Gregory fire, Queensland. Credit: iStock.

Australian bushfires continue to blaze – Expert Reaction

Fires continue to rage across south-eastern Australia and three blazes may join forces to create a mega fire on the Victoria-New South Wales border.

As well as turning Auckland’s skies orange on Sunday, smoke from the eastern Australian fires has now blanketed Melbourne. Over the weekend, Canberra laid claim to the worst air quality for any city in the world, with air quality more than 22 times the hazardous rating.

The SMC asked experts to comment on the current state of the bushfires. Feel free to use these comments in your reporting. 

Dr Tim Curran, Senior Lecturer in Ecology, Lincoln University, comments:

“Anthropogenic climate change is playing an important role in the current Australian bushfire crisis.

“In 2007, a report by Australia’s federal science agency (the Commonwealth Scientific and Industrial Research Organisation – CSIRO) found that under climate change projections south-eastern Australia was expected to get hotter and drier and that as a consequence the bushfire season would start earlier and fires would be more intense. Furthermore, that report stated that these effects ‘should be apparent by 2020’. Of course predictions regarding how Australian bushfires might be exacerbated by climate change go back even further, to research published in 1988.”

“2019 was both the hottest and driest year on average across Australia since records began over 100 years ago, and this has contributed to the current bushfire crisis by producing weather more conducive to fires (hot, dry and windy) and ensuring that fuels are very dry.”

Impacts on plants and animals

“While many Australian plants and animals are well known for their adaptations to and, in some cases, dependence on fire, the vast extent and severity of the current fires, which have burnt huge areas at high intensity, means that even those species adapted to fire may be pushed beyond their ability to recover.

“The large areas that have been burnt will make it difficult for species that rely on recolonisation by individuals that escaped the fires in unburnt areas. These fire-free locations will be rarer and more distant than normal, meaning fewer individuals are available to repopulate fire grounds. Also, those individuals that have survived in the vast burnt areas will face an added likelihood of starvation and increased risk of predation.

“Finally, any bushfire survivors will still have to contend with an unprecedented drought, and fire coupled with extreme drought can cause high mortality in certain plant species. This will not only impact such plants, but any animals that rely on them for food and shelter in the post-fire landscape.”

Relevance to New Zealand

“Climate change is predicted to increase the number of days of very high and extreme forest fire danger in many parts of New Zealand. Fortunately, New Zealand doesn’t have the same extent of highly flammable vegetation types that dominate the Australian continent, though we do have some native vegetation communities that are very flammable, such as tussock grasslands, and shrublands and forests dominated by mānuka and kānuka. We also have many highly flammable weeds, such as gorse, marram grass, pines and hakea, that are changing fire regimes (the spatial and temporal patterns of fire).

“Furthermore, the planned One Billion Tree Programme (1BT) will change the amount, continuity, and flammability of fuel loads across the country. Consequently, the 1BT Programme is likely to change fire regimes in New Zealand, potentially making fires hotter and more extensive in some places. While it is clear that we need a national revegetation programme in New Zealand to help solve a host of environmental problems, we need to be very careful in our planning of the 1BT Programme to best minimise fire hazard. One way to do this is to plant green firebreaks, strips of low flammability species, across the landscape to reduce or halt fire spread.”

Declared conflict of interest: Tim has received funding from the Miss E L Hellaby Indigenous Grasslands Research Trust, and Fire and Emergency New Zealand.

Dr Andrea Byrom, Co-Director, Biological Heritage National Science Challenge, comments:

Note: The following is an excerpt, the full comment is available on Sciblogs.

“As an ecologist, I can’t help but think of the stunning Australian ecosystems I have been privileged to visit in my career.  Tropical woodlands in the Northern Territory, Jarrah and Karri forests in Western Australia, sugar gums and sheoaks on pest-free Kangaroo Island in South Australia, subtropical rainforests in southern Queensland, sclerophyll and box gum woodlands in New South Wales, cool temperate wet Huon pine forests in Tasmania, old growth mountain ash and alpine snowgum forests in Victoria  – I’ve been there, and been lucky enough to meet or collaborate with some of the scientists studying the plants and animals in them.

“Without exception, they are all on fire.

“At times like this, the climate change debate heats up. What is missing, yet should be just as ‘front of mind’ for us all, is the link between climate change and loss of biodiversity. That link has become gruesomely explicit. The link is important, because it makes people care. Indeed, we know that people experience grief in relation to biodiversity loss.

“International media outlets are full of gut-wrenching images of burned koalas, video footage of fleeing kangaroos, and firefighters sharing water with wildlife. Judging by the public outpouring of emotion (and donations) in response, intuitively we know something is very, very wrong. We care about biodiversity, and we care a lot.

“The estimate put forward by ecologist Chris Dickman from the University of Sydney puts the loss of individuals from just three taxa (mammals, birds and reptiles) at more than 800 million in NSW alone. However, Prof Dickman acknowledges that this estimate is conservative: it does not include insects, bats or frogs. It also applies only to NSW and not to any of the other states currently affected by bushfires. By his estimate, it’s likely that the final estimate will be well over 1 billion animals affected directly and indirectly by fires across Australia. Given the rapidly-evolving bushfire scenario, it’s likely that this estimate will, with hindsight, seem small by the end of the bushfire season. And we’re not even talking (yet) about the loss of the habitats and ecosystems – the trees and soils – that support these animals. It will take years to properly quantify biodiversity loss in the 2019-20 bushfire season. The final toll will likely be incalculable.

“The only way to tackle the climate/biodiversity crisis is to focus on whole systems, not parts of them. In 2020, we shouldn’t still be entertaining simplistic arguments over whether high fuel loads or climate change are causing Australia’s mega-fires. Of course they interact. The mega-fires are an example of a highly complex system problem, with a myriad of contributing biophysical components and a tangled web of policies and decision-making at Shire, State and Federal level. As far as I can tell, almost no-one is taking an inter-generational view or looking at the big picture. And such a lack of vision and leadership is by no means a problem confined to Australia.

“Now is the time to empower people with the tools and governance strategies that they need to take action to protect biodiversity – at local, regional, national and global levels – because it is one of the most important ways we can keep our citizens healthy and restore both the people and the planet.”

Declared conflict of interest: None.

Associate Professor David McBride, Occupational and Environmental Medicine, University of Otago, comments:

“The Australian Bush Firefighters are dealing with an unpredictable and changing hazard as the fires spread quickly in the bone-dry environment, trees will be exploding and traditional fire fighting methods are not working. This makes operational planning and tactical decision making difficult, so there is a real danger that firefighters will be trapped. Novel problems are exacerbating the situation, an example are the pyrocumulonimbus clouds generated by the smoke, thunderstorms, and fire tornadoes, the latter recently having caused the death of a firefighter by overturning his 10 ton truck.

“Deaths have also been caused by falling trees and there have been reports of road crashes. The immediate effect on firefighters is physical exhaustion from heat stress, because they will be pushing themselves to the absolute limit.  Mental exhaustion is bound to happen too, which may be the main problem, anxiety, depression and probably post-traumatic stress injury.

“The acute effects of smoke inhalation cause lung injuries, and evidence is emerging that bush and forest firefighters develop chronic bronchitis and asthma.  Cardiovascular effects are also possible, and the inflammatory response may have adverse effects on other organs. The long term effects may well include cancers of the lung and bladder.”

Declared conflict of interest: None.

Professor Lutz Beckert, Respiratory specialist, Department of Medicine, University of Otago, Christchurch, comments:

“The Australian bushfires are for the people of Victoria and New South Wales what the earthquakes were for us in Canterbury. The disaster leaves people in distress, denial and disbelief for weeks after a bushfire.

“Many are dislocated from their home and environment, which will cause distress, likely difficulty falling and remaining asleep, anxiety, uncertainty about the future, disruption to normal routines, irritability, anger and frustration.

“Similar to the response to the earthquakes, ways to cope include linking to others such as family, friends and neighbours. People often call upon their own personal strengths that they have used in the past or in difficult situations (everyone has these).

“New Zealand is only indirectly affected.  In times of thick smog, the following practical advice may help:

  • If you have a respiratory condition take your regular preventer inhaler
  • Check inhalers aren’t empty or expired
  • Look after your whanau in particular if children, elderly relative or neighbours have a respiratory condition.
  • Postpone outdoor exercise like walking, running or gardening when particularly smoggy
  • If you have symptoms related to smog stay inside with closed windows
  • Seek medical help, if symptoms are worsening.”

Declared conflict of interest: None.

Our colleagues at the Australian Science Media Centre asked experts to comment on:


Dr Richard Thornton is CEO of the Bushfire and Natural Hazards CRC, comments:

“The complexities around hazard reduction burning are large and growing. The number of people and businesses continues to increase in previously empty forested regions; the impact of smoke is an issue; the management of water catchments is important; there is now more scientific evidence on the benefits and downsides of various fire treatments; and the windows for undertaking prescribed burning have shrunk due to drought and climate change.

“There is no universal ‘right’ level of prescribed fire because there are competing objectives to be considered, vastly differing ecosystems to be covered, and constantly shifting variables in demographics and land use. And even if you get all the objectives lined up you are still at the mercy of a fickle Australian weather system – too dry can be too dangerous to burn, too wet and little will burn.

“Overlaying all of this are successive changes in governments at the local, state and national level – all with differing positions and varied appetites for land management policy. The list of public inquiries into these matters is long and goes back decades.

“With many prescribed burns now conducted close to the expanding urban fringe and close to essential infrastructure and agriculture, the community tolerance levels are very low to heavy smoke and potential damage to delicate ecosystems. This has not been helped by some significant escapes of prescribed burns that have caused loss of houses and placed lives at risk.

“Fuel reduction burns can decrease wildfire intensity, flame height and the forward rate of spread. But the effectiveness of this reduction is strongly dependent on the weather conditions that prevail on the day they are impacted by a wildfire. On extreme high- temperature and high-wind days, the effectiveness of most prescribed burning on stopping runs of large fires is reduced because medium and long-range spotting will see these areas overrun. The fuel levels around properties and communities can make a significant difference to the intensity of the fire as it impacts private and public assets. However, no amount of fuel reduction burning can reduce the risk to zero. We will always need to accept some residual risk.”

Declared conflict of interest: None.

Dr Noel Preece, University Fellow, Charles Darwin University, and Adjunct Associate Professor, James Cook University, Director, Biome5 Pty Ltd – an environmental management and consultancy for Northern Australian businesses, comments: 

“Hazard reduction and prescribed burning are essential to reduce the impacts of increasingly intense and hotter fires, but are not sufficient in themselves. We need an urgent re-think about planning for bushfire prone areas, that is most of southern Australia. Fire authorities cannot implement necessary management fires when highly flammable bush runs up to houses and fences. Ever-encroaching residential and small-holder properties on native bush are increasing the threats to our natural environment and threats to biodiversity. The answer is not to clear more bush but to plan more intelligently.

“Reinstating indigenous fire management practices, coupled with fire authorities and national parks strategic burning must be increased across the landscape. This will require a large increase in funds and resources for full time people to apply these management fires. The time to start action on this will be after the fires are over, not in a few years’ time.”

Declared conflict of interest: None.


Professor Dale Dominey-Howes, Director, Asia-Pacific Natural Hazards and Disaster Risk Research Group, University of Sydney, comments:

“Time to approach disaster management (and its funding) in Australia differently.

“The current bushfire crisis impacting multiple states and territories simultaneously represents a ‘new normal’ of what climate-related disasters in Australia will look like.

“This crisis is stretching and breaking traditional disaster management responses services beyond coping capacity. Climate change will just add to the complexity. We need new approaches to disaster management – a professional paid workforce, capable of round the clock, round the year and around the country deployment, capable of responding to multiple disaster types.

“We also need new ways to fund this standing ‘disaster force’ and numerous mechanisms, from different taxes and government investment to private-public partnerships, are required to fund this.”

No conflict of interest declared.

Ms Maud Cassaigna, Lecturer, Department of Architecture, Monash University, comments:

“Due to climate change, there is an increased need to consider fire risk and fire-proofing when reconstructing towns and buildings in bushfire-prone areas.

“For instance, building according to higher fire-proofing standards, considering fire-resistant materials, emergency escape routes and in-built shelters.

“When communities are damaged or destroyed due to bushfires, when rebuilding, it’s important to reconsider the town’s access situation, and even location.

“In some cases, it might be valuable to evaluate whether a town needs to be moved to a less fire-prone area to improve bushfire resilience.”

No conflict of interest declared.

Dr David Holmes, Director, Climate Change Communication Research Hub, Monash University, comments:

“This isn’t just about cyclical drought which politicians like to use to normalise the current situation (‘we have always had droughts’), but about the fact that southern and inland areas of Australia are becoming much drier in a way that is overwhelming typical variability.

“In the last 15 years, Australia saw eight of its 10 warmest years on record. Climate scientists tell us that, with climate change, weather systems increasingly move poleward. This means that storm tracks that once brought moisture from the southern ocean right up the east coast are not reaching as far, and inland and forested areas are becoming much drier.”

No conflict of interest declared.

Dr Jim McLennan, Bushfire Safety Researcher and Adjunct Professor, School of Psychology and Public Health, La Trobe University, comments:

“In the leadup to the 2019/20 bushfire season authorities rightly emphasised the importance of timely evacuation in the face of bushfire threat. Media reports suggest that this has been effective. Early reports indicate very large numbers of homes destroyed. In the longer term, attention will have to be paid to making homes in at-risk areas less ‘ignitable’. This will require a fresh look at managing vegetation on private property and house construction and maintenance.”

Declared conflict of interest: None.

Dr Andrew Gissing, emergency management expert, Bushfire and Natural Hazard Cooperative Research Centre, and General Manager of Resilience at Risk Frontiers, comments:

“More people are living in high-risk bushfire areas, emergency services are stretched and the climate is rapidly changing. Future crises are inevitable. We must consider the prospect of a monstrous bushfire season, the likes of which we’ve never seen.

“Bushfire destruction in Queensland and New South Wales this summer is without precedence. Damage nationwide is still lower than the destruction caused by the 2009 Black Saturday Bushfires when 173 lives and over 2000 homes were lost. The crisis is not over and further disasters such as tropical cyclones, severe storms and floods are also possible over the coming months further compounding demands for government assistance.

“Risk Frontiers research through the Bushfire and Natural Hazards Cooperative Research Centre has found that there are significant opportunities to move beyond a government-centric disaster management model by expanding capabilities through embracing a wider number of partnerships across businesses, NGOs and communities. There is a need to consider the changing nature of emergency services during a catastrophe, from one that would typically undertake direct taskings to one that would be the facilitator of community-led actions.

“We spend too much on disaster relief and recovery and not enough on mitigation. We must consider the natural disaster risks we face across Australia. Floods, storms and tropical cyclones cause more financial damage, heatwaves and floods take more lives. This inevitably means we need more investment in mitigating floods, reducing impacts of heatwaves and strengthening buildings against cyclones, as well as responding in the aftermath of these bushfires.”

Conflict of interest statement: Andrew works for a private consultancy that provides research and modelling on natural disasters


Dr Mirella Di Benedetto, Psychology Lecturer, RMIT University, comments: 

“It is well known that firefighters and other first responders are at heightened risk of PTSD. The current number of fires in Australia and the tragic devastation they are causing is unprecedented. Therefore it is crucial that firefighters are able to recognise PTSD and other mental health issues and to get treatment if needed as soon as possible.

“However, many people avoid seeking help due the stigma that still surrounds mental health. Anonymous online or phone services are available to help those in need. It’s important to note that PTSD would be more likely to occur in the coming months, once the fire season is over.”

Declared conflict of interest: None.

Dr Colin Gallagher, Postdoctoral researcher, Centre for Transformative Innovation, Swinburne University of Technology, comments:

“Bushfires affect people and communities alike, with many mental, physical, and social consequences over the following days, months, and years.

“Three years after the 2009 Black Saturday bushfires, a quarter of respondents still reported clinically significant levels of mental health issues, made worse by a range of stressful life experiences (e.g., rebuilding, economic hardship, relationship difficulties).

“Looking ahead, an important recovery factor will be social cohesion within affected communities. Support should go to getting local groups and activities back up and running early, particularly those that are the only form of local activity for their members. For more information, please see the Beyond Bushfires final report.”

No conflict of interest declared.

Associate Professor Thayaparan Gajendran  is Research Director and Deputy Head of School- Resources in the School of Architecture and Built Environment at The University of Newcastle, comments:

“The recent bush fires are unprecedented in many ways-having such devastating impact on many communities and flora and fauna. Although the bush fire season is not over yet, many already affected communities will need significant help and support to start rebuilding their lives. Rebuilding infrastructure and supporting communities from such large-scale disasters may take several years, and recovering from the economic, health and social damages will be challenging.

“The scale of the bush fire impacts places significant pressure on recovery and reconstruction efforts. The different needs and challenges of the affected communities should be considered paramount in rebuilding their lives. Therefore, organisations that assist in these areas should refrain from using broad-brush approaches and focus on rebuilding for future conditions. In most instances, the immediate needs of the survivors are addressed, while the mid to long term support tend to face ongoing challenges. Therefore, the different agencies, NGO’s and other organisations need to coordinate and communicate to best assist the communities for long term recovery.”

Declared conflict of interest: None.

Dr Paul Read, Monash University, and Co-Director, National Centre for Research in Bushfire and Arson, comments:

“Despite resistance from people who become enraged at the very mention of climate or Greta Thunberg, these fires are unprecedented in Australian history and the reasons have all the hallmarks of climate change.

“‘It wrapped the whole country in a sheet of flame.’ This is how the Black Thursday fires of 6 February 1851 were described when a pair of bullockies left their burning campfire in a bone-dry field blasted by northerlies. The largest fire since European settlement, it consumed 5 million hectares. The cataclysmic megafires destroying Australia have now surpassed this, reaching 6.3 million hectares.

“Even with another three months to go before the end of bushfire season, current fires by New Years’ Eve had burnt 5.9 million hectares. For additional context, this represents a full 11 per cent of Australia’s habitable margins. Apart from sheer size, the current fires were already unprecedented because of timing. Every major fire since European settlement has peaked in the Summer months, early February, whereas these fires started in Spring.

“A month ago, Australia was confronted for the first time with the concept of the ‘mega-fire’ a word coined in 2005 to describe unsettling changes in wildfire behaviour across the United States. It was inspired by a fire that burnt for 25 days and consumed 56,000 hectares. Australia’s current fires dwarf this. They have burnt for 130 days, five times as long, and are now more than 1,000 times larger.

“This is uncharted territory. They began earlier than ever before, with a size and ferocity historically constrained to the first week of February. They promise to out-burn the largest fires of Australian history.

“The fact that mortality has not yet breached the numbers seen in Victoria’s Black Saturday fires of 2009 is testimony to the courage of communities and firefighters with the assistance of other states and nations, the military, new technologies and, in some cases, the policies put in place by the Royal Commission. Had these not been in place the death toll should have been, by now, sitting at around 240, ten times its actual number.”

No conflict of interest declared.


Professor Bruce Thompson, respiratory expert and Dean, School of Health Sciences, Swinburne University, comments:

“The smoke generated by the current bush fires is a very serious health issue especially for those with respiratory conditions such as Asthma, Emphysema, Bronchitis and even upper respiratory conditions such as laryngitis.

“Anyone with a respiratory condition must take medications as directed by their doctor. It is recommended to stay inside. Furthermore, if you are a runner then it would be a good idea to take the day off.

“The central issue is not only the large particles that are inhaled but more importantly the very fine particles that are less than 2.5microns (pm2.5). These particles cause inflammation and get inhaled very deep into the lungs causing the lung to become inflamed. This is a big problem for people with respiratory conditions. They also can cross over from the lung into the bloodstream and cause inflammation in areas such as the heart.”

Declared conflict of interest: None.

Professor Clare Murphy, School of Earth Atmospheric and Life Sciences, University of Wollongong, comments:

“The sheer numbers of people who have been exposed to very high levels of smoke pollution over extended time periods in the recent bushfire crisis is unprecedented. In addition to the fine particles that are damaging to human health, smoke from bushfires contains significant amounts of different gases that are also toxic (such as carbon monoxide, formaldehyde, acrolein and hydrogen cyanide).

“These additional airborne toxins are not measured at air quality monitoring stations (as they would usually be below the detection limits of available instruments) but nevertheless will impact on the health of those breathing the smoke. These gases fall into the toxicological classes of upper and lower respiratory tract disorders, eye irritation, disruption of oxygen transport and carcinogens. The combined effect of breathing in these gases and the particles is likely to put further stress on the body.”

Declared conflict of interest: None.


Professor Stuart Khan, Professor of Civil & Environmental Engineering, University of New South Wales, comments:

“Many of the bushfires have directly impacted important drinking water catchments. In particular, fires have severely and extensively burnt major drinking water catchments for Sydney and the Shoalhaven region in NSW. While rainfall is desperately needed to help extinguish fires and alleviate the drought, contaminated runoff to waterways will present a new wave of challenges regarding risks to drinking water quality.

“Bushfire ash is largely composed of organic carbon, which will biodegrade in waterways, potentially leading to reduced oxygen concentrations and poor water quality. Ash also contains concentrated nutrients including nitrogen and phosphorous, which may stimulate the growth of algae and cyanobacteria in waterways.

“Following the fires, these drinking water catchments are now in a very unstable condition and highly prone to erosion of topsoil. All of these impacts will challenge drinking water treatment plants and make it much more difficult to reliably produce high quality drinking water. While major impacts are unlikely to encountered before a substantial rainfall event, some will be long-term with observably poorer raw water quality likely to persist for years.”

Declared conflict of interest: None.

Dr Mark Diesendorf, Honorary Associate Professor,  Environment & Governance Group, UNSW Sydney, comments:

“One of the many issues raised by the continuing bushfire disaster is the competing demand for water needed to fight the fires versus water needed for agriculture and drinking. In the drought, there are very few potential inland water sources for fire-fighting, apart from the rivers that still have running water, such as the Murray and the Hawkesbury-Nepean. On the coast, much of the water-bombing of fires has to use salt water, which results in long-term damage to soils. Furthermore, some coal-fired power stations are using vast quantities of freshwater for coal washing and cooling. In particular, Mount Piper power station near Lithgow is diverting freshwater that would otherwise flow into Warragamba Dam, Sydney’s main source of drinking water.”

Declared conflict of interest: None.


Dr Euan Ritchie, Associate Professor, Wildlife Ecology and Conservation, Deakin University, comments:

“For decades now, climate, fire and ecological experts have all warned about the links between climate change and extreme fire events. Sadly, these predictions have now come to fruition, devastating both in scale and their impact on people, communities, and Australia’s remarkable and unique plants and animals.

“This terrible summer must be the point where we as a nation take urgent and substantial action to combat climate change and its dire consequences. It’s too early to assess the full toll of these fires on species, but given their huge size and severity, and that they’re still burning in many areas, already threatened species may have been pushed over the edge to extinction and once relatively common and more abundant species may now be vulnerable.

“We have grave fears for many rainforest species, which typically don’t experience fire and hence aren’t particularly resilient.

“Elsewhere, Kangaroo Island’s dunnart and glossy black cockatoo, Victoria’s long-footed potoroo, and regent honeyeaters, are among the many species likely to have suffered substantial impacts. It’s not too late to change our course however, and we must act swiftly to conserve Australia’s remarkable nature.”

Declared conflict of interest: None.

Dr Joe Fontaine, Lecturer, Environmental and Conservation Sciences, Murdoch University, comments:

“Reverberations of these epic bushfires will be felt for generations.  The current drought is as bad as the Federation drought but it is hotter. Hotter drought means both elevated bushfire risk and unstoppable fires as we’ve all seen in the media.  Hotter drought also has consequences after the flames pass — the capacity of plants and animals to both survive and subsequently recover is less certain under warmer, drier conditions.  Tree mortality and seedling survival as well as food and shelter for our animals are all threatened by harsher conditions. Further, we face a more fiery future and a real risk of more drought-heat-fire interplay further threatening our iconic landscapes. Effective policy and thinking will need to incorporate these realities going forward.”

Declared conflict of interest: None.

Professor Bob Hill, Director, Environment Institute, University of Adelaide, comments:  

“The fires around Australia are tragic at many levels and the cost in human life and of animals, both domestic and native, is appalling. Perhaps less well understood is the potential cost in terms of future vegetation. Australian plants in many vegetation types have evolved in response to a high fire regime over tens of millions of years and they are well known for their capacity to regenerate, either from seed or vegetatively, after major fires.

“However, the risk is that we are now seeing fires that are so intense that they are reaching temperatures where these adaptations are no longer effective, and if this continues we will begin to see plant species losses from burnt sites as their regeneration processes fail. Over time, this has the potential to be catastrophic. The short-term solution is to invest much more heavily in fire-fighting technology, but the only long term solution is to reverse the impact of climate change by reducing the level of critical greenhouse gases in the atmosphere. This is a global catastrophe that has now hit Australia hard. There is no reason to believe that this is an isolated event.”

Declared conflict of interest: None.

Professor Chris Dickman, Professor in Terrestrial Ecology, University of Sydney, comments: 

Note: Prof Dickman estimates that 480 million animals have been affected since bushfires in NSW started in September 2019. This statement released on Jan 3 explains how that figure was calculated. 

“This figure is based on a 2007 report for the World Wild Fund for Nature (WWF) on the impacts of land clearing on Australian wildlife in New South Wales (NSW).

“To calculate the impacts of land clearing on the State’s wildlife, the authors obtained estimates of mammal population density in NSW and then multiplied the density estimates by the areas of vegetation approved to be cleared.

“Estimates of density were obtained from published studies of mammals in NSW and from studies carried out in other parts of Australia in similar habitats to those present in NSW.

“The authors deliberately employed highly conservative estimates in making their calculations. The true mortality is likely to be substantially higher than those estimated.

“Using that formula, co-author of the original report Professor Chris Dickman estimates that 480 million animals have been affected since the bushfires in NSW started in September 2019. This figure only relates to the state of NSW. Many of the affected animals are likely to have been killed directly by the fires, with others succumbing later due to the depletion of food and shelter resources and predation from introduced feral cats and red foxes.

“The figure includes mammals, birds and reptiles and does not include insects, bats or frogs. The true loss of animal life is likely to be much higher than 480 million. NSW’s wildlife is seriously threatened and under increasing pressure from a range of threats, including land clearing, exotic pests and climate change.

“Australia supports a rich and impressive diversity of mammals, with over 300 native species. The continent is uniquely dominated by marsupials and is the only great land mass to contain three major groups of living mammals: marsupials, monotremes (egg-laying platypus and echidna) and placentals. About 244 species, or 81% of this distinctive fauna, are found only in Australia.

“Some 34 species and subspecies of native mammals have become extinct in Australia over the last 200 years, the highest rate of loss for any region in the world.”

Declared conflict of interest: None.