occurrence and severity of future fires. There are multiple fuel management strategies used in Australia, with varying levels of effectiveness. Each strategy has a diverse and complex set of challenges, benefits and limitations.

Fuel management in the ACT occurs on both public and private land. Fire management on public land is the responsibility of several agencies, including the ACT Emergency Services Agency, the ACT Rural Fire Service, and ACT Parks and Conservation Service. On private land, there are no formal objectives, but fuel management is usually undertaken to reduce fuel loads, remove dead material and reduce stubble, including through the ACT Emergency Services Agency Fire FarmWise program.

All fire-related fuel management activities on public land in the ACT are guided by the Strategic Bushfire Management Plan which establishes a framework for the comprehensive management of fire and fire-related activities for protecting human life, property, assets and the environment.

Some general techniques used to reduce future fire risks are described below.

Global shifts in climate will result in an increase in the number of days per year of weather conducive to dangerous fire spread. The ACT, like much of Australia, is predicted to have an increased risk of fire over the next 50-60 years. Key aspects of fire regime changes are i) the area burnt by bushfires and ii) changes in the number of fires an area experiences within a particular time frame (fire frequency).

A report by the FLARE Wildfire Research at the University of Melbourne was provided to OCSE to understand fire risks in the ACT. There is strong evidence that climate change will increase future bushfire risk in the ACT and surrounding regions by leading to an increase in fire weather conditions. Within the ACT, multiple studies indicate increasing dangerous fire weather. Increasing fire danger is likely to mean an earlier start to the fire season and a longer overall season.

In all the climate models used within the FLARE report, the annual area burnt around the ACT increased. Modelling shows that the highest fire frequency areas are outside of – but surrounding – the ACT. These areas may provide ignition sources for fires that spread into the ACT, particularly around the urban edge of Canberra. Some areas within the west of the ACT such as within Namadgi National Park, are predicted to experience an increase in fire frequency. This increase in fire frequency within ACT’s native forests may also lead to increased impacts on human communities on the urban edge.

Changes in fire regimes are likely to result in an increased risk to the environment as well as human life, property, and health (physical and mental). Previous studies have analysed the risk reduction benefits of various fire management approaches and found that:

Climatic changes are likely to overwhelm any reduction in fuel loads or shifting vegetation communities. Under shifting climates and fire regimes, conservation land management is going to provide the greatest challenge for the ACT. Intensification of fire regimes will increase the pressure on many species and communities, potentially resulting in shifting ecological formations and potentially permanent changes in ecological systems.

Figure 7. Change in the number of hectares burnt across a 100 year climate simulation for various fire frequencies.

Data sourced from: McColl-Gausden, S., Parkins, K., Clarke, H., Marshall, E., and Penman, T., 2023. Current role of fire management in altering risk to human and environmental assets within the ACT under current and future climates. FLARE Wildfire Research, School of Agriculture, Food and Ecosystem Sciences, The University of Melbourne.

Figure 8. The change in fire frequency in the ACT between current and future climate simulations.

Source: McColl-Gausden, S., Parkins, K., Clarke, H., Marshall, E., and Penman, T., 2023. Current role of fire management in altering risk to human and environmental assets within the ACT under current and future climates. FLARE Wildfire Research, School of Agriculture, Food and Ecosystem Sciences, The University of Melbourne.

The 2020 Orroral Valley bushfire occurred just 17 years after the devastating 2003 fires, which burnt 90% of Namadgi National Park. The 2003 burn area also included Tidbinbilla Nature Reserve and the Lower Cotter Catchment. Within the ACT, around 75,000 hectares burnt by the 2003 fires were re-burnt in 2020 (Figure 9).

Figure 9. Area burnt in the 2003 and 2020 bushfires, and area burnt by both fires.

Data sourced from: Environment, Planning and Sustainable Development Directorate.

Prior to the 2003 fires, a large fire also occurred in Namadgi National Park in January 1983 (Figure 10). The fire started near Mount Kelly, in the southwest of the ACT, burning around 34,700 hectares. There was significant overlap between the 1983, 2003 and 2020 bushfires. Nearly all the area burnt by the 1983 fires was burnt again in 2003, and again in 2020.

Figure 10. Area burnt in the 1983, 2003 and 2020 bushfires.

Data sourced from: Environment, Planning and Sustainable Development Directorate.

This makes the environmental impact of the Orroral Valley bushfire especially concerning because large areas of the ACT’s natural environment have now experienced severe and widespread burning twice in less than 20 years — and for some areas, three times in 37 years.

This will affect native vegetation, fauna and ecosystem health for decades to come (see Biodiversity). For example, Alpine Ash is considered to require at least 20 years between fires to enable the growth of trees that can produce the seed needed for recovery after severe bushfires. This short duration between fires means that it is uncertain whether severely burnt Alpine Ash stands will recover. It is also uncertain what the long-term impacts of frequent large fires will have on sensitive ecosystems such as Sphagnum bogs and fens.

The incidence of the two large and severe bushfires in 2003 and 2020 is without historical precedent in Namadgi National Park. The frequency of large fires in the pre-European period is thought to have been roughly once every 50-100 years. It is apparent that Namadgi National Park is undergoing a period of major ecological change in response to a changing climate and more frequent fire with some flora communities likely to further diminish in the future.

Climate change is expected to further increase the frequency of bushfires in the ACT (see Climate change), and the 2003 and 2020 fires may signal the beginning of a new fire regime. It is unclear whether the ACT’s natural environment can sustain and recover from more severe bushfires in the future. However, it is clear that the post-2020 bushfire recovery of ecosystems, flora and fauna will require significant effort and time.

Expert Comment

Professor Jason J. Sharples, FTSE, FRSN, FMSSANZ, University of New South Wales

Twenty years on from the devastating bushfires that burnt Canberra in 2003, there is much for the ACT community to reflect upon. While the fires were undoubtedly tragic — taking lives, destroying homes and livelihoods, and leaving many with significant psychological scars — it is important to note that the 2003 Canberra fires also gave us unprecedented insights into the anatomy of extreme bushfires.

The 2003 fires stand as some of the most scientifically important wildfire events ever recorded, having cast light onto some of the limitations of traditional bushfire knowledge and paving the way for new understanding of the complex processes that drive the development of large bushfires.

Bushfires burning under extreme conditions can behave in ways that are not well described by traditional bushfire prediction systems. Interactions between wind, terrain, and the fire itself can produce highly dynamic modes of bushfire propagation that contradict the notion that a particular set of environmental conditions uniquely defines the rate of spread of a bushfire.

The dynamic behaviour of bushfires becomes more pronounced as the moisture content of fuels falls below critical thresholds. This can happen, for example, when the compounding effects of drought and heatwaves desiccate landscapes, resulting in fires that burn at maximum intensity, generating massive numbers of firebrands and spreading expansively via profuse spotting.

The insights gained from the 2003 fires have resulted in a shift in paradigm around the way we understand the development and behaviour of large bushfires. This understanding has been bolstered through investigation of extreme bushfire events since 2003. These include the Great Divide fires of 2006—07, the Black Saturday fires of 2009, the fires in the Warrumbungles and Grampians in 2013 and 2014, the Sir Ivan fire of 2017 and of course the 2019—20 Black Summer fires.

The Black Summer fires smashed previous records for area of forest burnt, overall fire intensity and number of violent pyroconvective firestorms. The 2020 Orroral Valley fire, in particular, which burnt 80% of Namadgi National Park, was as a stark reminder for Canberrans of the inherent risk that we live with in our bushfire-prone part of the world.

The Black Summer season serves as a harbinger of the conditions we’ll more frequently be called upon to endure, as anthropogenic warming inevitably increases the likelihood of extreme bushfire seasons into the future. Research has demonstrated an increase in area burned annually in Australia’s forests and a decrease in the average number of years between fires over the past several decades. In addition, a marked increase in megafire years (i.e., years with fires that burn more than a million hectares) has been observed since the turn of the century. These changes are consistent with increasingly more dangerous fire weather and an increase in the prevalence of conditions conducive to violent pyroconvection, including fire-generated thunderstorms, all of which have been predicted as a consequence of anthropogenic climate change.

So, what does this mean for the ACT community as we encroach further into wildland areas, some of which already bear the scars of significant fires past?

The climate of the region and the predominantly north-westerly winds associated with our worst episodes of fire danger mean that the western edge of Canberra is particularly vulnerable. This doesn’t mean that those residing in the central or eastern suburbs of the ACT should consider themselves immune from bushfire — the legacy of the bush capital means that there are many patches of vegetation in and around the ACT that could carry a bushfire. However, the exposure of the western urban edge and the presence of the Brindabella mountains further to the west, puts these parts of the ACT at the greater risk of being impacted by an extreme bushfire.

The complex terrain of the Brindabellas lends itself to several dynamic processes that can significantly escalate bushfires, resulting in expansive regions of active flame and fire-atmosphere coupling that culminates in the development of violent pyroconvective events. This can then roll into Canberra suburbs, driven by dense spotting and strong pyrogenic winds – famously including a genuine tornado in the case of the 2003 fires.

The unique hazards associated with extreme bushfires have several implications for managing the risk of bushfires at the wildland-urban interface. Research following the 2003 firestorm revealed that embers were the leading cause of house loss – a result that has been confirmed in many extreme bushfire events since. However, the current Australian Standard for building in bushfire prone areas only superficially addresses embers as a bushfire attack mechanism, with the predominant focus placed on the effects of radiant heat on structures. The influence of strong pyrogenic winds is also not well accounted for in the Australian Standard, even though they can compromise structures in ways that permit easy incursion of embers and other burning material. More generally, the presence of dynamic fire behaviours typically associated with extreme bushfires undermine the validity of many of the assumptions that underpin the calculation of Bushfire Attack Levels in the Standard.

Protecting the lives and property of the ACT community against the threat of extreme bushfires requires the careful and concerted implementation of several measures. Prescribed burning programs play a key role in reducing the risk of dangerous bushfires, though it must be noted that prescribed burning comes with its own risks to public health and must be conducted within a narrowing window of opportunity, with climate change shifting conditions conducive to prescribed burning more towards winter and early spring. Mechanical removal of vegetation is another option for reducing fuel loads, though its cost must be weighed against its likely benefits.

Research has also confirmed the importance of Indigenous cultural burning in reducing bushfire risk as part of the broader goal of maintaining healthy Country. Recent post-fire inquiries have also highlighted its potential in mitigating extreme bushfires through targeted application in remote areas, particularly along ridges connected with ancient Songlines. As such, enhanced cultural burning programs not only have the potential to reduce bushfire risk, but can also benefit the physical and psychosocial wellbeing of Aboriginal people and the broader process of reconciliation in Australia.

There are a number of certainties when it comes to the threat of extreme bushfires to the ACT community. Extreme bushfires will occur again in the ACT region, and their likelihood will increase while anthropogenic warming remains unabated. The impacts of extreme bushfires extend from local to global scales – from the devastation wrought upon local communities through the immediate effects of fire, to the global disruption of the Earth system through the longer lasting effects of massive releases of carbon and severe stratospheric pollution. However, the more we learn about these extreme events, the more we will be able to identify options to manage their risk.

Ultimately, as part of the ACT community, we have no choice but to face the challenges of living in this current age of violent pyroconvection. It is a responsibility that we all share a part of.