Record fires are raging in Brazil’s Amazon rainforest, with more than 2,500 fires currently burning. They are collectively emitting huge amounts of carbon, with smoke plumes visible thousands of kilometres away.
Fires in Brazil increased by 85% in 2019, with more than half in the Amazon region, according to Brazil’s space agency.
This sudden increase is likely down to land degradation: land clearing and farming reduces the availability of water, warms the soil and intensifies drought, combining to make fires more frequent and more fierce.
1. Why the Amazon is burning
The growing number of fires are the result of illegal forest clearning to create land for farming. Fires are set deliberately and spread easily in the dry season.
Ironically, farmers may not need to clear new land to graze cattle. Research has found a significant number of currently degraded and unproductive pastures that could offer new opportunities for livestock.
New technical developments also offer the possibility of transforming extensive cattle ranches into more compact and productive farms – offering the same results while consuming less natural resources.
2. Why the world should care
The devastating loss of biodiversity does not just affect Brazil. The loss of Amazonian vegetation directly reduces rain across South America and other regions of the world.
The planet is losing an important carbon sink, and the fires are directly injecting carbon into the atmosphere. If we can’t stop deforestation in the Amazon, and the associated fires, it raises real questions about our ability to reach the Paris Agreement to slow climate change.
The Brazilian government has set an ambitious target to stop illegal deforestation and restore 4.8 million hectares of degraded Amazonian land by 2030. If these goals are not carefully addressed now, it may not be possible to meaningfully mitigate climate change.
3. What role politics has played
Since 2014, the rate at which Brazil has lost Amazonian forest has expanded by 60%. This is the result of economic crises and the dismantling of Brazilian environmental regulation and ministerial authority since the election of President Jair Bolsonaro in 2018.
Bolsonaro’s political program includes controversial programs that critics claim will threaten both human rights and the environment. One of his first acts as president was to pass ministerial reforms that greatly weakened the Ministry of the Environment
Regulations and programs for conservation and traditional communities’ rights have been threatened by economic lobbying.
Over the last months, Brazil’s government has announced the reduction and extinction of environmental agencies and commissions, including the body responsible for combating deforestation and fires.
4. How the world should react
Although Brazil’s national and state governments are obviously on the front line of Amazon protection, international actors have a key role to play.
International debates and funding, alongside local interventions and responses, have reshaped the way land is used in the tropics. This means any government attempts to further dismantle climate and conservation policies in the Amazon may have significant diplomatic and economic consequences.
For example, trade between the European Union and South American trading blocs that include Brazil is increasingly infused with an environmental agenda. Any commercial barriers to Brazil’s commodities will certainly attract attention: agribusiness is responsible for more than 20% of the country’s GDP.
Brazil’s continued inability to stop deforestation has also reduced international funding for conservation. Norway and Germany, by far the largest donors to the Amazon Fund, have suspended their financial support.
These international commitments and organisations are likely to exert considerable influence over Brazil to maintain existing commitments and agreements, including restoration targets.
5. There is a solution
Brazil has already developed a pioneering political framework to stop illegal deforestation in the Amazon. Deforestation peaked in 2004, but dramatically reduced following environmental governance, and supply change interventions aiming to end illegal deforestation.
Moreover, private global agreements like the Amazon Beef and Soy Moratorium, where companies agree not to buy soy or cattle linked to illegal deforestation, have also significantly dropped clearing rates.
We have financial, diplomatic and political tools we know will work to stop the whole-sale clearing of the Amazon, and in turn halt these devastating fires. Now it is time to use them.
Tasmania’s bushfires may have resulted in the release of significant amounts of mercury from burnt trees into the atmosphere. Our research shows that industrial mercury pollution from decades past has been locked up in west Tasmanian trees.
Mercury occurs naturally in Earth’s crust. Over the past 200 years, industrial activities have mobilised mercury from the crust and released it into the atmosphere. As a consequence, atmospheric mercury concentrations are now three to four times higher than in the pre-industrialisation era.
Mining is the largest source of the global atmospheric mercury, accounting for 37% of mercury emissions. When Europeans first arrived in Australia, there was, of course, no Environmental Protection Act in place to limit emissions from industrial activities. In western Tasmania, where mining has occurred for more than a century, this meant mercury was being released without control into the local atmosphere until changes in technology, market conditions, and later, regulation, conspired to reduce emissions.
Because mercury is also very persistent in the environment, past mining activity has generated a reservoir of mercury that could be released to the atmosphere under certain conditions. This is a concern because even small amounts of mercury may be toxic and may cause serious health problems. In particular, mercury can threaten the normal development of a child in utero and early in its life.
Tree rings can reveal past mercury contamination
How much mercury has been released into the Australian environment and when has remained largely unknown. However, in a new study we show how mercury levels in Tasmania have dramatically changed over the past 150 years due to mining practices. Long-lived Huon pine, endemic to western Tasmania, is one of the most efficient bioaccumulators of mercury in the world. This makes it a good proxy for tracking mercury emissions in western Tasmania. If concentrations of mercury in the atmosphere are high in a given year, this can be detected in the annual ring of Huon pine for that year.
Mercury pollution from past mining practices in western Tasmania has left a lasting environmental legacy. The sampled trees contained a significant reservoir of mercury that was taken up during the peak mining period in Queenstown. Changes in mercury concentrations in the annual rings of Huon pine are closely aligned with changes in mining practices in the region.
Increased concentrations coincide with the commencement of pyritic copper smelting in Queenstown in 1896. They peak between 1910 and 1920 when smelting was at its height. In 1922, concentrations begin to decline in parallel with the introduction of a new method to separate and concentrate ores. This method required only one small furnace instead of 11 large ones. In 1934, a new dust-collection apparatus was installed in the smelter’s chimney, coinciding with the further decrease in mercury concentrations in nearby Huon pine.
Toxic elements or compounds taken up by vegetation can also be released back into the local environment. Bushfires that burn trees that have accumulated mercury may release this mercury as vapour, dust or fine ash, potentially exposing people and wildlife to the adverse effects of mercury. It is estimated that bushfires release 210,000kg of mercury into the global atmosphere each year. As these fires become more frequent and ferocious in Australia, mercury concentrations in the atmosphere are likely to increase. Mercury released by bushfires can persist in the atmosphere for a year, allowing for long-distance transportation depending on wind strength and direction. This means that mining activity from over a century ago may have regional implications in the near future. The Tasmanian fires in December-February burned almost 200,000 hectares, including areas around Queenstown.
It is not currently possible to know how much mercury has been released by these recent fires. Our results simply highlight the potential risk and the need to better understand the amount of mercury taken up by vegetation that may one day be released back to the atmosphere via bushfires.
Although there is no simple way to remove bio-accumulated mercury from trees, the history of mercury contamination recorded in tree rings provides important lessons. Decreased uptake of mercury after upgrades to the Queenstown copper smelter operations demonstrates the positive impact that good management decisions can have on the amount of mercury released into the environment.
To control mercury emissions globally, the United Nations Environment Programme (UNEP) has developed the Minamata Convention on Mercury. Its primary goal is to protect human health and the environment from the negative effects of mercury. Australia has signed the convention and but has yet to ratify it. Once ratified, Australia would be required to record sources of mercury and quantify emissions, including those from bushfires.
But to do this, the government must first be able to identify environmental reservoirs of mercury. Our study, the first of its kind in the Southern Hemisphere, shows that the long-lived Huon pine can be used to for this purpose. Further work to determine what other tree species record atmospheric emissions of mercury and other toxic elements in other regions of Australia is required.
Larissa Schneider, DECRA fellow, Australian National University; Kathryn Allen, Academic, Ecosystem and Forest Sciences, University of Melbourne, and Simon Haberle, Professor, Australian National University
In January 2019, fires burned across a 100-kilometre length of the iconic Tjoritja National Park in the West MacDonnell Ranges, from Ormiston Gorge nearly to the edge of Alice Springs.
These fires affected an area comparable to the recent Tasmanian fires, but attracted relatively little national attention. This is partly because the fires in Tasmania were so unusual – but we believe the fires in central Australia were just as unexpected.
In the past, fires of this magnitude have tended to come after heavy rain that powers the growth of native grasses, providing fuel for intense and widespread fires. But our research highlights the new danger posed by buffel grass, a highly invasive foreigner sweeping across inland Australia and able to grow fast without much water.
Far from being pristine, Tjoritja and the Western MacDonnell Ranges are now an invaded landscape under serious threat. Our changing climate and this tenacious invader have transformed fire risk in central Australia, meaning once-rare fires may occur far more often.
Buffel grass in Australia
Buffel grass is tough and fast-growing. First introduced to Australia in the 1870s by Afghan cameleers, the grass was extensively planted in central Australia in the 1960s during a prolonged drought.
Introductions of the drought-resistant plant for cattle feed and dust suppression have continued, and in recent decades buffel grass has become a ubiquitous feature of central Australian landscapes, including Tjoritja.
Buffel grass has now invaded extensive areas in the Northern Territory, Queensland, Western Australia and South Australia and is spreading into New South Wales and Victoria. It was legally recognised as a key threat in 2014, but so far only South Australia has prohibited its sale and created statewide zoning to enforce control or destruction.
Buffel grass crowds out other plants, creating effective “monocultures” – landscapes dominated by a single species. In central Australia, where Aboriginal groups retain direct, active and enduring links to Country, buffel grass makes it hard or impossible to carry out important cultural activities like hunt game species, harvest native plant materials or visit significant sites.
But buffel grass isn’t only a threat to biodiversity and Indigenous cultural practices. In January the Tjoritja fires spread along dry river beds choked with buffel, incinerating many large old-growth trees. Much like the alpine forests of Tasmania, the flora of inland river systems has not adapted to frequent and intense fires.
We believe the ability of the fires to spread through these systems, and their increased intensity and size, can be directly attributed to buffel grass.
Fire and buffel grass
Because of the low average rainfall, widespread fires in central Australia have been rare in the recorded past, only following unusual and exceptionally high rainfall.
This extreme rain promoted significant growth of native grasses, which then provided fuel for large fires. There could be decades between these flood and fire cycles. However, since the Tjoritja (previously West MacDonnell Ranges) National Park was established in the 1990s, there have been three large-scale fires in 2001, 2011 and 2019.
What has changed? The 2001-02 and 2011-12 fires both came after heavy rainfall years. In fact, 2011 saw one of the biggest La Niña events on record.
Climate change predictions suggest that central Australia will experience longer and more frequent heatwaves. And although total annual rainfall may stay the same, it’s predicted to fall in fewer days. In other words, we’ll see heavy storms and rainfall followed by long heatwaves: perfect conditions for grass to grow and then dry, creating abundant fuel for intense fires.
If central Australia, and Tjoritja National Park in particular, were still dominated by a wide variety of native grasses and plants, this might not be such a problem. But buffel grass was introduced because it grows quickly, even without heavy rain.
The fires this year were extraordinary because there was no unusually high rainfall in the preceding months. They are a portent of the new future of fire in these ecosystems, as native desert plant communities are being transformed into dense near-monocultures of introduced grass.
The fuel that buffel grass creates is far more than native plant communities, and after the fire buffel grass can regenerate more quickly than many native species.
So we now have a situation in which fuel loads can accumulate over much shorter times. This makes the risk of fire in invaded areas so high that bushfire might now be considered a perpetual threat.
Changing fire threat
In spinifex grasslands, traditional Aboriginal burning regimes have been used for millennia to renew the landscape and promote growth while effectively breaking up the landscape so old growth areas are protected and large fires are prevented. Current fire management within Tjoritja “combines traditional and scientific practices”.
However, these fire management regimes do not easily translate to river environments invaded by buffel grass. These environments have, to our knowledge, never been targeted for burning by Aboriginal peoples. Since the arrival of buffel grass, there is now an extremely high risk that control burns can spread and become out-of-control bushfires.
Even when control burns are successful, the rapid regrowth of buffel grass means firebreaks may only be effective for a short time before risky follow-up burning is required. And there may no longer be a good time of year to burn.
Our research suggests that in areas invaded by buffel grass, slow cool winter burns – typical for control burning – can be just as, or more, damaging for trees than fires in hot, windy conditions that often cause fires to spread.
Without more effective management plans and strategies to manage the changing fire threat in central Australia, we face the prospect of a future Tjoritja in which no old-growth trees will remain. This will have a devastating impact on the unique desert mountain ranges.
We need to acknowledge that invasive buffel grass and a changing climate have changed the face of fire risk in central Australia. We need a coordinated response from Australia’s federal and state governments, or it will be too late to stop the ecological catastrophe unfolding before us.
The authors acknowledge the contribution of Shane Muldoon, Sarah White, Erin Westerhuis, CDU Environmental Science and Management students, and NT Parks and Wildlife staff to the research at experimental sites and ongoing tree monitoring in central Australia.
Martine Maron, The University of Queensland; Andrea Griffin, University of Newcastle; April Reside, The University of Queensland; Bill Laurance, James Cook University; Don Driscoll, Deakin University; Euan Ritchie, Deakin University, and Steve Turton, CQUniversity Australia
Australia’s high rates of forest loss and weakening land clearing laws are increasing bushfire risk, and undermining our ability to meet national targets aimed at curbing climate change.
This dire situation is why we are among the more than 300 scientists and practitioners who have signed a declaration calling for governments to restore, or better strengthen regulations to protect native vegetation.
Land clearing laws have been contentious in several states for years. New South Wales relaxed its land clearing controls in 2017, triggering concerns over irreversible environmental damage. Although it is too early to know the impact of those changes, a recent analysis found that land clearing has increased sharply in some areas since the laws changed.
The Queensland Labor government’s 2018 strengthening of land clearing laws came after years of systematic weakening of these protections. Yet the issue has remained politically divisive. While discussing a federal inquiry into the impact of these policies on farmers, federal agriculture minister David Littleproud suggested that the strenthening of regulations may have worsened Queensland’s December bushfires.
We argue such an assertion is at odds with scientific evidence. And, while the conservation issues associated with widespread land clearing are generally well understood by the public, the consequences for farmers and fire risks are much less so.
Tree loss can increase fire risk
During December’s heatwave in northern Queensland, some regions were at “catastrophic” bushfire risk for the first time since ratings began. Even normally wet rainforests, such as at Eungella National Park inland from Mackay, sustained burns in some areas during “unprecedented” fire conditions.
There is no evidence to support the suggestion that 2018’s land clearing law changes contributed to the fires. No changes were made to how vegetation can be managed to reduce fire risk. This is governed under separate laws, which remained unaltered.
In fact, shortly after the fires, Queensland’s land clearing figures were released. They showed that in the three years to June 2018, an area equivalent to roughly 570,000 Melbourne Cricket Grounds (1,138,000 hectares) of bushland was cleared, including 284,000 hectares of remnant (old-growth) ecosystems.
Tree clearing can worsen fire risk in several ways. It can affect the regional climate. In parts of eastern Australia, tree cover reductions are estimated to have increased summer surface temperatures by up to 2℃ and southwest Western Australia by 0.4–0.8℃, reduced rainfall in southeast Australia, and made droughts hotter and longer.
Removing forest vegetation depletes soil moisture. Large, intact areas of forest typically have cooler, wetter microclimates buffered from extreme temperatures. Over time, some forest types can even become fire-resistant, but smaller patches of trees are typically drier and more flammable.
Trees also form a natural windbreak that can slow the spread of bushfires. An analysis of the 2005 Wangary fire in South Australia found that fires spread most rapidly through paddocks, rather than through areas lined with native trees.
Farmers on the frontline of environmental risk
Extensive tree clearing also leads to problems for farmers, including rising salinity, reduced water quality, and soil erosion. Governments and rural communities spend significant money and labour redressing the aftermath of excessive clearing.
Sensible regulation of native vegetation removal does not restrict existing agriculture, but rather seeks to support sustainable production. Retained trees can help deal with many environmental risks that hamper agricultural productivity, including animal health, long-term pasture productivity, risks to the water cycle, pest control, and human well-being.
Rampant tree clearing is undoing climate policy too. Much of the federal government’s A$2.55 billion Emissions Reduction Fund has gone towards tree planting. But it would take almost this entire sum just to replace the trees cleared in Queensland since 2012.
In 2019, Australians might reasonably expect that our relatively wealthy and well-educated country has moved beyond a frontier-style reliance on continued deforestation, and we would do well to better acknowledge and learn lessons from Indigenous Australians with respect to their land management practices.
Yet the periodic weakening of land clearing laws in many parts of Australia has accelerated the problem. The negative impacts on industry, society and wildlife are numerous and well established. They should not be ignored.
Martine Maron, ARC Future Fellow and Associate Professor of Environmental Management, The University of Queensland; Andrea Griffin, Senior Lecturer, School of Psychology, University of Newcastle; April Reside, Researcher, Centre for Biodiversity and Conservation Science, The University of Queensland; Bill Laurance, Distinguished Research Professor and Australian Laureate, James Cook University; Don Driscoll, Professor in Terrestrial Ecology, Deakin University; Euan Ritchie, Associate Professor in Wildlife Ecology and Conservation, Centre for Integrative Ecology, School of Life & Environmental Sciences, Deakin University, and Steve Turton, Adjunct Professor of Environmental Geography, CQUniversity Australia
Ten years ago, on February 7, 2009, the Black Saturday bushfires killed 173 people. More than 2,000 houses were destroyed in Victoria, including at Kilmore, Kinglake, Vectis (Horsham), Narbethong, Marysville, Strathewan, Beechworth, Labertouche (Bunyip), Coleraine, Weerite, Redesdale, Harkaway, Upper Ferntree Gully, Maiden Gully, Bendigo, Eaglehawk, Lynbrook, St Andrews, Flowerdale, Narre Warren, Callignee, and my home town of Churchill, where my mother and father still lived. Their home wasn’t burned, but many of their neighbours were badly affected by the worst bushfire day in Australia’s history.
A week before, my uncle and aunt had to seek refuge at Mum and Dad’s place when a fire ember landed in their front yard during the Boolarra bushfires. Mum has since passed and Dad still lives in Churchill.
The climate is changing due to human induced greenhouse gas emissions, and this means more bushfire danger days in what is already one of the most fire-prone countries in the world. Unfortunately, we have not done enough to curb climate change and the situation is getting worse.
Climate change means more days of extreme heat, longer heatwaves and more frequent droughts. Droughts now occur further south than in the past and have been increasing in Australia’s southeast, including Tasmania. The records continue to tumble, and the evidence of dangerous climate change continues to mount.
Back in 2008, John Brumby was Premier of Victoria and Kevin Rudd was Prime Minister. I was working on climate change for the Victorian government, developing projections for increased risk of bushfires. A 2005 study had already predicted an increase in fire weather risk throughout most of southeastern Australia over the coming decades, with “very high” and “extreme” fire danger ratings likely to increase in frequency by 4-25% by 2020 and 15-70% by 2050.
There has been more research in this area, although certainly not enough, given the huge stakes. A 2007 report for the Climate Institute of Australia predicted increases in annual average fire danger of up to 30% by 2050, and a potential trebling in the number of days per year where the uppermost values of the index are exceeded. The largest changes are predicted for the arid and semi-arid interior of New South Wales and northern Victoria.
The 2008 Garnaut Climate Change Review also warned that fire seasons will begin earlier, end slightly later, and generally be more intense. “This effect increases over time but should be directly observable by 2020,” it said.
In 2015, a further study by CSIRO and the Bureau of Meteorology concluded that:
Projections of warming and drying in southern and eastern Australia will lead to increases in [forest fire danger index] and a greater number of days with severe fire danger. In a business as usual scenario (worst case, driest scenario), severe fire days increase by up to 160-190% by 2090.
By combining all of this research, I created the graph below.
This shows that while there is some uncertainty as to the extent of increase in the number of bushfire danger days in southeastern Australia, the situation is undoubtedly getting worse, and it’s time for action.
In 2017, the independent Climate Council published a report on Victoria’s growing bushfire threat, which made several stark findings and recommendations:
Climate change is increasing the risk of bushfires in Victoria and lengthening fire seasons.
Victoria is the state most affected by bushfires, and is on the front line of increasing bushfire risk.
The economic cost of bushfires in Victoria is an estimated A$180 million a year, and this is predicted to more than double by 2050.
Bushfires will continue to adversely affect human and environmental health.
In the future, Victoria is very likely to experience an increased number of days with extreme fire danger. Communities and emergency services across Victoria must be prepared.
Reducing greenhouse emissions is vital for protecting Australians.
Risk to water supplies
Our grandfathers and grandmothers had the wisdom to build amazing water infrastructure, protected by the “closed catchments” that give Melbourne and Victoria some of the best water in the world. Bushfires are a major risk to these water supplies – particularly in the catchments of major dams such as the Thomson.
A bushfire followed by a downpour that washes ash into the dam could potentially force the closure of the trillion-litre capacity Thomson reservoir, making it unusable for months. Firefighters have been battling exactly this kind of blaze at Mount Baw Baw in recent days and at the time of writing the situation has improved.
Major bushfires often occur in time of severe drought. Black Saturday itself happened towards the end of the 15-year Millennium Drought, when Victoria’s water supplies were already strained. I remember vividly the then chief executive of the Melbourne Water Corporation urging the government to deal with any fire in the Thomson Dam catchment immediately, given the threat to Melbourne’s water.
Fortunately, amid the devastation of Black Saturday we avoided major disruption to our water supplies. But this risk poses a huge challenge to both firefighters and policy-makers. The rule is that protection of human life is ranked above assets and infrastructure, and rightly so. But when there is a clear and present danger of towns and cities going without water, it’s also true that safeguarding water means saving human lives in the ensuing days.
The bitter lesson of the Californian fires
Any way you look at it, these are hard questions. On our current trajectory, we are heading for terrible trade-offs.
In 2050 my daughter Astrid and my son Atticus – Mum and Dad’s grandchildren – will be 45 and 43, respectively. I hope it is not too late for our leaders in Canberra, Davos and throughout the world to wake up and take urgent action to limit global warming 1.5℃. That would mean that the most fearful predictions of our bushfire future never come to pass.
Every year Tasmania is hit by thousands of lightning strikes, which harmlessly hit wet ground. But a huge swathe of the state is now burning as a result of “dry lightning” strikes.
Dry lightning occurs when a storm forms from high temperatures or along a weather front (as usual) but, unlike normal thunderstorms, the rain evaporates before it reaches the ground, so lightning strikes dry vegetation and sparks bushfires.
Dangerous, large fires occur when dry lightning strikes in very dry environments that are full of fuel ready to burn. Cold fronts in Tasmania, which often carry fire-extinguishing rain, have recently been dry, making these fires worse. The fronts draw in strong hot, dry northerly winds, fanning the flames.
Research has found that as climate change creates a drier Tasmania landscape, dry lightning – and therefore these kinds of fires – are likely to increase.
History and detection in Tasmania
Lightning has always started fires across Tasmania. Fire scars and other paleo evidence across Tasmania show large fires are a natural process in some places. However, frequent large, intense fires were rare. Now such fires are being fought almost every year.
Contrary to anecdotal belief, our recent preliminary work suggests that lightning activity has not increased over recent decades. So why do fires started by lightning appear to be increasing?
As temperatures rise, evaporation rates are increasing, but current rainfall rates are about the same. In combination this means the Tasmanian landscape is drying. The landscape is more often primed, waiting for an ignition source such as a dry-lightning strike. In such conditions, it only takes one.
When dry lighting strikes
Lightning struck just such a landscape in late December 2018, starting the Gell River bushfire in southwest Tasmania. This uncontrollable fire burnt about 20,000 hectares in the first half of January and is still burning. These large fires deplete the state’s resources, fatigue our volunteer and professional fire fighters and can have disastrous effects on natural systems.
With no significant rain falling over Tasmania since mid-December, the island is breaking dry spell records and thousands of dry lightning events have occurred. On January 15 alone over 2,000 lightning strikes sparked more than 60 bushfires.
Most of these were controlled rapidly, a credit to Tasmania’s emergency responders. One of the worst-hit areas was the Tasmanian Wilderness World Heritage Area, where many bushfires continue to burn in inaccessible locations.
This is putting some of Tasmania’s most pristine and valuable places in danger of being lost. The state stands to lose its most remarkable old-growth forests, like Mount Anne, which is home to some of the world’s largest King Billy Pines, a species endemic to Tasmania.
Increasing dry area
Ongoing climate change is making dry spells longer and more frequent, increasing the fire-prone area of Tasmania. Almost the whole state is becoming vulnerable to dry lightning.
Some regions of the west coast of Tasmania used to have very little to no risk of bushfires as they were always damp. However, this is no longer the case, resulting in species coming under threat.
Unlike most of Australia’s vegetation, many of Tasmania’s alpine and subalpine species evolved in the absence of fire and therefore do not recover after being burnt. Endemic species like Pencil Pine, Huon Pine and Deciduous Beech may be wiped out by one fire.
So what does the future hold? Using data from Climate Futures for Tasmania, we can peek into the future. Our models indicate that climate change is highly likely to result in profound changes to the fire climate of Tasmania, especially in the west.
Climate change already playing a role
With a warming climate, the rain-producing low-pressure systems are moving south and many storms that used to hit Tasmania are drifting south, leaving the island drier. This, combined with increasing evaporation rates, result in rapid drying of some areas. Areas that historically rarely experienced fire will become increasingly prone to burn. The drying trend is projected to be particularly profound throughout western Tasmania.
By the end of the century, summer conditions are projected to last eight weeks longer. This drying means that lightning events (and therefore dry lightning) will become an ever-increasing threat and the impact of these events will become more significant.
Higher levels of dryness will mean when bushfires occur the potential for these to burn into the rainforest, peat soils and alpine areas will be significantly increased.
How far away was that lightning?
These changes are already happening and will get progressively worse throughout the 21st century. Climate change is no longer a threat of the future: we are experiencing it now.
Nick Earl, Postdoctoral associate, School of Earth Sciences, University of Melbourne; Peter Love, Atmospheric Physicist, University of Tasmania; Rebecca Harris, Climate Research Fellow, University of Tasmania, and Tomas Remenyi, Climate Research Fellow, Climate Futures Group, Antarctic Climate and Ecosystems CRC, University of Tasmania