Tess Parker, Monash University and Ailie Gallant, Monash UniversityAt the tail end of winter in 2015, the ground in the Wimmera in northwestern Victoria had been a little dry but conditions weren’t too bad for farmers. The crop season was going well.
The start of September looked promising. It was cool, and there were decent rains. One Wimmera lentil grower said, “As long as it doesn’t get too hot, we should actually be OK.”
A few weeks later, summer weather had arrived early. At the start of October, the soils were baked dry. Lentils and other pulse crops were devastated.
This kind of event, where drier-than-normal conditions transform into severe or extreme drought in the space of weeks, is called a “flash drought”. While flash droughts are still not well understood, our research studies how they occur in Australia – which may help move us toward being able to warn of flash drought in advance.
The different kinds of drought
Scientists typically talk about drought as a lack or deficit of available moisture to meet various needs, such as in agriculture or for water resources. We often classify different types of drought depending on where there is a lack of water, or what its effects are:
meteorological drought is a deficit of rain or other precipitation
agricultural drought is a deficit of moisture in the soil and evaporating or transpiring into the air
hydrological drought is a deficit of water in runoff and surface storage such as dams
socioeconomic drought is a lack of water that affects the supply and demand of economic goods and services.
Different types of drought can occur at the same time, or a drought may evolve from one type to another. Droughts can last from months to decades, and can cover areas from a local region to most of the continent.
The different types of drought, showing how long they last and the size of the area they affect. Ailie Gallant, Author provided
Recently, a new characterisation of drought has been added to the drought spectrum: “flash” drought.
What causes flash droughts?
Flash droughts are droughts that begin suddenly and then rapidly become more intense. Droughts only occur when there is insufficient rainfall, but flash droughts intensify rapidly over timescales of weeks to months because of other factors such as high temperatures, low humidity, strong winds and clear skies.
These conditions make the air “thirsty”, which meteorologists call “increased evaporative demand”. This means more water evaporates from the surface and transpires from plants, and moisture in the soil is rapidly depleted.
Under these conditions, evaporation and transpiration increase for as long as moisture is available at the surface. When this moisture is depleted and there is no rain to replenish it, the lack of water limits evaporation and transpiration – and vegetation becomes stressed as drought emerges.
When there is a lack of rain accompanied by high temperature, low humidity, strong wind and clear skies, conditions are right for flash drought. Tess Parker, Author provided
Why haven’t we heard about flash drought before?
Flash droughts have always existed, and were first described in 2002. However, some particularly devastating flash droughts over the past decade have led to a surge of interest among researchers.
One such drought happened in the US Midwest. In May 2012, 30% of the continental United States was experiencing abnormally dry conditions. By August, that had extended to more than 60%. Although other rapidly developing droughts had been seen before, the widespread impacts of this event caught the attention of the US public and government.
Flash droughts are also increasingly a focus of attention in China and Australia. One of the few studies of flash drought in Australia examined an event when conditions in the country’s east suddenly changed from wet in December 2017, to dry in January 2018.
Anecdotal reports from farmers in the northern Murray–Darling Basin indicated removal of livestock from properties, and sheep numbers at record lows. By June 2018, there were reports of trees dying and a desert-like landscape, with little grass cover.
What happened in the Wimmera?
Our recent study of flash drought in Australia used several different measurements to capture a range of conditions related to drought.
precipitation describes the supply of moisture from the atmosphere to the surface
evaporative demand is the atmospheric demand for moisture from the surface
evaporative stress is the supply of moisture from the surface relative to the demand from the atmosphere
soil moisture is the wetness or dryness of the land surface.
The index we used to determine the atmospheric demand shows that the speed of development and the intensity of flash drought are driven by high temperatures, low humidity, strong winds and clear skies. All of these increase the demand for moisture from the surface.
After a drier than normal winter, southeast Australia experienced a cool and wet start to September 2015, with some rain in the first week of the month. Humidity and surface air pressure were roughly average, and surface sunshine below average, suggesting normal evaporative demand.
A warm spell began in mid-September, and intensified into a severe heatwave by early October, with temperatures over 35℃ persisting for several days in some areas. Throughout this period the overlying air became very dry. A persistent high-pressure system brought clear skies and increased sunshine.
By the end of October, the Wimmera was in severe or extreme drought conditions, devastating pulse and grain crops. Analysts estimated wheat production fell by 23%, with a loss of A$500 million in potential yields.
Flash drought in Australia
Flash droughts in Australia occur in all seasons. In the Wimmera, flash droughts are most frequent in summer and autumn. They can end as rapidly as they start, but in some cases may last many months.
In several instances, flash droughts in the Wimmera have started in summer or autumn, and the region has remained in drought through the following winter, and sometimes into spring. In this way, flash drought can be the catalyst for the common droughts lasting 6-12 months typical of southeast Australia.
But there is some potential good news. We have long known that seasonal-scale droughts in Australia are strongly related to the El Niño-Southern Oscillation (ENSO), which gives us some ability to predict them.
ENSO strongly affects rainfall, which means it can also be linked to flash droughts in winter and spring.
Further, sub-seasonal forecasting, which predicts the climatic conditions weeks to a month in advance, has improved considerably in recent years. Given flash droughts occur on these timescales, we can be optimistic that prediction of flash droughts may be possible.
Vanessa Pirotta, Macquarie UniversityIf you gaze at the ocean this winter, you might just be lucky enough to spot a whale migrating along Australia’s coastline. This is the start of whale season, when the gentle giants breed in the warm northern waters off Australia after feeding in Antarctica.
This north-south migration happens every year, but the whales can still surprise us. Thanks to a citizen scientist and his drone, humpback whales were seen feeding in a mass super group and “bubble-net feeding” off the New South Wales coast last year.
As my new research paper confirms, this a big deal for two reasons: it’s only the second time a super group of humpbacks has been observed in the southern hemisphere (a first for Australia) and the first time bubble-net feeding has been seen in Australia.
So what is bubble-net feeding, and why are these observations so important?
Blowing bubbles, catching krill
Bubble-net feeding is when whales deliberately blow bubbles from their noses to encircle their food — krill and fish — like a net, concentrating their prey into a tight ball. Then, the whale or group of whales swim together from beneath, rise to the surface opening their mouths, and gulp up their prey.
It remains a mystery as to why the whales feed in this way and how they learned to do it.
Drone footage of a super group of humpback whales, some of which are bubble-net feeding. Video: Brett Dixon.
2020 was a year full of unprecedented events, and the humpback whales certainly didn’t disappoint.
Humpback whales in this eastern Australian population are usually observed lunge feeding on their side, or feeding below the surface. Bubble-net feeding, on the other hand, is mostly documented in some Northern Hemisphere populations.
But we know there are individual whales in the eastern Australian humpback population who bubble-net feed in Antarctic waters. This means the unique behaviour in Australian waters may have evolved independently, or through cultural transmission (learning new behaviours from different whales).
The drone footage and observations made in September from whale-watching boats was the first to document bubble-net feeding. To add to the excitement, citizen scientists also documented bubble-net feeding behaviour further south of Tasmania a month later.
Drone footage captures humpback whales feeding in large numbers off the New South Wales coast. Brett Dixon
Using stills from the September drone footage, an estimated 33 humpback whales can be seen feeding at the same time. Unfortunately, it’s not known exactly what the whales were feeding on.
Until then, humpback whale congregations this large had never been observed in Australian waters.
In fact, the only other time a mass humpback feeding event has been seen in the Southern Hemisphere was off South Africa in 2011 (this now occurs regularly there). This was the first time the term “super group” was used to describe a group of 20 or more whales feeding this way.
Humpback whale rising up in the middle of a visible bubble-net to engulf its prey. Jessica Millar/Sapphire Coastal Adventures
But why were they feeding in ‘breeding waters’ anyway?
The majority of the east Australian humpback whale population spends the summer months feeding in Antarctic waters. They then head north to warm breeding waters in the Great Barrier Reef during winter (June-August) to mate and give birth.
They forego feeding for love — humpbacks can go for months without eating, relying instead on energy reserves in order to reproduce. Animals that do this are called capital breeders.
From August to November, humpbacks migrate southward back to Antarctica. Along the way, they sometimes take a “pit-stop” on parts of Australia’s east coast to feed.
It was originally thought this population never fed along the migratory route. However, we know they do now to possibly supplement their energy intake as they migrate.
Humpback whales migrate along the east coast of Australia annually for warmer breeding waters in the Great Barrier Reef. Dr Vanessa Pirotta
So why are these observations important?
Whales play important an important role in the ecosystem of the ocean because they feed in one area and poo in another.
This action — known as the “whale pump” — moves nutrients around the ocean. Their poo feeds tiny organisms, such as plankton, which are eaten by krill, and then eaten by whales.
Seeing these super group feedings highlights changes in our marine environment we might not have otherwise been aware of.
Bubble net feeding in Antarctica.
One possible explanation for this behaviour could be favourable environmental conditions. A combination of ideal water temperatures and nutrients may have resulted in an abundance of food, which saw large numbers of humpback whales feeding in the same area.
Or perhaps it has something to do with the recovery of the east coast humpback whale population, which has been increasing in numbers since whaling ended in the 1960s.
Humpback whales engulfing their prey after bubble-net feeding cooperatively off the New South Wales coast. Wayne Reynolds/Sapphire Coastal Adventures
Regardless, it’s important to understand how changes in the marine environment influence the extent humpback whales depend on feeding opportunities along their migratory route.
This will help to predict how whale populations respond to future changes in the ocean. This includes climate change, which will warm ocean temperatures and alter when and where the prey of humpback whales are found. As a result, humpback whales will also move to different locations.
One thing, at least, is abundantly clear: more eyes on land and sea through citizen science will provide a valuable opportunity to document such exciting future events. So keep your eyes peeled for whales this season, and be sure to tell a scientist if you see something unexpected.
A crocodile known locally as ‘Barrat’ emerges from the water of the lower Daintree River, Far North Queensland. Kevin Crook
Michael Bradley, James Cook UniversityThe wet season in tropical Australia begins with tension. Physical tension, caused by the friction of earth and clouds. Mental tension, caused by the heat, and the expectation of rain and relief. It is also an ecological tension, where every plant and animal is poised — genetically, physiologically — to grow, reap, sow and copulate within a few short months.
We call it the build-up. The tension builds, and then it breaks. It was at the point of breaking when Val Plumwood, a young philosopher from the temperate south, was taken by a crocodile.
She was an environmental activist, exploring Kakadu to experience the wilderness she’d had a hand in protecting. She was paddling upstream in a small, red, low-sided canoe when it began to rain. There are many attacks on visitors to the tropics, especially those in small watercraft, but we know more about this one than any other.
When Val began fighting for the protection of wild places in the 1970s, the saltwater crocodile was rare almost to the point of extinction. By the mid ‘80s they were protected, plentiful, and in remote places, lacked memory of the hunters’ gun. When Val climbed into her vessel that morning in 1985, she did so in good faith. They were not a known threat to someone travelling by canoe in a back channel lagoon.
But crocodiles are a threat. Young salties eat fish and crabs. As they grow, they move on to larger prey — dogs, pigs, people, horses and buffalo. Our species fits comfortably in their diet, slipping into the line-up between pigs and horses.
Crocodiles may be opportunistic hunters, but their encounters with prey aren’t chance. They think about it. They watch, and they learn. Wash your pots and pans on the riverbank every evening, and you are inviting an attack. For people along the coastline of the tropical arc between Eastern India and Australia, they colour the water’s edge with a lurking malice and the threat of a violent death.
A crocodile in Kakadu. Dean Lewins/AAP
We share our world with other dangerous animals. Sharks, for instance, kill every year. Poisonous snakes too. However, there is a difference. Snakes strike when threatened, usually by an unintentional kick in the ribs. Sharks do bite when unprovoked, but rarely, and they almost never consume us. We share our beaches with them, but you can spend your life in the water and never get bitten. The saltwater crocodile is a different beast, and it boils down to intent. As crocodile researcher Professor Grahame Webb has put it:
There is no way of avoiding nor sugarcoating the predatory nature of saltwater crocodiles. If you dive off the Adelaide River bridge, 60 km east of Darwin’s city centre, and start swimming, there is a 100% chance of being taken by a saltwater crocodile. It is not the same as swimming with sharks.
Like Val Plumwood, I too had come up north from the temperate south, and was not used to sharing my world with something that wanted to eat me.
There is a mountain range in north Queensland, cut off from the mainland by the sea. The space between is filled with a tangle of mangrove trees and snaking waterways. Heading down one of these channels in the early morning, my small boat cut around a bend, and on the far bank I saw a crocodile basking in the sun.
Hinchinbrook Channel, North Queensland. Kevin Crook
I eased back on the throttle and let my boat drag through the water. This was my chance to see one up close, as long as I didn’t scare it off. I was a young scientist, new to the tropics, and hadn’t yet seen a croc up close. I’d glimpsed them sliding off the banks as I motored past, or as eyes above the waterline, following my boat with interest.
I drifted closer, engine idling.
It was big. I turned the engine off to let momentum and the current take me closer. I didn’t want to disturb the creature. Apart from the occasional snapping of pistol shrimp in their burrows, the air was still and quiet. The forest around us was a deep green, reflected in the greasy green of the water. The mud bank was almost black with silt; waist-deep, from recent experience. I could see the heft of the animal as I approached.
Its muscular tail rested in an arc, and the great mass of its body bulged, unsupported on dry land. It didn’t flinch as I drew closer, it held its jaws open in a permanent, basking yawn.
Now I was close enough to see very clearly its long pointed teeth ringing the muscular bed of the lower jaw. I could see sinew and texture in the enormous muscle that connects upper and lower jaw, allowing it to slam the two shut with the bite force of Tyrannosaurus rex. I could see it too well. Current and momentum had conspired to bring me right to the bank where the animal lay. I was no longer worried about disturbing the creature. I was within striking distance. I was an outsider, intruding, and I was afraid.
The fear and fascination never quite reconciled. I had seen the crocodile as an indicator, both in the ecological sense, as my training had described, but also in a personal sense.
A crocodile in the mangroves of the lower Daintree River, Far North Queensland. Kevin Crook
Ecologists like indicator species, because they tell us about a complex world in a very simple way. They stand in for a whole range of factors.
A caddis-fly larva can tell you about the purity of the alpine pond you found it in, how recently it was frozen and the stability of the seasons. A stingray can tell you about the flooding patterns of a sandbank and the abundance of invertebrates therein. They do this just by showing up. Crocodiles, to me, indicated nutrient rich tropical waters providing a glut of large bodied prey. Warm winters and big barramundi.
The author baiting a camera trap. Sheree Marris
They indicated the sanctuary of the wild. Here was a place beyond the realm of humankind, remote, beautiful, and my place of work. They punctuated the landscape, and their presence transformed the place. In the temperate south, a bank in an inlet might be a good place to pull up for lunch, or cast a line. Here, it’s a place you don’t want to linger.
A floating log becomes an object of suspicion, and the value of a swimming hole, no matter how inviting, is measured in downstream barriers. We tend to hold crocs up as a symbols, and dangle the fact of their existence in front of southerners and tourists to prove our rugged credentials. But I had not reckoned with the animal itself.
As I fumbled for the ignition, the crocodile turned its full attention to me and slid down the bank. In one easy motion it slipped under the surface, and swam toward our boat.
I kicked the engine into gear. As the roar of my 15-horse motor sped us to safety, I wondered how on earth we live alongside these creatures. I also wondered how many of those 15 horses that croc could eat in its lifetime.
Living on the water’s edge
Crocodiles are not symbols — I was about to learn — they are living beasts capable of real material damage. I could venture into their world, but spent most of my time high above the waterline. For other people in that Indo-Pacific arc, contending with these animals is daily life. Work brought me to the islands of Papua New Guinea, where crocodiles are a threat to both people and property. While it might sound far flung, New Guinea is closer to my home in North Queensland than any Australian capital. It’s part of the same great landmass of Sahul, and shares a recognisable fauna and flora.
In the places I worked, people built their villages at the water’s edge, on volcanic black-sand beaches. That strip of coast contains all of everyday life; houses, fishing nets, canoes, livestock, children, dogs and cooking fires. So, when the largest reptile in the world crawls from the ocean of a nighttime, and carries away a squealing pig, it seems a reasonable price to pay. Especially considering the other potential prey sleeping in their beds.
Moving through a back channel of the Langalanga estuary, West New Britain, Papua New Guinea. Michael Bradley
I came across one of these sacrificial pigs, postmortem. I was investigating the small estuaries along the coast with a local man named Alfonse. We turned into a small creek, hidden from view by the angle of its entrance and a tall forest of mangrove trees. Estuaries in the tropics have a certain smell caused by things that want to rot, but don’t have the air to do so. Sealed under the mud, they turn black and change their chemistry. Mixed in with this is the salt, and the fresh-sap of the mangrove leaves. Some people hate it, but I relish it.
This creek had an altogether different odour. It was the smell of rotting flesh, but not the dry waft of roadkill by the side of the road. This was wet-rot. The pig had been stashed in a dead tree on the bank, and its skin was beginning to trail in the current. Crocodiles don’t like a fresh kill; they like to let it soften. That pig would have fed a village and perhaps been the central meal of a wedding or a funeral. Now it was bloating in the muddy water.
On a different trip, Alfonse told me the story of a fatal attack in his village. Alfonse is a serious man with a young family, a gentle sense of humour and a legitimate hatred of Malaysian logging companies. We were working in a system called the Langalanga, a great palm swamp, almost cut off from the sea. In the slanted afternoon light, the marine palms reflect crazily on the black water, and their fruit-rot nectar clots the air.
Some of Alfonse’s family were camped on the edge of the swamp, and had set out in a canoe to collect mussels — a happy scene repeated on occasion throughout the seasons.
A few years back, another family was doing the same, when the father was taken by a crocodile. As he was being dragged under by the legs, his wife held on to his arms, and in that brief battle there was enough time for him to say “take care of the kids”. By the time I left, a man from our team was taken by a crocodile somewhere in that same labyrinth of palms.
Late afternoon in the palm swamp, Langalanga estuary, West New Britain, Papua New Guinea. Michael Bradley
We are food
Crocodiles are murderous creatures. Not indifferent to our suffering, but actively in pursuit of it. They crave us, like we might crave a pizza, and they act on those impulses.
Val Plumwood learned this too, from the vantage point of her red canoe, as her path converged suspiciously with a floating log. The log was a crocodile, and from that point on, she was prey. The animal charged her craft several times. She tried to escape by climbing an overhanging tree. It burst from the water between her legs and clamped down on her torso. In that moment, in the force of realisation that accompanied the puncture wounds to her abdomen, she saw very clearly that she was food.
Murderous creatures: a crocodile in Kakadu. Dean Lewins/AAP
She was thrown into a death roll — crocodiles thrash with such force that all the air and struggle is sucked out of their prey, which they then hold underwater until drowned. Val, somehow, survived this experience. It was then repeated.
Incredibly, she surfaced and climbed to safety in the overhanging tree. She was plucked from the tree again, by her left leg, and the horror was repeated for the final time.
But, inexplicably, the crocodile’s jaws relaxed. Val wrestled free and scrambled up the mud bank. Her lower half was shredded, and she could see the raw meat of her leg muscle hanging from the bone. She staggered back through the bush until she began losing consciousness.
She gave out at the edge of the swamp, as the wet season floodwater rose around her. Here she accepted her end as food for the crocodiles waiting in the rising lagoon.
We know so much about this attack because Val survived it. But also because she was a philosopher. She didn’t just survive it, she thought about it, she examined its consequences, and she wrote about it.
The Australian philosopher Val Plumwood pictured in 1990. In her work, Val interrogated the human-nature dualism that lies at the heart of modern culture. Wikimedia Commons
One of the key Australian thinkers of our time, she challenged the way we look at the natural world. It took her the rest of her life to fully reckon with the experience of being prey. The result is a revelation of a book, pulled together posthumously, (Plumwood died of a stroke in 2008), called The Eye of the Crocodile. Val’s experience has become a centre point for me, around which all my encounters with crocodiles now pivot. The anchoring wisdom in a confusing set of facts and impulses.
At the heart of her insight is the knowledge that we are food — “juicy, nourishing, bodies” for the rest of the animal kingdom. We forget that. Or perhaps, we never really come to know it. Val knew, but when she found herself as prey, she rejected the idea. I’ll let her speak for herself here:
My disbelief was not just existential but ethical — this wasn’t happening,
couldn’t be happening. The world was not like that! The creature was breaking the rules, totally mistaken, utterly wrong to think I could be reduced to food. As a human being, I was so much more than food. Were all the other facets of my being to be sacrificed to this utterly undiscriminating use, was my complex organisation to be destroyed so I could be reassembled as part of this other being?
With indignation as well as disbelief, I rejected this event. It was an illusion! It was not only unjust but unreal! It couldn’t be happening. After much later reflection, I came to see that there was another way to look at it. There was illusion alright, but it was the other way around. It was the world of ‘normal experience’ that was the illusion, and the newly disclosed brute world in which I was prey was, in fact, the unsuspected reality, or at least a crucial part of it… both I and the culture that shaped my consciousness were wrong, profoundly wrong —about many things, but especially about human embodiment, animality and the meaning of human life.
In the end, we are just another animal, scratching around on the surface of the earth. Like a few other terrestrial vertebrates, we sometimes forage in shallow seas and there, form part of the coastal food chain. In the Indo-Pacific arc, at this moment in ecological history, that food chain finishes with the saltwater crocodile.
They are simply the inheritors of their evolutionary mantle, held long before we ever dipped our toes in the water. In our brief history on this earth, we have rarely been at the top of our own food chains.
We are food, and not just for crocodiles. We live our lives trying to avoid eye contact with the fact, but it is always there in our peripheral vision. We are victim to a constant gnawing of insects, bacteria, fungus, and when we die — no matter how hard we try to bury and embalm — we finally succumb. Diseases like Ebola haunt our collective imagination, but their worst symptoms are simply the failing of our own immune system to hold back the flood of decay that will find us all when we stop breathing.
‘Life as a circulation’
Ecologists no longer talk about food chains as if there is a top and a bottom. Food loops, cycles of productivity and nutrients, hold the great ecosystems of this earth in place, as vast organised structures of recycling viscera. Our denial of our place in them is what Val came to see as “dualism” — the belief in a hierarchy of nature with ourselves at the top; different, unique, separate. Outsiders on our own planet. Because of this, crocodiles seem like monsters of a senseless world, a world to be feared.
We think of ourselves as somehow separate from the rest of nature’s bloom and rot. This man vs wild illusion butts up against reality in ways that now threaten our existence.
The experience of being outside of nature allows us to deny the urgency of the many crises now facing our planet. We see the signs, but it is easy to distance the collapse of the natural world from the continuity of our own lives, and hold an unreasonable faith that the human world will go on indefinitely. But this is denial. Nature, as we know, can crush us in its jaws. To face the reality that confronts us as a species, we must feel like insiders — part of our own planet. But what would that look like?
In Arnhem Land, where Val was attacked, people have lived alongside crocodiles for thousands of years. They see themselves differently — not as outsiders, but as part of the landscape. Indigenous philosophies, such as those of the Yolngu, see human or animal life as existing for others, not just itself. The crocodile is not hideous for eating humans. They are animals to be understood and respected, through the kind of insider knowledge gained over thousands of years. They take life, but are also capable of acting in good faith.
A saltwater crocodile named Brutus pictured on the Bloomfield River, north of Daintree in Queensland, in 2014. Mike Darcy/AAP
Their maternal tenderness is equally important. They punctuate the landscape as powerful beings, reminding us to tread carefully, because the world is not arranged for our pleasure alone. This resonated with Val who understood “life as a circulation, as a gift from a community of ancestors”. Death, whether by crocodile or otherwise, is recycling, a “flowing into an ecological and ancestral community of origins”.
In the time it took me to write this, a man named Andrew Heard was taken from his dingy in that tangle of creeks in North Queensland where I still work. The police found his vessel upside down and some of his remains in the mangroves. They caught a four-metre crocodile, cut it open, and found the rest of him inside.
Then they killed another one. We could just keep going, get rid of them all. Fifty years ago, we almost did. At a time like this, with everyone reeling in shock, and grappling with some measure of personal fear, I understand the impulse.
I’m going out there again tomorrow, as usual. Older now, my fear and fascination have turned into something else. Despite their intentions for us, I like having them around. To me, they are indicators — but they indicate more than warm winters and big barramundi. They indicate a living world, giving and taking, and a society that’s starting to find its place in it.
As I motor down the creek, they punctuate the landscape, reminding me that we’ve decided, together, there are lives that matter beside our own. That despite the pain we may face in the future, we’re beginning to find our way. They indicate hope.
This essay received an Honourable Mention in the 2021 Nature Writing Prize.
However, the cultural heritage of the Wet Tropics isn’t recognised or celebrated with quite the same gusto, with the world heritage listing failing to acknowledge the rich, ongoing significance of Aboriginal culture.
Our recent paper assessed existing archaeological, paleoenvironmental, and historical evidence. And we showed the diverse ways these forests are globally significant — not just for their ecological heritage, but also for preserving traces of millennia of human activities.
But there’s much scope for cultural recognition to go further on a national level, too. While the Wet Tropics’ National Heritage Listing recognises Indigenous heritage, Traditional Owners should have more freedom to manage the region in our holistic way. This would lead to better outcomes for the environment.
The cultural significance of these rainforests
Aboriginal rainforest people used a wide variety of forest resources. For example, studies of ancient plant parts and stone tools show these communities were processing often-toxic rainforest nuts for eating from as early as 5,000 years ago.
Cassowaries may have once been tamed and then eaten in ceremonial feasts. Rene van Raders, Author provided
They also hunted local animals, such as tree kangaroos, pythons and wallabies. And they may even have captured and tamed the enigmatic cassowaries, later feasting on them during large ceremonial gatherings.
Rainforest people also used tropical forest plants for medicine and to manufacture artefacts. They also manipulated them – for example, evidence shows Aboriginal people strategically used fire to keep open pockets clear of invading rainforest for campsites and ceremonial grounds.
Their skillful forest management enabled pre-colonial Aboriginal populations to survive all year round in rainforests characterised by high humidity, rainfall, cyclones, heat, and dense vegetation.
Today, we can still see Aboriginal people’s ecological legacy in the region, such as through the clusters of rainforest food trees near cultural sites.
The long fight for recognition
Aboriginal rainforest occupation and land management was majorly impacted with European settlement across the region, and the subsequent clearing of rainforest for agriculture.
Aboriginal rainforest people were forcefully removed from their traditional lands and resettled on reserves and in missions, often far away from their homelands.
Traditional land practices were suppressed, which caused these rainforests to change. Weed infestations and feral pigs became widespread. Likewise, the rainforest understory thickened, as any area not felled by Europeans was left to “look after itself”.
After Aboriginal people were forced from their land, the rainforest understory thickened and became a bushfire risk. Shutterstock
These changes have exposed both biological and cultural heritage to increasingly intense fires, such as those we saw in the horror bushfire season of 2019-2020.
Since the World Heritage Area was declared in 1988, rainforest Aboriginal peoples have campaigned to be included in management plans.
In 1998, they produced the seminal report “Which Way Our Cultural Survival”, which reviewed the significant contribution rainforest Aboriginal people make to managing the Wet Tropics World Heritage Area.
Finally, in 2012, the Australian National Heritage List recognised the Wet Tropics’ cultural values. This is extremely important because it gives rainforest Aboriginal people a seat at the table in management decision making.
The northern bettong (or ‘rat kangaroo’) is one of the species benefiting from Indigenous knowledge. inaturalist/Wikimedia, CC BY-NC-ND
Rainforest Aboriginal people’s long fight for recognition in the Wet Tropics is now turning into direct action, as we apply our unique knowledge to Country. Today, Indigenous land and sea rangers manage biodiversity, threatened species, waterways and water quality, and we care for country through fire management programs.
For example, there are numerous management plans for threatened species that need a defined fire regime. This includes the northern bettong, whose forest habitat on the edge of rainforest requires frequent burning to keep the understorey open and grassy. Indigenous knowledge forms the basis of this.
But our campaign isn’t over yet
On a national level, we need to manage Country as a “whole”, not just one species at a time.
Fire is an integral tool for this management, and we need to apply the right fire for the right Country (something we’re showing through the Firesticks Alliance Indigenous Corporation). In traditional fire management, the dominant tree species and soils in a specific area determines the fire to apply to Country, and at what time of year. There’s no “one size fits all” solution.
Indigenous land managers care for country through fire management programs. Gerry Turpin, Author provided
Our research paper makes it clear “long-term” perspectives from oral history, archaeology, history, and paleoecology can make important contributions to conservation management plans for threatened species. This includes the northern bettong, cassowary and tree kangaroo.
Knowledge from Traditional Owners can also add important information on vegetation change over several decades. This knowledge allows us to reconstruct vegetation changes since European settlement. It also provides insights into past Aboriginal use of plants and animals, and mapping cultural sites and walking routes.
One example shows the potential for this. In September 2019, a Queensland government grant supported Jirrbal Traditional Owners to return to Urumbal Pocket, an archaeological site on the upper Tully River. Jirrbal Traditional Owners undertook surveys to identify imprints of past human activities left on the landscape.
A view of Urumbal Pocket from opposite side of the Tully River. Asa Ferrier, Author provided
They found significant changes to the region’s biodiversity since the removal of Aboriginal land management around 100 years ago. They noted, for example, that no new trees were naturally growing, and remnant sclerophyll tree species were dying, enhancing the rainforest takeover.
The visit also helped Traditional Owners reconnect with their Country, and initiated discussions relating to contemporary burning and other land management tools.
We need equal recognition of the Wet Tropics’ natural and cultural values, and more detailed investigations into how people shaped the rainforest. This will help raise awareness of the international importance of the cultural heritage, and eventually help get it recognised by UNESCO.
And this will help more Australians see the rainforest as a cultural landscape – one that has been managed and maintained by people, rather than just a relic unchanged since the dinosaurs.
The authors gratefully acknowledge the contributions of Ellen Weber from the Wet Tropics Management Authority.
Net-zero means emissions are still being generated, but they’re offset by the same amount elsewhere. Tasmania reached net-zero in 2015, because its vast forests and other natural landscapes absorb and store more carbon each year than the state emits.
And in November last year, Tasmania became fully powered by renewable electricity, thanks to the island state’s wind and hydro-electricity projects.
The big question for Tasmania now is: what comes next? Rather than considering the job done, it should seize opportunities including more renewable energy, net-zero industrial exports and forest preservation – and show the world what the other side of net-zero should look like.
Hydro-electric power and wind energy mean Tasmania runs on 100% renewable energy. Shutterstock
A good start
The Tasmanian experience shows emissions reduction is more straightforward in some places than others.
The state’s high rainfall and mountainous topography mean it has abundant hydro-electric resources. And the state’s windy north is well suited to wind energy projects.
What’s more, almost half the state’s 6.81 million hectares comprises forest, which acts as a giant carbon “sink” that sucks up dioxide (CO₂) from the atmosphere.
Given Tasmania’s natural assets, it makes sense for the state to go further on climate action, even if its goals have been met.
The Tasmanian government has gone some way to recognising this, by legislating a target of 200% renewable electricity by 2040.
Under the target, Tasmania would produce twice its current electricity needs and export the surplus. It would be delivered to the mainland via the proposed A$3.5 billion Marinus Link cable to be built between Tasmania and Victoria. The 1,500 megawatt cable would bolster the existing 500 megawatt Basslink cable.
But Tasmania’s climate action should not stop there.
The Marinus Link would provide a second electricity connection from Tasmania to the mainland. http://www.marinuslink.com.au
Other opportunities await
Tasmania can use its abundant renewable electricity to decarbonise existing industrial areas. It can also create new, greener industrial precincts – clusters of manufacturers powered by renewable electricity and other zero-emissions fuels such as green hydrogen.
Zero-emission hydrogen, aluminium and other goods produced in these precincts will become increasingly sought after by countries and other states with their own net-zero commitments.
Tasmania’s vast forests could be an additional source of economic value if they were preserved and expanded, rather than logged. As well as supporting tourism, preserving forests could enable Tasmania to sell carbon credits to other jurisdictions and businesses seeking to offset their emissions, such as through the federal government’s Emissions Reduction Fund.
The ocean surrounding Tasmania also presents net-zero economic opportunities. For example, local company Sea Forest is developing a seaweed product to be added to the feed of livestock, dramatically reducing the methane they emit.
Retaining, rather than logging, Tasmania’s forests presents an economic opportunity. Shutterstock
These updates give Tasmania a chance to be a global model for a post-net-zero world. But without firm action, Tasmania risks sliding backwards.
While having reached net-zero, the state has not legislated or set a requirement to maintain it. The state’s current legislated emission target is a 60% reduction by 2050 on 1990 levels – which, hypothetically, means Tasmania could increase its emissions in future.
Also, despite reaching net-zero emissions, Tasmania still emits more than 8.36 million tonnes of CO₂ each year from sources such as transport, natural gas use, industry and agriculture. Tasmania’s emissions from all sectors other than electricity and land use have increased by 4.5% since 2005.
Without a net-zero target set in law – and a plan to stay there – these emissions could overtake those drawn down by Tasmania’s forests. In fact, a background paper prepared for the Tasmanian government shows the state’s emissions may rise in the coming years and stay “positive” until 2040 or later.
The legislation update should also include a process to set emissions targets for each sector of the economy, as Victoria has done. It should also set ambitious targets for “negative” emissions – which means sequestering more CO₂ than is emitted.
Tasmania must cut emissions from industry and other sectors. Shutterstock
Action on all fronts
Under the Paris Agreement, the world is pursuing efforts to limit global warming to 1.5℃ this century. For Australia to be in line with this goal, it must reach net-zero by the mid-2030s.
Meeting this momentous task requires action on all fronts, in all jurisdictions. Bigger states and territories are aiming for substantial emissions reductions this decade. Tasmania must at least keep its emissions net-negative, and decrease them further.
Tasmania has a golden opportunity. With the right policies, the state can solidify its climate credentials and create a much-needed economic boost as the world transitions to a low-carbon future.
Kevin's Walk on the Wild Side 