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

Himawari-8, Author provided

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.
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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.

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Inside the world of tiny phytoplankton – microscopic algae that provide most of our oxygen

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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.

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Read more:
Tiny plankton drive processes in the ocean that capture twice as much carbon as scientists thought

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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.

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Read more:
Some animals have excellent tricks to evade bushfire. But flames might be reaching more animals naive to the dangers

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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.

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Frequent extreme bushfires are our new reality. We need to learn how to live with smoke-filled air

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Gabriel da Silva, University of Melbourne

As fires ravaged large sections of the Australian bush last summer, cities and towns all along the coast were blanketed in toxic smoke. Air pollutants were measured at unheard of levels across the country.

Hazardous air descended on cities hundreds of kilometres away from the fires themselves. This air was the most dangerous to breathe on the planet.

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The bushfire royal commission has made a clarion call for change. Now we need politics to follow

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The bushfire royal commission was tabled on October 30, with some sobering findings about fires and air pollution. Unfortunately, it showed that as a nation we were not prepared to deal with this public health emergency.

These disasters are inevitable under climate change, and while we need to urgently act on climate change to protect future generations, we also need to make changes now to mitigate the risks that already face us.

Australia must get better at communicating how to identify and then stay safe in hazardous air. A national set of air quality categories would go a long way to achieving this.

Over 400 deaths attributed to bushfire smoke

The royal commission heard that air pollution from the summer fires likely caused more than 400 deaths. Thousands of additional hospital admissions put added strain on our hospitals. All up the added burden to our health system was estimated at almost A$2 billion.

Even in the absence of extreme natural disasters, air pollution is one of Australia’s biggest public health concerns. Pollution from all sources causes thousands of deaths per year. This includes emissions from coal-fired power stations, diesel cars and wood-fired heaters.

Better preparing ourselves to deal with bushfire smoke will have flow-on benefits in tackling these problems.

Different state, different health advice

The royal commission found “there is an urgent need for national consistency in the categorisation of air quality”. At the moment, every state has their own system to categorise air quality and communicate it to the public.

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Read more:
How does bushfire smoke affect our health? 6 things you need to know

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But there are major discrepancies with how different states identify the worst air quality.

Air quality is the sum impact of the concentration of various unhealthy chemicals in the air. These include ozone, nitrogen and sulfur oxides, and fine particulate matter. To communicate this to the public, most countries convert these chemical concentrations into an Air Quality Index (AQI).

In the US, there is a standardised AQI categorisation for the whole country.

In Australia, the situation is very different. Every state has its own bands, with their own colour codes. These bands trigger at different pollutant levels and carry different health advice. The Royal Commission told us this needs to be standardised, and now.

For example, in NSW the worst air quality category is “Hazardous”, which triggers at an AQI of 200. South Australia, however, only recognises “Very Poor” as the worst class of air quality, with an AQI of 150 and above.

During the summer bushfires, AQI values as high as 5,000 were measured. It’s clear the highest bands of air pollution are no longer appropriate.

We need a national air quality system

We have faced a similar problem before. After Victoria’s Black Saturday fires in 2009, we recognised that our fire danger ratings were inadequate.

The Black Saturday royal commission found we needed a higher category for the most dangerous fire conditions. The “Catastrophic” category (“CODE RED” in Victoria) was added. It carried clear advice about what to do in such dangerous conditions, instructing people to safely leave as early as possible.

The ‘CODE RED’ or ‘Catastrophic’ fire danger rating was added after the Black Saturday fires.
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Something similar now needs to happen with air quality ratings.

When facing future extreme bushfires, we need a way to identify when catastrophic conditions have led to air so unhealthy that everyone should take precautions, such as staying indoors and wearing masks. We then need to get clear health advice out to the public.

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Read more:
Our buildings aren’t made to keep out bushfire smoke. Here’s what you can do

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A national air quality rating system could achieve this, and would also help address other important recommendations of the Royal Commission: That we need improved means of getting reliable information out to the public, along with better community education around what to do when air quality plummets.

There’s work to do

An Australian AQI should be featured on national weather reports and forecasts, providing important health information to the public every day of the year. At the same time it would familiarise Australians with air quality measures and actions that need to be taken to protect ourselves from unhealthy air.

But there is work to do. First, we need to develop a new set of air quality categories that work for the entire country, and reflects both the everyday hazards of industrial pollution and the extreme dangers of bushfires. These categories also need to be matched with sound health advice.

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Read more:
The bushfire royal commission has made a clarion call for change. Now we need politics to follow

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And if we are going to report these measures more widely then we also need to get better at measuring and predicting air quality across the nation — two other important royal commission recommendations.

Achieving all of this won’t be easy. But if we can get it right then we will be much better placed to deal with smoke risk the next time severe bushfires inevitably happen.

Gabriel da Silva, Senior Lecturer in Chemical Engineering, University of Melbourne

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

Australia’s bushfire smoke is lapping the globe, and the law is too lame to catch it

Smoke form Australia’s bushfires could be seen from space. But who should be held to account for the problem?
NASA EARTH OBSERVATORY

Eric Kerr, National University of Singapore and Malini Sur, Western Sydney University

Smoke from Australia’s bushfires has travelled far beyond its origins. It crossed New Zealand and South America, and within days had drifted halfway around the globe. NASA predicted the smoke would complete a full circuit and arrive back where it started.

As climate change takes hold and global temperatures rise, bushfires are set to increase in severity and frequency. The underlying cause of the fires and resulting smoke haze are often numerous – spanning both natural variability and climate change caused by individuals, governments and corporations.

Legal and policy frameworks – local, national and international – fail to capture these diffused responsibilities. Despite the proliferation of climate-related laws in recent decades, bushfire smoke still largely escapes regulation and containment. In this new era of monster fires, our laws need a major rethink.

Smoke haze blanketing Sydney late last year.
NEIL BENNETT/AAP

A short history of smoke

Smoke is obviously not a new phenomenon – it has polluted Earth’s air since the invention of fire.

In Egypt and Peru, evidence of ancient soot has been found in the lung tissue of mummies, thought to be the result of humans inhaling smoke particles from wood heaters and elsewhere.

The Romans referred to the gravioris caeli (“heavy heaven”) and infamis aer (“infamous air”). Ancient Roman philosopher and statesman Seneca wrote to a friend of his relief at escaping the polluted city:

No sooner had I left behind the oppressive atmosphere of the city Rome and that reek of smoking cookers which pour out, along with clouds of ashes, all the poisonous fumes they’ve accumulated in their interiors whenever they’re started up, than I noticed the change in my condition.

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Even for an air pollution historian like me, these past weeks have been a shock

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Smoke pollution grew worse during the Industrial Revolution, as coal-burning factories proliferated across Europe and the United States. In London, 12,000 people are believed to have died in the Great Smog of 1952.

In Australia too, air pollution, including from bushfire smoke, is not new. However laws to deal with it have traditionally targeted pollution from industry, transport, power generation, and vehicles. Until now, bushfire smoke has been seen as a natural phenomenon, outside human control.

Indonesian women wear protective masks as they perform a mass prayer for rain to combat the smoke haze and drought season in Indonesia.
AFRIANTO SILALAHI

Where to point the finger?

Australia’s fires are not the first to be felt far from their origin.

Slash-and-burn farming in Indonesia regularly spreads smoke across Southeast Asia. In September last year, winds reportedly carried the smoke north to Malaysia and Singapore, prompting schools to close and triggering a mass public health scare.

In 2018, smoke from wildfires on the west coast of the United States reportedly travelled to the east coast of the continent to states such as Missouri, Ohio, New York and Massachusetts.

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Watching our politicians fumble through the bushfire crisis, I’m overwhelmed by déjà vu

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As climate change worsens, and so too the frequency and extent of bushfires, it is critical that all efforts are made to prevent smoke from being emitted in the first place, and spreading around the world. However this requires identifying those responsible – a slippery concept when climate change is involved.

The Bureau of Meteorology recently confirmed what many strongly suspected: climate change contributed to Australia’s hottest, driest year on record on 2019, which led to the extreme bushfire season.

Following the latest bushfire outbreak, some declared Prime Minister Scott Morrison and his government responsible for failing to take meaningful action on climate change.

Sharnie Moran and daughter Charlotte look on as thick smoke rises from a fire near Coffs Harbour, NSW.
Dan Peled/AAP

The federal and state governments and some quarters of the media in turn blamed others, such as arsonists and conservationists, for the fires – claims which were quickly discredited.

There is also a strong argument to hold corporations responsible for climate change – one analysis in 2017 found that just 100 companies were responsible for more than 71% of the world’s greenhouse gas emissions since 1988.

But whether we blame a particular government or other human actors, the current suite of international laws are insufficient for holding them to account.

The law has failed

The number of global climate change laws has increased 20-fold between 1997 and 2017, from 60 to 1,260.

But despite this proliferation, the world is not on track to limiting planetary warming to less than 1.5℃ this century – a threshold beyond which the worst climate change impacts, including uncontrollable bushfires, will be felt.

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What do Sydney and other cities have in common? Dust

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This is because most of the laws and policies consist of “declarations” and soft law – that which is not legally binding, and so is easily ignored. Few deal with issues of restorative justice – until now a criminal law concept which involves repairing the harm caused by criminal behaviour.

Experts have argued that the idea could be applied to disasters, drawing all parties to come together to deal with its aftermath and implications for the future.

The United Nations, which last year released the first-ever assessment of global environmental rules, says weak enforcement was “a global trend that is exacerbating environmental threats” including climate change and pollution. It also pointed to the need to properly fund government agencies responsible for enforcing laws.

Beachgoers in Sydney amid smoke haze from bushfires in New South Wales.
STEVEN SAPHORE/AAP

Looking ahead

Many climate change impacts, such as sea level rise, are almost invisible. But bushfire smoke rapidly engulfs a city skyline. It travels beyond national borders and is impossible to ignore.

As fire seasons worsen, political leaders will come under increasing pressure to stem the emission and spread of bushfire smoke. Key to this will be stronger climate change laws and enforcement, which recognise that a bushfire in one country can quickly become the world’s problem.

Eric Kerr, Lecturer, National University of Singapore and Malini Sur, Senior Research Fellow, Institute for Culture and Society, Western Sydney University

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

Now Australian cities are choking on smoke, will we finally talk about climate change?

Blanche Verlie, University of Sydney

I moved to Sydney less than five weeks ago and the city has been shrouded in smoke haze on and off since then. I joke this is my “Sydney hazing” but it’s only now – having worked on climate change for over a decade – that I’m suddenly feeling burnt out. This is not in any way to compare my experience to those who have lost their homes, communities and loved ones to the bushfires.

But the smoke cuts through Australia’s clouds of climate denial that pretend we are neither vulnerable nor responsible.

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Australia needs stricter rules to curb air pollution, but there’s a lot we could all do now

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We often refer to the “atmosphere” and “climate” of a particular space or community. We can be “on cloud nine”, “under the weather”, or “snowed under”. We know the weather affects people’s moods. My research, and that from a range of disciplines, is increasingly finding that human emotional, social and embodied experiences are intimately related to the weather and climate.

So, might people’s climate concern be changing now Sydney and Canberra have air quality on a par with Delhi?

Psychological smokescreens

Research is mixed on how extreme weather changes people’s perspectives on climate change. After severe storms and floods hit the UK in 2013 and 2014, scientists found those directly affected were more worried about climate change and supported climate change policies beyond direct, flood-related mitigation.

On the other hand, climate-change sceptics polled in the US in 2011 were more likely to recall the summer of 2010-11 as a normal one, despite record-breaking heatwaves across the northern hemisphere.

Some research has suggested climate change can prompt “information aversion”, where we actively or subconsciously avoid distressing facts and construct a safer, more comforting narrative.

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Air pollution may be affecting how happy you are

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This tendency may be what drives such bracing platitudes as: “Australia is a sunburnt country”; “We’ve always had fires”; “Us Aussies are tough!”

A few face masks aside, the majority of us in Australia’s smoky cities have appeared to continue with business as usual: people just keep going to work. But I hope that, below this surface, the lingering taste of char at the back of our throats is sparking a change in the political atmosphere.

Igniting political change

No one should tell you how to feel about climate change, but I can tell you that you have a right to feel angry and sad. It is normal to feel overwhelmed – a word that once meant being literally inundated by water – in a world with rising seas and increasing floods.

Relatedly, droughts can leave us feeling drained. Awakening and sitting with these feelings is really important, but it’s also crucial not to dwell in despair.

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The rise of ‘eco-anxiety’: climate change affects our mental health, too

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The social atmosphere is changing, of course: over the last year, around the world, we have seen millions of people take to the streets demanding stronger action on climate change. Our Aussie kids have been leaders in this regard.

Research and polling consistently find the majority of Australians are highly concerned about climate change and would back government policies to rapidly decarbonise the economy.

But research also tells us hardly anyone talks about their climate concern. For example, a recent study from Yale University found only 18% of Americans hear people they know talking about climate change once a month or more. It makes sense: climate change is scary and has become highly politicised, meaning it is hard to know where to start, what to say, or who to talk to.

While this is a coping mechanism to try to protect ourselves emotionally, these norms work to deny the significance of climate change, prevent useful personal and social introspection and stall community action.

So how do we create a change in the political climate? Those of us for whom a smoky city is our only tangible experience, so far, of climate change, need to step up and demand our government not only meet minimum international obligations, but become the renewable energy and climate policy leaders we could be. We also need to talk about climate change more: with our friends, families, peers and communities.

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Expect family talks about climate change this Christmas? Take tips from Greta Thunberg

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Discussing the fires last week, one colleague mentioned she was fuming. This struck me as an empathetic echo of the smouldering state of our regional communities. My favourite sign from the school strikes has been “As oceans rise, so do we”. And now, I’d like to add, “As fires rage, so do we”.

Blanche Verlie, Postdoctoral research fellow, University of Sydney

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

The world’s carbon stores are going up in smoke with vanishing wilderness

James Watson, The University of Queensland; Bill Laurance, James Cook University; Brendan Mackey, Griffith University, and James Allan, The University of Queensland

The Earth’s last intact wilderness areas are shrinking dramatically. In a recently published paper we showed that the world has lost 3.3 million square kilometres of wilderness (around 10% of the total wilderness area) since 1993. Hardest hit were South America, which has experienced a 30% wilderness loss, and Africa, which has lost 14%.

These areas are the final strongholds for endangered biodiversity. They are also essential for sustaining complex ecosystem processes at a regional and planetary scale. Finally, wilderness areas are home to, and provide livelihoods for, indigenous peoples, including many of the world’s most politically and economically marginalised communities.

James Watson and James Allan explain their recent research.

But there’s another important service that many wilderness areas provide: they store vast amounts of carbon. If we’re to meet our international climate commitments, it is essential that we preserve these vital areas.

Many of the world’s biological realms now contain very low levels of wilderness.
http://www.greenfiresciene.com

Climate consequences

Large, intact ecosystems store more terrestrial carbon than disturbed and degraded ones. They are also far more resilient to disturbances such as rapid climate change and fire.

For instance, the boreal forest remains the largest ecosystem undisturbed by humans. It stores roughly a third of the world’s terrestrial carbon.

Yet this globally significant wilderness area is increasingly threatened by forestry, oil and gas exploration, human-lit fires and climate change. These collectively threaten a biome-wide depletion of its carbon stocks, considerably worsening global warming. Our research shows that more than 320,000sqkm of boreal forest has been lost in the past two decades.

Similarly, in Borneo and Sumatra in 1997, human-lit fires razed recently logged forests that housed large carbon stores. This released billions of tonnes of carbon, which some estimate was equivalent to 40% of annual global emissions from fossil fuels. We found that more than 30% of tropical forest wilderness was lost since the early 1990s, with only 270,000sqkm left on the planet.

Deforestation of Sumatra’s lowland rainforest.
Bill Laurance

How do we stop the loss?

All nations need to step up and mobilise conservation investments that can help protect vanishing wilderness areas. These efforts will vary based on the specific circumstances of different nations. But there is a clear priority everywhere to focus on halting current threats – including road expansion, destructive mining, unsustainable forestry and large-scale agriculture – and enforcing existing legal frameworks.

For example, most of the world’s remaining tropical rainforests are under an onslaught of development pressures. Much of sub-Saharan Africa is being opened up by over 50,000km of planned “development corridors” that criss-cross the continent. These will slice deep into remaining wild places.

In the Amazon, plans are being made to construct more than 300 large hydroelectric dams across the basin. Each dam will require networks of new roads for dam and powerline construction and maintenance.

In northern Australia, schemes are afoot to transform the largest savannah on Earth into a food bowl, jeopardising its extensive carbon stores and biodiversity.

We need to enforce existing regulatory frameworks aimed at protecting imperilled species and ecosystems. We also need to develop new conservation policies that provide land stewards with incentives to protect intact ecosystems. These must be implemented at a large scale.

For example, conservation interventions in and around imperilled wilderness landscapes should include creating large protected areas, establishing mega-corridors between those protected areas, and enabling indigenous communities to establish community conservation reserves.

In Sabah, Borneo, scientists from the UK’s Royal Society have been working with local government to establish networks of interlinked reserves stretching from the coast to the interior mountains. This provides a haven for wildlife that migrate seasonally to find new food sources.

Funding could also be used to establish ecosystem projects that recognise the direct and indirect economic values that intact landscapes supply. These include providing a secure source of fresh water, reducing disaster risks and storing vast quantities of carbon.

For example, in Ecuador and Costa Rica, cloud forests are being protected to provide cities below with a year-round source of clean water. In Madagascar, carbon funding is saving one of the most biodiversity-rich tropical forests on the planet, the Makira forest.

We argue for immediate, proactive action to protect the world’s remaining wilderness areas, because the alarming loss of these lands results in significant and irreversible harm for nature and humans. Protecting the world’s last wild places is a cost-effective conservation investment and the only way to ensure that some semblance of intact nature survives for the benefit of future generations.

James Watson, Associate professor, The University of Queensland; Bill Laurance, Distinguished Research Professor and Australian Laureate, James Cook University; Brendan Mackey, Director of the Griffith Climate Change Response Program, Griffith University, and James Allan, PhD candidate, School of Geography, Planning and Environmental Management, The University of Queensland

This article was originally published on The Conversation. Read the original article.