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Scientists pointing to green shoots of hope in unfolding catastrophes

Monitoring Desk

They read like scenes from a disaster movie, vignettes of a natural world slipping into decay.

In the tropical wet rainforests of far north Queensland, outside Cairns, an estimated 23,000 spectacled flying foxes – one-third of Australia’s total population – drop dead from the trees over just two days.

Across the continent in Western Australia’s world heritage-listed Shark Bay, a summer heatwave kills about a third of the area’s seagrass meadows, triggering a sharp fall in populations across the local marine ecosystem, including dolphins, dugong and turtles, and forcing commercial fisheries to abandon the area for years.

Down the Darling River in outback New South Wales, a million fish float belly-up to the surface of Menindee Lakes in one deadly summer burst. Many are threatened Murray cod, some of them up to 100 years old.

A scientist surveys the Gulf of Carpentaria from a helicopter
A scientist surveys the Gulf of Carpentaria from a helicopter, where a drought and heatwave killed off mangroves. Photograph: James Cook University

In the remote Gulf of Carpentaria, a prolonged and severe drought capped off by 18 days in which the maximum temperature never falls below 38.8C kills up to a quarter of the dense mangrove forests in some areas, triggering cascading shocks through reliant species and local communities.

These are just a handful of the catastrophes from the past decade included in a landmark paper by dozens of the country’s most respected scientists as part of a list of collapsing ecosystems across Australia and Antarctica.

Published in the peer-reviewed journal Global Change Biology, the study digs into the data for 20 struggling ecosystems and finds 19 have substantially changed, have a low likelihood of recovery and are heading towards permanent collapse.

As well as setting out the problem, the paper also focuses on what can be done to address it. It recommends a new way of responding that the scientists call the “3As” – short for improved awareness of the value of ecosystems, better anticipation of risks and rapid action to reduce them.

Prof Lesley Hughes, an ecologist, pro-vice-chancellor (research) at Macquarie University and one of the paper’s 38 authors, says many of the ecosystems are at a tipping point. For some, the change come abruptly – in a matter of weeks or months – but for others there was a slow decline over decades, or longer.

“The other message to take from this is simply the breadth of it,” she says. “It’s important we understand this is not just the Great Barrier Reef. These are ecosystems that go from the wet tropics to Antarctica, and many in between.”

Among the most shocking examples of collapse in the past couple of decades are the near freefall decline of sub-alpine forests across NSW and Victoria, where fires are now too frequent for the species to seed and grow, and the disappearance of Tasmania’s once omnipresent giant kelp forests due to marine heatwaves and the arrival of urchins that thrive in warmer waters. The best-known example is the unprecedented three mass bleaching events to hit the Great Barrier Reef in just five years, causing significant coral death.

These stories are simultaneously familiar and absent in the Australian political and media discussion – referenced, but mostly not treated seriously enough to justify elevating to alongside the economy or defence as a matter of national importance. It’s just the environment, after all.

The scientists say this lack of national focus fails to grasp not only the intrinsic value of the ecosystems in their own right, but their vital importance to human wellbeing and survival. The ecosystems in collapse provide water and food and support livelihoods across the continent.

The paper explains that the ecosystems are collapsing due to both chronic pressures and acute “pulses” that come and go in a rush.

Some of the thousands of spectacled flying foxes who succumbed to heat stress near Cairns
Some of the thousands of spectacled flying foxes who succumbed to heat stress near Cairns. Photograph: Lisa Eagleton/The Guardian

Hughes says climate change is the “big black cloud” sitting above a host of other long-term pressures, including environmental destruction due to industry, agriculture and urban expansion, pollution, over-extraction of fresh water, invasive species and over-harvesting of marine species.

The most disastrous signs of collapse are sometimes seen during rapid-onset extreme events such as heatwaves, fires and storms, but the impact on the ecosystems is cumulative. In the case of the spectacled flying fox, habitat loss and an underlying 1C average temperature increase over the past century were squeezing the species, long before an extreme heat spike caused an overnight disaster.

Hughes says coral reef bleaching and the mass fish kill at Menindee Lakes were other examples of cases where “there has been an underlying threat bubbling along for a long period of time and then a sudden brutal event tips things over”.

Dr Justine Shaw, a conservation ecologist with the University of Queensland and one of the initiators of the research, suggests it is a disaster that has been building in plain sight – that while the abrupt catastrophes were alarming, “if you talk to the scientists who work in the area, in most cases they were not really surprised”.

The scientists’ diagnosis is broadly consistent with other studies and reports to government, including the 2017 state of the environment report and the review of national environment laws by the former competition watchdog chief Graeme Samuel. Both stress that Australia’s natural heritage is in sharp decline and urgent change is needed.

Where the latest report differs from previous major government reports is its depth – it goes beyond a helicopter assessment and looks at what is happening within ecosystems.

Australia has a famously poor record in species protection, a point reinforced by government data released this week that again confirmed it has the world’s worst mammalian extinction rate. More than 10% of land mammals have been lost since European colonisation. The number of species of all types at risk is expected to have vaulted after last year’s catastrophic bushfires, in which it is estimated nearly 3bn animals were killed or affected.

The scientists who spoke to Guardian Australia stress that while there is rightly a focus on species loss, ecosystems – the complex webs of interdependent species within a specific environment – are harder to recover when they begin to decline.

Prof Brendan Wintle, a conservation biologist at the University of Melbourne and the director of the government-backed Threatened Species Recovery Hub, says public consciousness and was more attuned to threatened species – things with fur, faces and characters – than to entire ecosystems, but the report’s attention to those ecosystems was welcome and needed.

A kelp forest at Barrenjoey Island in Tasmania
Tasmania’s giant kelp forests have been hit by marine heatwaves. Photograph: Thomas Schmitt/Getty Images

He expects the focus will increasingly shift from protecting species to ecosystems in the years ahead for a simple reason: “We will start to see more concern towards collapsing ecosystems because it represents an existential risk to us.”

Scientists say monitoring of ecosystem health is almost non-existent, due in part to a lack of funding. Developments are generally approved on an individual basis, rather than the cumulative impact on whole ecosystems being considered. They say too little has been done to find ways to deliver the things humans need – housing and water and food – in a way that maintains the natural systems that sustain them.

Hughes says ecosystems are being hit by “multi-scaled problems that need multi-scaled solutions”. “Dealing with just one at a time doesn’t address the problem,” she says. “You need to deal with all of them.”

The paper doesn’t overplay how easy it is to do this but focuses on what could be achieved. It starts from a simple principle: in many cases – and particularly for high-profile examples including the Great Barrier Reef and the Murray-Darling basin – the solutions are known.

The report gives examples where there have been positive responses after catastrophic events. In early 2016, thousands of dry lightning strikes exacerbated by rising global temperatures sparked wildfires across Tasmania, including in ancient alpine ecosystems unique to the state’s world heritage wilderness.

We really need legislation that prioritises our life support system … We can’t just deal with one hectare at a time

Prof Lesley Hughes

Gondwanan species that had lived more than a thousand years and had not historically burned, such as pencil pines, were killed on the state’s central plateau. It led to warnings that governments should be doing more to protect internationally recognised landscapes as part of their fire response.

Shaw says the reaction in the wake of the fires has been heartening: the state’s Parks and Wildlife Service has installed sprinkler and fire retardant systems close to the central plateau so it will be able to respond more quickly and effectively next time.

“The Tasmanian story is a sign of what you can do,” she says. “The challenge is that in places like the Great Barrier Reef, the Murray-Darling basin and mountain ash forests the scale is huge but I would say it shows, at some scale, we can know what is necessary and what can be done at a local level.

“Put another way, what is happening is depressing because the problems are complex, but not because we don’t have the answers.”

The question is whether those answers are sought, let alone listened to. The Morrison government’s initial response to the Samuel review’s damning assessment of the state of the environment has been to introduce legislation that would hand development approval powers to the states and territories – a step that did nothing to improve ecosystem or species protection.

Hughes says here lies the glaring problem. “The issue is we don’t currently have a government that is tackling this,” she says. “We really need legislation that prioritises our life support system and is capable of dealing with complex and interacting risks. We can’t just deal with one hectare at a time.”

Sitting atop all this is the climate crisis, a problem not within Australia’s control, but on which the government is facing rising international pressure for not joining other countries in promising to do more.

The first signs of regrowth in a bushfire-hit forest
The first signs of regrowth in a bushfire-hit forest. Photograph: Joel Carrett/AAP

Prof James Pittock, of the Fenner school of environment and society at the Australian National University, recommends taking decisions out of politicians’ hands by introducing a built-in requirement to do less damage over time. He says far more attention should be paid to “no regret actions”, such as limiting invasive species and replanting to link wildlife corridors that would help the environment better cope with inevitable climate change.

The paper’s lead author, Dr Dana Bergstrom from the Australian Antarctic Division, stresses a key message: that ecosystems are not just for the animals and plants that live in them.

Speaking before the report was released this month, she said she hoped the “3As” mantra of improving awareness, anticipation and action would take hold.

“The point is our economic livelihoods, and ultimately our survival, are intimately connected to the natural world.”

Courtesy: The Guardian