For three years before the Black Summer megafires of 2019–20, cool season rainfall in southeastern Australia was only half that of normal. When fires broke out, intensely dry conditions helped them spread through areas typically resistant to burning, such as wetlands and rainforests.

After the fires came three years of above-average rainfall, and scientific reports charted rapid vegetation regrowth.

It’s easy to think the rains let nature repair itself. But is that the full story? In our new research, we looked at what happened to seven severely burnt plant communities in the Greater Blue Mountains, west of Sydney.

We found a mixed picture. Wet sclerophyll forests supporting tall eucalypts skirted by ferns recovered within five years. But Blue Mountains rainforests did not recover from burns of any severity. Nor did grassy woodlands.

How can we track recovery?

To find out how well forests and other communities recovered from the Black Summer fires, we tracked recovery across the million-hectare Greater Blue Mountains World Heritage Area. Seven severe fires hit this region over the 2019–20 summer. The biggest was the Gospers Mountain fire, which burned an area seven times the size of Singapore – the largest fire from a single ignition point in Australia’s recorded history.

Five years on, if you had looked out across the Blue Mountains landscape you might have thought recovery was well under way. Thick scrub quickly replaced charred undergrowth in many areas. Across our study sites, many burned regions had denser understoreys – the layer of vegetation between forest floor and canopy – than unburnt areas.

But recovery isn’t just about how much vegetation is there. It’s about whether the layers of shrubs and canopy trees that make up a functioning plant community have returned to their previous state.

After fire moves through, some plant species rapidly regrow, outcompeting their rivals for light and water. But these species are often short-lived, failing to survive beyond a few years. On the other hand, species such as eucalypts and banksia may take years to regrow but then live much longer.

This means depending on when we take our measurements, we might mistake a temporary pulse of growth for real recovery.

To address this issue, our study tracked plant growth using a time-series of satellite images. This way, we could see the full trajectory of recovery, not just a snapshot.

A plant community that has fully recovered from burns will look stable year to year and mirror patterns of growth at unburnt sites. Poorly recovered areas, in contrast, will show distinct fluctuations.

We used this method to track recovery from low- to extreme-severity fire at 760 forest, heath and wetland sites in the Greater Blue Mountains region.

What did we find?

An earlier large-scale synthesis two years after the Black Summer fires found wet forests had suffered greater declines than drier plant communities.

Our findings five years after the fires tell a more complex story.

Some wet forests, such as wet sclerophyll, were able to take advantage of the heavy rains to recover fully within five years.

Others were less fortunate. The Blue Mountains are home to rare remnant rainforest, featuring stands of trees such as coachwood, lilly-pilly and sassafras, whose ancestors date back to Gondwana. We found these had not recovered after fires of any severity.

The region’s grassy woodlands also showed no sign of recovery when burned, despite being dry, open areas.

Why? We suggest the intense rains following Black Summer made it difficult for the community’s characteristic grasses and tussocks – adapted to dry conditions – to successfully re-establish.

What if the big dry hadn’t ended?

The years of heavy rain after the Black Summer fires were unusual. If drought had continued, would we have seen different recovery outcomes?

To tease out this question, we modelled what recovery would have looked like for plant communities under drought stress.

Simply put, all would be worse off. In particular, wet sclerophyll forests and freshwater wetlands showed declines five times greater than other plant communities.

This is likely due to the fact that the plant species in these ecosystems need heavy rainfall to re-establish. For instance, freshwater wetlands often need to be completely flooded for species to return.

These communities may be pushed to the point of collapse if drought persists after the next megafire.

What can we do?

Ferocious fires have swept through Europe in recent months and the southern summer is likely to coincide with a strong El Niño event, bringing a higher risk of intense heatwaves, drought and fire.

As climate change accelerates, these extreme conditions will become more common. To protect our plant communities, we must tailor our fire-management strategies. No two communities respond to fire the same way, and recovery outcomes differ greatly depending on whether post-fire conditions are hot and dry or cool and wet. A one-size-fits-all approach won’t work.

During the Black Summer fires, a team of firefighters protected the last wild stand of the ancient, fire-averse Wollemi pine in the Blue Mountains.

To help rainforests and other fire-averse plant communities survive, we will need technologies that help us rapidly detect and suppress new fires – and long-term monitoring programs to let us know when species are at risk.

In other landscapes, we must rethink our reliance on fuel-reduction burns. This is because plants are at higher risk of damage from fire if they have been frequently burnt in the past. When we repeatedly burn an area, we inflate this risk and condemn many plants and animals to staggering losses in future fires.

Of course, all these efforts won’t matter if we fail to tackle the underlying reason why fires are getting more frequent and severe – climate change.

Emily Simpson, Doctoral Candidate in Ecology, University of Sydney; Aaron Greenville, Senior Lecturer in Spatial Agricultural and Environmental Sciences, University of Sydney; Chris Dickman, Professor Emeritus in Terrestrial Ecology, University of Sydney, and Glenda Wardle, Professor of Ecology and Evolution, University of Sydney

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

The lethal H5N1 strain of avian influenza is rapidly spreading along the coast of southern Australia, where it has killed thousands of wild birds and infected at least two long-nosed fur seals.

So where will it travel next, and what damage might it inflict? Much is uncertain, especially because many of Australia’s animals and ecosystems are so unlike those in other parts of the world.

But monitoring is vital if we are to understand the magnitude of this H5N1 outbreak and protect our most vulnerable species, including the threatened Australian sea lion.

What may be coming

It’s difficult to know how Australia’s current H5N1 crisis will unfold. But we can make four predictions, based on existing knowledge.

Waterfowl will carry the virus inland

Infected waterfowl from coastal southern Australia – such as ducks, herons and swans – will soon carry H5N1 to inland wetland systems. The timing is terrible.

In coming months, the hot and dry conditions created by the El Niño climate pattern will cause those wetlands to shrink. This means vast numbers of waterfowl, already debilitated by scarce resources, will congregate at the few remaining water sources. Weak flow and high densities of dead and dying birds will turn this water into a virus-contaminated soup, leading to further losses.

Macquarie Island’s wildlife will suffer major losses

To date, the significant seabird, seal and king penguin colonies on Macquarie Island have escaped the virus. However, H5N1 has devastated similar colonies on many other subantarctic islands, such as Keguelon and Crozet Islands.

Macquarie’s luck will soon run out, leaving its densely packed colonies of penguins, seals and petrels extremely exposed. In response to this threat, the Australian government has evacuated researchers from the island to protect their physical and psychological health.

Shearwaters will be widely infected

Within a few weeks, vast flocks of shearwaters will return from their global migration to nest on islands off southern Australia, such as those in Bass Strait. Bird flu, likely carried by other seabirds, will await them there. Losses may be substantial.

Scavengers will carry the virus beyond the coast and wetlands

Foxes, roaming cats, mynahs and other scavenger animals will bring H5N1 to our cities. This will have far-reaching impacts on urban wildlife, such as magpies and possums, consistent with declines of urban species overseas.

There is hope

However, it’s not all doom and gloom.

Bird flu has not yet caused extinction of any species elsewhere in the world. And after the initial outbreak, some affected species have started to recover – in some cases because survivors have stronger immunological responses. This should happen in Australia too.

What is critical now is assessing the conservation impacts of H5N1 on our wildlife.

Counts of dead birds tell us something about the flu’s spread and virulence. But while every death is saddening, corpse tallies alone don’t reflect conservation impact.

For example, thousands of greater crested terns have been killed by H5N1, but these deaths represent a fraction of the global population, estimated to number between 150,000 and 1.1 million. In contrast, there are only about 3,000 Christmas Island frigatebirds in existence, so any losses would be disastrous for that population.

What’s more, counts of deaths can be unreliable as many corpses may never be discovered. Instead, governments should focus on the proportion of a species’ total population that is killed by bird flu. This will allow us to assess the conservation consequences and, over time, the extent of recovery.

Assessing impact is not always straightforward

However, population-level impacts may be challenging to assess.

We have good estimates of population sizes for only a few Australian animal species. Fortunately, this includes some species that are most vulnerable to H5N1, including colonial-breeding seabirds and seals.

Without this data, monitoring can be used to estimate population density at a series of sampled sites or the incidence of certain bird species. Some current monitoring programs, such as the long-running aerial survey of waterfowl across eastern Australia, could provide critical data about the impacts of bird flu.

Interpreting monitoring data can also be complex. In inland Australia, the numbers of many species bounce around, particularly when the weather fluctuates between being wet or dry. With this statistical “noise”, identifying any population declines caused by bird flu is difficult.

There are biases and gaps in monitoring data. Most native mammals are not monitored, so we may have no idea how many die from H5N1. Losses in birds found in remote areas, such as the Heard Island black-faced sheathbill, are also likely to be missed due to lack of regular monitoring.

Where to from here

To understand the nuanced impacts of H5N1 bird flu, monitoring should assess the effectiveness of management actions, changes in breeding success and levels of immunity, mutations and the virulence of the virus itself.

It should also investigate survival rates of infected individuals, the broader environmental risks of losing large numbers of key species and the extent of recovery. Recovery may be harder and take longer for species that have low breeding output and take many years to mature, such as albatrosses.

Without effective monitoring, we will not grasp the true magnitude or significance of the current H5N1 outbreak. It’s what we need to both target emergency responses to the most affected species and measure the extent to which our actions are actually helping.

John Woinarski, Professor of Conservation Biology, Charles Darwin University

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

Australia’s Macquarie Island lies deep in the Southern Ocean, about 1,500 kilometres southeast of Tasmania. This World Heritage-listed sanctuary is a haven for species such as elephant and fur seals, penguins, albatrosses and petrels, and a key site for wildlife researchers.

But it is not safe from H5N1 bird flu. This lethal virus is rapidly spreading across the Australian mainland and Southern Ocean, already hitting other sub-Antarctic islands including Heard Island.

However, the Australian government has decided to withdraw all 24 expeditioners – including scientists, tradespeople and support staff – from the site. It says this is mainly to protect them from the psychosocial risks – the psychological harms of working in stressful or traumatic conditions – associated with living through a potential H5N1 outbreak and the wildlife casualties it may cause.

Those risks are real. Witnessing mass wildlife deaths could be deeply distressing for any person. But taking everyone off the island means the scientists who work there cannot document an outbreak as it unfolds, or understand what is happening to wildlife populations we have studied for decades.

At Macquarie, monitoring is vital

Scientists have worked at Macquarie Island for more than 70 years, and withdrawing all personnel will disrupt long-term wildlife, climate, atmospheric and geological monitoring, well beyond the bird flu response.

For southern elephant seals, the stakes are particularly high. The species is considered “vulnerable” on the IUCN Red List and under Australia’s Environment Protection and Biodiversity Conservation Act. Decades of monitoring show numbers of breeding females at Macquarie’s major colony have fallen sharply, dropping from 9,400 in 1949 to 2,550 in 2023. The federal recovery plan for this species identifies disease outbreaks as a threat and calls for regular, scientifically robust monitoring.

Bird flu is precisely this type of threat.

At Australia’s Heard Island, more than 13,000 elephant seal pups died during a recent H5N1 outbreak, while the number of breeding females fell by almost half at monitored sites on Britain’s South Georgia. The Australian Antarctic Division itself identified the need for 2026-27 population data to assess the impact of bird flu on Macquarie Island. But the government has now reversed course in withdrawing the island’s staff.

Psychosocial risk is real

Psychosocial or ecological grief – distress associated with the loss of species and places people care about – is well documented among conservation professionals.

But avoiding exposure to loss isn’t the only answer. Guidance from the World Health Organisation emphasises preparation, training and dedicated mental health and psychosocial support for personnel working in difficult emergency environments.

Other nations have already faced this problem. At other sub-Antarctic islands such as South Georgia, Crozet and Kerguelen and the Falklands, authorities boosted biosecurity measures – including providing personal protective equipment and guidance on wildlife sampling – to maintain essential science and disease surveillance. Similarly, the international Scientific Committee for Antarctic Research Action Group on Wildlife Health recommends assessing which activities should continue during outbreaks and outlines appropriate protective measures.

This raises important questions about how Australia reached its decision. Did the government seek advice from other programs that have successfully monitored outbreaks? Could a smaller specialist team remain with additional training, shorter deployments and dedicated psychological support?

The government hasn’t indicated what the long-term plan will be. Bird flu may not arrive this summer. Elsewhere in the Southern Ocean, outbreaks have recurred across multiple years. If the virus arrives next year or stretches over several years, will expeditioners be withdrawn indefinitely?

Can cameras replace scientists?

After Australia’s personnel leave, the government may rely on live cameras, drones and satellites to monitor Macquarie Island. These tools will be useful. At Heard Island, drones were invaluable for measuring the enormous scale of mortality.

But remote monitoring cannot replace biological sampling. A camera cannot swab a freshly dead pup, collect blood from a surviving animal or conduct a postmortem.

Across Crozet, Kerguelen, Heard, South Georgia and the Falkland Islands, scientists sampled dead and apparently healthy wildlife during major outbreaks. These samples confirmed infections, detected antibodies in survivors and enabled viral sequencing. In our recent research, 104 new virus genomes collected across six sub-Antarctic and Antarctic locations allowed us to map transmission over thousands of kilometres and show how the virus continues to evolve, including adapting to mammals.

Without field samples, we lose crucial information about how the virus is evolving and spreading, limiting our ability to anticipate what happens next.

Remote should not mean out of sight and out of mind

Surveillance, testing and reporting have been a top priority in our bird flu response on the Australian mainland. It should be no different on Macquarie Island, even though it is a remote location.

We cannot stop animals from dying if the lethal virus strain arrives. But we can understand which species are affected, which animals survive and where the virus may travel next.

We have monitored Macquarie’s declining elephant seal population for decades. We should not avert our eyes now.

We say this as scientists who have studied bird flu outbreaks and witnessed devastating wildlife losses firsthand. We are prepared for the difficult reality of studying wildlife disease. But what is much harder to accept is being forced to look away when science could still make a difference.

Jane Younger, Senior Lecturer in Southern Ocean Vertebrate Ecology, Institute for Marine and Antarctic Studies, University of Tasmania; Amandine Gamble, Assistant Professor, Department of Public and Ecosystem Health, Cornell University, and Augustin Clessin, PhD Candidate, Centre d'Ecologie Fonctionnelle et Evolutive, Université de Montpellier

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

Ever found a bare-nosed wombat napping under your house or heard a possum thumping around in your roof?

You’re not alone. Data from Wildlife Victoria reveals that about 2,400 native animals were reported by people as being in, on or under buildings over the past decade.

For our new study, we analysed these reports to find out which animals were taking up residence in buildings, which parts of dwellings they occupied and what they were doing there.

We uncovered 36 native species that either nest, forage or sleep in our homes, ranging from microbats sleeping in curtains to pacific black ducks nesting on balconies. These encounters show buildings have become de facto habitat for many animals with whom we share our cities.

As Australia races to build more houses, we must design them with at-risk animals in mind. Their survival may depend on it.

Unexpected residents

Our new research reveals wildlife use almost every part of buildings.

Building cavities are the most popular option, with 40% of studied species taking up residence between walls. We found 19% of animals in shelters and structures such as garages and 16% in external surfaces such as eaves, balconies and tops of roofs.

About 10% of animals were found living in interior rooms like bedrooms and kitchens, 9% in spaces under houses and 6% in utility services such as heaters and air conditioners.

These building features often serve similar functions to natural habitats. Roof and wall cavities replicate the conditions of tree hollows. Spaces under houses resemble sheltered ground or burrows. Balconies provide elevated ledges that act as cliff edges. Aircon and water heaters can become ideal microclimates for reptiles.

The habitat gap

Buildings are becoming increasingly important for conservation, as natural habitats rapidly disappear from our urban landscapes.

Natural features such as tree hollows – on which more than 300 Australian native species depend – can take centuries to form. Research shows the number of large, hollow-bearing trees in urban areas is declining. And replacement saplings won’t grow and provide habitat for a very long time.

Ecologists are working to address this gap by developing nest boxes, carved hollows, bee hotels and other creative solutions.

Relying on buildings for habitat is precarious. A renovation or repair can erase it overnight. Exclusion – using physical barriers or devices to keep wildlife out of buildings – may be necessary if an animal poses a genuine health, safety or welfare risk. This is best done by an expert wildlife carer.

The problem is not exclusion itself. Rather, it is the act of excluding an animal and removing its shelter without considering other safe alternatives. This approach will only exacerbate Australia’s extinction crisis.

Our research suggests there’s another largely overlooked way to protect our most vulnerable animals: adapting our houses.

Homes as habitat

Australia has a national target to build 1.2 million homes over the next five years.

Constructing a new home involves making many decisions, from where roof cavities will go to whether precious soil is concreted over. Together, these choices shape whole neighbourhoods, including whether they contain vital habitat or force local species to go elsewhere.

Meanwhile, Australia is strengthening standards around the energy efficiency of houses. For example, new builds must be properly sealed to limit air leaks, which account for between 15–25% of heat lost from homes in winter.

However, an energy-efficient home does not need to be a wildlife-free place. Habitat features can be weaved into house designs.

In Scotland, regulations require new buildings to have “swift bricks”, a type of nest box that can be installed in external walls as habitat for the common swift (Apus apus) population.

In Germany’s Brantstrasse building, designers have included swift bricks, bat boxes and hedgehog nest boxes in the actual structure. These approaches show adapting buildings for wildlife can be easy and effective.

Australia currently has no such policy. But several grassroots initiatives are emerging such as wildhouses, where builders fund one standalone bird, bat or glider nest box for every building they construct.

Urban designers and planners are increasingly designing cities with wildlife in mind. This approach, known as biodiversity sensitive urban design, aims to construct urban environments that minimise threats to plants and animals while accommodating their resource needs.

For example, a new suburb may decide to plant flowering meadows instead of lawn in streetscapes and parks. Both Canberra and Adelaide have adopted this approach in policy.

Where to from here?

Adapting buildings for wildlife must be based on robust ecological research. Certain features such as bird spikes, netting and reflective glass are designed to keep wildlife out. This so-called “hostile architecture” can wound and even kill animals.

In some cities, the design of buildings may favour a handful of urban-adapted species. In Melbourne, for example, a lack of suitable habitat for smaller forest birds such as fairy wrens and yellow robins means they are rapidly being pushed out by aggressive noisy miners.

Cities should not be places where concrete simply replaces nature. Research suggests urban areas will become increasingly important to tackling the extinction crisis. Australia urgently needs more homes. But in our rush to build them, we must not neglect the needs of the vulnerable animals that may have nowhere else to go.

Bethany Kiss, PhD Candidate, Faculty of Science, The University of Melbourne and Sarah Bekessy, Professor, Urban Ecology and Biodiversity, The University of Melbourne; RMIT University

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

For over a decade, the world has been trying to limit global warming to 1.5°C.

That’s no longer possible, according to a new United Nations report. We will likely pass 1.5°C in 2030. That’s not good news for anyone, least of all Australia’s Pacific Island neighbours who face rapidly rising seas.

In response to the report, Palau’s President Surangel Whipps Jr said:

It is hard to overstate the depth of emotion for those of us living on the frontline after having fought so hard to put the 1.5 degree limit at the heart of the Paris Agreement […] calls for greater ambition are no longer enough — we need to see an urgent and unprecedented increase in political will and investment in a climate safe future

The small silver lining is that it’s still possible for this to be a temporary overshoot of the target. If nations redouble their efforts to phase out fossil fuels and reduce other sources of emissions, they could limit peak warming to 1.8°C and then use carbon removal methods to bring temperatures back to 1.5°C or below this century.

In 2026, the world is already about 1.4°C warmer than pre-industrial levels, and the damage and death toll from climate-boosted disasters is ramping up. The United Kingdom is warning of possible food shortages amid a historic drought. Wildfires hit new areas in France and Spain, while glaciers are melting rapidly and the oceans are at their hottest level on record. The enormous El Niño event emerging in the Pacific is likely to bring major disruption. Every fraction of a degree makes things worse.

There are no good outcomes if we remain above 1.5°C. Urgent cuts to emissions and efforts to protect the most vulnerable are our best remaining options. Failure to do so risks irreversible harm.

Why does 1.5°C matter so much?

The 2015 Paris Agreement established a shared goal for the world: keep the rise in global average temperatures above pre-industrial levels “well below” 2°C and “pursue efforts” to hold warming to 1.5°C.

This goal was set based on expert scientific assessments that warming of more than 2°C would be dangerous and that limiting warming to 1.5°C was necessary to minimise climate risks.

Pacific nations fought hard to include 1.5°C in the agreement, arguing it was essential for their communities to “stay alive” in the face of rising sea levels and other climate-fuelled threats.

Last year, the world’s top court – the International Court of Justice – ruled that 1.5°C is the primary temperature limit nations have committed to work towards.

This ruling means that if governments fail to act as ambitiously as they can, they could be sued in international courts.

In May this year, a majority of nations voted in the UN General Assembly to endorse the court’s ruling and urge action to keep to 1.5°C.

It’s not time to give up

Warming of 1.5°C will be bad. But 1.6°C will be worse, and 1.7°C worse again. Every increase will bring more extreme weather, more loss of nature, more loss of land to the sea and more harm to humans.

If we stay over 1.5°C, we risk triggering climate tipping points – sudden shifts which cannot be undone on human timescales. These include the Greenland and West Antarctic ice sheets melting, the collapse of crucial heat-distributing currents in the Atlantic Ocean or the Amazon rainforest becoming a source of emissions.

Overshooting 1.5°C doesn’t mean it’s time to throw out the Paris Agreement. It’s not working fast enough, but it is working.

Solar power and electric vehicles have boomed and electrification has accelerated. Nations have cut emissions enough to avoid the worst climate futures of a 3°C rise or even higher. According to the Climate Action Tracker, the Paris Agreement has averted the equivalent of 1°C of warming. Rather than hitting 3.6°C by 2100, the world is on track for 2.6°C.

While this is progress, it is not enough. Global emissions are plateauing, but have still not begun to fall in earnest.

As damage from climate change mounts, leaders must do the work and begin rapidly cutting emissions to keep the goal of net-zero by 2050 alive.

To get temperatures back under 1.5°C, we will also need to pull gigatonnes of carbon dioxide back out of the atmosphere using tree planting and nature restoration. We may also need technological approaches such as rock weathering or ocean alkalinity enhancement, though these are not proven at scale and can come with other risks.

We are all in this together

It may seem as if climate action faces impossible headwinds, as populism surges and the current United States administration doubles down on fossil fuels.

It’s worth looking beyond these headlines. It took almost 70 years for the world to install a terawatt of solar power, but then just two years for the second and another two for the third terawatt. In ten years, that figure will likely have tripled. Developing nations are moving rapidly to take up non-polluting electric transport.

Climate change can no longer be ignored. As damage mounts, nations will have to cooperate to cut emissions as rapidly as possible and figure out how to safely and equitably pull carbon back out of the atmosphere. Action depends on strong political will, inclusive governance, and finance to help developing countries cut emissions and adapt.

In November, Australia will lead negotiations at the next international climate summit, COP31, in Turkey. Leaders and diplomats will work to keep 1.5°C in reach – even after overshoot. Australia can point to its own rapid clean energy transition and urge others to set clear pathways to go electric – and wean themselves off the production and use of fossil fuels.

Climate change has been described as a super wicked problem – big, complex and impossible to solve simply. The solution is to see the urgency of the issue and act cooperatively to tackle it. If we make it a problem for the next generation, there may be no way back to a safe climate.

Jacqueline Peel, Professor of Law, The University of Melbourne and Wesley Morgan, Research Associate, Institute for Climate Risk and Response, UNSW

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

Even as unprecedented fires and heatwaves rage across Europe, scientists track the retreat of Antarctic sea ice and a supercharged El Niño system heads our way, Australia’s largest companies are forecasting business-as-usual in a much hotter world.

Last year, Australia introduced mandatory company climate reporting. They must now disclose the climate “risks and opportunities” that may affect their prospects.

Several of Australia’s biggest energy and resource companies have now published new sustainability reports as part of annual financial reporting.

Their disclosures reveal the climate future they are planning for, and whether this is aligned with international science-based targets such as the Paris Agreement’s 1.5°C warming threshold.

What we’re seeing is alarming.

Companies planning for an unbearable future

Most of these reports indicate big companies are developing strategies on a climate change “base case” – a representation of what they consider most likely to happen – of more than 2°C of warming. The future temperature rise they’re planning for is one scientists say would deliver an unbearably hot planet.

Some of Australia’s largest miners have followed this approach. Both Rio Tinto and BHP expect global temperature increases of more than 2°C by the end of the century.

Not every company reveals the increase in global temperature they are planning for. But even if they don’t, their disclosures show they’re not expecting temperatures to hold to 1.5°C.

Energy companies AGL and Origin Energy both express confidence their strategies and business models will remain robust, even if temperatures accelerate beyond 2.6°C warming. This increase would put the Australian economy, environment and community at severe risk.

Companies hold power

Companies often argue that governments are responsible for creating policy to address global warming. But this underestimates the power corporate leaders hold to shape Australia’s shared climate future through financial decisions.

For example, mining giant BHP expects demand for steelmaking coal to remain robust for decades, with customers from China, India and Southeast Asia. This underpins the valuation of its major export commodities, and appears to justify the lack of plans to scale down steelmaking coal production. However, this assumption sits uneasily with the fact these same countries have their own net-zero targets.

Similarly, Rio Tinto confirms “no portfolio adjustments” are made to its future production plans. Its central case estimate of 2.1–2.3°C of warming by 2100 assumes developing countries will miss or delay their stated net-zero targets, underwriting business-as-usual production for the company.

Disclosures out of step with science

However, the assumption that business-as-usual will be possible in a hotter world is out of step with the latest science. The Paris Agreement’s temperature goal was set in 2015 based on exhaustive scientific assessments that warming of more than 2°C would be dangerous, and limiting warming to 1.5°C was necessary to minimise climate risks.

Scientific knowledge about how much global warming is “safe” has exponentially increased. It reemphasises the need to keep to 1.5°C with “limited overshoot”. This means we can only exceed 1.5°C temporarily, and simultaneously need to be working to bring temperatures back down. Only then will we minimise irreversible changes such as sea level rise, the disappearance of coral reefs or vast sea ice loss at the poles.

Scientific best estimates find we can’t go over 1.5°C by more than 0.1–0.3°C (a “peak temperature” of 1.6–1.8°C) and still return warming to safe levels. Even then, the longer we stay above 1.5°C and the extent to which we exceed this threshold, the more devastating the outcome.

Is this legal?

Legally, there’s no issue with companies using a base case for planning that exceeds 2°C of warming. But this approach isn’t in line with Australia’s broader international legal obligations. Companies will likely face increased investor scrutiny or reputational blowback when they walk back climate commitments.

In July 2025, the world’s highest court, the International Court of Justice (ICJ), confirmed 1.5°C is the temperature limit countries are aiming for. To meet their Paris Agreement promises, governments — including Australia — have to show the most ambitious action the country can realistically take to help keep warming under 1.5°C. Australia’s latest plan for a 62–70% emissions cut from 2005 levels was submitted in September 2025.

The court confirmed the Paris Agreement also requires governments to take action at home to cut emissions in line with the 1.5°C goal — including introducing rules for businesses operating in their countries. To follow international law, the Australian government needs to use every tool available to regulate the emissions of big companies, based on the best available science. Countries that don’t comply could be sued before the ICJ and ordered to pay compensation to other nations.

What about Australia’s climate policy?

Big companies in Australia contribute more than 30% of our domestic emissions. If we also include emissions from the fossil fuels some of these companies produce, it raises Australia’s global carbon footprint to around 4.5% of global fossil carbon dioxide emissions, second only to Russia. Making sure big companies do their bit to reduce emissions is essential for Australia to meet its climate targets.

This year, Australia is the “President of Negotiations” for COP31. This is an opportunity for Australia to show it’s doing all it can – internationally and in its own backyard – to support compliance with the Paris Agreement and accelerate climate action. From their new disclosures, it doesn’t seem that Australia’s biggest companies have got the memo.

Jacqueline Peel, Professor of Law, The University of Melbourne; Nina Araneta-Alana, Research fellow, Laureate Program on Global Corporate Climate Accountability, The University of Melbourne, and Suzanne Varrall, Research Fellow, Laureate Program on Global Corporate Climate Accountability, The University of Melbourne

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

Prime Minister Anthony Albanese is in Palau’s capital Koror this week for the annual Pacific Islands Forum, and regional security is expected to top the agenda.

China is testing nuclear-capable missiles in the Pacific, prompting talk of a new regional agreement. The United States-Iran war has exposed a reliance on costly fossil fuels that is undermining Pacific economies.

And as the world comes perilously close to the Paris Agreement’s 1.5°C temperature goal, a record-breaking El Nino looms in the Pacific Ocean.

But the forum will be missing key leaders – Solomon Islands Prime Minister Matthew Wale made a shock departure, flying out of Palau just hours after arriving, in order to deal with a looming leadership challenge back home.

And Kiribati President Taneti Maamau, Samoan Prime Minister Laʻauli Leuatea Schmidt, and Vanuatu’s prime minister, Jotham Napat, are also not attending. It is unclear if Fiji’s prime minister, Sitiveni Rabuka, will be present.

Pacific nations will want Albanese to address the world’s key security threat – climate change. As co-president of the COP31 climate talks in November, Australia can work with the Pacific to keep 1.5°C within reach, and secure much-needed finance for island nations at the climate frontline.

China’s missile test

Since the second world war, the United States has maintained fortified bases in the Pacific and an unrivalled deep-water navy (the US also regularly tests long-range missiles in the region). However, China’s investment in military capabilities has challenged the status quo.

In July, China launched a nuclear-capable test missile that flew over multiple Pacific nations and hit waters close to Tuvalu’s Exclusive Economic Zone.

This sparked calls for a new regional security agreement: Solomon Islands Prime Minister Matthew Wale said China’s missile test was “not the act of a friend”.

Ironically, it was Solomons Islands that signed a security deal with China in 2022. This changed the security dynamics of a region long aligned with the US and Australia (notwithstanding concerns about nuclear testing and decolonisation).

Since then, Canberra has pursued a web of bilateral deals to shore up Australia’s place as Pacific security partner – first with Tuvalu (2023), then Naoero (formerly Nauru) (2024), Papua New Guinea (2025) and Vanuatu (2026). Discussions are ongoing with Tonga and Solomon Islands. The most recent agreement, an “Ocean of Peace Alliance” signed with Fiji in July, is a mutual defence pact that is open to other Pacific nations to join.

Canberra was already pursuing a treaty allowing for coordinated regional responses to disasters and other crises. China’s missile test may have opened the door for something more.

Renewables the solution to fuel crisis

The Middle East conflict has pushed the Pacific toward an energy crisis. Around 80% of the region’s energy relies on imported oil products, much of which would normally transit the Strait of Hormuz. Even before the US-Iran war, Pacific island countries spent an eye watering percentage of GDP (between 10-25% buying fossil fuels to run power plants, generators, boats and vehicles. This compares to a regional average of 8% spent on education and 6% on health.

The Middle East conflict has only added to the bill. According to a new report, Fiji’s annual refined fuel import costs could rise by US$375 million (A$520 million) if high oil prices persist. This is more than Fiji’s entire healthcare budget.

Renewable energy offers a clear solution. Replacing diesel generators with grid-scale solar and battery storage could save Pacific countries around US$700 million (A$520 million) each year in avoided fuel costs.

The incoming chair of the Pacific Islands Forum, Palau president Surangel Whipps Jr, wants the region to become the first in the world 100% powered by renewables. He says investment of US$120 million (A$ 166 million) is needed for Palau to add 60MW of solar and battery storage, which would enable 90% of its power needs to be met by renewables.

Climate change remains greatest Pacific threat

When climate change was first debated at the UN Security Council in 2007, Pacific countries argued the impacts of a warming planet were “no less serious than those faced by nations and peoples threatened by guns and bombs”.

Since then, Pacific Islands Forum leaders have explicitly reaffirmed climate change is “the single greatest threat” to Pacific security.

In 2025, Earth was 1.44°C warmer than the long-term average. Pacific countries are reeling from stronger cyclones, dying reefs and ocean acidification. Without urgent action to shift away from coal, oil and gas impacts will get much worse. Just this week, the world’s oceans are the warmest on record, fueled by climate change and a rapidly intensifying El Niño event.

It is now almost certain the world will warm past 1.5°C. Yet it remains possible, following a temporary “overshoot”, that countries can limit warming to 1.5°C by the end of the century. This will require deep and immediate emissions reductions and some carbon dioxide removal to achieve “net-negative” emissions.

Limiting global warming to 1.5°C is a line in the sand for low-lying Pacific nations – “1.5 to stay alive” is the slogan. Pacific negotiators helped secure this temperature goal in the 2015 Paris Agreement.

Pacific nations expect Australia, as co-president of COP31 climate talks in November, to reaffirm global commitment to 1.5°C. Australia is helping Fiji and Tuvalu host a pre-COP summit in October that will remind world leaders the survival of island nations is at stake.

Pacific countries will also seek new finance for a Pacific-owned climate fund to invest in community-scale adaptation projects.

Some argue collaboration with the Pacific in the lead-up to COP31 is an expensive exercise. But climate action is crucial to Australian strategy in the region. Investing in renewables and adaptation in the Pacific is an investment in shared security, even as geopolitical competition sharpens between China and the United States.

Wesley Morgan, Research Associate, Institute for Climate Risk and Response, UNSW

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

In July 2026, more than 200 community members gathered at Mandoon Bilya (Helena River) in Perth’s eastern suburbs. They planted more than 3,000 native flora as part of a wetland restoration project. The hopeful scene was a stark contrast to what the river might have become.

Until recently, Mandoon Bilya was the proposed site of a hyperscale artificial intelligence (AI) data centre. It was scheduled to be one of Australia’s biggest. Aboriginal groups, environmental activists and local community groups successfully opposed the development.

Instead of a 120-megawatt AI facility, the area is now focused on ecological restoration and protecting Country. Community groups are working to realise new visions of the river’s future.

Yet the Mandoon Bilya opposition is about more than one defeated development proposal. As AI drives demand for new facilities, data centres are expected to proliferate across Australia.

The campaign highlights an urgent policy challenge. Policymakers have focused on regulating AI technologies. Yet Aboriginal communities have had little say in AI infrastructure planning.

This includes participating in decisions about the resources and infrastructure on which AI technologies depend. Decisions made now could shape Indigenous relations with the government around AI for years to come.

The case of Mandoon Bilya

Restoration work at Mandoon Bilya follows a hard-fought campaign. It was led by the Bibbul Ngarma Aboriginal Association and supported by environmental and community groups.

Developers planned the project on land containing Aboriginal heritage sites. Opponents argued the proposed data centre threatened a river system with cultural connections for local Aboriginal groups. The river also supports Perth’s drinking water and local ecosystems during warmer months.

All this raised concerns about adequate free, prior and informed consent and impacts on Country.

In May 2026, the proposal was cancelled before being considered by Western Australia’s Development Assessment Panel. Campaigners widely praised the decision. They have since shifted their focus towards broader ecological restoration plans.

The need for Indigenous leadership

Mandoon Bilya isn’t an isolated case; similar debates are emerging elsewhere in Australia. In Victoria, opposition to a proposed AI Hub has raised concerns about cultural heritage and environmental impacts.

AI is often talked about as something virtual. Yet it depends heavily on physical resources: land, water and energy. Data centres use large amounts of all three, creating environmental pressures familiar to many Aboriginal communities.

Internationally, on Turtle Island (what some local First Nations peoples call North America), Indigenous communities are also challenging proposed data centres. They argue such infrastructures compromise Indigenous rights, culturally significant sites and water systems. Such challenges underscore principles echoed in the United Nations Declaration on the Rights of Indigenous Peoples.

More people now recognise the importance of Indigenous leadership in data and digital technologies. We see this, for example, in commitments to Indigenous data sovereignty. This means Indigenous people get to own and control access to their data.

Indigenous leadership should also be central to decisions about the physical systems that make AI possible.

Towards working together

Some projects have begun to incorporate Indigenous participation and ownership. Western Australia’s largest data centre is pursued through an Indigenous Land Use Agreement with the Karajarri People. They are also co-owners of the project.

In the Northern Territory, Energy North has stated it is engaging with Traditional Owners. This consultation is part of the assessment process for its proposed hyperscale data centre.

Yet such examples remain the exception. While Australia is regulating AI infrastructure, few policies require Aboriginal leadership in decision-making.

Kaley Nicholson, chief executive of the Federation of Victorian Traditional Owner Corporations, confirms this. She argues current government expectations for data centres represent “an investment failure”. Such efforts don’t reference collaboration with Traditional Owner groups, despite lasting impacts on Country.

This raises an ongoing and crucial question. Who gets to decide about digital systems that directly impact Indigenous lands, rights and livelihoods?

Not just AI

Conflicts over AI infrastructure echo longstanding debates about resource extraction in Australia. Aboriginal peoples have long been excluded from decisions about such developments on or near their Country. However, they often bear the environmental, cultural, social and personal impacts.

Our own research with Aboriginal communities examines their experiences of agreements with the resource industry. It suggests consultation processes don’t always translate into meaningful influence. Communities often shoulder the work of engagement, negotiation and compliance, while key decisions are made elsewhere.

Agreements don’t always lead to better outcomes given the costs and challenges of culturally sensitive, meaningful participation. Participating in agreements requires a lot of time and unpaid work. This includes coordinating community members to translate complex legal documents.

This work often falls on Elders and leaders, who bear logistical and administrative burdens. As AI systems expand, the challenge is ensuring that partnership isn’t burdensome and is more than box-ticking.

The time to act is now

Right now is the time to shape how Australia involves Indigenous peoples into AI development policies – before detrimental practices are locked in.

Consultation alone is not enough. Aboriginal people must have a seat at the table and be included before concept design to inform better outcomes for all. Aboriginal communities should have formal and resourced roles in decisions about land access, approvals and ownership.

It’s not too late to embed meaningful Indigenous leadership and governance in our AI development policies, but we must act now.

Jenna Imad Harb, Research Fellow, School of Regulation and Global Governance, Australian National University and Shanine Ryan, Ngarluma Traditional Owner, Director of the Ngarluma Yindjibarndi Foundation Limited, Indigenous Knowledge

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

On the morning of August 26, a section of mountain near Langtang Lirung peak in Nepal suddenly collapsed.

A huge mass of rock, ice and debris plunged roughly 1,200 metres into the valley below, producing a hugely destructive flood on the Lhende Khola river. The flow travelled almost 100 kilometres downstream, washing villages and bridges away. Almost 1,000 people died and thousands more are still missing across the Nepal-China border.

What caused it? At first, it looked like a glacier collapse. But emerging satellite and photographic evidence suggests a more complex picture – an avalanche of rock and ice, rather than a simple glacier collapse.

The mountain face now has a sharply defined scar after the collapse, clearly marking the boundary between the remaining slope and the section which failed.

This isn’t the first rock-ice avalanche in the Himalayas, but it is by far the most devastating. Unfortunately, it is unlikely to be the last. Rising temperatures due to climate change mean the permanently frozen slopes of mountains in the region may begin to melt and destabilise.

How did a mountain collapse?

The steep mountain face was topped by a glacier – a heavy river of ice. It’s likely that the steep slope of bedrock collapsed first, followed by the overhang of ice.

As this enormous mass fell into the valley, it created a tremendous amount of energy. This would likely have melted the ice in the avalanche and any in the valley, adding large volumes of faster-moving water to the flow and intensifying the debris flood.

The rugged Himalayan terrain made the disaster even worse by providing a steep, confined pathway, accelerating the mass of water, rock, dirt and ice as it flowed into the river.

A landslide followed the first collapse and a small lake has formed within the newly created depression in the valley. The site will remain unstable for some time.

Now that we know more about how the Langtang collapse became a cascading disaster, we can find parallels.

The closest example is the February 2021 rock-ice avalanche in Chamoli, India, which began when a huge landslide down Ronti Peak triggered an avalanche carrying an estimated 27 million cubic metres of rock and ice. This became a fast-moving debris flowing down a river valley. Over 200 people were killed or left missing.

The high mountains are changing

The Himalayas are the best known feature of the High Mountain Asia region – a large area with an average elevation of 4,000 metres which includes mountain ranges and the Tibetan plateau.

Despite its height, the region is not safe from climate change. In fact, change is happening faster here.

As air temperatures warm past 0°C more often, glaciers are beginning to melt. Snow and rainfall patterns are changing.

Permafrost – long-frozen earth and rock – is also becoming vulnerable. This matters most for steep mountain slopes, where fractured rock can be held together by ice.

When the ice melts, these ice-rock bonds can break. Water can begin to move down through long-frozen mountain slopes and bedrock. That means long-stable slopes can suddenly fail.

It’s common to picture glaciers as a slow-moving river of ice in a valley. But this high region is home to many hanging glaciers and smaller ice masses perched on steep mountain slopes.

These are at particular risk because they often sit high above valleys. If their rock support collapses, they can too. If they take rock, sediment and water with them, a simple glacial collapse can become a much larger avalanche or debris flow.

As the climate heats up, warmer air can lead to faster melting of the glacier and change how tightly it is coupled to its rocky bed. A small change in conditions at the glacier’s base can make it unstable.

Which areas are at highest risk?

Predicting the next big mountain or glacier collapse is a very complex task.

But we can improve our understanding of the landscapes and environmental conditions associated with such failures. Recent analysis of large rock and ice avalanches across the High Mountain Asia region gives us important insight.

Of the 60 avalanches analysed, 86% began on slopes steeper than 30° and at elevations above 3,000 metres. Almost two-thirds (65%) began in areas where permafrost was probable.

Earthquakes, underlying rock types and structures, and changes to rainfall can also make these avalanches more likely.

Across this region, rock–ice avalanches have been documented to occur more often in the Western Himalayas, including the Karakoram and Pamir Ranges, and across southern and eastern Tibet.

We will need to treat these rock-ice avalanches as a cascading hazard separate to isolated glacier collapses or landslides.

Could we be forewarned?

Footage from the disaster shows many people were caught unaware. If we could predict which glaciers or mountain faces are at highest risk, we could potentially save lives.

It is not an easy task. Signs a collapse is imminent such as rock deformation or fractures can often be subtle.

One approach could be combining field observations and seismic monitoring with data from satellites equipped with sensors able to observe changes in mountain faces and make optical and thermal infrared observations. New techniques such as the use of drones to monitor inaccessible or dangerous terrain are also worth exploring.

Observations must feed into early-warning systems capable of rapidly communicating the danger to communities downstream.

Because many Himalayan rivers cross national boundaries, nations will have to work together to strengthen data sharing, joint monitoring and coordinated early-warning systems.

The task is increasingly urgent. Climate change is loading the dice for more disasters in this high, cold region.

Tirthankar Ghosh, Doctoral Student, School of Earth, Atmosphere and Environment, Monash University and Levan Tielidze, Research Fellow in Glacial Geomorphology, Monash University

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

Australia’s energy transition has never been more urgent.

Aging coal-fired power stations are retiring and energy bills are rising sharply. To address this, the obvious solution is to build more renewable energy projects and the transmission infrastructure to connect them at scale.

But a major hurdle remains: community opposition. In regional areas, where most of the renewable infrastructure must go, locals are protesting against new transmission lines and are locking farm gates to keep developers off their property.

However, regional communities should not be forced to choose between supporting the national energy transition and protecting their land and livelihoods.

Our new research suggests we’re asking the wrong question. Instead of querying “if” communities support renewable energy, we should be asking “under what conditions” will they back such projects.

Not simply for or against

Our new study took a closer look at how three regional Western Australian communities – Busselton, Kojonup and Albany – view renewable energy infrastructure.

To do this, we analysed online discussions about solar and wind projects slated for their communities, each at different stages of development. The online discussions took place from January 2024 to May 2025 across a range of platforms, including Facebook and X (formerly Twitter), as well as relevant local and regional media websites, newspapers, community forums and online noticeboards.

Our results challenge the assumption that communities can simply be divided into those who are “for” clean energy and those who are adamantly “against” it.

In Busselton on WA’s south-west tip, renewable projects are still in the planning stage. There, local residents were most concerned about land use, property values and the visual appeal of landscapes. Many residents raised consultation as a key issue, with some expressing the view consultation came too late or did not give residents any opportunity to influence the outcome.

In the inland town of Kojonup, south-east of Perth, the Kojonup wind farm is currently being rolled out. This community’s concerns were decidedly practical: who actually gets the jobs? Who receives the financial benefits? Who bears any disruptions, such as visual disruption and lower property values? Financial fairness was a major concern for locals, with some landowners receiving benefits such as local investment opportunities while their neighbours got nothing except interrupted views.

The port city of Albany has been home to working wind farms for more than two decades. Here, the picture is very different. Albany’s wind farm supplies the equivalent of 80% of the city’s annual electricity needs and attracts an estimated 200,000 visitors a year. Community sentiment was largely positive, associating the wind farm with various environmental benefits including reduced reliance on coal and gas, as well as tourism and regional identity.

It’s worth noting not every host community will embrace renewable energy in such a linear pattern. However, our findings suggest community support is not necessarily fixed and can change over time as a project progresses.

Lessons from abroad

Overseas, other countries are already trialling ways of giving host communities a more tangible stake in the renewable energy shift.

Since 2014, the Scottish government recommends wind developers pay a minimum of £5,000 (roughly A$9500) annually for each megawatt of power a renewable project generates.

These payments are channelled into community funds, where a local committee decides how the funds are spent. If a project stretches across multiple regions, the funds are split based on how many megawatts of power each community hosts. However, these payments are not mandatory so not all renewable companies are contributing to community funds.

In Denmark, a global leader in wind energy development, several communities have established energy cooperatives. While each has a slightly different model, these cooperatives allow residents to own a share of renewable energy projects and, as a result, actively engage in the green transition.

Where to from here

These international examples underscore the need to engage with host communities in innovative and thoughtful ways.

Our research suggests these three strategies could help:

1. recognising that if people resist local solar and wind projects, they are not simply “anti-renewables”

2. engaging communities early, listening to their concerns about proposed renewable projects, involving them in decision-making processes and providing clear, transparent information about how any risks will be managed and benefits will be shared

3. monitoring online discussions, particularly to identify emerging concerns before they become entrenched as opposition and potentially fracture trust between communities, government and renewables companies.

Australia, like many countries, is racing to shore up its renewable sector and shift away from fossil fuels. We must build more wind turbines and solar farms. But to ensure our energy transition works, building trust with local communities is just as crucial.

Mingming Cheng, Professor, School of Management and Marketing, Curtin University and Peta Ashworth, Professor and Director, Curtin Institute for Energy Transition, Curtin University

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

The color of penguin poop, as seen from space, is offering a new window into how the ecology and the environment of Antarctica are changing over time.

Adélie penguins are one of the most abundant predators in the Southern Ocean. They rely on food sources in the ocean, but nest on rocky outcrops all around the Antarctic continent.

Penguin colonies often have hundreds of thousands of nesting birds, which generate a lot of guano – so much so that it can be readily identified from space, using NASA’s Landsat satellites.

A multidisciplinary group of scholars that I led has used thousands of satellite images dating as far back as the 1980s to examine these patches of penguin guano, to reveal what these birds are eating and how changes in the environment are affecting their diets – which also affect their survival.

In particular, we found that when there is an abundance of sea ice at a colony, Adélie penguins there tend to rely more on small fish. When there is less sea ice, they depend more on krill, which are small shrimplike crustaceans.

The color of food

Krill have a pink exoskeleton that penguins don’t fully digest, which contributes a rosy shade of pink to their guano. It is the color of guano that we can use to determine what penguins are eating.

This approach relies on a quantitative approach we developed that examines guano color and links that to the share of a penguin’s diet that is krill.

To develop the linkage, we collected penguin guano at several locations. With a spectrometer, we determined the color of each sample as a satellite would see it. This was done in a small makeshift lab on a ship in the Antarctic, which likely smells of penguin guano to this day. We analyzed what was in this guano, using tools from environmental chemistry, to determine the diet that had generated that color of guano.

That information, along with some statistical modeling, allowed us to determine what penguins are eating based on the color of their guano as observed from satellites. More broadly, it provides a window into what is happening in the larger Antarctic marine food web – information typically hidden under the surface of the Southern Ocean. To our knowledge, this is the first effort to directly monitor what animals are eating from space.

Using information from around 4,000 satellite images, we looked at how penguins’ diets varied over both time and space. We found that penguins do eat different things across the Antarctic continent, and that what they eat varies both across the year as well as from one year to the next.

Links between sea ice, food webs and penguin populations

Our data reveals how climate change is shifting penguins’ diets and how the Antarctic food web as a whole is changing.

Since the 2010s, sea ice has declined precipitously around the continent, with several years setting new historical sea ice minimums. Less sea ice means fewer fish, which is bad news for penguins: Adélie penguin chicks are typically heavier when fed fish as opposed to krill, and heavier chicks are more likely to survive into adulthood.

Our findings indicate that in locations where penguins eat less fish, the number of penguins has declined over the past few decades across the species’ entire range. By contrast, penguin colonies that eat more fish are more likely to be stable or increasing.

Unfortunately, large-scale declines in sea ice are projected to continue into the future. Adélie penguins are also now facing increased competition for fish and krill from other marine life and from humans.

For example, in the Antarctic Peninsula region, the area directly below South America, baleen whale populations, which feed largely on krill, have rebounded substantially since the end of commercial whaling decades ago. Gentoo penguins are shifting their range from the sub-Antarctic southward to the Antarctic as the climate warms, adding to the numbers of predators hunting in those waters.

Fishing trawlers are also now harvesting large quantities of krill to be used in fish feed and human dietary supplements, which may put additional pressures on Adélie penguins in these regions.

The power of big data

Only by using thousands of satellite images could our research team understand how Adélie penguins’ diets vary across the range of the species, how it shifts over the seasons, and how it is responding to a changing environment over the past several decades.

Information from satellites is particularly valuable for remote and hard-to-reach areas like Antarctica’s penguin colonies, as other methods of collecting this data would take massive amounts of personnel, planning and travel and survival logistics.

As satellite technologies continue to improve, with increasing resolution, shorter intervals between images and new sensors for collecting information, there are opportunities to fundamentally change how we monitor some wildlife, providing critical information about how the world is changing and how humanity might respond to these changes.

Casey Youngflesh, Assistant Professor of Biological Sciences, Clemson University

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

When a wildfire threatens a community, most people don’t think to ask whether the firefighters coming to help slept enough the night before, recovered from the previous day’s shift or have enough energy left for another day on the fire line. They simply expect firefighters to show up.

But that workforce is increasingly being stretched to its limits.

The U.S. national fire preparedness level has been at 5 for weeks in summer 2026, its highest level, suggesting firefighting resources are fully committed and some regions may need emergency staffing measures to meet the demand. Crews were battling more than 90 large fires in late August, and firefighters in the Southwest and Texas faced daytime temperatures over 100 degrees Fahrenheit (38 degrees Celius) at times.

In conditions like this, the unrelenting heat, stress and smoke take a toll on firefighters’ bodies.

Training, fitness and protective equipment allow firefighters to work in these extraordinary environments. But as a nurse practitioner, firefighter and founder of Purdue University’s FIRE Lab, I know too well that none of that makes the human body’s capabilities limitless.

Heat hits firefighters from 3 directions

Wildland firefighters face heat from the environment, the fire and their own bodies.

Hiking steep terrain with heavy equipment, clearing brush and cutting fire line to stop fires from spreading creates internal metabolic heat. Sun and high air temperatures add environmental heat, while flames and smoldering fuels contribute radiant heat.

The body responds by sending more blood toward the skin to release that heat while continuing to supply oxygen to working muscles. The heart works harder to support both jobs.

As fluid losses increase, the volume of blood circulating through the body can fall, the heart rate rises, and the work of fighting fires feels harder.

Field studies show how this strain can become severe. In one study of 221 wildland firefighters on the job, 61% reached a core temperature of at least 100 F (38 C). About 50% reached a physiological strain index of 6 or greater on a 0-to-10 scale that combines heart rate and core temperature to measure how hard the body is working to cope with heat. Among those whose body temperatures crossed 100 F, the majority remained above that temperature for more than 30 minutes.

A core temperature of 100 F does not by itself mean heat stroke, but it signals substantial physiological strain. Staying hydrated helps the body sweat and keep blood circulating, but even a fully hydrated firefighter can overheat when the body gains and produces heat faster than it can release it.

Immediate consequences can develop quickly

Heat strain may begin with fatigue, headache, dizziness, weakness or nausea and progress to heat exhaustion or heat stroke. Severe hyperthermia can affect the brain, heart, kidneys and liver.

Wildland firefighters can also face rhabdomyolysis, a breakdown of skeletal muscle that can contribute to kidney injury. The National Institute for Occupational Safety and Health reported 62 severe cases among wildland firefighters from 2010 to 2020 and cautioned that the true number was probably higher.

Heat adds to fatigue when firefighters must anticipate fire behavior and make rapid decisions.

A 2025 field study found that wildland firefighters averaged 13.8-hour shifts on days when they were fighting fires and got around 6.7 hours of sleep. Poorer sleep and longer shifts were associated with reduced cognitive function, which can affect a firefighter’s ability to make split-second calls, such as when to retreat from an escalating fire.

Effects stay with bodies beyond one shift

The effects of heat and exhaustion can also add up. A firefighter can finish a shift hot, smoke-exposed and physically depleted, sleep in a warm camp and return to the line before fully recovering. Repeating that pattern across days and fire seasons may place ongoing strain on the heart, lungs and kidneys.

Smoke adds another health risk. Wildland firefighters commonly work in smoke without the kind of protection that firefighters use when fighting blazes inside buildings.

A 2019 exposure-modeling study estimated that, depending on the number of fire days worked over a career, cumulative smoke exposure could increase a wildland firefighter’s risk of dying from lung cancer by 8% to 43% and dying from cardiovascular disease by 16% to 30%. These are estimates, but they show why career-long exposure deserves attention.

Kidney health is another emerging concern. A 2025 study of 39 wildland firefighters found temporary decreases in kidney function and changes in kidney-injury biomarkers during one midseason fire incident. More research is needed to determine whether firefighting over seasons and years can lead to persistent kidney damage.

These findings raise an important occupational health question: What happens when heat, dehydration, smoke, sleep disruption and extreme physical exertion accumulate not only across one incident but across an entire career?

How to lower the risk

The heat isn’t going away, but there are ways wildfire management agencies can reduce the risk to firefighters.

First, firefighter health should be an important part of national wildfire readiness policies. Having adequate staffing so firefighters aren’t overworked and have meaningful enough recovery time to rehydrate, cool down and sleep between shifts are important. So are conditions that allow real sleep between shifts.

Monitoring firefighters’ health can also help catch early warning signs, such as kidney stress or burnout.

The public can also help by reducing the likelihood of high-stress fire situations.

The National Interagency Fire Center estimates that about 85% of U.S. wildfires are caused by human activities. Some of those can be avoided by fully extinguishing campfires, checking local fire restrictions, avoiding spark-producing activities on dry, windy days when fire risk is high, and maintaining vehicles and trailers so metal does not drag and ignite vegetation.

If you live in wildfire-prone country, creating defensible space and reducing combustible material around your home can reduce the fuel for fires. Evacuating promptly in an emergency also reduces the likelihood firefighters will have to put themselves in high-stress situations to rescue you.

We all expect firefighters to be there when the worst happens. Making sure they can do their jobs and stay healthy will allow them to continue to show up.

Julian L. Gallegos, Assistant Professor of Nursing, Purdue University

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

Temperatures have warmed dramatically across the equatorial Pacific Ocean in 2026, signaling the onset of a strong and potentially historic El Niño. These events can affect weather around the world, and the intensity of recent El Niño events is raising alarm that, as global temperatures rise, they are becoming stronger and more destructive.

To understand how these climate patterns are changing, we need to understand what happened during El Niño events in the past, but observations go back only a few decades. So, my colleagues and I went to the Galápagos Islands – at the heart of the El Niño pattern – to find answers from some of nature’s best record keepers: corals.

In records preserved by living and ancient fossil corals, we found that, on average, El Niño events have been stronger in the past 40 years than at any time in the past millennium, with higher temperatures that lead to more powerful effects on weather.

That intensification also coincides with human-caused global warming.

Our results, just published in the journal Science, suggest that the 1982-83 and 1997-98 El Niños – two of the strongest in recent memory – may be harbingers of more extreme events to come as the planet warms.

El Niño comes for the Galapagos

One of the strongest El Niños hit in 1982, with devastating consequences for the Galápagos Islands. It triggered a marine heat wave that reverberated through one of the most distinctive and unspoiled ecosystems on the planet.

Exceptionally warm surface water blocked the usual upwelling of cool, nutrient-rich water that fuels the food chain for marine life. The result ravaged communities that rely on the ocean – fish, birds, marine mammals, and people who fish for their livelihoods throughout the eastern tropical Pacific. In the extraordinary heat, more than 95% of Galápagos corals died.

The heat wave was caused by an exceptionally strong El Niño event, part of a climate pattern that begins in the eastern tropical Pacific Ocean, around the Galápagos Islands, as the trade winds shift. El Niño’s warm ocean water alters the atmospheric circulation above, diverting storm tracks and changing patterns of floods, droughts and tropical storms around the globe.

The 1982-83 El Niño contributed to climate extremes worldwide, from flooding in Kenya and Peru to drought in Indonesia and Brazil, costing the global economy as much as US$4 trillion by some estimates. A similarly strong El Niño in 1997-98 resulted in 23,000 deaths from disease and climate disasters.

But we wanted to know: Are such powerful El Niño events unusual in the context of history?

Even in 1983, scientists were surprised to find that such a strong event had been underway. Historical records of El Niño are sparse before the era of satellite observations. Fortunately, long-lived corals growing in the tropical Pacific can provide a history of El Niño that extends our view into the past.

How corals record history

As corals grow, they preserve a record of local ocean temperatures over time. In the Galápagos, because of their location, that record reveals the history of El Niño events and of their cooler counterpart, La Niña.

Like trees that produce annual growth rings, corals add skeletal layers of calcium carbonate year after year. The alternating bands of higher and lower density reveal changes in the coral’s growth rate during each year and can serve as a timekeeper. The history of the ocean temperature is embedded in the chemical composition of the skeleton itself.

To track the history of water temperatures, we measured two chemical parameters – the ratio of heavy to light oxygen isotopes and the ratio of strontium to calcium – both of which reflect the seawater temperature in which the coral grew.

In the Galápagos, because of the islands’ location, the sea surface temperature swings between warm El Niño years and colder La Niña years, when upwelling of nutrients is stronger.

The largest living corals in the Galápagos grow in the northern islands of Wolf and Darwin, in water 20 to 50 feet deep. To study their history, we dived down and took core samples from long-lived corals, some 8 to 10 feet tall.

Every core we drilled from a living coral showed evidence in its calcified skeleton that the coral had suffered during the 1982-83 El Niño event. We saw obvious “death horizons” – dense layers of calcified material produced by other reef organisms such as algae, gastropods and barnacles interrupting the lattice of the skeleton.

We also took samples of fossil corals around the archipelago – mostly dead coral boulders found along the islands’ shorelines. Radiometric dating told us that these fossil corals were up to 4,500 years old. Those samples provide an even deeper view of El Niño’s history.

Back in the lab, we sliced the coral cores lengthwise into slabs and used a drill to extract powdered samples, each representing about one month’s growth, along a path from youngest to oldest. We analyzed the geochemistry of each sample. In the chemical ratios from thousands of samples, we found seasonal cycles spanning many decades and exceptional warm and cold years that revealed a unique history of El Niño and La Niña events.

A history of ENSO through time emerges

Our data show clearly that the strength of the El Niño-Southern Oscillation has intensified as global temperatures have warmed.

The chemistry of the corals revealed that El Niño events from the past 40 years were stronger than at any other time sampled in the past millennium.

The coral data aligns with ocean temperatures measured from thermometers over the past century. But the coral records extend much further back in time, providing long-term context to show that modern El Niño events are more extreme than before the industrial era began.

The El Niño intensification we observed, starting in the mid- to late 20th century, is also greater than what nearly all climate models suggest would result from natural causes. It appears to be closely connected to human-caused global warming – a conclusion in line with expectations from most climate models.

Not all models anticipate El Niños strengthening as the climate warms, but our data shows that unusual strengthening has accompanied recent warming – an association that may allow scientists to identify models that most closely track observations.

Looking ahead

A stronger El Niño-Southern Oscillation means more intense and damaging climate extremes across the globe. If humanity can anticipate those hazards, we can prepare and perhaps avoid the worst damage.

Fortunately, scientists understand enough about El Niño and La Niña events today to be able to forecast them up to a year in advance. But such predictions depend on continuous, careful climate measurements from satellites and buoys across the remote tropical Pacific, coupled with continuous improvements in climate modeling and forecasting capabilities.

Those capabilities are now more important than ever as global warming accelerates.

Julia Cole, Professor of Earth and Environmental Science, University of Michigan

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

The massive January 2022 eruption of Hunga volcano in the Kingdom of Tonga took the world by surprise.

It blasted a plume more than 50km into the atmosphere, sent pressure waves around the globe and generated a series of tsunamis, devastating parts of Tonga and killing at least three people.

But one of the most important things we’ve learned since this historic event is that these tsunamis did not all stem from the same cause.

The first were generated by enormous explosions during the opening stages of the eruption. On nearby Tongatapu, waves with run-ups of one to four metres began arriving within minutes.

Then, more than an hour later, something much more destructive happened. A tsunami with run-ups reaching 18 to 40 metres struck islands within 100km of Hunga, destroying resorts and villages across southern and central Tonga.

Our newly published research shows this largest tsunami was generated not by another explosion, but by the sudden collapse of the volcano’s caldera – and that the collapse produced an underwater sound detectable thousands of kilometres away.

That finding could point to a new way of warning communities about some of the most unpredictable types of tsunamis on Earth.

Listening to an underwater volcano

Monitoring submarine volcanoes is notoriously difficult. There are hundreds scattered around the Pacific “Ring of Fire”, yet we know relatively little about their state of activity – and even less about how to respond when they erupt.

Satellites can detect changes in heat and gas emissions, along with eruption plumes when clouds don’t obscure the view. These observations can provide timely warnings of eruptions and help protect aircraft.

But satellites cannot tell us whether a deadly tsunami is on its way. Nor are conventional seismometers necessarily much help.

The closest seismometer to Hunga during the 2022 eruption was in Fiji, about 750km away. At that distance, many of the seismic signals produced by volcanic processes are poorly transmitted through the Earth.

So instead, we listened to what Hunga was doing in the ocean.

Underwater sound travels extremely efficiently over long distances as hydro-acoustic signals known as tertiary waves, or T-waves. An isolated volcano rising from the ocean floor can effectively act like a bell, radiating the sounds of violent underwater processes through the surrounding ocean.

We re-analysed records from 14 seismic stations around the southwest Pacific, some as far as 2,600km from Hunga.

During the first hour of the eruption, we could “hear” submarine landslide flows racing down the volcano’s flanks. These flows were powerful enough to destroy submarine communications cables and their acoustic signals could be detected hundreds of kilometres away.

But the loudest underwater signal was still to come.

The sound of a volcano collapsing

At about 6.28pm Tonga time, the centre of Hunga began collapsing in on itself.

The collapse ultimately produced a caldera about 4km wide and more than 850 metres deep. Moving such an enormous volume of rock and seawater generated the largest local tsunami of the eruption.

Yet remarkably, the collapse was only weakly detected through conventional seismic monitoring.

Underwater, it was a different story. The collapse generated an enormous T-wave that radiated across the Pacific. We detected it at 14 stations, including sites more than 2,000km away.

The strongest part of the signal lasted about five minutes, giving us an indication of just how rapidly the main collapse occurred.

But to establish that this collapse had generated the devastating tsunami, we needed to know precisely when that wave reached Tonga. That required a rather different kind of evidence.

The tower that stopped transmitting

At Kanokupolu, on the western side of Tongatapu, a telecommunications tower stood 180 metres inland and about 13 metres above sea level.

The earlier tsunami had already swept ashore and residents had evacuated, but the tower remained standing. A weather station attached to it sent its last scheduled data transmission at 6pm.

Eventually, the much larger tsunami arrived. It flattened the tower and tore it apart, with pieces later found hundreds of metres further inland.

But exactly when had that happened?

Our team worked with Tonga Communications Corporation to examine data traffic through the tower. The answer was remarkably precise: communications stopped at 6:45:24pm.

That timestamp provided another piece of the puzzle. The huge underwater acoustic signal indicated Hunga’s caldera had begun collapsing at about 6.28pm.

The destruction of the tower roughly 17 minutes later was consistent with the time needed for the resulting tsunami to develop and travel across the roughly 60km separating Hunga from western Tongatapu.

Eyewitness accounts provided another check. People had experienced the earlier, smaller waves and had time to evacuate before the catastrophic tsunami arrived.

All of this evidence enabled us to reconstruct something that conventional seismic monitoring had largely missed: a sudden submarine caldera collapse that generated the eruption’s most destructive local tsunami.

Sound waves travel through the ocean at around 1.5km per second – more than seven times faster than a tsunami.

If monitoring systems can automatically recognise and locate these signals, they could provide early warning of volcanic tsunamis – much as existing systems do for those triggered by earthquakes.

Shane Cronin, Professor of Earth Sciences, University of Auckland, Waipapa Taumata Rau and Jose Carlos Borrero, Adjunct Assistant Research Professor, Department of Civil and Environmental Engineering, University of Southern California

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

Heatwaves claimed the lives of tens of thousands of people in Europe’s capital cities this summer, as they experienced record temperatures.

In London, emergency wards filled with elderly patients injured after fainting in the heat. Meanwhile, the dry weather created subsidence and left homes with cracks.

In Paris temperatures exceeded 40°C in late June and people struggled to carry on their lives, and in Madrid, heatwaves burned thousands of hectares on the outskirts of the city.

How trees can help

Thami carried out preliminary research on the results of extreme heat on European cities this summer. The study looked into how many buildings have adequate shade from trees. The results were striking.

In London, Paris and Madrid over 90% of buildings did not have enough shade around them to prevent urban heat island effects. These were among the worst results in cities we studied, but even the best performers had a majority of residents without adequate heat protection – cities like Hamburg (56% unprotected) and Barcelona (70% unprotected).

This builds on past research that shows how major cities around the world – including in Europe – tend to struggle to reach useful levels of tree canopies to create shade close to homes and workplaces. It suggests that that homes should have a view of three trees and be within a 300 m walk of a park.

Early results for my research suggests that huge portions of European cities are exposed to avoidable heat island effects.

Map showing tree cover and heat in European cities

How urban heat islands work

On many days during summer 2026 it didn’t get much cooler in the evening. This is because of what is known as the urban heat island effect. Cities typically lack shade, due to high rates of tree removal, sparse planting, and poor tree health and there are vast amounts of asphalt, clay and concrete. These are almost the perfect materials to soak up and hold heat from all that direct sunshine. Unshaded asphalt can reach over 70°C on heatwave days.

Even after sunset, cities stay hot because roads, buildings and footpaths begin to radiate their absorbed heat back at us as they cool. The urban heat island effect can add significantly to ambient temperatures, making a day that is already very hot (perhaps 35°C) even more dangerous in high-asphalt, low shade locations (over 40°C).

What could help?

Tree shading is an effective strategy to address this urban heat, with a range of other mental and physical health benefits to local residents. Trees prevent solar radiation reaching heat-absorbing materials such as asphalt, and also keep the sun off our bodies. Tree shade has been shown to reduce the heat absorbed by pedestrians by up to 18°C.

Healthy trees also push water out of their leaves as they photosynthesise, which soaks up heat as it evaporates. This evaporative cooling effect adds an extra few degrees of cooling, in addition to shading people and preventing heat island effects, even during heatwaves as long as trees still have access to water.

Where trees are needed

Planting more trees in cities in the wake of this summer’s heatwaves is going to help cool urban areas down. The thinktank, the Create Streets Foundation, found the temperature on an exposed paved area in London during one heatwave was 55°C but was 25-30°C in a shaded area metres away.

Looking at a city such as London, you might argue that it already has plenty of trees: around 8 million.

But trees are only effective tools against urban heat when they’re close to homes. A lush shady park 800m away isn’t going to prevent dangerous localised heat island effects for you and your neighbours.

The other crucial factor is that there are thresholds of shade cover that have to be reached for trees to actually offer substantial cooling. A few isolated trees creating small islands of shade aren’t enough. Adding more tree canopy has been shown to be effective at preventing urban heat islands when it reaches 30-40% overall shade cover, within 60m of homes and workplaces.

It will also be important to plant trees that are best able to cope with increasingly hot temperatures in Europe.

Adding just a few degrees to an already hot day sharply ramps up the danger that heat poses. In locations where heat islands bump up the ambient air temperature from 33°C to 37°C, or 35°C to 41°C, there’s an increase in patients attending hospital admissions’ rooms due to heat related illness. When air temperature increases above 35°C the human body’s ability to manage the heat is greatly reduced; cardiovascular strain, dehydration, potentially leading to heatstroke and the need for medical intervention.

When it makes nights hotter there are other ramifications. It is during the cooler night hours that the body loses heat to reset for the following day. If the body is still trying to cope with warm temperatures, 24°C and above, this impacts recovery and impairs sleep quality. This means we start the next day in deficit, both physiologically and cognitively, to cope with another hot day. Repeated exposure to days of high heat mean that the deficit builds over time.

Adding more trees works

Medellin in Colombia is an example of what happens when more plants are added to urban streets.

In just a few years, millions of plants and over 12,500 trees were added to form a network of lush greenways across Colombia’s second largest city.

This project has resulted in significant drops in temperature (of 4.5°C in some areas, and 2°C citywide).

There are signs that Paris and London are aware they need to make changes. The recently announced Heat Ready London plan includes a focus on urban greening.

Paris is already starting to add more green space. The city’s school streets programme not only creates safe, car-free areas close to local schools, but also has added more trees. Evidence already suggests that surfaces in school streets are 5°C cooler than their traffic-heavy counterparts, with fewer trees.

As Europe prepares for more hot summers, planting trees close to homes needs to be high on the agenda to help people cope.

Thami Croeser, Vice-Chancellor's Research Fellow, Centre for Urban Research, RMIT University and Simon Hodder, Professor in Environmental Ergonomics, Loughborough University

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

Freely available satellite radar imaging is being used for the first time to help track colonies of endangered emperor penguins in Antarctica throughout the winter months.

Typically satellite images need sunlight to be useful, and Antarctica is dark in the winter. This has meant that colonies have been hidden at a critical time in the emperor penguin breeding cycle, when eggs are laid, chicks hatch and adults take part in those iconic huddles.

Almost 70 colonies of emperor penguins, many of which have never been visited by humans, occupy the sea ice that is fastened to the coastline surrounding Antarctica.

Now using synthetic aperture radar (SAR), an instrument operating on satellites that sends microwave pulses down to Earth, and measures how those pulses return, our research team has been able to track what the penguins do during these months.

Unlike other forms of satellite imagery, SAR is not reliant on sunlight, or affected by cloud, and therefore provides radar imagery of Antarctica through the dark polar winter.

SAR’s signal is sensitive to the properties of what it interacts with, and has been used for years in the poles to research things like the properties of sea ice and melt on glaciers.

When looking at SAR images from the free European Space Agency satellite, Sentinel-1, showing the location of an emperor penguin colony during winter, my team started to notice a bright white splodge of pixels moving around against a backdrop of dark, smooth sea ice.

Features like icebergs or rough sea ice can look bright in SAR imagery, but it didn’t make sense for those to be moving around at that time of year, when the sea ice was fixed and stable. Could it be the emperor penguin colony?

We soon found the same thing at the locations of other colonies – clusters of bright moving pixels on stable ice. We were then able to obtain optical images from September when the sunlight first starts returning, and compare them with the SAR, and confirmed it was indeed the colonies we were observing.

Tracking through the whole year

This finding opened up an exciting opportunity to track colonies throughout the whole breeding cycle, by combining SAR images in winter with optical images in spring/summer, and all using freely available data that has been routinely collected for years.

We went back through eight years, from 2017 to 2024, and followed three of the largest colonies year-round. We were able to follow their movement, sometimes even daily from early in the winter until chicks grow their first feathers in December and January.

We observed that colonies were typically less mobile in the winter, before spreading out and moving greater distances in the spring and summer. Interestingly, we found that the Atka Bay colony moved up from the sea ice onto the glacier ice that flows from the continent in seven of the eight years in the early spring. The colony did this despite the sea ice – the typically preferred habitat for the species – being stable. We need more research to understand why this is.

Satellite remote sensing has been a crucial tool for observing the emperor penguins in the summer months since 2009. It was discovered then that colonies could be found in satellite images because of the dark guano stains they leave on the snow and ice. Overall, these observations have revolutionised our understanding of the species and have led to the discovery of many more colonies.

After a period of stability, Antarctic sea ice has declined markedly since 2016 and likely entered a new state, characterised by lower extent and increased instability. Earlier this year, emperor penguins were added to the International Union for Conservation of Nature’s red list and classified as endangered, predominantly due to projected declines in sea ice.

This makes better understanding and monitoring of emperor penguins more important than ever. The ability to observe colonies throughout the breeding cycle using freely available, routinely collected satellite data creates opportunities to better understand their response to changing environmental conditions.

Grant Macdonald, Postdoctoral Researcher, Department of Geography, Durham University

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

Some 90 years after the death of the last documented thylacine – better known as the Tasmanian tiger – the species remains a global symbol of human-made extinction.

The carnivorous marsupial fell victim to 19th-century colonists’ perception that unfamiliar creatures were primitive, vermin-like imitations of more familiar European animals. The species was later exterminated due to sensationalist claims that it was a ferocious, wolf-like predator of sheep.

However, our new study, published in Nature Communications, suggests the thylacine defied the colonialists’ assumptions in every way. It was unique among modern predatory mammals by subduing its prey with high-impact snaps of slender, oversized jaws.

Our focus was on one of the most widely cited cases of evolutionary convergence – the dog-shaped skull of the thylacine, which inspired its species epithet cynocephalus (“dog-head”). This is a striking similarity as thylacines are separated from dogs by more than 120 million years of evolution.

So we set out to understand how deep the similarity really goes.

A massive head with a flimsy face

We used 3D shape analysis to compare scanned thylacine skulls from museums around the world with those of other predatory mammals. This revealed that different regions of the thylacine’s skull resemble those of several other animals.

The thylacine’s long and thin snout looks pretty fragile, most like that of small foxes and jackals. By contrast, the back of the thylacine’s skull resembles that of wolves, dingos and dholes (also known as the Asiatic wild dog).

But the standout feature of this odd patchwork was the thylacine’s enormous head. Its relatively puny 17 kilogram body carried a skull as large as that of wolves, which are more than twice the thylacine’s weight.

So why this skinny jaw on an outsized head?

We suspect this combination allowed thylacines to subdue their prey with powerful snapping bites. Thylacine jaws are clearly built for speed: the longer a jaw is, the faster its tip moves during biting.

Combined with the animal’s famously large gape, this should increase the impact of the strike. Long jaws like this are usually quite weak, but the huge size of the thylacine’s skull would have added enough substance to withstand lethal snaps into potentially unsuspecting bandicoots.

The mammalian answer to crocodiles?

But it is the features that are not found in other predatory mammals that may have taken the thylacine’s snaps to a new deadly level.

The thylacine’s upper jaw is exceptionally tall, with a distinctive “pinched” hourglass shape at the tip. This combination is perfect for resisting the stress of high-impact, upwards-directed bites. It also matches earlier results that thylacine canine teeth seem most suited to puncturing, crushing bites (rather than pulling, tearing, or holding).

Thylacines were probably the last modern predatory mammals to sport such a tall, mace-like snout. But similar jaw types are found across other vertebrates, such as crocodiles, and are usually interpreted as adaptations for hunting fast-moving prey.

But some extinct mammals also had thylacine-like snouts, most notably in the gigantic extinct predator Andrewsarchus.

Our results are particularly tantalising in view of earlier genomic work which suggested that natural selection acted on regulatory genes in some shared developmental pathways of wolves and thylacines.

It is possible these genomic similarities are behind some of the shared aspects of skull shape between wolves and thylacines. However, as we know wolves and thylacines did not fill the same ecological niche, we might ask how these genomic convergences produced such a uniquely specialised marsupial predator.

A lesson for urgent and thoughtful future science

Our results highlight – yet again – that the thylacine’s eradication targeted an animal that only existed in the early colonial imagination. But they are also a timely reminder we cannot afford to repeat this mistake through negligence.

Australia has the worst mammal extinction rate in the world. Its wildlife faces escalating threats from environmental degradation and climate change, as well as new threats such as bird flu.

Museum-based research like ours is needed to illustrate how these statistics reflect irreplaceable biodiversity lost with every extinction.

But we also need to remember Western science is only part of the story – respectfully requesting knowledge from Indigenous custodians about the unique Australian wildlife should be key to our future research.

After all, the people who lived alongside thylacines for tens of thousands of years knew exactly what kind of animal it was.

Vera Weisbecker, Professor in Evolutionary Biology, College of Science and Engineering, Flinders University; Andrew Pask, Professor, School of BioSciences, The University of Melbourne, and Douglass S Rovinsky, Associate Research Scientist, School of Biological Sciences, Monash University

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