An act of God, or just bad management? Why trees fall and how to prevent it


AP

Gregory Moore, The University of MelbourneThe savage storms that swept Victoria last week sent trees crashing down, destroying homes and blocking roads. Under climate change, stronger winds and extreme storms will be more frequent. This will cause more trees to fall and, sadly, people may die.

These incidents are sometimes described as an act of God or Mother Nature’s fury. Such descriptions obscure the role of good management in minimising the chance a tree will fall. The fact is, much can be done to prevent these events.

Trees must be better managed for several reasons. The first, of course, is to prevent damage to life and property. The second is to avoid unnecessary tree removals. Following storms, councils typically see a spike in requests for tree removals – sometimes for perfectly healthy trees.

A better understanding of the science behind falling trees – followed by informed action – will help keep us safe and ensure trees continue to provide their many benefits.

tree lying on home
We must try to stop trees falling over to prevent damage to life and property.
James Ross/AAP

Why trees fall over

First, it’s important to note that fallen trees are the exception at any time, including storms. Most trees won’t topple over or shed major limbs. I estimate fewer than three trees in 100,000 fall during a storm.

Often, fallen trees near homes, suburbs and towns were mistreated or poorly managed in preceding years. In the rare event a tree does fall over, it’s usually due to one or more of these factors:

1. Soggy soil

In strong winds, tree roots are more likely to break free from wet soil than drier soil. In arboriculture, such events are called windthrow.

A root system may become waterlogged when landscaping alters drainage around trees, or when house foundations disrupt underground water movement. This can be overcome by improving soil drainage with pipes or surface contouring that redirects water away from trees.

You can also encourage a tree’s root growth by mulching around the tree under the “dripline” – the outer edge of the canopy from which water drips to the ground. Applying a mixed-particle-size organic mulch to a depth of 75-100 millimetres will help keep the soil friable, aerated and moist. But bear in mind, mulch can be a fire risk in some conditions.

Root systems can also become waterlogged after heavy rain. So when both heavy rain and strong winds are predicted, be alert to the possibility of falling trees.




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People inspect trees fallen on cars
A combination of heavy rain and strong winds can cause trees to fall.
Shutterstock

2. Direct root damage

Human-caused damage to root systems is a common cause of tree failure. Such damage can include roots being:

  • cut when utility services are installed
  • restricted by a new road, footpath or driveway
  • compacted over time, such as when they extend under driveways.

Trees can take a long time to respond to disturbances. When a tree falls in a storm, it may be the result of damage inflicted 10-15 years ago.

tree uprroted
This elm, growing very close to a footpath, fell in Melbourne during a 2005 storm.
Author provided

3. Wind direction

Trees anchor themselves against prevailing winds by growing roots in a particular pattern. Most of the supporting root structure of large trees grows on the windward side of the trunk.

If winds come from an uncommon direction, and with a greater-than-usual speed, trees may be vulnerable to falling. Even if the winds come from the usual direction, if the roots on the windward side are damaged, the tree may topple over.

The risk of this happening is likely to worsen under climate change, when winds are more likely to come from new directions.

4. Dead limbs

Dead or dying tree limbs with little foliage are most at risk of falling during storms. The risk can be reduced by removing dead wood in the canopy.

Trees can also fall during strong winds when they have so-called “co-dominant” stems. These V-shaped stems are about the same diameter and emerge from the same place on the trunk.

If you think you might have such trees on your property, it’s well worth having them inspected. Arborists are trained to recognise these trees and assess their danger.




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The years condemn: Australia is forgetting the sacred trees planted to remember our war dead


car bumper stopped at fallen tree trunk
Storms can trigger falling trees which block roads.
Shutterstock

Trees are worth the trouble

Even with the best tree management regime, there is no guarantee every tree will stay upright during a storm. Even a healthy, well managed tree can fall over in extremely high winds.

While falling trees are rare, there are steps we can take to minimise the damage they cause. For example, in densely populated areas, we should consider moving power and communications infrastructure underground.

By now, you may be thinking large trees are just too unsafe to grow in urban areas, and should be removed. But we need trees to help us cope with storms and other extreme weather.

Removing all trees around a building can cause wind speeds to double, which puts roofs, buildings and lives at greater risk. Removing trees from steep slopes can cause the land to become unstable and more prone to landslides. And of course, trees keep us cooler during summer heatwaves.

Victoria’s spate of fallen trees is a concern, but removing them is not the answer. Instead, we must learn how to better manage and live with them.




Read more:
Here are 5 practical ways trees can help us survive climate change


The Conversation


Gregory Moore, Doctor of Botany, The University of Melbourne

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

Peatlands worldwide are drying out, threatening to release 860 million tonnes of carbon dioxide every year


Shutterstock

Yuanyuan Huang, CSIRO and Yingping Wang, CSIROPeatlands, such as fens, bogs, marshes and swamps, cover just 3% of the Earth’s total land surface, yet store over one-third of the planet’s soil carbon. That’s more than the carbon stored in all other vegetation combined, including the world’s forests.

But peatlands worldwide are running short of water, and the amount of greenhouse gases this could set loose would be devastating for our efforts to curb climate change.

Specifically, our new research in Nature Climate Change found drying peatlands could release an additional 860 million tonnes of carbon dioxide into the atmosphere every year, by around 2100. To put this into perspective, Australia emitted 539 million tonnes in 2019.

To stop this from happening, we need to urgently preserve and restore healthy, water-logged conditions in peatlands. These thirsty peatlands need water.

Peatlands are like natural archives

Peatlands are found across the world: the arctic tundra, coastal marshes, tropical swamp forests, mountainous fens and blanket bogs on subantarctic islands.

They’re characterised by having water-logged soil filled with very slowly decaying plant material (the “peat”) that accumulated over tens of thousands of years, preserved by the low-oxygen environment. This partially decomposed plant debris is locked up in the soils as organic carbon.




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Peatlands can act like natural archives, letting scientists and archaeologists reconstruct past climate, vegetation, and even human lives. In fact, an estimated 20,500 archaeological sites are preserved under or within peat in the UK.

As unique habitats, peatlands are home for many native and endangered species of plants and animals that occur nowhere else, such as the white-bellied cinclodes (Cinclodes palliatus) in Peru and Australia’s giant dragonfly (Petalura gigantea), the world’s largest. They can also act as migration corridors for birds and other animals, and can purify water, regulate floods, retain sediments and so on.

Giant dragonfly on a branch
The giant dragonfly (Petalura gigantea) is listed as endangered under NSW environment law.
Christopher Brandis/iNaturalist, CC BY-NC

But over the past several decades, humans have been draining global peatlands for a range of uses. This includes planting trees and crops, harvesting peat to burn for heat, and for other land developments.

For example, some peatlands rely on groundwater, such as portions of the Greater Everglades, the largest freshwater marsh in the United States. Over-pumping groundwater for drinking or irrigation has cut off the peatlands’ source of water.

Together with the regional drier climate due to global warming, our peatlands are drying out worldwide.

What happens when peatlands dry out?

When peat isn’t covered by water, it could be exposed to enough oxygen to fuel aerobic microbes living within. The oxygen allows the microbes to grow extremely fast, enjoy the feast of carbon-rich food, and release carbon dioxide into the atmosphere.

A marsh in Les Sables d Olonne, France. Some peatlands are also a natural sources of methane, which is a more potent greenhouse gas than carbon dioxide.
Arthur Gallois, Author provided

Some peatlands are also a natural source of methane, a potent greenhouse gas with the warming potential up to 100 times stronger than carbon dioxide.

But generating methane actually requires the opposite conditions to generating carbon dioxide. Methane is more frequently released in water-saturated conditions, while carbon dioxide emissions are mostly in unsaturated conditions.




Read more:
Emissions of methane – a greenhouse gas far more potent than carbon dioxide – are rising dangerously


This means if our peatlands are getting drier, we would have an increase in emissions of carbon dioxide, but a reduction in methane emissions.

So what’s the net impact on our climate?

We were part of an international team of scientists across Australia, France, Germany, Netherlands, Switzerland, the US and China. Together, we collected and analysed a large dataset from carefully designed and controlled experiments across 130 peatlands all over the world.

In these experiments, we reduced water under different climate, soil and environmental conditions and, using machine learning algorithms, disentangled the different responses of greenhouse gases.

Our results were striking. Across the peatlands we studied, we found reduced water greatly enhanced the loss of peat as carbon dioxide, with only a mild reduction of methane emissions.

A swamp forest in Peru.
Rupesh Bhomia, Author provided

The net effect — carbon dioxide vs methane — would make our climate warmer. This will seriously hamper global efforts to keep temperature rise under 1.5℃.

This suggests if sustainable developments to restore these ecosystems aren’t implemented in future, drying peatlands would add the equivalent of 860 million tonnes of carbon dioxide to the atmosphere every year by 2100. This projection is for a “high emissions scenario”, which assumes global greenhouse gas emissions aren’t cut any further.

Protecting our peatlands

It’s not too late to stop this from happening. In fact, many countries are already establishing peatland restoration projects.

For example, the Central Kalimantan Peatlands Project in Indonesia aims to rehabilitate these ecosystems by, for instance, damming drainage canals, revegetating areas with native trees, and improving local socio-economic conditions and introducing more sustainable agricultural techniques.

Likewise, the Life Peat Restore project aims to restore 5,300 hectares of peatlands back to their natural function as carbon sinks across Poland, Germany and the Baltic states, over five years.

But protecting peatlands is a global issue. To effectively take care of our peatlands and our climate, we must work together urgently and efficiently.




Read more:
People, palm oil, pulp and planet: four perspectives on Indonesia’s fire-stricken peatlands


The Conversation


Yuanyuan Huang, Research Scientist , CSIRO and Yingping Wang, Chief research scientist, CSIRO

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

Spiders are cloaking Gippsland with stunning webs after the floods. An expert explains why


Darren Carney

Lizzy Lowe, Macquarie UniversityStunning photographs of vast, ghostly spider webs blanketing the flood-affected region of Gippsland in Victoria have gone viral online, prompting many to muse on the wonder of nature.

But what’s going on here? Why do spiders do this after floods and does it happen everywhere?

The answer is: these webs have nothing to do with spiders trying to catch food. Spiders often use silk to move around and in this case are using long strands of web to escape from waterlogged soil.

This may seem unusual, but these are just native animals doing their thing. It’s crucial you don’t get out the insecticide and spray them. These spiders do important work managing pests, so by killing them off you would be increasing the risk that pests such as cockroaches and mosquitoes will get out of control.




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Using silk to move around

What you’re seeing online, or in person if you live locally, is an amazing natural phenomena but it’s not really very complicated.

We are constantly surrounded by spiders, but we don’t usually see them. They are hiding in the leaf litter and in the soil.

Spider webs blanket the ground in Gippsland
When floods happen, spiders use silk to evacuate quickly.
Darren Carney

When these flood events happen, they need evacuate quickly up out of holes they live in underground. They come out en masse and use their silk to help them do that.

You’ll often see juvenile spiders let out a long strand of silk which is caught by the wind and lifted up. The web catches onto another object such as a tree and allows the spider to climb up.

That’s how baby spiders (spiderlings!) disperse when they emerge from their egg sacs — it’s called ballooning. They have to disperse as quickly as possible because they are highly cannibalistic so they need to move away from each other swiftly and find their own sites to hunt or build their webs.

Small spiders have been seen on a post in Gippsland after floods.
AAP Image/JEFF HOBBS

That said, I doubt these webs are from baby spiders. It is more likely to be a huge number of adult spiders, of all different types, sizes and species. They’re all just trying to escape the flood waters. These are definitely spiders you don’t usually see above ground so they are out of their comfort zone, too.

This mass evacuation of spiders, and associated blankets of silk, is not a localised thing. It is seen in other parts of Australia and around the world after flooding.

It just goes to show how versatile spider silk can be. It’s not just used for catching food, it’s also used for locomotion and is even used by some spiders to lay a trail so they don’t get lost.

Don’t spray them!

The most important thing I need readers to know is that this is not anything to be worried about. The worst thing you could do is get out the insecticide and spray them.

These spiders are making a huge contribution to pest control and you would have major pest problems if you get rid of all the spiders. The spiders will disperse on their own very quickly. In general, spiders don’t like being in close proximity to each other (or humans!) and they want to get back to their homes underground.

If you live in Gippsland, you probably don’t even need to clear the webs away with a broom. There’s no danger in doing so if you wish, but I am almost certain these webs will disperse on their own within days.

Until then, enjoy this natural spectacle. I wish I could come down to see them with my own eyes!




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City spiders are getting bigger — but that’s a good thing


The Conversation


Lizzy Lowe, Researcher, Macquarie University

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

Bones and all: see how the diets of Tasmanian devils can wear down their sharp teeth to blunt nubbins


Zoos Victoria, Author provided

Tahlia Pollock, Monash University; Alistair Evans, Monash University; David Hocking, Monash University, and Marissa Parrott, The University of MelbourneTasmanian devils are expert scavengers, with strong jaws and robust teeth that give them the notorious ability to eat almost all of a carcass — bones and all.
Scientists have even found echidna spikes in their poo.

But regularly crunching through bone comes at a cost: extreme tooth wear. In our new study, we analysed the skulls of nearly 300 devils, and show how regularly crunching through bones wears a devil’s teeth down from sharp-edged weapons to blunt nubbins.

Tasmanian devils are endangered and their wild population is continuing to decline. A key part of conserving this marsupial is by maintaining healthy and happy devils in captivity.

Understanding how their food affects their teeth can help us see if captive devils have the same types of tooth wear as their wild counterparts, and look for signs of any unusual or harmful wear.

Is there anything a devil won’t eat?

Tasmanian devils are the largest marsupial carnivore alive today. As scavengers, they occupy a unique niche in the Australian ecosystem by disposing of dead animal carcasses.

Devil standing over a dead carcass
Captive Tasmanian devils are given a variety of foods to replicate what they’d find in the wild. This photo was taken during a carcass feed at Healesville Sanctuary.
Zoos Victoria, Author provided

Devils are highly opportunistic and can eat many different types of prey. While their favourites are the carcasses of native mammals such as wombats and wallabies, they’ll also eat reptiles, amphibians, birds, fish, and even insects.

We know this because we find hair, feathers, scales, small bones, claws and more in their poo.

Almost nothing is off limits to devils — they’ll even have a go at a stranded whale given the chance. Although devils prefer to scavenge, they’re also accomplished hunters.




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But due to a transmissible cancer, devil facial tumour disease, wild numbers of these remarkable marsupials have plummeted by around 80%.

Right now, 45 Australian zoos and wildlife sanctuaries, plus an island and a fenced peninsula, are collaborating to maintain a healthy population of disease-free devils. It’s important for these institutions to provide captive animals with the right kinds of food for their health and to help make their future release back to disease-free wild locations successful.

Devils naturally wear their teeth down from sharp points and edges to blunt, almost flat surfaces by regularly eating bones.
Tahlia Pollock, Author provided

This is especially crucial for carnivores, who rely on tough foods to help them develop strong jaws.

Like hyaenas, but stronger

The types of food an animal eats will wear their teeth down differently. For example, big cats such as lions prefer to eat the softer parts of a carcass, like flesh or organs, and leave the bones behind.

Spotted hyaenas, however, will happily eat the bones. As a result, hyaenas have incredibly high tooth wear compared with lions.

This might not hinder the hyaena or devil as much as you might think. Both have very strong jaws that can compensate for the loss of sharp teeth. In fact, devils have the strongest bite force per body weight of any living mammal.

In the interactive below, you can check out 3D models of devil skulls to get a better idea of how much their teeth wear down.

Comparing wild and captive diets

By comparing the tooth wear of wild and captive devils, we can see if captive animals are encountering enough hard foods in their diets.

In the Save the Tasmanian Devil Program — an initiative of the federal and Tasmanian governments — captive devils are given a variety of small and large foods at different times, replicating what they’d find in the wild.

We found no signs of different or harmful tooth wear in captive devils, and they showed much the same patterns and types of wear as wild devils.




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However, we noticed captive devils wore their teeth more slowly than those in the wild. This may be due to eating higher quality food, such as carcasses that were fresh, whole, and yet to be scavenged.

This means captive institutions are doing a good job of providing devils with the right types of food for their teeth and encouraging wild behaviours.

Part of the health check for wild devils involves looking at their teeth. This particular devil has nice sharp tips and edges on their canines and molars.
Marissa Parrott/Zoos Victoria, Author provided

Collecting data about Tassie devils after they’ve been released confirms this. In 2012 and 2013, devils were released onto Maria Island in Tasmania after being born and raised for around a year in captivity.

Encouragingly, these devils kept the behaviours required to scavenge and hunt prey, and had diets similar to wild devils.

How you can help save Tasmanian devils

Our research is one small, but promising, piece in the overall puzzle. While captive research and breeding programs help conserve the Tasmanian devil, there are ways you can help, too.

Because they like to scavenge the carcasses of dead animals, road kill is especially tempting for devils. But being so close to the road is dangerous and road mortality is the second-biggest killer of wild devils.

So take care on the roads to help wildlife, especially if driving at night. And if you’re in Tasmania and see a devil that’s been hit on the road, log it in the Roadkill TAS app.

This will help identify road kill hotspots and protect this impressive, but endangered, species.




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The Conversation


Tahlia Pollock, PhD candidate, Monash University; Alistair Evans, Associate Professor, Monash University; David Hocking, Curator of Vertebrate Zoology and Palaeontology at the Tasmanian Museum and Art Gallery (TMAG) | Adjunct Research Associate at Monash University, Monash University, and Marissa Parrott, Reproductive Biologist, Wildlife Conservation & Science, Zoos Victoria, and Honorary Research Associate, BioSciences, The University of Melbourne

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

DIY habitat: my photos show chainsaw-carved tree hollows make perfect new homes for this mysterious marsupial


William Terry, Author provided

William Terry, Southern Cross UniversityEnvironmental scientists see flora, fauna and phenomena the rest of us rarely do. In this series, we’ve invited them to share their unique photos from the field.


As a result of logging and severe bushfires, Australian wildlife is facing a severe shortage of tree hollows — holes in the trunks and branches of large old trees. More than 300 species of birds and mammals, including possums, bats, cockatoos, owls and kookaburras, rely on tree hollows for shelter or breeding.

A sacred kingfisher using a natural tree hollow for nesting.
William Terry

In Australia, hollows are usually formed through the decay of a tree scar, and it can take hundreds of years for tree hollows big enough for medium-sized animals to form naturally.

This includes phascogales — the rat-sized, carnivorous marsupials that live in open woodlands across Australia and are the focus of my research and photography. But like many of Australia’s forest-dwelling mammals, phascogales are vulnerable to extinction.

So with hollows becoming harder to find, I venture into forests and study how well artificial hollows, made with chainsaws, can replace them. And, incredibly, it’s working: my research shows phascogales and other native animals are enthusiastically moving into the new real estate.

Meet the mysterious brush-tailed phascogale

Phascogales are an important species to Australia but, unfortunately, their cryptic behaviour and nocturnal habits mean people rarely see them.

Brush-tailed phascogales live in trees, but will come to the ground to forage for food among leaf litter and fallen timber.
William Terry
Phascogales belong to the same family as the Tasmanian devil, quoll (pictured) and the tiny antechinus.
William Terry, Author provided

Phascogales feed on insects after stripping bark from eucalypts. But through my close interactions and radio tracking, I’ve documented phascogales eating other more unusual foods, including bird eggs and sometimes even small birds, such as grey-shrike thrush.

I’ve also recorded them taking dead birds, such as the rosella pictured below. They even have a reputation among farmers as being a fierce chicken killer, but this may be exaggerated.

A phascogale inspects a dead crimson rosella it found at the base of a tree. Moments later, this phascogale dragged the bird away. It was unclear what happened next.
William Terry

Phascogales have an unusual life. Shortly after mating between April and May, all males die at about 11 months of age from stomach ulcers. This frees up resources for the next generation of young joeys that will emerge from the nest in early summer.

But will they survive in the future?

Tragically, at least one species, the brush-tailed phascogale, is threatened with extinction, primarily due to habitat loss, climate change, and feral predators such as foxes and cats.

The brush-tailed phascogale (Phascogale tapoatafa tapoatafa) occurs across the eastern side of Australia, from southern Queensland to Victoria. It’s now extinct in South Australia.

Likewise, the much smaller red-tailed phascogale (Phascogale calura) once survived across a vast swathe of land from Western Australia to Victoria. Today, it survives only in small pockets in the Western Australia wheatbelt.

Brush-tailed phascogales were once known as ‘bottle-brush squirrels’, due to the stunning resemblance of its tail to the iconic native flowers.
William Terry
The red-tailed phascogale has been lost from much of its former range and now only exists in the Western Australian wheatbelt.
William Terry, Author provided

Household cats are a particularly major issue for phascogales, and many cat owners in central Victoria have a story about their cat bringing home a phascogale (so please keep your pet cat inside at all times).




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Last year, research confirmed climate change would reduce the available areas phascogales could survive. This research found areas with a phascogale-friendly climate would decline by up to 79% in Queensland, 67% in Victoria and 17% in NSW, by 2070.

Climate change also threatens to bring longer, more frequent and severe heatwaves. For phascogales and many other mammals, this could be a death sentence.

Tree hollows with thick walls can protect the animals sheltering inside from the high temperatures outside.

But these are getting increasingly rarer, and this is where my research on chainsaw hollows comes in. Thick-walled hollows may be very important for the long-term survival of phascogales and other species in a warming climate.

A relative to the phascogale, the tiny agile antechinus commonly uses tree hollows on the ground.
William Terry, Author provided

Carving them a home

A chainsaw hollow is a cavity constructed inside a tree. A faceplate is then attached over the top, with a hole drilled into it for the animal to enter. They offer refuge for Australia’s endangered mammals and birds.

For our project, we carved 45 chainsaw hollows in dry forests and woodland where phascogales are known to occur. We also installed similar-sized nest boxes — which are more commonly used to offset the loss of hollows — on nearby trees. We monitored these for two and a half years.

A chainsaw hollow constructed for phascogales.
William Terry, Author provided
Chainsaw hollow creation is a specialised skill. Here, tree climber Lachlan installs a chainsaw hollow on a red ironbark tree.
William Terry, Author provided

Research from 2018 shows nest boxes offer little protection from outside temperatures. I’ve collected data, which is not yet published, that confirms this.

My research shows chainsaw hollows provide 27% more protection from extreme temperatures during heatwaves compared to nest boxes, which provided almost no protection.




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Two phascogales peeking out of a nest box.
William Terry, Author provided

So it’s no wonder we observed and recorded phascogales and the more common sugar glider (Petaurus notatus) more frequently sheltering in chainsaw hollows than in nearby nest boxes.

Other animals used the chainsaw hollows, too. This includes the feather-tailed glider, yellow-footed antechinus, and the white-throated treecreeper.

Brush-tailed phascogale inspects a chainsaw hollow.
Sugar gliders also frequently used chainsaw hollows.
William Terry

But like nest boxes, the chainsaw hollows showed signs they would be only an interim measure, requiring maintenance with bark growing over entrance holes and issues with a buildup of moisture.

In any case, further research into this species is needed, as it will aid land managers to conserve this enigmatic species as more challenges are thrown their way into the future.




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Photos from the field: the stunning crystals revealing deep secrets about Australian volcanoes


The Conversation


William Terry, PhD Researcher, Supervision by Associate Prof. Ross Goldingay, Southern Cross University

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

Even without new fossil fuel projects, global warming will still exceed 1.5℃. But renewables might make it possible


Shutterstock

Sven Teske, University of Technology Sydney and Sarah Niklas, University of Technology SydneyThe International Energy Agency (IEA) last month made global headlines when it declared there is no room for new fossil fuel investment if we’re to avoid catastrophic climate change.

However, our new research suggests the horse may have already bolted. We found even if no new fossil fuel projects were approved anywhere in the world, carbon emissions set to be released from existing projects will still push global warming over the dangerous 1.5℃ threshold.

Specifically, even with no new fossil fuel expansion, global emissions would be 22% too high to stay within 1.5℃ by 2025, and 66% too high by 2030.

However, keeping global warming under 1.5℃ is still achievable with rapid deployment of renewables. Our research found solar and wind can supply the world’s energy demand more than 50 times over.

The stunning potential of wind and solar

While our findings were alarming, they also give us a new reason to be hopeful.

We analysed publicly available oil, gas and coal extraction data, and calculated the future production volume. We worked under the assumption no new fossil fuel extraction projects would be developed, and all existing projects would see production declining at standard industry rates.

We found fossil fuel projects already in the pipeline will, by 2030, produce 35% more oil and 69% more coal than what’s consistent with a pathway towards a 1.5℃ temperature rise.

Power station at night
Fossil fuels account for over 75% of carbon dioxide emissions.
Shutterstock

Fossil fuels are the main driver of climate change, accounting for more than 75% of carbon dioxide emissions. Continuing to expand this sector will not only be catastrophic for the climate, but also for the world’s economy as it locks in infrastructure that will become stranded assets.

Ultimately, it’s not enough to simply keep fossil fuels in the ground. To meet our climate goals under the Paris Agreement, we must phase down existing production.




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Solar and wind power technologies are already market ready and cost competitive. And as our analysis confirms, they’re ready to be scaled up to meet the energy demands of every person on the planet.

We mapped all the potential areas where wind and solar infrastructure can be built, and the energy potential across six continents.

Even after applying a set of robust, conservative estimates that take environmental safeguards, land constraints and technical feasibility into account, we found that solar and wind energy could meet the world’s energy demand from 2019 — 50 times over.

It’s clear we don’t need new fossil fuel development to ensure 100% energy access in the future.

Australia’s laggard status

In Australia, the Morrison government refuses to set new emissions reduction targets, and continues to fund new fossil fuel projects, such as a A$600 million gas plant in the New South Wales Hunter Valley.

Despite Australia’s laggard status on climate change, there are positive moves elsewhere around the world.

The progress was evident ahead of the G7 summit this past weekend, where climate change was firmly on the agenda. Ahead of the summit, environment ministers worldwide agreed to phase out overseas fossil fuel finance and end support for coal power.

And in recent weeks, three global fossil fuel giants – Shell, Chevron and ExxonMobil – faced legal and shareholder rebukes over their inadequate action on climate change.




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Coming on top of all that, the IEA last month set out a comprehensive roadmap to achieve net-zero emissions by 2050. It included a stark warning: no new fossil fuel projects should be approved.

Natural carbon storage is key

However, the IEA’s findings contradict our own on several fronts. We believe the IEA underestimated the very real potential of renewable energy and relied on problematic solutions to fill what it sees as a gap in meeting the carbon budget.

For example, the IEA suggests a sharp increase in bioenergy is required over the next 30 years.

This would require biofuels from energy plantations — planting crops (such as rapeseed) specifically for energy use.

But conservationists estimate the sustainable potential for biofuels is lower. They also say high volumes of bioenergy might interfere with land use for food production and protected nature conservation areas.

Our research found the exact opposite is needed: rapid phase out of deforestation and significant reforestation alongside the decarbonisation of the energy sector.

Bioenergy should be produced predominantly from agricultural and organic waste to remain carbon neutral.




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Likewise, the IEA calls for an extreme expansion of carbon capture and storage (CCS) projects — where carbon dioxide emissions are captured at the source, and then pumped and stored deep in the ground.

In its roadmap, the IEA expects CCS projects to grow from capturing 40 million tonnes of carbon dioxide (as is currently the case), to 1,665 million tonnes by 2030.

This is quite unrealistic, because it means betting on expensive, unproven technology that’s being deployed very slowly and is often plagued by technical issues.

Establishing natural carbon sinks should be prioritised instead, such as keeping forest, mangrove and seagrass ecosystems better intact to draw carbon dioxide from the atmosphere.

Phasing out early

As a wealthy country, Australia is better placed than most to weather any economic disruption from the energy transition.

Our research shows Australia should phase out fossil fuels early and urgently. The Australian government should also ensure communities and people reliant on fossil fuel industries are helped through the transition.

We must also support poorer countries highly dependent on fossil fuels, particularly in the Asia-Pacific region.

There is new international momentum for climate action, and the future of the fossil fuel industry looks increasingly dire. The technologies to make the transition are ready and waiting – now all that’s needed is political will.




Read more:
Tracking the transition: the ‘forgotten’ emissions undoing the work of Australia’s renewable energy boom


The Conversation


Sven Teske, Research Director, Institute for Sustainable Futures, University of Technology Sydney and Sarah Niklas, Research Consultant, Institute for Sustainable Futures, University of Technology Sydney

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

Check your mirrors: 3 things rooftop solar can teach us about Australia’s electric car rollout


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Bjorn Sturmberg, Australian National University; Kathryn Lucas-Healey, Australian National University; Laura Jones, Australian National University, and Mejbaul Haque, Australian National UniversityGovernments and car manufacturers are investing hundreds of billions of dollars on electric vehicles. But while the electric transport revolution is inevitable, the final destination remains unknown.

The electric vehicle transition is about more than just doing away with vehicles powered by fossil fuels. We must also ensure quality technology and infrastructure, anticipate the future and avoid unwanted outcomes, such as entrenching disadvantage.

In Australia, the electric vehicle rollout has been slow, and federal action limited. But some state governments are working to electrify bus fleets, roll out public charging networks and trial smart vehicle charging in homes.

Australia’s world-leading rollout of rooftop solar power systems offers a guide to help navigate the transition. We’ve identified three key lessons on what’s gone well, and in hindsight, what could have been done differently.

solar panels on roofs
Australia’s rooftop solar boom offers insights into the electric vehicle revolution.
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1. Price isn’t everything

Solar systems and electric vehicles are both substantial financial investments. But research into rooftop solar has shown financial considerations are just one factor that guides purchasing decisions. Novelty, concerns about climate change and a desire for self-sufficiency are also significant – and electric vehicle research is producing similar findings.

When considering the electric vehicle rollout, understanding these deeper motivators may help avoid a race to the bottom on price.

About one in four Australian homes has rooftop solar, with almost three million systems installed. Solar companies have often sought to highlight the low price of rooftop systems over other considerations. This has created consumer demand for low-priced, lower-quality products – and led to potentially hundreds of thousands of substandard installations across Australia.




Read more:
On the road again: here’s how the states can accelerate Australia’s sputtering electric vehicle transition


So what are the lessons here for the electric vehicle rollout? First, when planning public infrastructure where electric vehicles can be charged, construction costs should not be the only consideration. Factors such as night-time safety and disability access should be prioritised. Shortcuts today will reinforce barriers for women and people with disabilities and create complex problems down the track.

Like rooftop solar, the point of sale of electric vehicles offers a unique opportunity to teach customers about the technology. Companies, however, can only afford to invest in customer education if they aren’t too stressed about margins.

“Smart” charging is one measure being explored to ensure the electricity network can handle future growth in electric vehicle uptake. Smart chargers can be remotely monitored and controlled to minimise their impact on the grid.

The point of sale is a pivotal moment to tell new owners of electric vehicles that their charging may at times be managed in this way.

EVs on charge
Electric vehicle charging infrastructure should be safe and accessible.
Shutterstock

2. Plan ahead

The uptake of rooftop solar in Australia has been a raging success. In fact, rooftop solar is now the largest generator in the national power system.

This raises issues, such as how rooftop solar systems will respond to a major disturbance, such as the failure of a transmission line. A large amount of solar power feeding into the grid can also challenge electricity network infrastructure.

In response, electricity networks have implemented changes such as limiting solar exports and therefore, returns to solar system owners, and charging fees for exporting solar.

Such retrospective changes have been unpopular with solar owners. So to maintain reliable electricity supplies, and avoid angering consumers, it’s vital to plan where and when electric vehicles are charged.

If every vehicle in Australia was electric, this would add about a quarter to national power demand. The rise in demand would be greatest near bus and logistics depots and ultra-fast highway chargers.




Read more:
Owners of electric vehicles to be paid to plug into the grid to help avoid blackouts


Timing is key to maximising the use of a network connection without overloading it. For example, if everyone charged their vehicle in the evening after they get home from work, as this would put further pressure on electricity supplies at this peak time.

Governments and electricity providers should encourage electric vehicle charging during the day, when demand is lower. This might mean, for example, providing vehicle charging facilities at workplaces and in public areas.

Until Australia’s power grid transitions to 100% renewables, the use of solar energy should be strongly encouraged. This would ensure the vehicles were charged from a clean, cheap energy source and would help manage the challenges of abundant solar.

The question of road user charges for electric vehicles drivers is another example where it’s best to avoid retrospective changes. Such charges are necessary in the long run and best introduced from the outset.

woman's arm holds EV charger on car
Vehicle charging during the day, when power demand is lowest, should be encouraged.
Shutterstock

3. Coordination is key

Electric vehicle policy spans many government portfolios: transport, infrastructure, energy, planning, environment and climate change. Nationally, and from state to state, different ministers are in charge.

This makes coordination difficult, and creates the risk of policies undermining each other. For example, one policy might encourage the charging of electric vehicles from rooftop solar, to reduce carbon emissions. But because solar energy is so cheap, this might encourage more private vehicle use, which worsens road congestion.

So policies to encourage electric vehicle uptake should not come at the cost of creating more attractive and efficient public transport networks.

And new technologies can entrench societal disadvantage. For example, the rooftop solar rollout often excluded people who could not afford to buy the systems. Without policies to address this, the electric vehicle transition could lead to similar outcomes.

traffic queues in Sydney
Encouraging electric vehicle use could worsen road congestion, if not well managed.
Shutterstock

Lessons in the rear-view mirror

As Australia’s experience with rooftop solar has shown, successful technology transitions must be carefully planned and attentively steered.

In the case of electric vehicles, this will ensure the benefits to owners, society and the environment are fully realised. It will also ensure a smooth-as-possible transition, the gains from which all Australians can share.




Read more:
The US jumps on board the electric vehicle revolution, leaving Australia in the dust


The Conversation


Bjorn Sturmberg, Research Leader, Battery Storage & Grid Integration Program, Australian National University; Kathryn Lucas-Healey, Research Fellow, Australian National University; Laura Jones, Senior Analyst – Economics and Business models, Australian National University, and Mejbaul Haque, Research Fellow, Battery Energy Storage and Grid Integration Program, Research School of Engineering, Australian National University

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

How rain, wind, heat and other heavy weather can affect your internet connection


Gordonekoff / Shutterstock

James Jin Kang, Edith Cowan University and Paul Haskell-Dowland, Edith Cowan UniversityWhen your Netflix stream drops out in the middle of a rainstorm, can you blame the wild weather?

Quite possibly. The weather can affect the performance of your internet connection in a variety of ways.

This can include issues such as physical damage to the network, water getting into electrical connections, and wireless signal interference. Some types of connection are more vulnerable to weather than others.

The behaviour of other humans in response to the weather can also have an effect on your connection.

How rain can affect your internet connection

Internet connections are much more complicated than the router and cables in our homes. There are many networking devices and cables and connections (of a variety of types and ages) between our homes and the websites we are browsing.

How do we connect to the Internet?

An internet connection may involve different kinds of physical link, including the copper wiring used in the old phone network and more modern fibre optic connections. There may also be wireless connections involved, such as WiFi, microwave and satellite radio.

Example of multi-layered internet access.
Ferran, CC BY-SA 4.0 https://creativecommons.org/licenses/by-sa/4.0, via Wikimedia Commons

Rain can cause physical damage to cables, particularly where telecommunication networks are using old infrastructure.

ADSL-style connections, which use the old phone network, are particularly vulnerable to this type of interference. Although many Australians may be connected to the National Broadband Network (NBN), this can still run (in part) through pre-existing copper wires (in the case of “fibre to the node” or “fibre to the cabinet” connections) rather than modern optical fibres (“fibre to the home”).

Different types of NBN connection.
Riick, CC BY-SA 3.0 http://creativecommons.org/licenses/by-sa/3.0/, via Wikimedia Commons

Much of the internet’s cabling is underground, so if there is flooding, moisture can get into the cables or their connectors. This can significantly interfere with signals or even block them entirely, by reducing the bandwidth or causing an electrical short-circuit.

But it isn’t just your home connection that can be impacted. Wireless signals outside the home or building can be affected by rainfall as water droplets can partially absorb the signal, which may result in a lower level of coverage.

Even once the rain stops, the effects can still be felt. High humidity can continue to affect the strength of wireless signals and may cause slower connection speeds.

Copper cables and changed behaviour

If you are using ADSL or NBN for your internet connection, it is likely copper phone cables are used for at least some of the journey. These cables were designed to carry voice signals rather than data, and on average they are now more than 35 years old.

Only around 18% of Australian homes have the faster and more reliable optical-fibre connections.

There is also a behaviour factor. When it rains, more people might decide to stay indoors or work from home. This inevitably leads to an increase in the network usage. When a large number of people increase their internet usage, the limited bandwidth available is rapidly consumed, resulting in apparent slowdowns.




Read more:
How to boost your internet speed when everyone is working from home


This is not only within your home, but is also aggregated further up the network as your traffic is joined by that from other homes and eventually entire cities and countries.

Heatwaves and high winds

In Australia, extreme cold is not usually a great concern. Heat is perhaps a more common problem. Our networking devices are likely to perform more slowly when exposed to extreme heat. Even cables can suffer physical damage that may affect the connection.

Imagine your computer fan is not running and the device overheats — it will eventually fail. While the device itself may be fine, it is likely the power supply will struggle in extremes. This same issue can affect the networking equipment that controls our internet connection.

Satellite internet services for rural users can be susceptible to extreme weather, as the satellite signals have to travel long distances in the air.

Radio signals are not usually affected by wind, but hardware such as satellite dishes can be swayed, vibrated, flexed or moved by the wind.

Most of the time, human behaviour is the main cause

For most users, the impact of rain will be slight – unless they are physically affected by a significant issue such as submerged cables, or they are trying to use WiFi outside during a storm.

So, can weather affect your internet connection? Absolutely.

Will most users be affected? Unlikely.

So if your favourite Netflix show is running slow during in rainy weather, it’s most likely that the behaviour of other humans is to blame — holed up indoors and hitting the internet, just like you.




Read more:
Internet traffic is growing 25% each year. We created a fingernail-sized chip that can help the NBN keep up


The Conversation


James Jin Kang, Lecturer, Computing and Security, Edith Cowan University and Paul Haskell-Dowland, Associate Dean (Computing and Security), Edith Cowan University

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

Tracking the transition: the ‘forgotten’ emissions undoing the work of Australia’s renewable energy boom


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Hugh Saddler, Australian National University and Frank Jotzo, Australian National UniversityWorld leaders including Prime Minister Scott Morrison will gather in the UK this weekend for the G7 summit. In a speech on Wednesday ahead of the meeting, Morrison said Australia recognises the need to reach net-zero emissions in order to tackle climate change, and expects to achieve the goal by 2050.

So has Australia started the journey towards deep cuts in greenhouse gas emissions?

In the electricity supply system, the answer is yes, as renewables form an ever-greater share of the electricity mix. But elsewhere in the energy sector – in transport, industry and buildings – there has been little or no progress.

This situation needs to change. These other parts of the energy system contribute nearly 40% of all national greenhouse gas emissions – and the share is growing. In a new working paper out today, we propose a way to track the low-carbon transition across the energy sector and check progress over the last decade.

woman cooks in kitchen with gas stove
Energy emissions from buildings, such as from gas cooktops, have largely escaped scrutiny.
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A stark contrast

The energy sector can be separated into three major types of energy use in Australia:

  • electricity generation
  • transport and mobile equipment used in mining, farming, and construction
  • all other segments, mainly fossil fuel combustion to provide heat in industry and buildings.

In 2018-19, energy sector emissions accounted for 72% of Australia’s national total. Transition from fossil fuels to zero-emissions sources is at the heart of any strategy to cut emissions deeply.

The transition is already happening in electricity generation, as wind and solar supplies increase and coal-fired power stations close or operate less.

But in stark contrast, elsewhere in the sector there is no evidence of a meaningful low-emissions transition or acceleration in energy efficiency improvement.

This matters greatly because in 2019, these other segments contributed 53% of total energy combustion emissions and 38% of national greenhouse gas emissions. Total energy sector emissions increased between 2005 (the reference year for Australia’s Paris target) and 2019.

As the below graphic shows, while the renewables transition often gets the credit for Australia’s emissions reductions, falls since 2005 are largely down to changes in land use and forestry.



Let’s take a closer look at the areas where Australia could do far better in future.

1. Transport and mobile equipment

Transport includes road and rail transport, domestic aviation and coastal shipping. Mobile equipment includes machinery such as excavators and dump trucks used in mining, as well as tractors, bulldozers and other equipment used in farming and construction. Petroleum supplies almost 99% of the energy consumed by these machines.

Road transport is responsible for more than two-thirds of all the energy consumed by transport and mobile equipment.

What’s more, prior to COVID, energy use by transport and mobile equipment was steadily growing – as were emissions. The absence of fuel efficiency standards in Australia, and a trend towards larger cars, has contributed to the problem.

Electric vehicles offer great hope for cutting emissions from the transport sector. As Australia’s electricity grid continues to decarbonise, emissions associated with electric vehicles charged from the grid will keep falling.

cars on freeway from rear
Electric vehicles would slash road transport emissions.
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2. Other energy emissions

Emissions from all other parts of the energy system arise mainly from burning:

  • gas to provide heat for buildings and manufacturing, and for the power needed to liquefy gas to make LNG
  • coal, for a limited range of heavy manufacturing activities, such as steel and cement production
  • petroleum products (mainly LPG) in much smaller quantities, where natural gas is unavailable or otherwise unsuitable.

Emissions from these sources, as a share of national emissions, rose from 13% in 2005 to 19% in 2019.

These types of emissions can be reduced through electrification – that is, using low- or zero-carbon electricity in industry and buildings. This might include using induction cooktops, and electric heat pumps to heat buildings and water.

However the data offer no evidence of such a shift. Fossil fuel use in this segment has declined, but mainly due to less manufacturing activity rather than cleaner energy supply.

And in 2018 and 2019, the expanding LNG industry drove further emissions growth, offsetting the decline in use of gas and coal in manufacturing.

How to track progress

Over the past decade or so, Australia’s emissions reduction policies – such as they are – have focused on an increasingly narrow range of emission sources and reduction opportunities, in particular electricity generation.

Only now are electric vehicles beginning to be taken seriously, while energy efficiency – a huge opportunity to cut emissions and costs – is typically ignored.

Our paper proposes a large set of new indicators, designed to show what’s happening (and not happening) across the energy sector.

The indicators fall into four groups:

  • greenhouse gas emissions from energy use
  • primary fuel mix including for electricity generation
  • final energy consumption including energy use efficiency
  • the fuel/technology mix used to deliver energy services to consumers.

Our datasets excludes the effects of 2020 COVID-19 lockdowns. They’re based on data contained in established government publications: The Australian Energy Statistics, the National Greenhouse Gas Inventory and the Australian Bureau of Statistics’ national accounts and population estimates.

By systematically tracking and analysing these indicators, and combining them with others, Australia’s energy transition can be monitored on an ongoing basis. This would complement the great level of detail already available for electricity generation. It would also create better public understanding and focus policy attention on areas that need it.

In some countries, government agencies monitor the energy transition in great detail. In some cases, such as Germany, independent experts also conduct systematic and substantial analysis as part of an annual process.

The road ahead

Australia has begun the journey to a zero-emissions energy sector. But we must get a move-on in transport, industry and buildings.

The technical opportunities are there. What’s now needed is government regulation and policy to encourage investment in zero-emissions technologies for both supplying and using all forms of energy.

And once available, the technology should be deployed now and in coming years, not in the distant future.




Read more:
Check your mirrors: 3 things rooftop solar can teach us about Australia’s electric car rollout


The Conversation


Hugh Saddler, Honorary Associate Professor, Centre for Climate Economics and Policy, Australian National University and Frank Jotzo, Director, Centre for Climate and Energy Policy, Australian National University

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

Friday essay: a rare bird — how Europeans got the black swan so wrong


Bernard Spragg/flickr

David Haworth, Monash UniversityThe black swan is an Australian icon. The official emblem of Western Australia, depicted in the state flag and coat-of-arms, it decorates several public buildings. The bird is also the namesake for Perth’s Swan River, where the British established the Swan River Colony in 1829.

The swan’s likeness has featured on stamps, sporting team uniforms, and in the logo for Swan Brewery, built on the sacred Noongar site of Goonininup on the banks of the Swan.

But this post-colonial history hides a much older and broader story. Not only is the black swan important for many Aboriginal people, it was also a potent symbol within the European imagination — 1500 years before Europeans even knew it existed.

Native to Australia, the black swan or Cygnus atratus can be found across the mainland, except for Cape York Peninsula. Populations have also been introduced to New Zealand, Japan, China, the United Kingdom and the United States.

Right now, the breeding season of the black swan is in full swing across southern Australia, having recently ended in the north. In waterways and wetlands, people are seeing pairs of swans — a quarter of which are same-sex — tending carefully to their cygnets, seeing off potential threats with elaborate triumph ceremonies, or gliding elegantly across the water, black feathers gleaming in the winter sun.

Yet once upon a time in a land far away, such birds were described as rare or even imaginary.

swans on water
Winter is breeding season in Australia’s southern states.
Unsplash/Mitchell Luo, CC BY

The impossible black swan

In the first century CE, Roman satirist Juvenal referred to a good wife as a “rare bird in the earth, and very like a black swan”.

Casual misogyny aside, this is an example of adynaton, a figure of speech for something absurd or preposterous — like pigs flying, or getting blood from a stone.




Read more:
Guide to the Classics: Juvenal, the true satirist of Rome


Over the centuries, versions of the phrases “black swan” and “rare bird” became common in several European languages, describing something that defied belief. The expressions made sense because Europeans assumed, based on their observations, that all swans were white.

Around the same time that Juvenal coined these phrases, Ptolemy devised a map of the world that included an unknown southern continent, Terra Australis Incognita. Many believed this distant southland was populated with monsters and fabulous races, like the Antipodes, imagined by Cicero as “men which have their feet planted right opposite to yours”.

In a quirk of history, both the impossible black swan and the hypothetical southland were indeed real. Even more unbelievably, they would be found at the same geographic coordinates.

Once they were white

Black swans are significant totems for many Aboriginal people and incorporated within songlines and constellations (where they are called Gnibi, Ginibi, or Gineevee).

Yet the Noongar people in WA, and the Yuin and Euahlayi in New South Wales, tell ancestral stories about white swans, which had most of their feathers torn out by eagles.

black and white print of early Australian river scene
Print by an unknown artist after a drawing by Frederick Garling or watercolour by Frederick R. Clause, who accompanied Captain Stirling on his 1827 trip down the Swan River.
State Library of Western Australia

In the Noongar story Maali, the swan, is proud and boastful of its beauty, and has its white feathers ripped out by Waalitj, the eagle, as punishment. In the Yuin story the swan, Guunyu, humble and quiet, is attacked because the other birds are jealous of his beauty.

And in the Euahlayi story, two brothers are transformed into swans, or Byahmul, as part of a robbery. Later they are attacked by eagles as an act of revenge.

In each story, after the swans have their white plumage torn out, crows release a cascade of feathers, turning the swans black, except for their white wing tips. Their red beak still shows blood from the attack.

These stories are keenly observant of, and offer an explanation for, the black swan’s colouration. They acknowledge the possibility swans could be white — even though it’s unlikely First Nations people observed white swans in their surroundings prior to British settlement.

This contrasts starkly with the European assumption that, having never seen a black swan, they couldn’t possibly exist.

Painting of black swans
Australian painter Neville Cayley’s Black Swans (circa 1890).
National Library Australia



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From myth to wonder

European assumptions were destined to shatter once Dutch ships began visiting Australia’s western coastline in the 1600s. Seeing the mythical black swan in the flesh must have been like seeing a unicorn emerge from the shadows of the forest.

In 1636, Dutch mariner Antonie Caen observed black birds “as large as swans” at sea off Bernier Island — probably the first recorded European sighting.

In 1697, Willem de Vlamingh’s expedition to the west coast sighted many swans on what they dubbed Swarte Swaane Drift or Black Swan River. Noongar people know this river as Derbarl Yerrigan. If de Vlamingh was amazed at the sight of black swans, he did not record it, simply noting, “They are quite black”. Three swans were captured and taken to Batavia (Jakarta), but died before they could be brought to Europe.

Reports of the black swan made it back to the Netherlands and then to England, but it took another century for its mythical status to dissipate completely.

English ornithologist John Latham gave the black swan its first scientific name, Anas atrata, in 1790. Yet knowledge of its existence was still not widespread.

In 1792, the botanist on Bruni d’Entrecasteaux’s expedition, Jacques Labillardiere, made note of black swans at Recherche Bay in Tasmania, apparently unaware they were already known to Europeans.

drawing of black swan
The black swan (Chenopis atrata) by Ebenezer Edward Gostelow (1938).
National Library Australia

In 1804, Nicolas Baudin’s expedition brought the first living specimens to Europe. These became part of the Empress Josephine Bonaparte’s garden menagerie at the Château de Malmaison.

The black swan had migrated from myth to the far edge of reality, joining the kangaroo and the platypus as awe-inspiring wonders from the distant, topsy-turvy southland — real, but only just.

Good versus evil

Black swans never established large populations in the wild after being brought to Europe. It’s speculated this is because black animals were considered bad omens, in league with witches and devils, and often driven away or killed.

Beliefs like these reflect the ancient assumption, found everywhere from the Dead Sea Scrolls to Star Wars, that darkness and the colour black represent evil and corruption, and that light and the colour white represent goodness and purity.

Frantz Fanon once argued that “the colonial world is a Manichean world”, in which light and dark, white and black, and good and evil are starkly divided. These divisions have been deeply implicated in the histories of colonialism and racism — often with devastating consequences.

Two swans, one dancer

The symbolic contrast of light and dark features heavily in Pyotr Ilyich Tchaikovsky’s most famous ballet, Swan Lake. Prince Siegfried falls in love with Odette, the innocent and virtuous white swan. But he is tricked into promising himself to her double, the seductive and malevolent Odile.

The ballet’s story was inspired by a long tradition of European fairy tales depicting Swan Maidens, but Tchaikovsky was also reportedly inspired by the life of King Ludwig II of Bavaria, known as the Swan King. Both Ludwig II and Tchaikovsky were caught between the societal pressure to marry and their own same-sex desires.

The roles of Odette and Odile are often played by the same ballerina, a tradition that started in 1895, two years after Tchaikovsky’s death. But it was not until 1941 that Odile was first depicted wearing black, and afterwards became known as the black swan.

Swan Lake suggests a Manichean worldview in which good and evil are polar opposites, as far away from each other as Europe is from the Antipodes. By having the same ballerina portray both roles, the ballet also suggests the world is not so simple — things can be black or white, or both at once.

False black swans

For 1500 years, Europeans had been spectacularly wrong about the black swan. Once its existence was accepted, its transmogrification from myth to reality became a metaphor within the philosophy of science. The black swan had shown the difficulty of making broad claims based on observable evidence.

Austrian philosopher Karl Popper used the black swan in 1959 to illustrate the difference between science that can be verified versus science that can be falsified.

To verify that all swans are white is practically impossible, because that would require assessing all swans — yet a single black swan can disprove the theory. In 2007, essayist and mathematic statistician Nassim Nicholas Taleb argued organisations and individuals should be robust enough to cope with “black swan events”: consequential but unexpected moments in history.

black and white photo of kids at lake with birds
Children with black swans and ducks in Centennial Park, circa 1934.
Wikimedia Commons/State Library NSW



Read more:
Friday essay: the long history of warrior turtles, from ancient myth to warships to teenage mutants


The white black swan

This Australian winter, those enjoying the sight of black swans and their cygnets might assume, based on observable evidence, that all Australian native swans are black. But as black swans have shown, and as Taleb argued, we should expect the unexpected.

Last month, some four centuries after Europeans were awe-struck by the sight of black swans on our waters, Tasmanian fisherman Jake Hume rescued a white-plumaged black swan, the only one known to exist.

white swan at vet
Odette, the white black swan, is recovering from bullet wounds.
Bonorong Wildlife Sanctuary/Instagram

The swan is not an albino, because it still has pigmentation around its beak and eye. Its white feathers are the expression of a rare genetic mutation. First sighted in the area in 2007, the bird was found riddled with shotgun pellets. It is recovering in Bonorong Wildlife Sanctuary until ready to be released.

Simultaneously a black swan, a white swan, and a metaphor, this assumption-shattering “rare bird” captures the complex cultural history surrounding this species.The Conversation

David Haworth, Senior Research Officer, Monash University

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