January 2, 2020

expert reaction to Australian bushfires

Reaction to the ongoing wild fires in Australia.

Dr Matthew W Jones, Senior Research Associate, School of Environmental Sciences, University of East Anglia, said:

“Bushfires are commonplace in Australia and were long before records began.  Much of Australia’s native flora is fire-adapted, and in particular the Eucalyptus forests have thrived in the naturally fire-prone conditions.

“There are records of large historical fires in Australia, many of which have been deadly and destructive.  Among the most devastating of these were the 1939 ‘Black Friday’ fires, the 1967 ‘Black Tuesday’ Fires, the 1983 ‘Ash Wednesday’ fires and the 2009 ‘Black Saturday’ fires.  Bushfires are not an exceptional feature of the Australian landscape, and they have always been a threat to populations living in these areas.

“Australian bushfires result from regional-scale weather conditions that promote drought.  The drought experienced in recent months has been linked to an exceptionally cool surface ocean in the east of the Indian Ocean, which has led to unusually dry air in North and West Australia.  This has been coupled with unusually strong westerly winds, which have brought the dry air over the Australian land mass.  The dry air arriving in southeast Australia has been strongly warmed during its passage over the landmass.  Temperatures have been record-breaking and rainfall has been below average for several months, leading to the drying out of forest vegetation and surface fuels – the perfect conditions for fire.

“While it is not possible to place blame squarely on climate change, there is no doubt that climate change increases the likelihood of major fire events occurring.  When regional-scale weather conditions develop as they have done recently, their effect is exaggerated by higher background temperatures.

“In Australia, annual average surface temperatures have already increased to around 1°C above those of a century ago.  This shift in ‘normal’ temperatures is also leading to more extreme ‘extremes’.  During extreme events, fine temperature margins of 1°C or less can determine whether a forest dries out and ignites.

“Climate change also intensifies the global hydrological cycle, and a general rule of thumb is that dry places are becoming drier and wet places are becoming wetter.  As an already dry place, Australia is particularly vulnerable to more frequent and intense droughts.

“In a warming and more drought-prone world, we must expect to see more devastating droughts and fires like the ones we have seen in Australia, California and the Mediterranean in recent years.

“The impacts on the lives and livelihoods of residents and wildlife makes for truly painful viewing, but sadly these scenes are set to become increasingly familiar.

“The Australian Bureau of Meteorology is predicting severe, extreme and catastrophic fire danger over the coming days across many regions of South and East Australia.  However, in its longer-term forecast, the Bureau is predicting that the regional-scale weather conditions that are driving the current drought will subside over the next few months.  Temperatures are forecast to remain above average, however the westerly winds bringing dry air to southeast Australia will weaken and rainfall is forecast to be typical for the summer period.

“The major problem that Australia faces in the coming months is the legacy effect of a dry spring.  Surface fuels, such as dropped leaves, twigs and other dead vegetation, and the living forest vegetation have dried out and are primed for fire.  All those affected by the fires will be hoping for above-average summer rainfall to moisten Australia’s forests, but the long-term forecast does not look so hopeful.”

Prof Gabi Hegerl FRS, Professor of Climate System Science, University of Edinburgh, said:

“The smoke can be blown far afield, for example, to New Zealand.  It’s not easy for air masses to cross the equator so I can’t see this going to the UK.

“Volcanic eruptions have a long term (months to years) climate effect if they are explosive enough to launch reflective particles into the stratosphere.  It has been recently shown that wildfire smoke can under the right conditions reach the lowermost stratosphere, with soot warming it.  This is quite different from volcanic eruptions which can cause longterm cooling by reflecting incoming sunlight – soot absorbs.

“Each fire crisis has its own unique conditions (drought, fuel loading, management conditions etc.) but if all else is the same, in warmer conditions, moisture evaporates quicker and the land dries out more quickly, so scientists have warned for a while that increased fire activity is expected with climate change in many regions – as the recent IPCC report on land for example highlights.”

Dr Karsten Haustein, Environmental Change Institute, University of Oxford, said:

“It is known that the fire threat is a function of temperature, winds and cumulative rainfall deficit.  Currently, large parts of Australia suffer from anomalously high temperatures and extreme drought conditions.  In combination with gusty winds, the fire risk is therefore extremely high.  While natural variability (primarily related to El Nino Southern Oscillation) plays a considerable role, climate change exacerbates the fire danger, turning a bad year for fires into one which is potentially apocalyptic for some.”

Prof Ilan Kelman, Professor of Disasters and Health, UCL, said:

“Mental health impacts are often overlooked.  The survivors deserve extensive support in dealing with trauma, bereavement, and loss.  Feelings of home and security might be shattered, their community might never be the same, and they may experience debilitating fear of the next fire.  With those affected already having suffered substantially, interventions are essential to address depression, suicide, anxiety, stress, and other mental health challenges.”

Mr Martin Kealy, Fire Consultant and Managing Director of MKA Fire, said:

“Wildland fires are a natural and essential part of our ecosystem, they clean, renew and increase biodiversity.  Controlled burns (aka backburning) can also reduce greenhouse gas emissions.  The problem is if controlled burns are not carried out and smaller bush fires extinguished, the chances of a larger fire occurring later increase as the combustibles pile up.  Large fires typically occur where there is low humidity and high wind speeds.  Controlled backburning would be carried out in favourable weather conditions and preferably during day time.

“In addition people like to live in communities surrounded by trees/vegetation, this risk can also be mitigated by understanding the standoff distances required.

“In the USA the National Fire Protection Association has published a code: NFPA 1144, Standard for Reducing Structure Ignition Hazards from Wildland Fire 2018 edition.  The Society of Fire Protection Engineers (SFPE) of which I am a member, provides up to date research and building design advice including fire modelling of wildland fires:

https://www.sfpe.org/page/FPE_ET_Issue_32

https://www.sfpe.org/page/FPEExtraIssue10?&hhsearchterms=%22wildland%22

https://en.wikipedia.org/wiki/Controlled_burn

“Unfortunately all the above good advice and knowledge is too late for the Australians in the current fire season, they need to evacuate to a safe area.”

Dr Nicolas Bellouin, climate scientist at the University of Reading’s Department of Meteorology, said:

“Australia’s bushfires are a terrible and dramatic reminder of the impact that extreme weather can have on people and on nature.  As well as the obvious damage to property and habitats, thousands of people may be suffering from the poor air quality as they breathe in smoke and ash in the air.

“We know that droughts, heatwaves and wildfires are becoming more common across the world as our planet heats up.  The Australian bushfires are not only a taste of what is to come in the future as a result of our changing climate, but also a reminder that planting trees is unlikely to be the panacea to fight climate change that some might hope.

“Planting trees will not prevent further climate change if the trees go up in flames every summer.  When forests burn, they don’t store much carbon.

“The current situation suggests that solutions based on tree planting can only be applied in a limited number of regions, thus limiting the amount of carbon that can actually be stored for long periods.  Australia has always had bushfires, but as the climate changes, regions of the world that previously rarely saw forest fires are experiencing them much more often.  Even the North of England, Scotland and Sweden see large wildfires nowadays.”

Prof Bill McGuire, Emeritus Professor of Geophysical & Climate Hazards, UCL, said:

“In recent years, as summer temperatures have rocketed, the bushfire season has taken on a terrifying life of its own.  In 2009, fires took more than 180 lives and in recent years have increasingly impinged upon lives and communities.  But in a record going back 150 years, nothing – so early in the season – has approached the scale and ferocity of the current fires, which have already burned an area about the size of Denmark and show no signs of being reigned in.  In a country where temperature records were smashed twice in December, it would seem unthinkable to question a role for global heating in this unprecedented level of bushfire activity.”

Prof Tim Palmer, Royal Society Research Professor, University of Oxford, said:

“Have the bushfires been made worse by human-induced climate change?  There are two aspects to this question.  One is easy to answer, the other is more difficult.  The heat and drought in Australia are primarily due to very large-scale atmospheric circulation patterns over both the Indian and Southern Oceans.  These large-scale circulation patterns are not primarily caused by climate change but are associated with natural (internal) climate variability involving interaction between the atmosphere and the underlying oceans.

“However, the simple fact that the Earth is warming due to human climate change means that the heat (and associated drying of the land surface) associated with these circulation patterns has been intensified, a phenomenon we have seen studying heat waves around the world.

“However, a crucial question for Australia is whether the circulation patterns that lead to such intense fires will become more or less likely in the future as a result of climate change – how will climate change affect the patterns of natural climate variability which affect Australia?  This is not a question that the current generation of climate models can answer with any confidence.”

Prof Ilan Kelman, Professor of Disasters and Health, UCL, said:

“Despite the heat and these fires’ intensity and extent, plenty could be done over the long-term to avoid a catastrophe.  Over past decades, cities have expanded significantly into burnable areas.  Home owners can design and maintain their houses and land to reduce the chance of them catching alight.  No guarantees ever exist of saving property, but we have seen the difference in Australia between those whose dwellings survived and those who sadly lost everything or who tragically perished while staying behind to defend.  The key is preparing years in advance, including being ready to lose one’s home, knowing that fires are part of the ecosystem and could happen any year, even if now being much worse.”

Dr Carola de Koenig, Director of the Flood and Coastal Engineering Programme, Brunel University London, said:

“Australia has seen widespread rainfall deficiencies over the last 36 months and in particular in the last 18 months.  This combined with sustained high temperatures and strong winds leaves forests and vegetation tinder-dry, so it does not take much to start and sustain bush fires.”

Declared interests

Dr Matthew W Jones: His area is the global carbon cycle and the role of landscape fires and fossil fuel combustion in this.  He has no interests to declare.

Dr Nicolas Bellouin: “No conflict of interest.”

Prof Bill McGuire: “I was a contributing author to the IPCC report on climate change and extreme events.”

Prof Tim Palmer: “No interests to declare.”

Prof Ilan Kelman: “Author of Disaster By Choice (Oxford University Press, 2020).  Also, Professor II at the University of Agder, Norway.  No other interests to declare.”

None others received.