Smoke from the Black Summer fires created an algal bloom bigger than Australia in the Southern Ocean

Christina Schallenberg, University of Tasmania; Jakob Weis, University of Tasmania; Joan Llort, Barcelona Supercomputing Center-Centro Nacional de Supercomputación (BSC-CNS); Peter Strutton, University of Tasmania, and Weiyi Tang, Princeton UniversityIn 2019 and 2020, bushfires razed more than 18 million hectares of land in Australia. For weeks, smoke choked major cities, leading to almost 450 deaths, and even circumnavigated the southern hemisphere.

As the aerosols billowed across the oceans many thousands of kilometres away from the fires, microscopic marine algae called phytoplankton had an unexpected windfall: they received a boost of iron.

Our research, published today in Nature, found this caused phytoplankton concentrations to double between New Zealand and South America, until the bloom area became bigger than Australia. And it lasted for four months.

This enormous, unprecedented algal bloom could have profound implications for carbon dioxide levels in the atmosphere and for the marine ecosystem. But so far, the impact is still unclear.

Meanwhile, in another paper published alongside ours in Nature today, researchers from The Netherlands found the amount of carbon dioxide emitted by the fires that summer was more than double previous estimates.

Absorbing 680 million tonnes of carbon dioxide

Iron fertilises phytoplankton and helps them grow, in the same way nutrients added in soil help vegetables grow. And like plants on land, phytoplankton photosynthesise — they absorb CO₂ as they grow and produce oxygen for fish and other marine creatures.

Bushfire smoke is an aerosol made up of many different chemicals, including iron.
Shutterstock

We used satellite data to estimate that for phytoplankton to grow as much as they did in the Southern Ocean, they would have absorbed 680 million tonnes of CO₂. This means the phytoplankton absorbed roughly the same amount of CO₂ as released by the bushfires, according to the latest estimates released today.

The Dutch researchers found the bushfires released 715 million tonnes of CO₂ (or ranging 517–867 million tonnes) between November 2019 and January 2020. This surpasses Australia’s normal annual fire and fossil fuel emissions by 80%.

To put this into perspective, Australia’s anthropogenic CO₂ emissions in 2019 were much less, at 520 million tonnes.

Phytoplankton can have dramatic effects on climate

But that doesn’t mean the phytoplankton growth absorbed the bushfire’s CO₂ emissions permanently. Whether phytoplankton growth extracts and keeps CO₂ from the atmosphere depends on their fate.

If they sink to the deep ocean, then this represents a carbon sink for decades or even centuries — or even longer if phytoplankton are stored in ocean sediments.

But if they’re mostly eaten and decomposed near the ocean’s surface, then all that CO₂ they consumed comes straight back out, with no net effect on the carbon balance in the atmosphere.

Himawari satellite image showing the January aerosol plume stretching over the South Pacific.
Himawari-8, Author provided

In fact, phytoplankton have very likely played a role on millennial time scales in keeping atmospheric CO₂ concentrations down, and can affect the global climate in the long term.

For example, a 2014 study suggests iron-containing dust billowing over the Southern Ocean caused increased phytoplankton productivity, which contributed to reducing atmospheric CO₂ by about 100 parts per million. And this helped transition the planet to ice ages.

Phytoplankton blooms can also have a big impact on the marine ecosystem as they make excellent food for some marine creatures.

For example, more phytoplankton means more food for zooplankton that feed on phytoplankton, with effects up the food chain. It’s also worth noting this huge bloom occurred at a time of year when phytoplankton are usually in decline in this part of the ocean.

But whether there were any long-lasting effects from the bushfire-fuelled phytoplankton on the climate or ecosystem is unclear, because we still don’t know where they ended up.

Using revolutionary data

The link between fire aerosols and the increase in phytoplankton demonstrated in our study is particularly relevant given the intense fire activity around the globe.

Droughts and warming under global climate change are expected to increase the frequency and intensity of wildfires, and the impacts to land-based ecosystems, such as habitat loss and air pollution, will be dramatic. But as we now know, wildfires can also affect marine life thousands of kilometres away from land.

A robotic float being deployed on board the CSIRO RV Investigator.
Jakob Weiss, Author provided

Previous models have predicted the iron-fertilising effect of bushfire aerosols, but this is the first time we’ve observed and demonstrated the connection at a large-scale.

Our study is mainly based on satellite data and observations from robotic floats that roam the oceans and collect data autonomously. These robotic floats are revolutionising our understanding of chemical cycling, oxygen variability and ocean acidification.

During the bushfire period, our smoke tracers reached concentrations at least 300% higher than what had ever been observed in the 22-year satellite record for the region.

Interestingly, you wouldn’t be able to observe the resulting phytoplankton growth in a true-colour satellite image. We instead used more sensitive ocean colour sensors on satellites to estimate phytoplankton concentrations.

So what’s next?

Of course, we need more research to determine the fate of the phytoplankton. But we also need more research to better predict when and where aerosol deposition (such as bushfire smoke) will boost phytoplankton growth.

For example, the Tasman Sea — between Australia and New Zealand — showed only mildly higher phytoplankton concentrations during the bushfire period, even though the smoke cloud was strongest there.

Was this because nutrients other than iron were lacking, or because there was less deposition? Or perhaps because the smoke didn’t stick around for as long?

Whatever the reason, it’s clear this is only the beginning of exciting new lines of research that link forests, wildfires, phytoplankton growth and Earth’s climate.

Christina Schallenberg, Research Fellow, University of Tasmania; Jakob Weis, Ph.D. student, University of Tasmania; Joan Llort, Oceanógrafo , Barcelona Supercomputing Center-Centro Nacional de Supercomputación (BSC-CNS); Peter Strutton, Professor, Institute for Marine and Antarctic Studies, University of Tasmania, and Weiyi Tang, Postdoc in Biogeochemistry, Princeton University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

More livestock, more carbon dioxide, less ice: the world’s climate change progress since 2019 is (mostly) bad news

Thomas Newsome, University of Sydney; Christopher Wolf, Oregon State University, and William Ripple, Oregon State UniversityBack in 2019, more than 11,000 scientists declared a global climate emergency. They established a comprehensive set of vital signs that impact or reflect the planet’s health, such as forest loss, fossil fuel subsidies, glacier thickness, ocean acidity and surface temperature.

In a new paper published today, we show how these vital signs have changed since the original publication, including through the COVID-19 pandemic. In general, while we’ve seen lots of positive talk and commitments from some governments, our vital signs are mostly not trending in the right direction.

So, let’s look at how things have progressed since 2019, from the growing number of livestock to the meagre influence of the pandemic.

Is it all bad news?

No, thankfully. Fossil fuel divestment and fossil fuel subsidies have improved in record-setting ways, potentially signalling an economic shift to a renewable energy future.

The graph on the left shows an increase in fossil fuel divestment by 1,117 organisations based on data from 350.org, and the graph on the right shows a decrease in subsidies for fossil fuels based on the International Energy Agency subsidies database. The red lines show changes since our original publication in 2019.

However, most of the other vital signs reflect the consequences of the so far unrelenting “business as usual” approach to climate change policy worldwide.

Especially troubling is the unprecedented surge in climate-related disasters since 2019. This includes devastating flash floods in the South Kalimantan province of Indonesia, record heatwaves in the southwestern United States, extraordinary storms in India and, of course, the 2019-2020 megafires in Australia.

In addition, three main greenhouse gases — carbon dioxide, methane and nitrous oxide — set records for atmospheric concentrations in 2020 and again in 2021. In April this year, carbon dioxide concentration reached 416 parts per million, the highest monthly global average concentration ever recorded.

Time series of three climate-related responses. The red lines show changes since our original publication in 2019.

Last year was also the second hottest year in recorded history, with the five hottest years on record all occurring since 2015.

Ruminant livestock — cattle, buffalo, sheep, and goats — now number more than 4 billion, and their total mass is more than that of all humans and wild mammals combined. This is a problem because these animals are responsible for impacting biodiversity, releasing huge amounts of methane emissions, and land continues to be cleared to make room for them.

There are now more than 4 billion livestock on Earth.
Flickr

In better news, recent per capita meat production declined by about 5.7% (2.9 kilograms per person) between 2018 and 2020. But this is likely because of an outbreak of African swine fever in China that reduced the pork supply, and possibly also as one of the impacts of the pandemic.

Tragically, Brazilian Amazon annual forest loss rates increased in both 2019 and 2020. It reached a 12-year high of 1.11 million hectares deforested in 2020.

Ocean acidification is also near an all-time record. Together with heat stress from warming waters, acidification threatens the coral reefs that more than half a billion people depend on for food, tourism dollars and storm surge protection.

Map of land-ocean temperature index anomaly in June, relative to the 1951-1980 baseline.
Oregon State/NASA

What about the pandemic?

With its myriad economic interruptions, the COVID-19 pandemic had the side effect of providing some climate relief, but only of the ephemeral variety.

For example, fossil-fuel consumption has gone down since 2019 as did airline travel levels.

But all of these are expected to significantly rise as the economy reopens. While global gross domestic product dropped by 3.6% in 2020, it is projected to rebound to an all-time high.

So, a major lesson of the pandemic is that even when fossil-fuel consumption and transportation sharply decrease, it’s still insufficient to tackle climate change.

There is growing evidence we’re getting close to or have already gone beyond tipping points associated with important parts of the Earth system, including warm-water coral reefs, the Amazon rainforest and the West Antarctic and Greenland ice sheets.

Warming waters are threatening West Antarctic and Greenland ice sheets.
Flickr

OK, so what do we do about it?

In our 2019 paper, we urged six critical and interrelated steps governments — and the rest of humanity — can take to lessen the worst effects of climate change:

prioritise energy efficiency, and replace fossil fuels with low-carbon renewable energy
reduce emissions of short-lived pollutants such as methane and soot
curb land clearing to protect and restore the Earth’s ecosystems
reduce our meat consumption
move away from unsustainable ideas of ever-increasing economic and resource consumption
stabilise and, ideally, gradually reduce human populations while improving human well-being especially by educating girls and women globally.

These solutions still apply. But in our updated 2021 paper, we go further, highlighting the potential for a three-pronged approach for near-term policy:

a globally implemented carbon price
a phase-out and eventual ban of fossil fuels
strategic environmental reserves to safeguard and restore natural carbon sinks and biodiversity.

A global price for carbon needs to be high enough to induce decarbonisation across industry.

And our suggestion to create strategic environmental reserves, such as forests and wetlands, reflects the need to stop treating the climate emergency as a stand-alone issue.

By stopping the unsustainable exploitation of natural habitats through, for example, creeping urbanisation, and land degradation for mining, agriculture and forestry, we can reduce animal-borne disease risks, protect carbon stocks and conserve biodiversity — all at the same time.

A kangaroo in burnt bushland — There has been a worrying number of disasters since 2019, including Australia’s megafires.
Shutterstock

Is this actually possible?

Yes, and many opportunities still exist to shift pandemic-related financial support measures into climate friendly activities. Currently, only 17% of such funds had been allocated that way worldwide, as of early March 2021. This percentage could be lifted with serious coordinated, global commitment.

Greening the economy could also address the longer term need for major transformative change to reduce emissions and, more broadly, the over-exploitation of the planet.

Our planetary vital signs make it clear we need urgent action to address climate change. With new commitments getting made by governments all over the world, we hope to see the curves in our graphs changing in the right directions soon.

Thomas Newsome, Academic Fellow, University of Sydney; Christopher Wolf, Postdoctoral Scholar, Oregon State University, and William Ripple, Distinguished Professor and Director, Trophic Cascades Program, Oregon State University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

New research finds native forest logging did not worsen the Black Summer bushfires

David Bowman, University of TasmaniaThe Black Summer bushfires shocked the world and generated enormous global media interest. Fire scientists like myself found themselves filling a role not unlike sport commentators, explaining the unfolding drama in real time.

Scientists who engaged with the media during the crisis straddled two competing imperatives. First was their duty to share their knowledge with the community while knowing their understanding is imperfect. Second was the ethical obligation to rigorously test hypotheses against data analysis and peer review – the results of which could only be known long after the fires were out.

One area where this tension emerged was around the influential idea that logging exacerbated the bushfire disaster. During the fire crisis and in the months afterwards, some scientists suggested logging profoundly affected the fires’ severity and frequency. There were associated calls to cease native forestry and shift wood production to plantations.

But there is no scientific consensus about the possible effects of logging on fire risk. In fact, research by myself and colleagues, published in Nature Ecology and Evolution today, shows logging had little if any effect on the Black Summer bushfires. Rather, the disaster’s huge extent and severity were more likely due to unprecedented drought and sustained hot, windy weather.

These findings are significant for several reasons. Getting to the bottom of the bushfires’ cause is essential for sustainable forest management. And, more importantly, our research confirms the devastating role climate change played in the Black Summer fires.

Firefighters recover after battling blazes at Kangaroo Island on 10 January 2019.
David Mariuz/AAP

Looking for patterns

Our research focused on 7 million hectares of mostly eucalyptus forests, from the subtropics to temperate zones, which burned between August 2019 and March 2020.

There is some evidence to suggest logged areas are more flammable that unlogged forests. Proponents of this view say logging regimes make the remaining forests hotter and drier, and leave debris on the ground that increases the fuel load.

In our research, we wanted to determine:

the relative roles logging and other factors such as climate played in fires that destroyed or completely scorched forest canopies
whether plantations are more vulnerable to canopy scorch than native forests.

To do so, we used landscape ecology techniques that could compare very large areas with different patterns of land use and fire severity. We sampled 32% of the area burnt in three regions spanning the geographic range of the fires.

firefighters run past fire — The research used landscape ecology techniques to compare large areas.
Shutterstock

What we found

Fire intensity is classified according to the vertical layer of vegetation burnt. A scorched tree canopy suggests the most intense type of fire, where the heat extended from the ground to the treetops.

We found several predictors of canopy damage. First, completely scorched canopy, or canopy consumed by fire, typically occurred across connected swathes of bushland. This most likely reflected instances where the fire made a “run”, driven by localised winds.

Extreme weather fire conditions were the next most important predictor of canopy damage. The drought had created vast areas of tinder-dry forests. Temperatures during the fire season were hot and westerly winds were strong.

Southeast Australia’s climate has changed, making such extreme fire weather more frequent, prolonged and severe.

Logging activity in the last 25 years consistently ranked “low” as a driver of fire severity. This makes sense for several reasons.

As noted above, fire conditions were extraordinarily extreme. And there was mismatch between the massive area burnt and the comparatively small areas commercially logged in the last 25 years (4.5% in eastern Victoria, 5.3% in southern NSW and 7.8% in northern NSW).

Fire severity is also related to landscape features: fire on ridges is generally worse than in sheltered valleys.

Our research also found timber plantations were as prone to severe fire as native forestry areas. In NSW (the worst-affected state) one-quarter of plantations burned – than 70% severely. This counteracts the suggestion using plantations, rather than logging native forest, can avoid purported fire hazards.

plantation forest divided by road — Plantation forests were found to be highly flammable.
Shutterstock

A challenge awaits

Our findings are deeply concerning. They signal there is no quick fix to the ongoing fire crisis afflicting Australia and other flammable landscapes.

The crisis is being driven by relentless climate change. Terrifyingly, it has the potential to turn forests from critical stores of carbon into volatile sources of carbon emissions released when vegetation burns.

Under a rapidly warming and drying climate, fuel loads are likely to become less important in determining fire extent and severity. This will make it increasingly difficult, if not impossible, to lower fuel loads in a way that will limit bushfire severity.

A massive challenge awaits. We must find socially and environmentally acceptable ways to make forests more resilient to fire while the also produce sustainable timber products, store carbon, provide water and protect biodiversity.

The next step is a real-world evaluation of management options. One idea worth exploring is whether the fire resistance of native forests can be improved in specific areas by altering tree density, vegetation structure or fuel loads, while sustaining biodiversity and amenity.

Commercial forestry could potentially do this, with significant innovation and willingness to let go of current practices.

Through collective effort, I’m confident we can sustainably manage of forests and fire. Our study is but a small step in a much bigger, zig-zagging journey of discovery.

forest regenerating after fire — Forests must become fire-resilient while performing other functions.
Shutterstock

David Bowman, Professor of Pyrogeography and Fire Science, University of Tasmania

This article is republished from The Conversation under a Creative Commons license. Read the original article.

5 remarkable stories of flora and fauna in the aftermath of Australia’s horror bushfire season

hamiltonphillipa/iNaturalist, CC BY-NC-SA

Will Cornwell, UNSW; Casey Kirchhoff, UNSW, and Mark Ooi, UNSW

Around one year ago, Australia’s Black Summer bushfire season ended, leaving more than 8 million hectares across south-east Australia a mix of charcoal, ash and smoke. An estimated three billion animals were killed or displaced, not including invertebrates.

The impact of the fires on biodiversity was too vast for professional scientists alone to collect data. So in the face of this massive challenge, we set up a community (citizen) science project through the iNaturalist website to help paint a more complete picture of which species are bouncing back — and which are not.

Almost 400 community scientists living near or travelling across the firegrounds have recorded their observations of flora and fauna in the aftermath, from finding fresh wombat droppings in blackened forests, to hearing the croaks of healthy tree frogs in a dam choked with debris and ash.

Each observation is a story of survival against the odds, or of tragedy. Here are five we consider particularly remarkable.

Greater gliders after Australia’s largest ever fire

The Gospers Mountain fire in New South Wales was the biggest forest fire in Australian history, razing an area seven times the size of Singapore. This meant there nothing in history scientists could draw from to predict the animals’ response.

So it came as a huge surprise when a community scientist observed greater gliders deep within the heart of the Gospers Mountain firegrounds in Wollemi National Park, far from unburned habitat. Greater gliders are listed as “vulnerable” under national environment law. They’re nocturnal and live in hollow-bearing trees.

A greater glider with shining eyes at night — A citizen scientist snapped this photo of a greater glider in the heart of the the Gospers Mountain firegrounds.
Mike Letnic/iNaturalist, CC BY-NC

How gliders survived the fire is still unknown. Could they have hidden in deep hollows of trees where the temperature is relatively cooler while the fire front passed? And what would they have eaten afterwards? Greater gliders usually feed on young leaves and flowers, but these foods are very rare in the post-fire environment.

Finding these gliders shows how there’s still so much to learn about the resilience of species in the face of even the most devastating fires, especially as bushfires are forecast to become more frequent.

Rare pink flowers burnishing the firegrounds

The giant scale of the 2019-20 fires means post-fire flowering is on display in grand and gorgeous fashion. This is a feature of many native plant species which need fire to stimulate growth.

Excitingly, community scientists recorded a long-dormant species, the pink flannel flower (Actinotus forsythii), that’s now turning vast areas of the Blue Mountains pink.

Pink flannel flowers are bushfire ephemerals, which means their seeds only germinate after fire.
Margaret Sky/iNaturalist, CC BY-NC

Pink flannel flowers are not considered threatened, but they are very rarely seen.

Individuals of this species spend most of their life as a seed in the soil. Seeds require a chemical found in bushfire smoke, and the right seasonal temperatures, to germinate.

Rediscovering the midge orchid

Much of Australia’s amazing biodiversity is extremely local. Some species, particularly plants, exist only in a single valley or ridge. The Black Summer fires destroyed the entire range of 100 Australian plant species, incinerating the above-ground parts of every individual. How well a species regenerates after fire determines whether it recovers, or is rendered extinct.

The midge orchid.
Nick Lambert/iNaturalist, CC BY-NC

One of these is a species of midge orchid, which grows in a small area of Gibraltar Range National Park, NSW.

All of the midge orchid’s known sites are thought to have burned in late 2019. The species fate was unknown until two separate community scientists photographed it at five sites in January 2021, showing its recovery.

Like many of Australia’s terrestrial orchids, this species has an underground tuber (storage organ) which may have helped part of it avoid the flames’ lethal heat.

Don’t forget about insects

Despite their incredible diversity and tremendous value to society, insects tend to be the forgotten victims of bushfires and other environmental disasters.

Many trillions of invertebrates would have been killed in the fires of last summer. A common sight during and after the bushfire season was a deposit of dead insects washed ashore. Some died from the flames and heat, while others died having drowned trying to escape.

Dead insects washed up on the beach was a common sight in the fire aftermath.
BlueBowerStudio/iNaturalist, CC BY-NC

One dead insect deposit — one of hundreds that washed up near Bermagui, NSW on Christmas Eve — included a range of species that have critical interactions with other organisms.

This includes orchid dupe wasps (Lissopimpla excelsa), the only known pollinator of the orchid genus Cryptostylis. Transverse ladybirds (Coccinella transversalis), an important predator of agricultural pests such as aphids, also washed up. As did metallic shield bugs (Scutiphora pedicellata), spectacular iridescent jewel bugs that come in green and blue hues.

Some insects died from the flames and heat, while others died having drowned trying to escape the flames.
BlueBowerStudio/iNaturalist, CC BY-NC

The unlikely survival of the Kaputar slug

Creatures such as kangaroos or birds have a chance to flee bushfires, but smaller, less mobile species such as native slugs and snails have a much tougher time of surviving.

The 2019-2020 bushfire season significantly threatened the brilliantly coloured Mount Kaputar pink slug, found only on the slopes of Mount Kaputar, NSW. When fires ripped through the national park in October and November 2019, conservationists feared the slug may have been entirely wiped out.

But park ranger surveys in January 2020 found at least 60 individuals managed to survive, likely by sheltering in damp rock crevices. Community scientists have spotted more individuals since then, such as the one pictured here found in September 2020.

But the slug isn’t out of the woods yet, and more monitoring is required to ensure the population is not declining.

Bright pink slug — A community scientist spotted this rare slug in firegrounds.
Taylor/iNaturalist, CC BY-NC

Continuing this work

While community scientists have been documenting amazing stories of recovery all across Australia, there are still many species which haven’t been observed since the fires. Many more have been observed only at a single site.

The Snowy River westringia (Westringia cremnophila), for instance, is a rare flowering shrub found on cliffs in Snowy River National Park, Victoria. No one has reported observing it since the fire.

So far these community scientist observations have contributed to one scientific paper, and three more documenting the ability for species to recover post-fire are in process.

Recovery from Black Summer is likely to take decades, and preparing a body of scientific data on post-fire recovery is vital to inform conservation efforts after this and future fires. We need more observations to continue this important work.

Will Cornwell, Associate Professor in Ecology and Evolution, UNSW; Casey Kirchhoff, PhD Candidate, UNSW, and Mark Ooi, Senior Research Fellow, UNSW

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Open data shows lightning, not arson, was the likely cause of most Victorian bushfires last summer

Dianne Cook, Monash University

As last summer’s horrific bushfires raged, so too did debate about what caused them. Despite the prolonged drought and ever worsening climate change, some people sought to blame the fires largely on arson.

Federal Coalition MPs were among those pushing the arsonist claim. And on Twitter, a fierce hashtag war broke out: “#ClimateEmergency” vs “#ArsonEmergency”.

Fire authorities rejected the arson claims, saying most fires were thought to be caused by lightning.

We dug into open data resources to learn more about the causes of last summer’s bushfires in Victoria, and further test the arson claim. Our analysis suggests 82% of the fires can be attributed to lightning, 14% to accidents and 1% to burning off. Only 4% can be attributed to arson.

Lightning in the sky — Lightning, not arson, caused most Victorian bushfires last summer.
Twitter

What we did

We started with hotspots data taken from the Himawari-8 satellite, which shows heat source locations over time and space, in almost real time. We omitted hotspots unlikely to be bushfires, and used a type of data mining called “spatiotemporal clustering” – where time dimension is introduced to geographic data – to estimate ignition time and location.

We supplemented this with data from other sources: temperature, moisture, rainfall, wind, sun exposure, fuel load, as well as distance to camp sites, roads and Country Fire Authority (CFA) stations.

Victoria’s Department of Environment, Land, Water and Planning (DELWP) holds historical data on bushfire ignition from 2000 to the 2018-19 summer. The forensic research required to determine fire cause is laborious, and remotely sensed data from satellites may be useful and more immediate.

By training our model on the historical data, we can more immediately predict causes of last summer’s fires detected from satellite data. (Note: even though we were analysing events in the past, we use the term “predict” because authorities have not released official data.)

DELWP’s data attributes 41% of fires to lightning, 17% to arson, 34% to accidents and 7% to hazard reduction or back burning which escaped containment lines (which our analysis refers to as burning off).

Causes of fires from 2000-2019. Lightning is most common cause. The number of fires is increasing, and this is mostly due to accidents.
Own work

To make predictions for the 2019-20 bushfires, we needed an accurate model for causes in the historical data. We trained the model to predict one of four causes – lightning, accident, arson, burning off – using a machine learning algorithm.

The model performed well on the historical data: 75% overall accuracy, 90% accurate on lightning, 78% for accidents, and 54% for arson (which was mostly confused with accident, as would make sense).

The most important contributors to distinguishing between lightning and arson (or accident) ignition were distance to CFA stations, roads and camp sites, and average wind speed.

As might be expected, smaller distances to CFA stations, roads and camp sites, and higher than average winds, meant the fire was most likely the result of arson or accident. In the case of longer distances, where bush would have been largely inaccessible to the public, lightning was predicted to be the cause.

Spatial distribution of causes of fires from 2000-2019, and predictions for 2019-2020 season.
Own work

What we found

Our model predicted that 82% of Victoria’s fires in the summer of 2019-2020 were due to lightning. Most fires were located in densely vegetated areas inaccessible by road – similar to the historical locations. (The percentage is double that in the historical data, though, probably because the satellite hotspot data can see fire ignitions in locations inaccessible to fire experts).

All fires in February 2020 were predicted to be due to lightning. Accident and arson were commonly predicted causes in March, and early in the season. Reassuringly, ignition due to burning off was predicted primarily in October 2019, prior to the fire restrictions.

Spatio-temporal distribution of cause predictions for 2019-2020 season. Reassuringly, fires due to burning off primarily occurred in October, prior to fire restrictions. February fires were all predicted to be due to lightning.
Own work

Quicker fire ignition information

Our analysis used open-data and open-source software, and could be applied to fires elsewhere in Australia.

This analysis shows how we can quickly predict causes of bushfires, using satellite data combined with other information. It could reduce the work of fire forensics teams, and provide more complete fire ignition data in future.

The code used for the analysis can be found here. Explore the historical fire data, predictions for 2019-2020 fires, and a fire risk map for Victoria using this app.

This analysis is based on thesis research by Monash University Honours student Weihao Li. She was supervised by the author, and former Principal Inventive Scientist at AT&T Labs Research, Emily Dodwell. The Australian Centre of Excellence for Mathematical and Statistical Frontiers supported Emily’s travel to Australia to start this project. The full analysis is available here.

Dianne Cook, Professor of Business Analytics, Monash University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Before and after: 4 new graphics show the recovery from last summer’s bushfire devastation

Airborne Research Australia, Author provided

Jorg Michael Hacker, Flinders University

Two days before Christmas last year, a fire reached our heritage-protected bush property in the Adelaide Hills, and destroyed our neighbour’s house. For the next two weeks we were on constant alert to keep the fire in check.

Green shoots of grass trees after bushfire — Grass trees are some of the first plants to regrow after a bushfire.
Wikimedia, CC BY

A few weeks later, I flew over fire-affected areas in the Adelaide Hills and had my first aerial view of the devastation. Fighting fires around my home, and what I saw on this flight, convinced me to get involved with helping recovery in the aftermath of the fires.

In the past year, I’ve taken high-resolution aerial data to monitor the recovery of fire-affected areas and help with post-fire efforts. This work includes clearing access tracks into burnt forests, locating unburnt areas within burnt forests to serve as refuges for wildlife, or simply documenting the degree of destruction.

I now have a unique dataset – a combination of very high-resolution and detail from three sensors: aerial photography, airborne Lidar (a way to measure distances with laser light) and hyperspectral imaging (looking at the landscape and vegetation with hundreds of narrow wavelengths).

Flying at just 250 metres above the ground, it’s possible to generate complete three-dimensional views and animations of the landscape and its features at resolutions in the 10cm-range.

Usually such airborne data is only available to government agencies, industry and sometimes researchers, but rarely to the general public. So we decided to make the data publicly available, so anyone can download it. It will help you appreciate the level of destruction, and how it varied for different landscapes.

My property, for example, is showing strong regrowth, but most of our neighbour’s block burnt so intensely that even now, after nearly one year, there’s very little regrowth even in terms of ground cover.

Here are a few examples of the landscape’s recovery around Kangaroo Island, generated from our data.

Bushfires decimated almost half of Kangaroo Island. The image sequence above shows a small area on Kangaroo Island before the fires and about one, three and nine months afterwards.

Before the fires, the landscape was dominated by dense bushland, which the fires nearly completely destroyed. The first signs of regrowth were visible after three months, and even more so after nine months.

The imagery is so detailed you can inspect the regrowth even for individual trees and scrubs. And in the slider below, you can more clearly compare how well the bushland regrew between February and October this year.

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Much of Australia’s native flora have evolved to cope with fire. Grass trees are among the first species to recover, and the Lidar data below demonstrates just how dramatic this recovery is.

Thousands of grass trees (“yuccas”) on Kangaroo Island grew up to seven metre-high flowers in the months after the fires. This is a typical phenomenon for this species after fire, and we were lucky enough to see this first hand on our bushland property, too.

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}

The video below shows the regrowth in and around a tree plantation on Kangaroo Island, directly after the fires and then after nine months. You can clearly see the intense regrowth on the ground and near the bottom of the burnt trees.

Usually firegrounds are observed via satellite imagery, imagery captured from high-flying survey aircraft and, more recently, using unmanned aerial vehicles (drones). None of these observations can map the landscape at the exceptionally high detail over large areas and with the combination of sensors as we have flown.

High-resolution aerial photographs at pixel sizes as small as five centimetres can be put together in a mosaic, covering many square kilometres. Combined with Lidar, and the hyperspectral scanner, we get detailed animations, such as those in the video, which can zero in on various intricate aspects, such as vegetation health.

How these datasets can help bushfire recovery

With a some moderate funding, we can continue these regular mapping flights next year and beyond to learn how these areas develop. We can put this into context with other factors, such as burn severity, soil structure and vegetation type.

Such detailed datasets would assist researchers assessing flammability and fuel load (dried vegetation) which, in turn, would help prevent and even fight future fires.

Flammability and fuel load, alongside the slope of the landscape, are key parameters in computer simulations of fire behaviour. High resolution datasets depicting landscapes before and after bushfire can verify the simulation results, and help to improve the performance of the models.

Our datasets can also be useful for people needing to access areas directly after the fires, such as identifying where burnt trees have fallen, or are just about to do so.

For our own bushland block in the Adelaide Hills, these detailed imagery and datasets means we can study the regrowth from the Cudlee Creek Fire almost a year ago, as well as from previous fires. For example, some areas were burnt in the 2015 Sampson Flat Fire and had already regrown over the four years — only to be burnt again.

Continuing such flights would require a comparatively low amount of funding. However, this is currently not available in the standard government grant system. You can download data from the mapping flights over Adelaide Hills and Kangaroo Island.

Jorg Michael Hacker, Chief Scientist at Airborne Research Australia (ARA); and Professor, Flinders University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

3 billion animals were in the bushfires’ path. Here’s what the royal commission said (and should’ve said) about them

Ashleigh Best, University of Melbourne; Christine Parker, University of Melbourne, and Lee Godden, University of Melbourne

The Black Summer bushfires were devastating for wildlife, with an estimated three billion wild animals killed, injured or displaced. This staggering figure does not include the tens of thousands of farm animals who also perished.

The bushfire royal commission’s final report, released on October 30, recognised the gravity of the fires’ extraordinary toll on animals.

It recommended governments improve wildlife rescue arrangements, develop better systems for understanding biodiversity and clarify evacuation options for domestic animals.

While these changes are welcome and necessary, they’re not sufficient. Minimising such catastrophic impacts on wildlife and livestock also means reducing their exposure to these hazards in the first place. And unless we develop more proactive strategies to protect threatened species from disasters, they’ll only become more imperilled.

What the royal commission recommended

The royal commission recognised the need for wildlife rescuers to have swift and safe access to fire grounds.

In the immediate aftermath of the bushfires, some emergency services personnel were confused about the roles and responsibilities of wildlife rescuers. This caused delays in rescue operations.

To address this issue, the royal commission sensibly suggested all state and territory governments integrate wildlife rescue functions into their general disaster planning frameworks. This would improve coordination between different response agencies.

Another issue raised by the commission was that Australia does not have a comprehensive, central source of information about its native flora and fauna. This is, in part, because species listing processes are fragmented across different jurisdictions.

For example, a marsupial, the white-footed dunnart, is listed as vulnerable in NSW, but is not on the federal government’s list of threatened species.

To better manage and protect wild animals, governments need more complete information on, for example, their range and population, and how climate change threatens them.

As a result, the royal commission recommended governments collect and share more accurate information so disaster response and recovery efforts for wildlife could be more targeted, timely and effective.

A wildlife rescuer holds a koala with burnt feet in a burnt forest — Adelaide wildlife rescuer Simon Adamczyk takes a koala to safety on Kangaroo Island.
AAP Image/David Mariuz

Helping animals help themselves

While promising, the measures listed in the royal commission’s final report will only tweak a management system for wildlife already under stress. Current legal frameworks for protecting threatened species are reactive. By the time governments intervene, species have often already reached a turning point.

Governments must act to allow wild animals the best possible chances of escaping and recovering on their own.

This means prioritising the protection and restoration of habitat that allows animals to get to safety. As a World Wildlife Fund report explains, an animal’s ability to flee the fires and find safe, unburnt habitat — such as mesic (moist) refuges in gullies or near waterways — directly influenced their chances of survival.

Wildlife corridors also assist wild animals to survive and recover from disasters. These connect areas of habitat, providing fast moving species with safe routes along which they can flee from hazards.

And these corridors help slow moving species, such as koalas, to move across affected landscapes after fires. This prevents them from becoming isolated, and enables access to food and water.

Hazard reduction activities, such as removing dry vegetation that fuels fires, were also a focus for the royal commission. These can coexist with habitat conservation when undertaken in ecologically-sensitive ways.

As the commission recognised, Indigenous land and fire management practices are informed by intimate knowledge of plants, animals and landscapes. These practices should be integrated into habitat protection policies in consultation with First Nations land managers.

The commission also suggested natural hazards, such as fire, be counted as a “key threatening process” under national environment law. But it should be further amended to protect vulnerable species under threat from future stressors, such as disasters.

Governments also need to provide more funding to monitor compliance with this law. Another new World Wildlife Fund report warns that unless it is properly enforced, a further 37 million native animals could be displaced or killed as a result of habitat destruction this decade.

And, as we saw last summer, single bushfire events can push some populations much closer to extinction. For example, the fires destroyed a large portion of the already endangered glossy black-cockatoo’s remaining habitat.

What about pets and farm animals?

Pets and farm animals featured in the commission’s recommendations too.

During the bushfires, certain evacuation centres didn’t cater for these animals. This meant some evacuees chose not to use these facilities because they couldn’t take their animals with them.

To guide the community in future disasters, the commission said plans should clearly identify whether or not evacuation centres can accommodate people with animals.

Evacuation planning is crucial to effective disaster response. However, it is unfortunately not always feasible to move large groups of livestock off properties at short notice.

For this reason, governments should help landholders to mitigate the risks hazards pose to their herds and flocks. Researchers are already starting to do this by investigating the parts of properties that were burnt during the bushfires. This will help farmers identify the safest paddocks for their animals in future fire seasons.

Disasters are only expected to become more intense and extreme as the climate changes. And if we’re to give our pets, livestock and unique wildlife the best chance at surviving, it’s not enough only to have sound disaster response. Governments must preemptively address the underlying sources of animals’ vulnerability to hazards.

Ashleigh Best, PhD Candidate and Teaching Fellow, University of Melbourne; Christine Parker, Professor of Law, University of Melbourne, and Lee Godden, Director, Centre for Resources, Energy and Environmental Law, Melbourne Law School, University of Melbourne

This article is republished from The Conversation under a Creative Commons license. Read the original article.

From Kangaroo Island to Mallacoota, citizen scientists proved vital to Australia’s bushfire recovery

Alan Finkel, Office of the Chief Scientist and Erin Roger, CSIRO

Following the Black Summer bushfires of 2019-20, many people throughout Australia, and across the world, wanted to know how they could help in response to the environmental disaster.

Hundreds contacted the Australian Citizen Science Association (ACSA), Australia’s peak citizen science body, for guidance on how to participate in relevant scientific projects.

It was a golden opportunity to show that science can be, and is, done by all kinds of people – not just those working in labs with years of training and access to high-powered instruments. A scientist can be you, your children or your parents.

And this recognition led to the establishment of the Citizen Science Bushfire Project Finder, a key outcome from the bushfire science roundtable, which was convened in January by Federal Science Minister Karen Andrews.

To establish the project finder database, ACSA partnered with the CSIRO and the Atlas of Living Australia to assist the search for vetted projects that could contribute to our understanding of post-bushfire recovery.

Five months on, the value is evident.

Science as a way of thinking

In response to the bushfires, one citizen science project set up was the Kangaroo Island Dunnart Survey. A record number of citizen scientists answered the call to assist in recovery efforts for this small marsupial.

The Kangaroo Island dunnart was already listed as endangered before the fires, with population estimates between 300-500 individuals. And initial post-fire assessments indicated a significant further decline in its population, highlighting the importance of tracking the species’ recovery.

Meanwhile, nearly 1,500 kilometres away from Kangaroo Island, a local resident set up “Mallacoota After Fires” in the small community of Mallacoota, Victoria – a region hit hard by the bushfires.

This has enabled the community to record and validate (via an app and website) how the fires impacted the region’s plants and animals.

So far, the project has documented the existence of a range of flora and fauna, from common wombats to the vulnerable green and golden bell frog. It has also captured some amazing images of bush regeneration after fire.

Science does not just belong to professionals. As eminent US astronomer Carl Sagan noted, “science is a way of thinking much more than it is a body of knowledge”.

This suggests that, when properly enabled, anyone can actively participate. And the output goes beyond the rewards of personal involvement. It contributes to better science.

The need for ongoing engagement

Citizen science is significantly contributing observations and expertise to bushfire research. Across southeast New South Wales and the ACT, several hundred citizen scientists have:

conducted targeted landscape-wide surveys of threatened species, or new weed or pest incursions
collected specified data from plot locations stratified against fire history
assessed whether wildlife actually use water and feed stations established by communities after a fire has been through. (Data suggests the use of the stations is limited).

And it’s not just in local communities. Platforms such as DigiVol have enabled citizen scientists from around the world to review thousands of camera trap images deployed post-fire to monitor species survival and recovery.

Still, there is much more to do. Australia is a vast continent and as we saw last summer, the fire footprint is immense.

But there is also a huge community out there that can help support the implementation of science and technology, as we adapt to our changing climate.

Reaching out at the right time

In January, Prime Minister Scott Morrison asked the CSIRO, supported by an expert advisory panel chaired by one of us (Alan Finkel), to develop recommendations for practical measures that would increase Australia’s disaster and climate resilience.

The report on Climate and Disaster Resilience gives due emphasis to the importance of citizen science in complementing traditional research-led monitoring campaigns and sharing locally specific advice. One component of the response also brought together national stakeholders, to develop a series of more detailed recommendations regarding the critical role of citizen science.

Citizen scientists can be involved in important data collection and knowledge building. They can collaborate with disaster response agencies and research agencies, to develop additional science-based community education and training programs.

Also, citizen science is a way to collect distributed data beyond the affordability and resources of conventional science.

With that in mind, the task now is to better marry the “professional” scientific effort with the citizen science effort, to truly harness the potential of citizen science. In doing so, we can ensure environmental and societal approaches to disaster recovery represent a diversity of voices.

The role of the community, particularly in developing resilience against environmental disaster, can be a most useful mechanism for empowering people who may otherwise feel at a loss from the impact of disaster. Furthermore, by working with communities directly affected by bushfires, we can help measure the extent of the impact.

We call on our professional scientist colleagues to actively collaborate with citizen science groups. In doing so, we can identify priority areas with critical data needs, while also informing, enriching and engaging with diverse communities in science.

Equally, we encourage citizen scientists to share and tell their stories across social and political settings to demonstrate the impact they continue to have.

The beneficiary will be science.

Alan Finkel, Australia’s Chief Scientist, Office of the Chief Scientist and Erin Roger, Citizen Science Program Lead, CSIRO

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Humans see just 4.7km into the distance. So how can we truly understand what the bushfires destroyed?

Nanda Jarosz, University of Sydney

When the ashes from Australia’s last bushfire season cooled, we were left with a few mind-boggling numbers: 34 human lives lost, more than a billion animals dead, and 18.6 million hectares of land burned.

But those figures don’t necessarily help us understand what was lost. The human mind struggles to grasp very large scales. And in Australia, our colonial past skews the way we view landscapes today.

This disconnect is important. Many scientific concepts, including climate change, happen at scales outside human perception.

Understanding the scale of destruction wrought by bushfires is vital if governments and societies are to adapt in the future. So how can Australians truly come to terms with the damage wrought by last summer’s bushfires?

Dead koala in burnt forest — More than a billion animals died in last summer’s fires.
Daniel Mariuz/AAP

Beyond human perception

On average, humans can only see about 4.7 kilometres into the distance. So perceiving the true extent of the destruction bushfires requires using our imaginations.

This is not only true of bushfires. It also applies to human understanding of climate change, nanoseconds, the size of the Universe and the geological time scale (the millions of years over which continents, oceans and mountains formed).

But science has shown humans have trouble understanding, or imagining, large orders of magnitude. In one US study for example, university students struggled to understand the relative relationships between the age of the Earth, the time required for the origin of the first life forms, and the evolution of dinosaurs and humans.

Even university students studying STEM subjects (science, technology, engineering and mathematics) have been shown to struggle with identifying and comparing magnitudes at large scales.

So what’s actually going on in our brains here? Research suggests humans use both numerical and “categorical” information – concepts drawn from their prior experience – to estimate the size of an object. For example, a person estimating the width of a truck might set it as a proportion of the presumed width of highway lanes.

The use of this prior experience can improve the accuracy of estimations. But it can also introduce bias and lead to inexact estimations.

Students in lab — Even university students studying STEM subjects struggled to comprehend large orders of magnitude.
Shutterstock

Understanding vast landscapes

During the fires, satellite images and interactive maps sought to help us understand the scale of the crisis. But they can’t give a full picture of the life destroyed. So how might we otherwise understand the richness lost in a burnt landscape?

Unfortunately, our colonial views of the land are not much help here. British colonisation of Australia, and subsequent land laws, were established on the basis of “terra nullius” – meaning the land belonged to no one. This denied Indigenous people’s prior occupation of the land in order to legitimise its “lawful” settlement by Europeans.

Settlers tended to describe the Australian landscape as empty and unpopulated when, in fact, it was biologically [abundant] and peopled by Indigenous Australians.

These colonial views have had lasting effects. It took more than 200 years before the terra nullius myth was formally dispelled by the 1992 Mabo decision.

Seeking to understand Indigenous perspectives of Country might help non-Indigenous Australians to truly comprehend the loss brought by bushfires. As Indigenous academic Bhiamie Williamson wrote on The Conversation in January:

the experience of Aboriginal peoples in the fire crisis engulfing much of Australia is vastly different to non-Indigenous peoples. How do you support people forever attached to a landscape after an inferno tears through their homelands: decimating native food sources, burning through ancient scarred trees and destroying ancestral and totemic plants and animals?

A human-centric view

Beyond the colonial influence, our generally human-centred view of the world also tends to render invisible the plants and wildlife within it. As Australian researcher Brendan Wintle and others noted in a recent paper, firefighting strategies routinely overlook the need to protect natural assets. They wrote:

It may be unrealistic to expect critical habitats of our most precarious species to compete for firefighting resources with houses and farms. We are far too self-interested. However, could we imagine the last remaining habitat for a brush-tailed rock-wallaby (Petrogale penicillata) might feature as an asset for protection in a fire that is burning through a wilderness area? Surely that needs doing.

In other words, gaining a better understanding the scale of a fire’s destruction means taking a more holistic view of what dwells in the landscape, and might need saving.

Brush-tailed rock wallaby and joey — Rock wallaby habitat should be protected from fire.
Taronga Zoo

Future fires

Under climate change, bushfires in Australia will become more severe and frequent. So bearing in mind our limited abilities to perceive the potential scale of loss next time, what can we do to prepare?

As Wintle argues, more work is needed to organise conservation efforts before, during, and immediately after a bushfire. That includes establishing “insurance populations” of species and keeping them out of harm’s way, and better monitoring and surveying before a fire, so we know which places need protecting.

Williamson wrote of how most Indigenous Australians “have been consigned to the margins in managing our homelands”, watching on as they were “mismanaged and neglected”, which increased the bushfire risk.

The current bushfire royal commission has pledged to consider ways Indigenous land and fire management practices could improve our resilience to natural disasters. There is much room for ancient traditions to be incorporated into mainstream fire management.

It will take some time to grasp the repercussions of the last bushfire season. But it’s clear that we must transcend colonial, non-Indigenous, human-centred perceptions of the land if we’re to truly understand what was lost.

Nanda Jarosz, PhD Candidate, University of Sydney

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Click through the tragic stories of 119 species still struggling after Black Summer in this interactive (and how to help)

Anthea Batsakis, The Conversation and Wes Mountain, The Conversation

This article is part of Flora, Fauna, Fire, a special project by The Conversation that tracks the recovery of Australia’s native plants and animals after last summer’s bushfire tragedy. Explore the project here and read more articles here.

Before the summer bushfires destroyed vast expanses of habitat, Australia was already in the midst of a biodiversity crisis. Now, some threatened species have been reduced to a handful of individuals – and extinctions are a real possibility.

The Kangaroo Island dunnart, a small marsupial, was listed as critically endangered before the bushfires. Then the inferno destroyed 95% of its habitat.

Prospects for the Banksia Montana mealybug are similarly grim. This flightless insect lives only on one species of critically endangered plant, at a high altitude national park in Western Australia. The fires destroyed 100% of the plant’s habitat.

And fewer than 100 western ground parrots remained in the wild before last summer, on Western Australia’s south coast. Last summer’s fires destroyed 40% of its habitat.

Fish, crayfish and some frogs are also struggling. After the fires, heavy rain washed ash, fire retardants and dirt into waterways. This can clog and damage gills, and reduces the water’s oxygen levels. Some animals are thought to have suffocated.

Here, dozens of experts tell the stories of the 119 species most in need of help after our Black Summer.

How can I help?

Recovery from Australia’s bushfire catastrophe will be a long road. If you want to help, here are a few places to start.

Donate

Australian Wildlife Conservancy

Bush Heritage Australia

WWF

Birdlife Australia

Also see this list of registered bushfire charities

Volunteer

Parks Victoria

NSW National Parks and Wildlife Service

Queensland Parks and Wildlife Service

Conservation Volunteers Australia

Landcare

Anthea Batsakis, Deputy Editor: Environment + Energy, The Conversation and Wes Mountain, Multimedia Editor, The Conversation

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Absorbing 680 million tonnes of carbon dioxide

Phytoplankton can have dramatic effects on climate

Using revolutionary data

So what’s next?

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Is it all bad news?

What about the pandemic?

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Is this actually possible?

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Looking for patterns

What we found

A challenge awaits

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Greater gliders after Australia’s largest ever fire

Rare pink flowers burnishing the firegrounds

Rediscovering the midge orchid

Don’t forget about insects

The unlikely survival of the Kaputar slug

Continuing this work

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What we did

What we found

Quicker fire ignition information

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How these datasets can help bushfire recovery

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What the royal commission recommended

Helping animals help themselves

What about pets and farm animals?

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Science as a way of thinking

The need for ongoing engagement

Reaching out at the right time

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Beyond human perception

Understanding vast landscapes

A human-centric view

Future fires

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How can I help?

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