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South Australia is desperate for help to tackle an unprecedented harmful algal bloom that has decimated marine life up and down the coast. While the extent of the damage is still unknown, my preliminary research suggests there’s no end in sight. It may just get better over winter before it gets worse next summer.

The Karenia mikimotoi bloom first appeared in March on two surf beaches outside Gulf St Vincent, about an hour south of Adelaide. It has since spread, killing all kinds of marine organisms – from crabs and small fish to sharks and rays. Only the neighbouring Spencer Gulf, far west coast and southeast coasts have been spared. For now.

In preliminary research now undergoing peer review, I have predicted the bloom’s future spread using a new computer model. In the worst-case scenario, the harmful algal bloom would reach the Spencer Gulf and spread – from Port Lincoln to Whyalla and across to Port Pirie – next summer and autumn. That would be extremely bad news for the thriving seafood, aquaculture and tourism industries. They may need help to prepare.

Some help is on the way. Federal Environment Minister Murray Watt yesterday announced A$14 million in federal funding. SA Premier Peter Malinauskas convened an Emergency Management Cabinet Committee meeting today and signed off on a $28 million support package.

A rolling disaster

The algal bloom was first noticed when dozens of surfers and beachgoers on the southern coast of the Fleurieu Peninsula fell ill after exposure to seawater in March.

Soon, dangerous sea foam appeared. Then the killing began in earnest. Many marine species started washing up dead or dying.

The bloom began to spread. In mid-April, K. mikimotoi was detected in water samples from Edithburgh and Coobowie on the southeastern corner of Yorke Peninsula.

In early May, the Kangaroo Island Council announced the bloom had spread across the Investigator Strait affecting the island’s northern coastline.

Wild weather in June pushed the bloom through the Murray Mouth into the Coorong.

By July, the state government had detected K. mikimotoi along Adelaide’s metropolitan coastline. Videos of fish kills near the Ardrossan Jetty in the northern Gulf St Vincent also emerged.

So far, the bloom has not been detected in Spencer Gulf. But my modelling suggests it’s only a matter of time.

Predicting the future

I was the first to discover the seasonal upwelling of nutrients in several regions along SA’s southern coastal shelf. This nutrient source fuels the marine food chain. It’s a big part of the reason why the marine life in our Great Southern Australian Coastal Upwelling System is so diverse.

I also simulated the ocean currents in South Australian gulfs using computer models as early as 2009.

I have now developed a computer model to predict where the algae will spread next.

Preliminary results from this research have been submitted to the journal Continental Shelf Research and are being reviewed. But given the speed at which this situation is developing, it’s worth sharing a preprint of this manuscript.

My model matches what’s known about the early spread of the bloom. It began in the coastal waters of the southern Fleurieu Peninsula. It then invaded Investigator Strait, between the Yorke Peninsula and Kangaroo Island, before slowly spreading in a clockwise circulation across the wider Gulf St Vincent.

When the model is used to forecast how the algae bloom will evolve, the story becomes deeply concerning.

It predicts the algal bloom will weaken over this winter, as the growth rate will slow in cooler water. In my model, the algae had already invaded the lower Spencer Gulf in May 2025 but at very low concentrations.

Then, in the worst-case scenario of high growth rates and nothing stopping it, the model predicts the bloom will affect both gulfs – Gulf St Vincent and Spencer Gulf – and Investigator Strait, with severe conditions predicted for the coming summer.

A bloom in the Spencer Gulf could decimate stocks of Australian sardine in the lower gulf, and potentially also western king prawns and the giant Australian cuttlefish in the upper Spencer Gulf. Some research suggests algal growth may be limited in the hypersaline upper reaches of the gulfs, but the spread of the algae as far as Ardrossan indicates otherwise.

Under the best-case scenario, the algae’s natural predator, zooplankton, would eat more of the algae, suppressing future flare-ups. So there is some hope, but more research is needed to better understand how zooplankton could control these algae.

SA also needs to make continuous efforts to monitor K. mikimotoi concentrations. This includes analysis of water samples in both gulfs. It’s important to note satellite images only show the peak phase of the toxic algal bloom, and can be misleading as they also display other species including blooms of “good” algae.

Fortunately, the $28 million support package includes $8.5 million for early detection and monitoring of harmful algal bloom species. This will involve real-time sensors (buoys), satellite imagery and oceanographic modelling. A new $2 million national testing laboratory will check for toxins, while $3 million will be spent on a rapid assessment of fish stocks and fisheries.

But if the algae stick around, there may be little anyone can do to protect our marine environment.

Jochen Kaempf, Associate Professor of Natural Sciences (Oceanography), Flinders University

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

A report card into the A$13 billion Murray–Darling Basin Plan has found much work is needed to ensure the ecology of Australia’s largest river system is properly restored.

The assessment, by the Murray–Darling Basin Authority, is the most comprehensive to date.

The authority says the river system is doing better now than it would have without the plan, which aims to ensure sustainable water use for the environment, communities and industries. But it found there is more to be done.

We are water, economics and environmental researchers with many years of experience working in the Murray-Darling Basin. We agree more work is needed, but with a more local focus, to restore the basin to health.

This requires more than just more water for the environment. Coordinated local efforts to restore rivers and the surrounding land are desperately needed. There’s so much more to the river system than just the water it contains.

What’s the plan?

The Murray-Darling Basin is Australia’s food bowl. But for too long, the health of environment was in decline – rivers were sick and wildlife was suffering. The river stopped flowing naturally to the sea because too much water was being taken from it.

Poor land management has also degraded the river system over time. Floodplain vegetation has been damaged, the river channel has been re-engineered, and pest plants and animals have been introduced.

The Murray-Darling Basin Plan was established in 2012. It aimed to recover water for the environment and safeguard the long-term health of the river system, while continuing to support productive agriculture and communities. It demanded more water for the environment and then described how this water would be delivered, in the form of targeted “environmental flows”.

Since 2012, the allocation of water to various uses has gradually changed. So far, 2,069 billion litres (gigalitres) of surface water has been recovered for the environment. Combined with other earlier water recovery, a total of about 28% of water previously diverted for agriculture, towns and industry is now being used by the environment instead.

A mixed report card

The evaluation released today is the first step towards a complete review of the plan next year. The 2026 review will make recommendations to Environment and Water Minister Murray Watt. It will then be up to him to decide whether any changes are needed.

It is a mixed report card. Ecological decline has been successfully halted at many sites. But sustained restoration of ecosystems across the basin is yet to be achieved, and native fish populations are in poor condition across 19 of the basin’s 23 catchments.

Climate change is putting increasing pressure on water resources. More intense and frequent extreme climate events and an average 20–30% less streamflow (up to 50% in some rivers) are expected by mid-century.

The evaluation also called for better policy and program design. Specifically, flexible programs have proven more effective than prescriptive, highly regulated programs.

Finally, the report also highlights that the cost of water reform is increasing.

Direct buybacks of water licences, mostly from irrigators, account for around two-thirds of the water recovered for the environment under the basin plan. Buybacks are the simplest and most cost-effective way to recover water but are controversial because of concerns about social and economic impacts.

Much of the remaining water has been recovered through investment in more efficient water supply infrastructure, with water savings reserved for environmental use.

The authority suggests different approaches will be needed for additional water recovery.

Healthy rivers need more than water

For the past two decades, measures to restore the Murray-Darling Basin have focused largely on water recovery. But research suggests attention now needs to be paid to other, more local actions.

In March, one author of this article – Samantha Capon – identified nine priority actions to restore Australia’s inland river and groundwater ecosystems at local levels. They included:

• revegetating land alongside waterways
• retiring some farmland
• modifying barriers to fish movements
• installing modern fish screens on irrigation pumps.

The study estimated such actions would cost around A$2.9 billion a year, if completed over the next 30 years.

Works to restore vegetation or other environmental conditions at these critical habitats will only occur with landholders, as well as Traditional Owners.

That’s because most of the basin’s wetlands and floodplain areas are on private property, including in irrigation districts.

Irrigator involvement is needed to place fish screens on private irrigation pumps or retire farmland. There is a growing interest and some early experience in using private irrigation channels to deliver environmental water. This also requires local partnerships.

The basin plan should include targets for environmental outcomes, not just water recovery. This will allow the benefits from local restoration measures and environmental flows to be included when tracking the plan.

Such ecosystem accounting tools already exist. Research is urgently needed to make these tools both locally relevant and suitable for the basin plan.

Time for a local approach

To date, water for the environment under the basin plan has been recovered largely through centralised government-led programs. Decisions around the delivery of environmental flows are also largely in the hands of government agencies.

But other local restoration actions are also needed.

A business-as-usual approach would leave responsible agencies struggling to complete these vital local measures with limited funding, resources and accountability.

Michael Stewardson, CEO One Basin CRC, The University of Melbourne; Neville Crossman, Professorial Research Fellow in Economics, Flinders University; Samantha Capon, Professor in Ecology, Griffith University, and Seth Westra, Professor of Hydrology and Climate Risk, University of Adelaide

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

Picture this. A small, rainbow-coloured chick emerges from its nest for the first time. It stretches its wings and prepares to take flight. But before the fledgling’s life in the wild has begun, a sharp-beaked predator swoops in, leaving nothing but a tiny skeleton.

This is the sad scenario playing out on Cape York Peninsula, new analysis shows. There, trees are invading the open, grassy habitat of the endangered golden-shouldered parrot (Psephotellus chrysopterygius). The trees give cover to predators – meaning they can lie in wait, before striking the adult birds and their young.

The golden-shouldered parrot is endangered, now found in just 5% of its original range. The new findings suggest more work is needed to restore grassland habitat to its former open state, to ensure the parrots’ survival.

A vanishing species

The initial decline of the golden-shouldered parrot was likely caused by a loss of food plants and degradation of the termite mounds in which it nests. Birds that remained in two small areas in central Cape York Peninsula faced other issues.

In the 1990s, researchers began studying the parrot on Artemis Station, to better understand why numbers were declining. A new suspect was identified: native woody plants, such as the broad-leaved tea-tree (Melaleuca viridiflora), which had crept into the birds’ grassy habitat.

The change was largely due to overgrazing, which reduced fuel loads and led to fewer fires. This allowed the woodland trees to overtake the grasslands. But exactly how were these trees affecting the survival of the golden-shouldered parrot? New research by my colleagues and I set out to answer this question.

Counting eggs, nest by nest

We monitored 108 termite-mound nests over three years, tracking the success of 555 eggs. We visited each nest every few days to record whether chicks successfully fledged (grew strong enough to leave the nest) or died.

We also counted the number of trees around the nests, and recorded signs of interference from predators.

So what did we find? The proportion of nests that produced a fledgling from every egg decreased in proportion to the number of trees around the nest. The percentage of eggs, chicks and adults that were killed or disappeared from a nest also increased in line with tree numbers.

That’s because the trees bring different predators – and places for them to hide.

We suspected reptiles were the main predators. This was due to scratches on the nests and disappearance of eggs without any other signs of damage. While the exact species of reptile predator was hard to pinpoint, we know tree snake numbers increase as woodlands encroach.

However, of all predators, we found butcherbird numbers increased most strongly as trees crept in. Butcherbirds tear prey apart with their strong, hooked beaks. Trees close to the nests give butcherbirds cover, enabling them to wait for adults or their young to emerge.

Tragically, we found skulls of chicks pierced by the butcherbirds’ sharp bills. In one case, the shredded flesh of a bird was wedged atop a termite mound.

Parrots successfully fledged from just over half of the 555 eggs we monitored.

In the most dense woodlands, the number of birds that successfully fledged was just one-third of the rate needed to maintain the golden-shouldered parrot’s population.

Adult birds were lost from one-third of the nests we studied. This is especially troubling. Modelling from similar tropical birds shows this rate of adult deaths can push a species towards extinction.

Restoring the parrots’ grassland home

The world’s grassland habitats are under threat. This has devastating consequences for species that depend on them – including the golden-shouldered parrot.

Our findings show Cape York’s grasslands should be maintained and restored to ensure the survival of the golden-shouldered parrot. Much work is needed to ensure the species avoids the fate of its closest relative, the paradise parrot, which is presumed extinct.

Work is already underway. Golden-shouldered parrot habitat in national parks and on Indigenous-owned land has been destocked, and more traditional Indigenous fire regimes reinstated. This will help maintain open grasslands and reverse early woodland encroachment. Such work is also being undertaken at the study site on Artemis Station.

Where woody plant invasion is more advanced, more intensive methods have been deployed. At the study site, this includes using chainsaws and brush-cutters to clear trees, before the stump is poisoned.

Other measures include installing electric fences to keep out reptiles, reseeding grasslands with food plants and providing feeding stations in seasons when food is scarce.

Land managers across Cape York have also been provided guidelines for managing woodland encroachment.

These efforts must be sustained in the long-term, to ensure the golden-shouldered parrot can return to its former range.

Gabriel Crowley, Adjunct Associate Professor in Geography, University of Adelaide

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

Australia’s climate is changing. To avoid catastrophic disruptions from successive supercharged disasters, society must adapt. But change takes time and it’s not always clear how much progress we’re making.

We wanted to find out what Australia’s governments, industries and local groups are doing to adapt to climate change. Our work culminated in the Australian Adaptation Database, which captures more than 700 initiatives so far.

Standout examples from this first national stocktake include Ramblers Reef in Victoria – an artificial reef of rocks and shells 500 metres offshore that has helped reduce coastal erosion. In Adelaide, urban cooling and greening projects are transforming the city and suburbs across 17 councils .

Our project shows climate adaptation is happening in Australia, but there’s plenty of room for improvement. The more society can do now to prepare for change, the better off we’ll be in the long run.

What does climate change adaptation in Australia look like?

Australia is lagging behind many other nations when it comes to managing climate action. The federal government is yet to release its first national adaptation plan, while other countries are up to their third or fourth versions.

Why track Australia’s progress in climate adaptation? First, it enables progress to be reported efficiently to governments and international bodies such as the United Nations.

The database also helps people share knowledge. Anyone striving to improve their resilience to climate change can look to the database for ideas and inspiration.

The data was mainly gathered from conversations we had with people in state and territory government departments, local government associations, not-for-profit organisations and private companies across Australia.

On Wednesday, we will present the database at the opening of the national Climate Adaptation 2025 conference in Perth.

The project shows the vast range of ways Australians are preparing for a warmer world. Examples include:

• planting trees to cool cities such as Adelaide and rural towns such as Birchip in Victoria

• building artificial reefs to protect the coastline on the Bellarine Peninsula near Geelong

• changing land use on the Sunshine Coast and building levee banks to better manage flood risks in Roma, Queensland

• restoring and rejuvenating the environment to reduce the impact of drought in Mulloon, New South Wales or flood risk in Brisbane

• moving houses and businesses from hazardous locations such as Grantham in Queensland’s Lockyer Valley, and land swaps in South Murwillumbah.

Anyone can explore and search the database. It’s not an exhaustive record of all climate adaptation in Australia, but provides more detail than ever before. It’s constantly being updated as new examples are added.

But the database is only as good as the information we feed into it, so we need everyone to contribute. All you need to do is hit the “submit an entry” button on the homepage to get started.

The role of government: local, state and federal

Much work to date in climate adaptation has involved laying the foundations for practical actions.

For example, South Australia’s Climate Ready Coasts program aims to improve planning for coastal hazards. This joint effort between state and local governments make sense, given both have a role to play, and it helps ensure adaptation actions are efficient and coordinated.

At the federal level, the Australian government has focused on funding for national disasters such as the Future Drought Fund. Another example, the Infrastructure Betterment Fund, involves making roads, rail, bridges and other infrastructure more resilient to climate change.

Australia is yet to release its first National Adaptation Plan. This document is expected to clarify the federal role in climate adaptation.

The private sector

The private sector is beginning to adapt to climate change. Examples include:

• relocating wine grape production to more suitable climates

• creating new fireproof home designs

• improving building standards, so properties are more resilient to extremes

• preparing guidelines for the financial sector, to better manage the risk to investments

• planning more climate-resilient property developments

• adopting new farming technologies and supporting more regenerative agriculture.

Knowledge sharing and capacity building

We also found extensive efforts to communicate and share information about adapting to change.

Such activities include knowledge building for organisations and communities through workshops, training sessions and simulation games.

Examples include Western Australia’s “being waterwise in the home” tips, and Hobart’s Sparking Conversations, Igniting Action Program for bushfire preparedness. These activities help lay the groundwork for practical action.

What’s next?

Our research shows the policy and governance mechanisms to drive adaptation are largely in place. The knowledge and networks to support meaningful action are gradually being developed.

But the next “heavy lifting” phase – putting plans into action – is yet to begin in earnest.

There’s a clear need to channel funding to those best placed to deliver frontline projects and programs, especially local governments and community organisations.

The Australian Local Government Association is calling for a A$400 million climate adaptation fund to support Australian councils to deliver place-based adaptation actions.

Last year, the Australian Council of Social Services called for a $2 billion investment in a national housing retrofit program to make Australia’s 670,000 low-income houses cooler in summer to reduce illness and death from extreme temperatures. Neither of these calls has been answered.

Let’s get moving

This research is part of a three-year project exploring how to encourage and promote best practice in adapting to climate change across Australia.

The next step is to measure progress around climate adaptation, which is difficult and rarely done – even though it’s required under the Paris Agreement.

The good news is Australia has made a start, but there is much more to do to ensure the wellbeing of our country through a changing climate.

Tia Brullo, Research Fellow in Climate Change Adaptation, The University of Melbourne; Elissa Waters, Lecturer in Human Geography, Monash University; Jon Barnett, Professor, School of Geography, The University of Melbourne, and Sarah Boulter, Associate Professor of Climate Adaptation, University of Tasmania

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

As the electrification of transport and heating accelerates, many worry the increased demand could overload national power grids. In Australia, electricity consumption is expected to double by 2050.

If everyone charges their car and heats water using electric systems at the same time, peak demand could rise sharply, forcing costly grid upgrades. But this would only happen if there’s no planning done.

The shift to electric vehicles (EVs) and electric water heating has a huge silver lining. As more Australians make the switch, they’re quietly expanding a vast network of distributed energy storage. In a fully electrified future, each person could have on average about 46 kilowatt hours worth of energy storage – both in EV batteries and hot water systems.

Scaled up, that’s a huge resource. If all cars and water heaters run on electricity, their combined flexible energy storage could reach over 1,000 gigawatt-hours (GWh) across Australia. That’s far beyond the 350 GWh capacity of the Snowy 2.0 hydroelectric project and all existing grid-scale batteries put together.

Authorities can use these devices to help operate the grid more efficiently and slash infrastructure costs. In fact, our new research shows that with the right coordination, cities can transform from energy consumers into flexible energy hubs able to store energy and release it as necessary. This would make it possible to avoid billions of dollars worth of grid upgrades.

Storage built in

Electrification replaces fossil fuel-burning technology with electric-only systems, powered by a grid getting steadily cleaner.

For households, electrification means switching a combustion engine car for an EV and replacing gas hot water with electric systems such as heat pumps. Both slash carbon emissions when run on grids with high levels of renewables.

EVs and electric hot water systems offer more than just mobility or heating. They also have built-in energy storage. EV batteries store huge amounts of electricity – usually several times the size of a house battery. Hot water systems store energy too, in the form of heat.

Both of these resources are very useful to power grid authorities, because they can help optimise how the grid operates.

Power grids are a constant balancing act, where supply and demand have to be carefully matched up. At times of intense demand, such as during a heatwave, demand can outstrip normal supply and send prices skyrocketing.

When EVs are charged and water heated during off-peak periods, the strain on the grid can be significantly lessened.

Canberra is pointing the way

Since 2020, Canberra has been 100% powered by renewable electricity. The ACT Government is aiming for net zero by 2045.

In our modelling, we found this goal could get a lot closer if EVs and hot water systems are used cleverly. We found changing the time cars are charged and water heated would shift around 5 kWh of electricity per person per day. That’s about a third of each Canberra resident’s average daily electricity use.

Unmanaged charging and water heating would cause peak load to jump 34%. But if charging and heating was shifted to off-peak hours overnight, it could restrict the rise in peak load to just 16%.

Reducing the rise in peak load would make it possible to avoid billions of dollars in grid upgrades such as expanding substations and building more transmission lines.

Where flexibility matters most

We found Canberra’s new energy storage resources are concentrated in storage hotspots – densely populated areas with many electric hot water systems and where many EVs are parked during the day.

Importantly, these hotspots don’t stay put. During working hours, vehicle batteries tend to concentrate in high-density office areas where EVs are parked. Storage capacity rose up to 31% in some Canberra working districts during the working week.

It would make sense to make the most of these hotspots by installing smart chargers, which optimise the timing of EV charging and creating virtual power plants, which can coordinate the time when household devices and EVs draw power.

Both of these approaches offer a cost-effective way to aggregate small scale household devices into a large coordinated storage resource.

Aligning demand with solar peaks means using renewable energy which might otherwise go to waste during peak times.

Policy needs to catch up

Capturing the huge benefits from these new storage resources won’t happen automatically. It requires smart systems and supportive policies.

Technologies such as smart chargers and virtual power plants already exist. South Australia’s Virtual Power Plant shows what’s possible in practice.

But to date, most Australian households don’t have these kinds of smart systems. In many areas, electricity pricing is relatively inflexible and there’s limited coordination between flexible energy use and the needs of the grid.

To unlock the full potential of this huge new energy storage resource, governments and energy companies should:

• encourage uptake of smart chargers and smart water heaters in buildings

• expand dynamic pricing schemes which better reflect real-time supply and demand to help shift electricity use to off-peak periods

• focus on rolling out workplace EV chargers in high-density areas to boost charging during solar peak periods

• develop smart energy systems able to aggregate devices in individual households into a large grid-supporting fleet.

More demand – but more storage

As Australia increasingly goes electric, cities are becoming more than just energy consumers.

Rather, they’re becoming flexible energy hubs able to help balance supply and demand.

Used wisely, humble electric water heaters and EVs can do more than meet household needs — they can help power Australia’s clean energy future.

Bin Lu, Senior Research Fellow in Renewable Energy, Australian National University and Marnie Shaw, Associate Professor in Engineering, Australian National University

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

Representatives from 175 countries will gather in Geneva, Switzerland, in August for the final round of negotiations on a legally binding UN treaty to end plastic pollution. Non-governmental organisations, academics and industry lobbyists will also be in the room. They will all be hoping to influence what could be the world’s first truly global agreement on plastics.

The summit, known as “INC-5.2”, follows a failed attempt to reach agreement in Busan, South Korea, late last year. That meeting ended without resolving important issues, despite hopes that it would conclude the treaty process. Now, it’s crunch time in Geneva.

Either countries bridge their political divides, or risk the whole process falling apart.

I’ve been researching the effects of plastic for more than a decade and have been involved in the UN treaty process since 2022. I’ve attended several of the negotiations and will be in Geneva next month. The science is clear: we need ambitious action which tackles every stage of the plastics lifecycle, from production through to disposal. But the question is, will countries deliver?

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In 2022, the UN Environment Assembly agreed to develop a legally binding treaty to end plastic pollution. Since then, progress has been slow. Negotiations have repeatedly stalled over issues such as whether the treaty should limit plastic production or regulate chemicals, how to define terms, and how to fund implementation.

Industry lobbying has also played a powerful role throughout. At the last round of talks, lobbyists for the petrochemical and plastics industries made up the single largest delegation. They outnumbered representatives from the EU, all of Latin America, the Pacific islands, independent scientists and Indigenous communities. This imbalance threatens to weaken the science-based action that is urgently needed.

Although countries failed to reach agreement in Busan, a foundation was laid. They agreed to continue negotiations using the “chair’s text”, which is a draft treaty with multiple options still on the table. That document forms the starting point in Geneva. But it remains uncertain whether enough common ground can be found to finalise the text.

What’s at stake?

This treaty is a once-in-a-generation chance to tackle one of the world’s most urgent environmental crises. More than 450 million tonnes of plastic are produced every year. That figure is expected to double by 2045 if current trends continue.

Only around 9% of plastic is ever recycled. The rest is landfilled, incinerated or ends up polluting the environment.

An estimated 139 million tonnes of plastics pollute marine and fresh water. But that could be significantly higher when considering leakages of plastics to land, and from microplastics, which are plastics smaller than 5mm in diameter.

Plastic is found in the deepest oceans, the remotest mountains and inside the human body. While scientists are only beginning to understand the long-term implications for human health, biodiversity and climate, studies show harmful effects of plastics and their chemicals on animals and ecosystems.

Plastic pollution doesn’t respect national borders. It moves through rivers, oceans and air, and gets carried across continents. Global supply chains and waste exports have made this a problem no country can solve alone. That’s why a global treaty is essential.

Crossroads

Despite this growing urgency, a disparity in positions has hindered progress and continues to divide delegations.

Some, such as members of the High Ambition Coalition, a group of countries committed to progressive climate action, want strong rules to cap plastic production, phase out toxic chemicals and hold polluters accountable. Others, often with prominent petrochemical industries, argue for a weaker, voluntary approach focused mainly on recycling and waste management.

If these divisions aren’t resolved, there’s a real risk the treaty will end up being too watered down to make a difference. A patchy, fragmented agreement would fail to curb rising plastic production and could undermine the integrity of global action.

Between December’s meeting in Busan and next month’s talks, countries have been holding smaller meetings to try to find compromise. That momentum must now be carried into the final negotiations.

Important articles in the draft treaty, including those on chemicals and products, plastic production and finance, remain contested. Whether those provisions are strengthened or diluted will shape the treaty’s effects for decades to come.

Flexibility will be needed. But leadership is also crucial. Countries that support an ambitious outcome must stand firm and bring others with them.

As we approach what may be the final negotiating round, we’re at a critical crossroads. The world has the chance to take meaningful action on plastic pollution. Let’s not waste it.

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Winnie Courtene-Jones, Lecturer in Marine Pollution, Bangor University

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

Almost half of all Australian properties are at risk of bushfire, while 17,500 face risk of coastal erosion. By 2030, more than 3 million will face riverine flood risk.

Meanwhile, housing demand continues to outpace supply. With climate-related disasters projected to increase in frequency and severity, the task of ensuring safe and adequate housing for all Australians remains a challenge.

In other words, disasters are worsening the housing shortage, rendering more people at risk of homelessness.

There is growing consensus in the homelessness and emergency management sectors that Australia needs a national policy response.

We must ensure secure and safe housing options are a disaster planning priority.

Like ‘living a disaster every day’

Climate disasters displace 22,261 Australians on average each year. People with the lowest incomes make up 80% of this. The very poorest 3%, despite being small, make up 14% of displaced households.

Australia is not alone. Globally, 70% of internal displacement in 2024 resulted from disasters, often disproportionately affecting low socioeconomic areas.

Loss of housing affects everything from a person’s health and employment to education and relationships. One person who’d experienced disaster-related housing loss said it was like

living a disaster every day, but without the assistance and support given to most disaster survivors.

Renters, rough sleepers and people living in unattached dwellings are most vulnerable.

Slipping through the cracks

The catastrophic Northern Rivers floods in 2022 provide an instructive example.

The floods rendered over 3,500 homes uninhabitable and more than 8,000 were damaged. Over 1,400 people were displaced and offered emergency accommodation by the New South Wales government.

The total number of people experiencing homelessness post-floods remains unclear. This is due to existing overcrowding and because people left the area or became uncontactable.

Recent research colleagues and I conducted with homeowners and renters, commissioned by the Australian Housing and Urban Research Institute, examined 17 people’s experiences of securing shelter after disaster.

In Lismore, a key barrier was poor communication and increased competition for rental housing. One person told us:

The real estate basically dropped the ball after a month. I had to chase them up, and the return of my bond and all that. […] I applied for ten different properties and never heard back. […] I ended up sourcing my own accommodation, a camper trailer, and camped out at the local showgrounds.

For renters, the disaster couldn’t have come at a worse time. A preexisting rental crisis across the region meant the private market was already tight.

Homeowners, by contrast, were able to use insurance to cover transitional housing costs or were eligible for several funding sources to repair properties. This highlights a policy emphasis toward homeowners.

In this context, people can slip through the cracks, increasing the risk of homelessness.

Post-disaster housing can compound vulnerability

Temporary shelters – such as crisis shelters, motels, short-term rentals, pods, cabins and caravans – can be a stop-gap against the risk of homelessness after disaster. However, temporary shelter comes with trade-offs and downsides.

Crisis and commercial options can be damaged during disaster, limiting their use. Pod villages provide mass shelter but are costly, slow to deliver, and there’s often no meaningful plan for people to transition out of them.

Some 18 months after the 2022 Northern Rivers floods, 1,021 people were still living in temporary pod villages and 257 people remained in caravans.

Rent is not usually charged. When relied on beyond the immediate term, this can compound vulnerability by creating gaps in people’s rental history.

A NSW government audit found 724 households were on the waitlist for temporary housing a year after the floods, though this list was rarely updated.

Overall, relatively few households have secured long-term housing solutions. This year, four pod villages will be demobilised amid the region’s ongoing rental crisis.

This comes at a time when Australia is facing a shortfall of 640,000 social and affordable homes.

Around 110,000 requests for homelessness services go unassisted annually.

A national framework is needed

In 2024, a national symposium, convened by the Australian Red Cross, Homelessness Australia and UNSW Sydney’s HowWeSurvive initiative, brought together 125 professionals from the housing, homelessness, emergency management, government and academic sectors.

The report, released in June 2025, called for a national framework focused on disasters, housing and homelessness.

Several policies deal separately with these areas at the Commonwealth, state and territory levels. A unified approach, however, would reposition shelter after disaster from a stop-gap to a central part of disaster planning.

The aim is to strengthen housing options before a natural hazard occurs and prevent disaster-related homelessness.

Australia needs a coordinated strategy and taskforce to align housing, homelessness, and disaster policies and programs. Homelessness planning should be part of disaster planning, and vice versa, to ensure housing type and tenure does not place people at risk of homelessness when disaster strikes.

This requires going beyond just linking displaced households with crisis services.

We must plan for each stage of housing before and after a disaster and anticipate diverse needs, especially for renters and those at risk of homelessness.

Responses should be trauma-informed and able to adapt individual experiences.

Now is the time to act – before the next disaster strikes.

Timothy Heffernan, Lecturer in Anthropology, Australian National University

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

The Albanese government has today confirmed it will lift biosecurity restrictions on beef imports from the United States. The timing of this decision has raised some eyebrows.

Back in April, US President Donald Trump had singled out what he characterised as an Australian “ban” on US beef as he announced 10% baseline tariffs on imports from Australia.

Responding to today’s announcement, Nationals leader David Littleproud said it appeared the restrictions have been “traded away to appease Donald Trump”.

But Trade Minister Don Farrell said there was “nothing suspicious about this”. And some Australian industry groups have since expressed their confidence in the decision.

So, has Australia’s beef industry been sold out for the benefit of a trade deal? Or is it just a poorly timed announcement at the end of a review into Australia’s restrictions?

Biosecurity concerns

Australia’s biosecurity rules, particularly around beef products, have long been a source of friction with the United States. These rules date back to the late 1990s and were strengthened following a US mad cow disease scare in 2003.

In 2019, a ban was lifted on beef products from cattle that had been born, raised and slaughtered in the US. However, a ban remained on any products from cattle originating in Mexico or Canada that had been slaughtered in the US.

This was a cause for some tension, because the traceability requirements in the US were not as stringent as in Australia. That meant it wasn’t always possible to determine the origins of US products. So the 2019 change effectively only applied to shelf-stable products – not fresh meat.

Last month, the Albanese government made assurances Australia’s biosecurity rules wouldn’t be compromised in trade negotiations. But it also confirmed a review of the rules was underway.

The National Farmers’ Federation acknowledged the government’s decision in a statement today:

The report released today is the result of a long-standing, science-based review by the Australian Government into the biosecurity risks posed by cattle raised in Canada and Mexico, but processed in and exported from the US.

Speaking on ABC Radio, Cattle Australia chief executive Will Evans acknowledged “a lot of people” may feel “blindsided” by the government’s decision, but expressed his confidence in the government’s process.

Boom times for Australian beef

Australians are some of the highest per-capita consumers of beef products in the world. But Australia is also the world’s second-largest beef exporter, trailing only Brazil.

In contrast, the US is the world’s second-largest importer of beef, behind only China.

That poses the question: how much do we actually need beef from the US? Is it even worth lifting this ban, if it will impact so few people?

The beef industry might be fair to question whether this is for the benefit of their industry, when it seems the existing 10% baseline tariffs have had no impact on the volumes of beef being exported from Australia. Quite the opposite.

In June, Australia’s beef exports broke an all-time monthly record, and the US continued to be our largest export market.

In addition, it is important to recognise the US tariffs on beef would theoretically be absorbed by the consumer, rather than the exporter.

The trade war rages on

Theory suggests that international trade is a good thing (though not everyone is a “winner”). Where there is trade between nations, competitive pricing is encouraged and consumers may enjoy more product variety.

Most restrictions on trade are viewed unfavourably by economists, but there are some notable exceptions. The health and safety of food products and assurance of biosecurity standards are such concerns.

Overnight, comments from the Trump administration suggest the 10% tariffs on imports from Australia could be raised, with a new baseline tariff rate of 15%.

To apply these to Australian beef is in direct conflict with the Australia and United States Free Trade Agreement (AUSFTA). This agreement progressively removed tariffs on Australian beef, with all tariffs eliminated by 2023.

Consequently, any new US tariff would violate these terms, threatening a trade relationship that has seen beef exports to the US flourish.

Is our reputation on the line?

It is important to note that the biosecurity rules in Australia and the traceability requirements for our producers are a point of national pride.

Central to Australia’s biosecurity framework is the Biosecurity Act 2015 and the National Livestock Identification System, which ensures traceability, food safety, disease control and animal welfare.

This imposes strict requirements on Australian beef producers – and as a result, imposes costs. It also means Australian beef is considered a premium product in much of the world.

Australians should hope the evidence from the government’s review fully supports this action.

Given the unpredictability of the Trump administration, it remains to be seen whether lifting these restrictions will win Australia any concessions on trade anyway.

Felicity Deane, Professor of Trade Law and Taxation, Queensland University of Technology

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

One of Aotearoa New Zealand’s oldest settlement sites is at risk of being washed away by rising seas, according to new research.

Te Pokohiwi o Kupe (Wairau Bar) near Blenheim is a nationally significant archaeological site. It dates back to the first arrival of people and holds the remains of first-generation Polynesian settlers as well as many cultural artefacts.

The site is significant for the local iwi, Rangitāne o Wairau, because of its history of colonial exploitation and the eventual repatriation of koiwi tangata (ancestral remains) in 2009, which marks an important moment in the modern history of Rangitāne.

Coastal flooding is already a hazard at Te Pokohiwi o Kupe, but this increases dramatically as sea level rises. The study, led by Te Rūnanga a Rangitāne o Wairau in partnership with researchers at Earth Sciences NZ, shows about 20% of the site could be inundated during a 100-year storm event under current sea levels.

But with 50 centimetres of climate-driven sea-level rise, which could occur as soon as the 2050s under high-emissions scenarios, more than half of the site could flood in the same event. If sea levels rise to a metre, which could be reached during the early 2100s, three-quarters of the site will be inundated and subject to significant erosion.

From grave robbers to collaborators

During the first part of the 20th century, the site was raided by fossickers searching for curios. In 1939, they uncovered an urupa (cemetery) and disinterred the remains of one of the earliest ancestors, along with their sperm whale tooth necklace and moa egg.

Further “discoveries” drew Roger Duff, then an ethnologist at the Canterbury Museum, to the site in 1942. He led several excavations until the summer of 1963-64.

The Rangitāne community protested the excavations. Tribal elder Hohua Peter MacDonald was particularly vocal, but the tribe was unable to prevent the digs and the removal of ancestors and their burial goods.

In 2003, Rangitāne presented their Treaty of Waitangi claims before the Waitangi Tribunal. The tribunal agreed the Crown had breached the treaty in its dealings with the tribe and subsequent negotiations saw land at Te Pokohiwi returned to Rangitāne. These land parcels were close to where ancestors had been taken and the remains were eventually returned in 2009.

Prior to the repatriation, the University of Otago, Canterbury Museum and Rangitāne agreed that research, including genetic sequencing of the koiwi tangata and an archaeological survey of the site, would take place before the reburial. Due to their past experiences, Rangitāne had little trust in the scholastic community. But in a first of its kind, a memorandum of understanding was signed between the parties.

Maintaining connections

Our study used high-resolution, local-scale analysis of sea-level rise and coastal change to assess the risk to archaeological taonga (treasures) and wāhi tapu (sacred sites) at Te Pokohiwi o Kupe.

By combining the knowledge of Rangitāne hapū (sub-tribal groups) about the site’s boundaries and locations of ancestral or archaeological taonga with LiDAR-derived topographic data, the research team mapped its exposure to present-day and future coastal inundation from spring tides and storm-wave events.

Sea-level scenarios were consistent with the latest projections by the Intergovernmental Panel on Climate Change and national guidelines to estimate the likely timing of future inundation.

Results suggest climate-driven shoreline changes and permanent inundation will increasingly threaten this culturally and archaeologically significant site.

While this research focused on relative and extreme sea-level inundation risks, earlier palaeo-tsunami studies show the area is also known to be exposed to tsunami hazards.

Ongoing research supported by a Natural Hazards Commission grant seeks to expand on our findings by integrating multiple inundation types with iwi-led experiences of impacts and mitigation. The goal is to develop new inclusive approaches for quantifying the effects of compounding inundation hazards.

The integrated place-based approach underpinning this research supports dialogue about adaptation and rescue options for protecting sacred sites threatened by climate change through a combination of locally led and nationally supported interventions.

For Rangitāne, Te Pokohiwi o Kupe is a place where relationships are maintained, responsibilities upheld and identity reaffirmed. While its archaeological value is widely recognised, its deeper significance lies in the enduring connection Rangitāne maintain with the whenua (land) and with the stories, knowledge and obligations it carries.

Over time, the nature of that relationship has evolved. What was once marked by protest and exclusion has shifted into a place of active management and leadership, in part supported through the return of the land as part of the iwi’s treaty settlement.

Now, with growing threats posed by sea-level rise and coastal erosion, that connection faces a different kind of challenge. The concern is not only for what may be physically lost, but for what it might mean to lose the ability to stand in that place, to gather there and to sustain the relationship that has grounded generations of Rangitāne people in Wairau.

The focus is not only on preserving what remains, but on ensuring the connection to Te Pokohiwi continues, even as the landscape changes. More than protecting a site, this is about protecting the ability of Rangitāne to remain in meaningful relationship with Te Pokohiwi o Kupe, its stories and its significance.

Peter N. Meihana, Senior Lecturer in History, Te Kunenga ki Pūrehuroa – Massey University; Corey Hebberd, Kaiwhakahaere Matua, Te Rūnanga a Rangitāne o Wairau Trust, Indigenous Knowledge, and Shaun Paul Williams, Group Manager for Environmental Hazards, Earth Sciences New Zealand

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

Former Treasury Secretary Ken Henry has warned Australia’s global environmental reputation is at risk if the Albanese government fails to reform nature laws this term.

In his speech to the National Press Club on Wednesday, Henry said reform was needed to restore nature and power the net zero economy.

Speaking as chair of the Australian Climate and Biodiversity Foundation, Henry said with “glistening ambition”, Australia can “build an efficient, jobs-rich, globally competitive, high-productivity, low-emissions nature-rich economy”.

The speech comes at a crucial time for nature law reform in Australia. The new Environment Minister Murray Watt has committed to prioritise reform, after the Albanese government failed to achieve substantial changes to these laws in the last parliament.

On Wednesday, Henry condemned previous failed attempts to reform the laws. He described delays in improving environmental management as “a wilful act of intergenerational bastardry”.

The need for fundamental reform

The Albanese government abandoned efforts to pass important reforms in its first term.

Environment Minister Murray Watt has committed to achieving reforms within 18 months, acknowledging “our current laws are broken”.

In his speech on Wednesday, Henry agreed with this sentiment. He described the Environment Protection and Biodiversity Conservation Act as “a misnomer, if ever there was one”.

Henry is both a former Treasury Secretary and former chair of National Australia Bank. He also wrote Australia’s most important white paper on tax reform.

Henry has previously said environmental law reform could be a template for other essential, difficult law reform, such as fixing Australia’s broken tax system.

He understands Australia’s broken environmental laws. In 2022-23, he led an independent review into nature laws in New South Wales. That review found the laws were failing and would never succeed in their current form.

At the start of his speech on Wednesday, Henry came close to tears when he acknowledged Greens Senator Sarah Hanson-Young’s support for those who look after injured and orphaned native animals.

As a bureaucrat in Canberra, Henry also used to rescue injured animals and nurse them back to health.

Big challenges ahead

As Henry noted on Wednesday, Australia faces enormous challenges. These include the need to rapidly build more housing and triple renewable energy capacity by 2030.

But before building suburbs, wind farms, transmission lines, mines and roads, projects need to be assessed for their potential to harm the environment.

Henry called for sweeping changes, drawing on Graeme Samuel’s 2019-20 review of the EPBC Act. The changes include:

• genuine cooperation across all levels of government, industry and the community
• high-integrity evidence to inform decision making
• clear, strong and enforceable standards applied nationwide
• an independent and trusted decision-maker, in the form of a national Environment Protection Authority
• a natural capital market, which – if well-designed – could provide a financial incentive for nature restoration and carbon storage in the form of tradable credits.

Without the reforms, Henry said, Australia would not “retain a shred of credibility” for two global commitments: reaching net zero emissions, and halting and reversing biodiversity loss.

The net zero commitment is at risk because existing laws are not sufficient to protect carbon sinks, such as forests. The roll out of renewable energy is also being slowed by inefficient approvals processes.

Henry said the concept of “ecologically sustainable development”, which seeks to balance economic, social, and economic goals, needs serious rethinking. This concept has been the foundation of environment policy in Australia, including the EPBC Act, for the past 30 years.

Henry wrote the first Intergenerational Report for the federal government in 2002. He has criticised governments for allowing environmental destruction that will leave future generations worse off.

He has variously described Australia’s failure to steward our natural resources as an intergenerational tragedy, as intergenerational theft, and a wilful act of intergenerational bastardry – claims he repeated on Wednesday.

Making money grow on trees

Henry grew up on the Mid North Coast of NSW where his father, a worker in the timber industry, helped log native forests.

Land clearing is the main threat to Australian biodiversity, and preventing native vegetation loss would also cut greenhouse gas emissions.

The foundation Henry chairs advocates for the protection and restoration of Australia’s native forests. Henry has previously backed a plan to store carbon in native forests, which would mean trees were protected and not cut down.

In his Press Club address, Henry lamented ongoing land clearing, poor fire management in remnant forests, and logging of habitat for endangered species such as the koala and the greater glider.

He also called for nature laws that enable projects to be delivered in a way that not only protects but also restores nature. For instance, he said carbon credits could help fund the Great Koala National Park proposed for NSW.

What’s the Australian government doing?

Despite Murray Watt’s stated commitment to nature law reform, there are signs the environment may again come off second-best.

At a recent meeting with key stakeholders, including industry and environment groups, Watt said compromise was needed. He warned environmental protections must come with streamlined project approvals “to improve productivity”.

Henry on Wednesday acknowledged faster approvals were needed, saying:

We simply cannot afford slow, opaque, duplicative and contested environmental planning decisions based on poor information mired in administrative complexity.

But he said faster approvals should not come at a greater cost to nature. In his words:

with due acknowledgement of the genius of AC/DC, there is no point in building a faster highway to hell.

Henry said the current parliament has time to put the right policy settings in place. The remedies also enjoy broad stakeholder support. “We’ve had all the reviews we need,” he said. “All of us have had our say. It is now up to parliament. Let’s just get this done.”

Phillipa C. McCormack, Future Making Fellow, Environment Institute, University of Adelaide

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

The snow petrel, a strikingly white bird with black eyes and a black bill, is one of only three bird species ever observed at the South Pole. In fact, the Antarctic is the only place on Earth where this bird lives.

It isn’t alone in this. Antarctica and the sub-Antarctic harbour a large number of endemic species, which means these species are only found in one or a few locations in the world.

In other words, these regions have a high degree of “endemism” – an important metric that tells us where to focus species conservation efforts.

But our new study shows that the degree of endemism in Antarctica and the sub-Antarctic – and in the southern hemisphere more generally – has been underestimated.

This is important because areas with a high degree of endemism harbour species with restricted ranges, unique evolutionary history or unique ecological functions. This makes them potentially more vulnerable to disturbances such as climate change, fundamental changes in habitat, or invasive introduced species.

If the degree of endemism is underestimated, conservation efforts may overlook the sites that are home to irreplaceable birds.

Biased measurements

There are two reasons why global patterns of species endemism aren’t well defined. First, the most common method used to calculate endemism tends to give higher values to places with more species overall – this is known as species richness.

In addition, global studies of diversity often exclude areas that are comparatively species-poor. These areas are mainly in the southern hemisphere – most notably the Antarctic region. When sites that only contain a few species are left out, this influences the estimates of endemism for all other sites.

An alternative way to calculate endemism takes into account a site’s “complementarity”. This metric considers whether species found at a site are also found elsewhere. With this method, we can find sites that have the highest percentage of species with a restricted range.

At such highly endemic sites, the local ecosystem relies heavily on species with restricted ranges to function, which makes them all the more irreplaceable.

Global hotspots for endemic species

This is the approach we used in our new study to reassess the endemism of birds worldwide. In our study, we also considered other aspects of bird diversity. We measured endemism with regard to whether sites hold irreplaceable evolutionary history and ecological functions of birds.

We found that southern-hemisphere communities showed higher rates of local endemism than northern-hemisphere communities across all aspects of diversity. The sub-Antarctic islands and the High Andes, as well as several regions in Australia, Aotearoa New Zealand and southern Africa, stand out as global hotspots of endemism.

These regions hold many charismatic birds with unique evolutionary histories or unique ecological functions, and these birds are largely restricted to the southern hemisphere.

Among these are the palaeognaths – the bird lineage that includes kiwis, emus, cassowaries and ostriches. They also include the lyrebirds and the New Zealand wrens, as well as iconic Antarctic species such as penguins and albatrosses.

Not much land, a lot of ocean

The higher rates of endemism in the southern hemisphere are likely related to the uneven global distribution of landmass. Put simply, there is much more available landmass in the northern hemisphere. As you go further south, landmasses become increasingly separated by vast expanses of ocean.

Because of the smaller and separated landmasses, species in the southern hemisphere have much smaller ranges than species in the northern hemisphere. Consequently, local species communities share fewer species with each other. This leads to the higher observed endemism in the southern hemisphere.

A heightened vulnerability

Our findings suggest that birds in the northern and southern hemisphere might react differently to environmental pressures. Unfortunately, most studies on the impact of climate change to date are from the northern hemisphere.

In response to climate change in particular, species are expected to shift their ranges towards cooler climates. While northern-hemisphere birds are likely free to shift their ranges across large stretches of uninterrupted landmass, birds in the southern hemisphere are hindered by vast expanses of ocean that separate the different landmasses on which they live.

For species at the southern tips of South America, Africa or Australia, the nearest major landmass towards the south is Antarctica. But it is unsuitable for most bird species.

The potentially heightened vulnerability of southern-hemisphere birds suggests they deserve more protection. In addition to known species diversity hotspots that hold large numbers of species, conservation efforts should consider areas that might hold only a small number of species, but irreplaceable ones that aren’t found anywhere else.

Matthias Dehling, Researcher, School of Biological Sciences, Monash University

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

Bad climate news is everywhere. Africa is being hit particularly hard by climate change and extreme weather, impacting lives and livelihoods.

We are living in a world that is warming at the fastest rate since records began. Yet, governments have been slow to act.

The annual global climate change conference of the parties (COP30) is just months away. All of the 197 countries that belong to the United Nations were supposed to have submitted updated national climate plans to the UN by February this year. These plans outline how each country will cut its greenhouse gas emissions in line with the legally binding international Paris Agreement. This agreement commits all signatories to limiting human-caused global warming to no more than 1.5°C above pre-industrial levels.

Governments must also bring their newly updated national climate action plans to COP30 and show how they plan to adapt to the impacts that climate change will bring.

But so far, only 25 countries, covering around 20% of global emissions, have submitted their plans, known as Nationally Determined Contributions. In Africa, they are Somalia, Zambia and Zimbabwe. This leaves 172 still to come.

The nationally determined contributions are very important in setting out countries’ short- to medium-term commitments on climate change. They also provide a direction of travel that can inform broader policy decisions and investments. Aligning climate plans with development goals could lift 175 million people out of poverty.

But arguably only one of the submitted plans – the UK’s – is compatible with the Paris Agreement.

We are climate scientists, and one of us (Piers Forster) leads the global science team that publishes the annual Indicators of Global Climate Change report. This report gives an overview of the state of the climate system. It is based on calculations of the net emissions of greenhouse gases globally, how these are concentrating in the atmosphere, how temperatures are rising on the ground, and how much of this warming has been caused by humans.

The report also looks at how extreme temperatures and rainfall are intensifying, how much the sea levels are rising, and how much carbon dioxide can still be emitted before the planet’s temperature exceeds 1.5°C more than it was in pre-industrial times. This is important because staying within 1.5°C is needed to avoid the worst impacts of climate change.

Our report shows that human-caused global warming reached 1.36°C in 2024. This boosted average global temperatures (a combination of human-induced warming and natural variability in the climate system) to 1.52°C. In other words, the world has already reached the level where it has warmed so much that it cannot avoid significant impacts from climate change. There is no doubt we are in dangerous waters.

Our dangerously hot planet

Although last year’s global temperatures were very high, they were also alarmingly unexceptional. The data speaks for itself. Continued record high levels of greenhouse gas emissions have led to rising atmospheric concentrations of carbon dioxide, methane and nitrous oxide.

The result is rising temperatures that are rapidly eating into the remaining carbon budget (the amount of greenhouse gases that can be emitted within an agreed time). This will be exhausted in less than three years at current levels of emissions.

We need to face this head on: the window to stay within 1.5°C is essentially shut. Even if we can bring temperatures back down in future, it will be a long and difficult road.

At the same time, climate extremes are intensifying, bringing long-term risks and costs to the global economy but also, importantly, people. The African continent is now facing its deadliest climate crisis in over a decade.

It would be impossible to imagine economies operating without fast access to trusted data. When share prices plummet or growth stalls, politicians and business leaders act decisively. None would tolerate outdated intelligence on sales or the stock market.

But when it comes to climate, the speed of climate change often outpaces the data available. This means fast decisions can’t be made. If we treated climate data as we do financial reports, panic would ensue after each dire update. But while governments routinely pivot when faced with an economic downturn, they have been far slower to respond to what key climate indicators – the Earth’s vital signs – are telling us.

What needs to happen next

As more countries develop their climate plans, it’s time for leaders across the globe to face the hard truths of climate science.

Governments need to have fast access to trusted climate data so that they can develop up-to-date national climate plans. The national climate plans need to take a global perspective too. This is really important for fairness and equity. For example, developed countries must acknowledge that they’ve emitted more greenhouse gases and take the lead in presenting ambitious mitigation efforts and in providing finance for other countries to decarbonise and adapt.

In Africa, the UN is hosting UNFCCC Climate Week in Addis Ababa in September. As well as making plans for COP30, there will be sessions on accessing climate finance and ensuring that the transition to zero human-caused carbon emissions by 2050 (net zero) is just and equitable. The summit also aims to support countries that are still working on their national climate plans.

If nationally determined contributions are implemented, the pace of climate change will slow down. This is vital not just for the countries – and economies – currently on the frontline against climate change, but for a functioning global society.

Just five of the G20 countries have submitted their 2035 plans: Canada, Brazil, Japan, the United States and the United Kingdom. But the G20 is responsible for around 80% of global emissions. This means that South Africa’s current G20 presidency can help to ensure that the world prioritises efforts to help developing countries finance their transition to a low-carbon economy.

Another worrying factor is that just 10 of the updated nationally determined contributions have reaffirmed or strengthened commitments to move away from fossil fuels. This means that national climate plans from the European Union, China and India will be key in testing their climate leadership and keeping the Paris Agreement’s 1.5°C temperature goals alive. Many other countries will be scrutinising what these countries commit to before they submit their own national climate plans.

The data in our report helps the world to understand not just what’s happened in recent years, but also what to expect further down the track.

Our hope is that these and other countries submit ambitious and credible plans well before COP30. If they do, this will finally close the gap between acknowledging the climate crisis and making decisive efforts to address it. Every tonne of greenhouse gas emissions matters.

Piers Forster, Professor of Physical Climate Change; Director of the Priestley International Centre for Climate, University of Leeds and Debbie Rosen, Research and Innovation Development Manager for the Priestley Centre for Climate Futures, University of Leeds

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

You may have read that the deep sea is a very different environment from the land and shallow water. There is no light, it is very cold, and the pressure of all the water above is immense.

Plants can’t grow there, and the energy powering life mostly comes from organic matter sinking from the sunlit surface. These facts have been known for more than 150 years.

But I want to tell you something you probably don’t know about the deep sea: for animals on the seafloor, it is a very connected environment. There are few environmental barriers to stop animals slowly expanding their distribution to cover thousands of kilometres. Over a million years, deep-sea animals can spread from Iceland to Tasmania.

In a new study published today in Nature, we map the distribution and relatedness of a single group of marine animals across all ocean seafloors, from the coast down to the abyssal plains of the deep sea, from the equator to the pole.

Five arms, no brain, no eyes or heart

We sequenced the DNA of thousands of animal specimens stored in natural history collections of museums across the globe, deposited from hundreds of research voyages. For the first time, we have enough data to explore how marine life has evolved and dispersed across the oceans over the past 100 million years.

We studied a group of animals called brittle stars, strange spiny creatures with a disc-like body and five sinuous or branched arms. They have a central mouth and gut, but no brain, no eyes and no heart.

While these shy animals would not be always familiar to beach combers or snorkelers, they are perfect for our project as they are found in abundance across deep seafloors and frequently surveyed by research expeditions. They have inhabited our planet for more than 480 million years, efficiently consuming and recycling organic matter.

Deep-sea lifestyles

Life in the deep is distributed in a different way to that in shallow seas.

In shallow waters, the temperature differs a lot between the tropics, the temperate regions (mid latitudes) and the poles. This imposes a barrier to the movement of marine life. Animals (and plants) generally adapt to a narrow range of temperatures and only rarely spread to other climates.

So, if you are a tropical shallow-water species, you cannot migrate through frigid waters around South America, or through the Canadian Arctic, to get from the Pacific to Atlantic Ocean. For tens of millions of years, shallow marine species have evolved independently in different oceans and seas.

But we found the deep sea is not like that. Species in different regions are much more closely related.

In fact, the age and geographic distribution of species on a family tree of deep-sea brittle stars resembles that of a group of seabirds or marine mammals. Yet these brittle stars don’t have wings or fins to get around.

How eggs and larvae roam the globe

The secret of how slow-moving brittle stars migrate across oceans appears to be their eggs and larvae.

In warm, shallow waters, a yolk-filled food reserve is rapidly used up by the developing larva. But in the cold deep sea, a yolky larva can survive with very slow metabolic activity, drifting on slow-moving currents for more than a year before settling. This greatly expands the range of a brittle star’s offspring.

Moreover, there are numerous seamounts, ridges and plains on the oceanic seafloor that offer transit points for long-distance migration at different depths. This dispersal across oceans has been going on for a long time.

The most prominent of these dispersal highways is across the southern Indian Ocean, transporting deep-sea animals from the Atlantic and Southern Oceans to Australia and New Zealand. In contrast, very few shallow-water animals have traversed such vast distances.

A patchwork of deep-sea life

While brittle star populations show lots of evidence of long-distance connections, deep-sea communities are not uniform around the planet.

Life in the deep is perilous. There is always the threat that a given species may be wiped out in particular regions.

Seawater conditions can change, as can currents and food supplies. New predators or diseases may arrive at any time.

Over time, the combination of high connectivity and high rates of regional extinction has led to a patchwork of deep-sea species distributions across oceans.

To conserve these ecosystems into the future, we will need a much better understanding of the global patterns of deep-sea life.

Tim O'Hara, Senior Curator of Marine Invertebrates, Museums Victoria Research Institute

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

Birds are perhaps the most colourful group of animals, bringing a splash of colour to the natural world around us every day. Indeed, exclusively black and white birds – such as magpies – are in the minority.

However, new research by a team from Princeton University in the United States has revealed a surprising trick in which birds use those boring black and white feathers to make their colours even more vivid.

In the study, published today in Science Advances, Rosalyn Price-Waldman and her colleagues discovered that if coloured feathers are placed over a layer of either white or black underlying feathers, their colours are enhanced.

A particularly striking discovery was that in some species the different colour of males and females wasn’t due to the colour the two sexes put into the feathers, but rather in the amount of white or black in the layer underneath.

Why birds are so bright – and how they do it

Typically, male birds have more vivid colours than females. As Charles Darwin first explained, the most colourful males are more likely to attract mates and produce more offspring than those that aren’t as vivid. This process of “sexual selection” is the evolutionary force that has resulted in most of the colours we see in birds today.

Evolution is a process that rewards clever solutions in the competition among males to stand out in the crowd. Depositing a layer of black underneath patches of bright blue feathers has enabled males to produce that extra vibrancy that helps them in the competition for mates.

The reason the black layer works so well is that it absorbs all the light that passes through the top layer of coloured feathers. The colour we see is blue because those top feathers have a fine structure that scatters light in a particular way, and reflects light in the blue part of the spectrum.

The feathers appear particularly vivid blue because the light in other wavelengths is absorbed by the under-layer. If the under-layer was paler, some of the light in the other parts of the light spectrum would bounce back and the blue would not “pop out” as much.

Different tricks for different colours

Interestingly, in the new study, the researchers found that for yellow feathers the opposite trick works. Yellow feathers contain yellow pigments – carotenoids – and in this case they are enhanced if they have a white under-layer.

The white layer reflects light that passes through the yellow feathers, and this increases the brightness of these yellow patches, making them more striking in contrast to surrounding patches of colour.

A surprisingly common technique

The authors focused most of their work on species of tanager, typically very colourful fruit-eating birds that are native to Central and South America.

However, once they had discovered what was happening in tanagers, they checked to see if it was occurring in other birds.

This additional work revealed that the use of black and white underlying feathers to enhance colour is found in many other bird families, including the Australian fairy wrens which have such vivid blue colouration.

This widespread use of black and white across so many different species suggests birds have been enhancing the production of colour in this clever way for tens of millions of years, and that it is widely used across birds.

The study is important because it helps us to understand how complex traits such as colour can evolve in nature. It may also help us to improve the production of vibrant colours in our own architecture, art and fashion.

Simon Griffith, Professor of Avian Behavioural Ecology, Macquarie University

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

Most people’s encounters with lemurs have occurred through their representations in popular children’s media, like Zoboomafoo or Madagascar. However, most people don’t know that lemurs play an important role in forest renewal and that they’re currently in grave danger from climate change.

In my home country of Madagascar, there is an amazing array of creatures that are not found anywhere else in the world. Madagascar is a biodiversity hotspot, and approximately 90 per cent of plant and animal species on this island are endemic.

Among them are lemurs, a group of primates that are not only the flagship symbols of the island’s fauna, but also one of the key players in the health and stability of Madagascar’s ecosystems because they do the very important work of dispersing seeds.

I am a primatologist who researches the interactions between infant-and-mother lemur dyads in wild. Their bond is a reminder of what we stand to lose, as it shows care, learning and viability. When forests disappear, so does this fragile bond, and a whole way of life we can never replace.

Lemurs’ habitats and survival are increasingly being threatened by human activities such as deforestation, forest resource exploitation and hunting. There is an urgent need for conservation projects that involve local communities in preserving Madagascar’s unique biodiversity.

Charismatic animals

Due to their charisma, media attention and their biological significance, lemurs attract tourists and researchers to Madagascar. The viability of lemurs is essential to the island’s future, both economically but especially in terms of protecting biodiversity. As they eat fruits from trees like ebony, mammea and wild coffee and then scatter seeds through their droppings, they help new plants grow.

Among the 105 lemur species of Madagascar, Propithecus candidus, commonly known as the silky sifaka, is one of the most endangered species. Only around 250 of them are currently living in the wild.

As their name implies, silky sifakas have visually striking long white hair, and they can only be found in the misty, mountainous rainforests of northeastern Madagascar.

Silky sifakas are primarily active during the daytime, and can travel very quickly through the trees by vertically clinging to them and leaping from tree to tree using their powerful legs. They have highly specialized diets consisting of leaves, flowers and fruits like Diospyros pervilleana, a native ebony species from Madagascar.

Observing mothers and infants

I have spent 10 years studying and following lemurs daily. During my fieldwork in northeastern Madagascar, I closely observed how deforestation and habitat fragmentation affect silky sifaka females and their young.

I studied these females during their lactation season in three different forest contexts: Marojejy National Park (a mostly untouched primary rainforest), Makira Natural Park (a mix of old-growth and re-generating forest) and Anjanaharibe-Sud Special Reserve (known as COMATSA-Sud, a primary forest with heavily degraded areas).

At each forest, the forest canopy, which provides both shelter and food for the lemurs, measured above 10 metres at all sites, but was semi-open, which is a sign of habitat degradation. A semi-open canopy allows more light to permeate the forest canopy, but it also exposes animals to predators and decreases the quantity of high-quality food.

Mothers’ movements and behaviours

One clear difference between the three sites is how mother–infant pairs move and use space. In Marojejy, where the forest is more continuous even if the canopy is partly open, mothers and babies stay within fairly fixed areas, following the same paths and resting spots.

But in places like Makira and COMATSA-Sud, where the forest is broken up into separate patches, mothers have to travel farther and more unpredictably, moving between these isolated patches. This extra travelling causes them to burn more energy and face higher risks from predators and hunters.

These differences show that fragmentation doesn’t just affect food availability, but also changes how these lemurs move and survive.

Forest fragmentation affects lemurs’ social behaviour and grouping patterns to deal with low food availability. It also impacts their health and development; a poor diet causes malnourishment in the lemurs.

Poor nutritional quality

While the food availability for silky sifakas in northeastern Madagascar during the lactation season is relatively abundant, it is of low nutritional quality.

This leads to increased stress and competition as dominant lactating females, desperate to feed their infants, attack subordinates to accumulate more nutrients to produce higher quality milk.

As offspring start to feed on non-milk foods, the poor nutritional quality of available plants after weaning can lead to poor health and stunted growth.

Engaging the community

The decline of lemur populations, particularly silky sifakas, shows the need for urgent conservation action. Continued monitoring — as well as sustained support and funding for Malagasy scientists — is crucial for long-term lemur and biodiversity conservation.

When it comes to the effects of human activity, this decline — habitat fragmentation, global climate change and deforestation — is the result of large-scale activites such as extraction, tourism and state infrastructural development.

Education and awareness campaigns are crucial, both in Madagascar and internationally, to inform people about lemurs’ habitat needs and what can be done to prevent their extinction.

Conservation will never be successful without building an appreciation of the environmental, cultural and economic value of lemurs and the forests they inhabit.

Colombe Nirina Sehenomalala, PhD candidate, Anthropology, Université de Montréal and Iulia Bădescu, Associate Professor, Anthropology, Université de Montréal

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

This week, the Federal Court found the Australian government has no legal duty to protect Torres Strait Islanders from climate change. The ruling was disappointing, but it’s not the end of the matter.

The plaintiffs, Uncle Paul Kabai and Uncle Pabai Pabai, hail from the low-lying islands of Saibai and Boigu, near Papua New Guinea. They argued the Commonwealth was negligent for failing to take strong action on climate change.

While the judge accepted the devastating effects climate change has wrought on the Torres Strait Islands, he found the Uncles did not prove their case of negligence.

However, the judge found previous Australian governments had not taken the best available science into account when setting emissions reduction targets. The finding tightens the screws on the Albanese government, which is due to announce Australia’s long-awaited targets to cut emissions out to 2035.

To protect communities in the Torres Strait, and across Australia, the government must set a 2035 target that is in line with the science.

And the court finding is unlikely to stem the tide of litigation seeking greater government accountability for climate change – especially for those most vulnerable to its harms.

Much of the case was proven

The Uncles’ case did not fail because there was no merit in their allegations. It failed because Justice Michael Wigney ruled negligence law was not the appropriate vehicle to deal with climate change policy.

The finding left open the possibility an appeal court may revisit the state of the law, and recognise the duty of care claimed by the Uncles.

This would require an appeal to the full court of the Federal Court. Wigney was a single judge and considered himself bound by past precedent set by the full court.

Justice Wigney found the Torres Strait Islanders proved much of their case, including that Australia’s emissions targets set in 2015, 2020 and 2021 were not consistent with the best available science. That science dictates national governments should set emissions reduction targets in line with international efforts to hold global temperature rise to 1.5°C.

The Coalition was in power during the period in question. Justice Wigney found the government of the day “did not engage with or give real or genuine consideration to the best available science” when setting its targets.

Looking ahead to our 2035 targets

The Labor government is currently weighing its 2035 emissions reduction target. The Climate Change Authority, which provides independent advice to government on climate policy, is expected to recommend a target between 65% and 75%.

But evidence suggests this may not be in line with the best available science.

For example, according to some scientists, emissions reduction of 90% by 2035, based on 2005 levels, would be required to stay in line with the 1.5°C goal.

Australia’s 2035 targets are not just crucial to the global effort to tackle climate change. They will also affect our standing in the Pacific at a time of deepening geostrategic competition.

Australia is bidding to host the UN climate talks next year in partnership with Pacific island countries. Our climate policy for the decade ahead will be a powerful signal to our Pacific neighbours about our commitment to the region, and to climate justice.

A shifting legal landscape

Around the world, courts and human rights bodies are holding governments accountable for climate inaction. It is possible for Australian law to do the same.

Courts in the Netherlands and Belgium, for example, have recognised government duties to heed the science to address foreseeable harms of climate change.

Next week, the International Court of Justice – the world’s highest court – will issue an historic legal opinion on the obligations of nations to tackle climate change.

This opinion will clarify the obligations of countries to prevent human rights harms caused by climate change, and to limit pollution of the Earth’s oceans and climate system. The opinion will be non-binding, but could influence future climate litigation.

What’s more, attribution science is improving all the time. This field of science examines how greenhouse gas emissions affect a particular weather event or climate pattern.

Clearer attribution science will provide courts an ever-stronger basis to consider how government policy decisions on emissions cause climate impacts – and resulting harms to people.

As the legal responsibilities of governments are clarified, further strategic litigation in Australia is likely.

Change is coming

In his judgement, Justice Michael Wigney said the law currently “provides no real or effective legal avenue” for people or communities to seek legal recourse for government inaction on climate change. That will remain the case until the law changes, he said.

To remain legitimate, legal norms must reflect changing social expectations. History shows laws can adapt when they are challenged repeatedly by those who are harmed by the status quo. Eventually, the dam wall breaks, and law is reinterpreted.

A clear example is the Mabo case of 1992. The High Court of Australia acknowledged the obvious fact that Indigenous peoples have lived on this continent for tens of thousands of years, and that the “terra nullius” (land belonging to no-one) concept was a legal myth.

The Mabo decision allowed common law to recognise native title. It was a departure from previous rulings which relied on the terra nullius concept to reject native title claims.

Australia’s legal norms largely pre-date the scientific consensus on climate change. They must evolve to better recognise climate impacts that are harming Australians. While this week might not have been the time, change is inevitable.

As Justice Wigney said, until the law adapts, the key avenue for change is public advocacy, protest and voter action at the ballot box.

Wesley Morgan, Research Associate, Institute for Climate Risk and Response, UNSW Sydney and Riona Moodley, Lecturer, Faculty of Law and Justice, UNSW Sydney

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

Think back to a time you helped someone move a heavy object, such as a couch. While at first the task may have appeared simple, it actually required a suite of advanced behaviours.

The job needed verbal commands for social coordination (“pivot!”) and anticipation of near-future events (moving other furniture out of the way). It also required a clear, shared vision of the final goal (which room to take the couch to).

It’s a small but satisfying example of human cooperation. But before we all get too pleased with ourselves, consider that ants – creatures with tiny brains and no capacity for speech – routinely pull off feats that rival, and sometimes exceed, our own.

Understanding ant intelligence

Earth is literally crawling with ants. Scientists estimate there are at least 20 quadrillion ants on Earth. That’s 20 followed by 15 zeros – more ants than stars in our galaxy!

These incredible insects are amongst the most successful organisms on the planet. Part of the success comes from an ability to form complex societies, ranging from a few individuals to millions. And those societies, or colonies, are remarkably co-operative.

Take, for example, ants’ abilities to move large food items. To do it, they mobilise teams of dozens – or even hundreds – of fellow workers. Together, they efficiently work together to transport the load back to the nest.

Longhorn crazy ants (Paratrechina longicornis) are even known to clear debris from a path before a heavy object arrives – seemingly anticipating its trajectory and preparing the way.

One experiment pit longhorn crazy ants against humans, all tasked with moving T-shaped objects (scaled to body size) through tight spaces. In some trials, the human teams were not permitted to speak or use gestures.

And the result? Ants performed better in larger groups compared to smaller ones, showing the clear benefits of collective action. In contrast, human performance did not improve with group size. And when communication was restricted, human performance declined as group size increased.

All this highlights how ants rely on collective intelligence, without the need for central control or sophisticated cognition.

Expert farmers

Humanity’s invention of agriculture 12,000 years ago is understandably hailed as one of our greatest achievements.

But leaf cutter ants beat us to it. These ants (from the species Atta and Acromyrmex) evolved to undertake large-scale agriculture about 55 million years ago.

These ants cut and transport fresh leaves not to eat directly, but to feed a fungus that serves as their main food source.

This evolutionary partnership allows the ants to feed colonies with populations in the millions.

Remarkably, leaf cutter ants have also evolved a form of biological pest control to protect their crops from bacteria. Some worker ants patrol the gardens, detecting infected sections of the fungus. Then they apply antibiotics produced by bacteria that live on their bodies.

What’s more, many ant species farm aphids and other sap-sucking insects.

As these farmed insects feed on plant sap, they excrete a sugary liquid the ants eagerly collect. In return, ants serve as bodyguards, defending their tiny livestock from predators such as ladybirds and lacewings.

In some species, queen ants gently carry sap-sucking insects in their jaws as they fly off to start new colonies. Fossilised ants preserved in amber suggest this behaviour evolved up to 20 million years ago, long before humans domesticated animals.

Ant medicine

Medical care may seem like a distinctly human innovation. But several ant species have evolved sophisticated ways to treat injuries.

When a Florida carpenter ant (Camponotus floridanus) is injured during a battle between colonies, its nest-mates will amputate a damaged limb to prevent infection from spreading. Ants receiving this battlefield care are more likely to survive than ants left untreated.

Some ants can also detect infection and treat infected wounds by cleaning them and applying antimicrobial secretions from specialised glands.

Master builders

Some ant species are known to literally put their bodies on the line for the colony.

Army ants (Eciton burchellii) join their bodies together to form structures. These include bridges across gaps on the forest floor, and “scaffolds” across steep terrain to prevent other ants from slipping.

Even the nest is made of hundreds of thousands of ants joined together, complete with tunnels and chambers housing the larvae and the queen. The entire structure is packed up and rebuilt each day, after the colony emigrates a few hundred metres into the forest.

Weaver ants (Oecophylla smaragdina), meanwhile, self-assemble into rope ladders to span vertical gaps.

They also form a line of workers that pull leaves together in treetops to form nests. Once the leaves are winched into place, other ants arrive with ant larvae in their jaws. Each larva produces a tiny blob of silk which the ants use to glue the leaves together.

Fire ants (Solenopsis invicta), a major pest species, owes its invasive success partly to a unique method of dispersal.

When their underground nests are flooded by rain, the ants join together into a huge raft which floats on a layer of buoyant larvae. These rafts can ride floodwaters in safety for hundreds of kilometres, until the ants reach dry land.

Lessons for humanity?

Humans rightly take pride in our greatest achievements – agriculture, medicine, engineering and building civilisations. But remarkably, ants mastered these innovations millions of years before we did.

Ants may be tiny – but by working together they can build complex societies and solve many problems. They might even teach humans a thing or two.

Tanya Latty, Associate Professor in Entomology, University of Sydney and Chris R. Reid, ARC Future Fellow in behavioural ecology, Macquarie University

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

Have you ever examined timber floorboards and pondered why they look the way they do? Perhaps you admired the super-fine grain, a stunning red hue or a swirling knot, and wondered how it came to be?

Or perhaps you don’t know what tree species your floorboards are made from, and how to best look after them?

Finely polished floorboards reveal detail about the timber that can be much harder to detect in unpolished boards or other sawn timbers.

“Reading” the knots, stubs and other characteristics of floorboards can reveal what type of tree produced it and how it grew. It can also reveal fascinating details about the lives of the trees they once were.

Telling soft from hard

A variety of tree species are used to make timber floors. Hardwood species include the pale cream of Tasmanian oak, the honeyed hues of spotted gum and the deep red of jarrah.

Other times, softwood such as pine or spruce is used. Such species are often fast-growing, and prized for their availability and affordability.

Hardwoods are, by definition, flowering trees, while softwoods are from cone-bearing trees. Paradoxically, not all softwoods are soft or hardwoods hard. The balsa tree, for example, is a fast-growing hardwood tree renowned for its soft wood.

It’s not always easy to tell if a floor is hardwood or softwood, but there are discernible differences in their appearance.

Tales in the grain

The real differences between softwood and hardwood lie in the anatomy and structure of the “xylem tissues” that make up the wood. These tissues transported water and nutrients from the roots to the rest of the plant when the tree was alive.

The arrangement of xylem tissue in the tree largely determines the “grain” in your floorboards. The grain is the appearance of wood fibres in the timber. The grain can be straight, wavy or spiralled.

In floorboards with straight grains, a tree’s growth history may be clear. As a tree trunk grows in diameter, it typically produces a layer of bark on the outside and a lighter layer of xylem tissue on the inside. When a tree is cut horizontally, the growth appears as rings. In a tree cut lengthwise (which happens when floorboards are milled) the growth appears as long lines in the timber.

If the lines in floorboards are very close together, this indicates the tree grew slowly. Wider lines suggest the tree grew rapidly.

Vessels in a tree’s xylem transport water from the roots to the rest of the plant. Hardwood tree species tend to have large vessels. This gives hardwood floorboards a coarser-grained and less uniform appearance. In contrast, softwood species such as conifers have smaller, dispersed vessels and produce more fine-grained, smoother timber.

Knotty histories

Knots in floorboards occur when a branch dies or is cut, then tissue grows over the stub. The bigger the missing branch, the more substantial the knot.

Knots in floorboards can reveal much about the source tree. Pine, for example, often features multiple small knots originating from a common point. This reflects the growth pattern of young plantation pines, where several branches grow out from the trunk at the same height from the ground.

Often, the distance between knots tells us how quickly the tree grew. The greater the distance between the knots, the faster the tree grew in height.

Clever chemical defence

The presence of a tree’s “defence chemicals”, known as polyphenols, can be seen clearly in some floorboards.

Polyphenols protect plants against stressors such as pathogens, drought and UV radiation.

The chemicals contribute to the red hue in some floorboards. Because polyphenols have a preservative effect, they can also make timber more durable.

Dark reddish or brown timbers containing a high concentration of polyphenols include mahogany, merbau, red gum, ironbark and conifers such as cedar and cypress.

In cases where a tree is burnt by fire, or attacked by insects or fungus, it produces a lot of polyphenols at the site of the damage.

In these cases, the presence of polyphenols in floorboards can be very obvious – sometimes appearing as a section that is dark brown verging on black.

Keeping your floorboards for longer

It’s widely known that living trees store carbon, and that this helps limit climate change. It’s less well known that timber floorboards also store carbon. And as long as that timber is preserved – and not destroyed by fire, decay or wood rot – that carbon will stay there.

If floorboards have to be removed, try to make sure the timber is reused or repurposed into other products.

And if you are installing a new polished timber floor, or already have one, there are steps you can take to make it last for a long time.

Softwood boards will benefit from a hard surface coating, especially in high-use areas.

Reducing the floor’s exposure to bright sunlight can preserve the colour of the floorboards and prolong the life of the coating and the timber itself.

Large knots in floorboards can twist and start to protrude from the surface. To ensure the floor remains even and safe, and to prevent the board from splitting, secure the knot to a floor joist with a nail or glue.

And take the time to understand the lessons embedded in your floorboards. They have much to teach us about biology and history, if we take the time to read them.

Gregory Moore, Senior Research Associate, School of Agriculture, Food and Ecosystem Sciences, The University of Melbourne

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

England’s privatised water industry may one day be considered a textbook case study of failed corporate responsibility, regulation and governance. The Cunliffe review, the recent report into England’s privatised water industry, concluded that the financial regulator, OfWat, needs to be disbanded and a new water regulator will be introduced.

For that to work effectively, better pollution monitoring and more clearly defined pollution incident criteria are essential. While politicians and water companies have claimed to be reducing pollution incidences, they might not strictly be tackling sources of pollution, so communications must be carefully scrutinised for disinformation.

The UK’s environment minister Steve Reed MP has described the water industry as “broken”. The public have rising water bills. Water companies owe over £60 billion in debts and have left the country with uncertain water security in the face of climate change.

The Environment Agency (EA) in England recently announced that serious pollution incidents in 2024 rose by 60% to 75 from 47 in the previous year. The EA classifies pollution incidents using a four-point scale called the common incident classification scheme. Trained EA officers consider the evidence reported via their incident hotline to assess its credibility and severity.

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Category 1 is for major incidents, 2 for significant, 3 for minor incidents and 4 for no impact. Category 1 and 2 typically involve visible signs of dead fish floating. For salmon, if more than 10 adult or 100 young fish are dead, this is category 1. With fewer than ten adult and 100 young fish dead, it’s category 2.

No dead fish, no serious problem? The EA can also record damage on protected habitats as “pollution incidents” but these are harder to substantiate without investigative research that takes time and money.

Last year, more than 450,000 sewage discharges were recorded by event duration monitors. These are devices fitted to the end of overflow pipes that indicate when and for how long they have been discharging.

These discharges represent 3.6 million hours of untreated sewage going into our rivers and coasts. These contain chemical contaminants including pharmaceuticals, detergents and human pathogens. Only 75 incidents were recorded as serious or significant in 2024. Another 2,726 were classed as minor.

So lots of sewage discharges are not being classified as pollution incidents, despite containing pollutants. The EA advises its investigating officers to “record substantiated incidents that result in no environmental impact, or where the impact cannot be confirmed, as a category 4”.

The EA has been criticised for turning up late to 74% of category 1 and 2 pollution incidents and for being pressured to ignore low-level pollution – all claims that they have denied. However, they admit they are constrained by finances. Any new regulator must be adequately resourced and independent.

In their recent report into pollution incidences, the EA states that they respond to all category 1 and 2 (serious and significant) water industry incidents and will be increasing their attendance at category 3 (minor) incidents. They highlight that more inspections will identify more issues. This shows some acceptance that the more incidents they attend, the more would be substantiated or recorded appropriately.

Most sewage discharges would not have been reported to, or recorded by, the EA as pollution incidents because they were permitted discharges from combined stormwater overflows. Water companies are allowed to discharge untreated wastewater under exceptional rainfall or snowfall conditions to prevent sewage backing up through the pipes.

Extra water flow in rivers from rainfall is meant to dilute chemical contaminants in wastewater. However, some discharges can last days or weeks. The EA is currently investigating whether water companies have been breaching their permits and discharging untreated wastewater when there is low or even no rainfall.

What counts as pollution?

The UN classifies pollution as “presence of substances and energy (for example, light and heat) in environmental media (air, water, land) whose nature, location, or quantity produces undesirable environmental effects”. This definition differs markedly from the EA’s working definition of pollution incidents.

Many sewage discharges containing low concentrations of pollutants won’t kill fish but might still be harmful to fish larvae or small insects, for example.

However, the broad picture from EA data is that invertebrate communities at least are in a better state than they were three decades ago before wastewater treatment plants were upgraded following the EU’s Urban Wastewater Directive.

Some pollutants bioaccumulate through the food chain, so they become concentrated in top predators such as orcas. Some chemicals mimic reproductive hormones even in low concentrations and can feminise fish, for example. High levels of nutrients from agriculture and sewage in rivers can cause fungal diseases in seagrass meadows.

Other families of chemicals build up in wildlife and people, such as persistent “forever chemicals”, much of which comes from wastewater discharges. Continued discharges of antibiotics into waterways might not be classified as pollution incidents but still pose a substantial risk to human and ecosystem health through bacteria developing antibiotic resistance.

The government has just committed to cut sewage pollution by 50% by December 2029 based on 2024 data. But it’s not yet clear whether these involve cutting the frequency of discharges, the duration or both.

This data could also be manipulated so that a large number of small discharges can be consolidated into one official discharge event. Currently, the volume of discharges from stormwater overflows isn’t known. Without this vital data we can’t ascertain the risk posed by their contaminants.

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Alex Ford, Professor of Biology, University of Portsmouth

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

Australia is home to more than 60 species of carnivorous marsupials in the family Dasyuridae. Almost a quarter of those have only been scientifically recognised in the past 25 years.

Other than the iconic Tasmanian devil, chances are most of these small, fascinating species have slipped under your radar. One of the rarest and most elusive is the kultarr (Antechinomys laniger), a feisty insect-eater found in very low numbers across much of the outback.

To the untrained eye, the kultarr looks very much like a hopping mouse, with long legs, a long tail and a tendency to rest on its hind legs. However, it runs much like a greyhound – but its tiny size and high speed makes it look like it’s hopping.

Kultarr or kultarrs?

Until now, the kultarr was thought to be a single widespread species, ranging from central New South Wales to the Carnarvon Basin on Australia’s west coast. However, a genetic study in 2023 suggested there could be more than one species.

With backing from the Australian Biological Resources Study, our team of researchers from the University of Western Australia, Western Australian Museum and Queensland University of Technology set out to investigate.

We travelled to museums in Adelaide, Brisbane, Darwin, Melbourne, Sydney and Perth to look at every kultarr that had been collected by scientists over the past century. By combining detailed genetic data with body and skull measurements, we discovered the kultarr isn’t one widespread species, but three distinct species.

Three species of kultarrs

The eastern kultarr (A. laniger) is the smallest of the three, with an average body length of about 7.5cm. It’s darker in colour than its relatives, and while its ears are still big, they are nowhere near as big as those of the other two species.

The eastern kultarr is now found on hard clay soils around Cobar in central NSW and north to around Charleville in southern Queensland.

The gibber kultarr (A. spenceri) is the largest and stockiest, with an average body length of around 9cm. They are noticeably chunkier than the other two more dainty species, with big heads, thick legs and much longer hindfeet.

As its name suggests, the gibber kultarr is restricted to the extensive stony deserts or “gibber plains” in southwest Queensland and northeast South Australia.

The long-eared kultarr (A. auritus) is the middle child in terms of body size, but its ears set it apart. They’re nearly as long as its head.

It’s found in patchy populations in the central and western sandy deserts, living on isolated stony plains.

Are they threatened?

All three species of kultarr are hard to find, making it difficult to confidently estimate population sizes and evaluate extinction risk. The long-eared and gibber kultarrs don’t appear to be in immediate danger, but land clearing and invasive predators such as cats and foxes have likely affected their numbers.

The eastern kultarr, however, is more of a concern. By looking at museum specimens going back all the way to the 1890s, we found it was once much more widespread.

Historic records suggest the eastern kultarr used to occur across the entirety of arid NSW and even spread north through central Queensland and into the Northern Territory. We now think this species may be extinct in the NT and parts of northwest Queensland.

What’s next?

To protect kultarrs into the future, we need targeted surveys to confirm where each species still survives, especially the eastern kultarr, whose current range may be just a shadow of its former extent. With better knowledge, we can prioritise conservation actions where they’re most needed, and ensure these remarkable, long-legged hunters don’t disappear before we truly get to know them.

Australia still has many small mammal species that haven’t been formally described. Unless we identify and name them, they remain invisible in conservation policy.

Taxonomic research like this is essential – we can’t protect what we don’t yet know exists. And without action, some species may disappear before they’re ever officially recognised.

The authors wish to acknowledge the important contributions of Adjunct Professor Mike Westerman at La Trobe University to the research discussed in this article.

Cameron Dodd, PhD Student in Evolutionary Biology and Taxonomy, The University of Western Australia; Andrew M. Baker, Associate Professor in Ecology and Environmental Science, Queensland University of Technology; Kenny Travouillon, Curator of Mammals, Western Australian Museum; Linette Umbrello, Research associate, Western Australian Museum, and Renee Catullo, Senior Lecturer, School of Biological Sciences , The University of Western Australia

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

In remote central Arnhem Land, finding a northern brushtail possum is encouraging for the local Indigenous rangers. Though once common, such small native mammals are now rare. Many are threatened with extinction.

Over the past 30 years, small mammals have been disappearing from Australia’s tropical savannas. This landscape is among the nation’s most remote and seemingly untouched. But it is no longer safe from feral animals, overgrazing livestock, poor fire management and other threats.

Despite growing awareness of the problem, a lack of consensus on the most effective management actions has hindered efforts to reverse these losses. Our new research sought to overcome this hurdle and finally reach consensus on the best way forward.

We achieved this by working with experts from various land management groups and research institutes, including Traditional Owners and Indigenous rangers within the region.

Building on 15 years of targeted research

In 2010, the scale and severity of mammal declines in northern Australia became clear. Research in Kakadu National Park found the number of native mammal species at survey sites had halved, and the number of individual animals dropped by more than two-thirds.

This prompted a major review of the causes, and more research.

Advances in technology played a crucial role in efforts to gather further evidence. Motion-activated cameras known as camera traps enabled monitoring over vast areas.

Extensive surveys using camera traps provided data on the distribution and abundance of small mammals and feral cats. Meanwhile, collar-mounted GPS units and video cameras provided new information about feral cat behaviour.

What we did and what we found

Our new research concerns the higher-rainfall tropical savannas of the Northern Territory and Western Australia. This area covers 950,000 square kilometres from the Kimberley in the west to the Gulf of Carpentaria in the east.

First we reviewed the literature on the topic of small mammal declines in the region. We found more than 100 relevant studies had been published since 2010.

From these research papers, we identified 11 plausible threats to small mammals. Then we asked 19 experts to score and rank each threat according to severity and scale, and whether the threat could be effectively mitigated.

We found the most severe and widespread threat to small mammals was feral cats. But broad-scale cat control is not very effective.

Ranked second was the habitat destruction caused by livestock (buffalo, horses, donkeys and cattle) and by inappropriate patterns of fire.

Actions aimed at reducing feral livestock numbers and improving fire regimes would increase vital resources such as food and shelter. Such actions can also make it harder for cats to prey on small mammals.

Future threats and research priorities

Habitat loss from land clearing for urban, agricultural or industrial development currently affects only a small proportion of northwestern Australia. But proposed expansions — particularly for cotton and other intensive agriculture — are concerning. These developments overlap with high-rainfall areas in the Top End, where small mammal communities are still relatively intact.

Our expert group also expressed deep concern and uncertainty about the future as the climate changes. Rising temperatures and more intense rainfall events are expected to increase the frequency, extent and severity of fires. However, managing feral livestock and improving fire regimes can make the ecosystem more resilient to change.

Developing more effective tools to directly control feral cats remains a top research priority. It’s estimated cats kill around 452 million native mammals a year in Australia. About a third of these deaths occur in the tropical savannas. So while improved land management will alleviate some pressure, certain species will remain highly vulnerable unless cats can be better managed.

Support Indigenous leadership on Country

Globally, Indigenous stewardship is closely linked to improved biodiversity outcomes.

In Australia, the historic disruption of Indigenous customary responsibilities — especially fire management — has contributed to the loss of small mammals.

Fortunately, Indigenous ranger programs and Indigenous Protected Areas have expanded in recent years. Increasingly widespread recognition and application of Indigenous knowledge has deepened and broadened our understanding of mammal declines.

In northern Australia, Indigenous ranger groups are global leaders in fire management. They monitor and manage some of the most remote and inaccessible parts of the continent. The land management actions needed to conserve our small mammals rely in large part on the continued support and funding of these groups.

Unfortunately, these programs are under threat. The NT government recently cut A$12 million from its Indigenous ranger funding program.

While the federal government has committed funding to expand ranger programs nationally, ranger groups say the investment falls short of what’s needed. Mimal Land Management Aboriginal Corporation chief executive officer Dominic Nicholls told us:

Given the scale at which Indigenous ranger groups operate – and the critical role they play in protecting Australia’s biodiversity and leading innovation in the carbon industry – the level of allocated funding is insufficient to meet the basic delivery costs of these programs.

A clear path forward

Our research shows reducing feral livestock numbers and improving fire regimes in northern Australia currently offers the greatest benefit to small mammal populations — especially in the absence of effective cat controls.

But success will depend on sustained, long-term support for Indigenous rangers, who carry out much of this work. Investing in these programs is not just essential for conserving biodiversity — it also supports cultural connection, community wellbeing and climate resilience.

The authors gratefully acknowledge the Traditional Knowledge offered by participants from Mimal Land Management Aboriginal Corporation and Warddeken Land Management Limited as part of this research.

Alyson Stobo-Wilson, Research Adjunct in Conservation Ecology, Research Institute for the Environment and Livelihoods, Charles Darwin University and 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.

The Federal Court has handed down its long-awaited judgement in a four-year climate case brought by Torres Strait Islanders.

Elders Uncle Pabai Pabai and Uncle Paul Kabai took the Australian government to court on behalf of their community, arguing the government has a duty of care to protect them from climate change. They also asked the court to legally recognise the cultural loss and harm they are experiencing from sea-level rise and climate-induced flooding.

But the court declined to recognise either duty or to legally recognise cultural harm.

Many climate justice advocates hoped today’s decision would be the climate equivalent of the famous Mabo decision, which recognised native title. There are many parallels. At stake was the legal recognition of the harms and loss of connection to Country that Australia’s First Peoples are experiencing through government inaction on climate change.

Vulnerability and leadership

Torres Strait Islanders are well placed to bring this kind of legal claim.

To sue a government for climate inaction, plaintiffs often have to show they are particularly impacted by climate harms over and above the rest of the population.

Claims across the world have been brought by Indigenous peoples, farmers, young people who will experience catastrophic climate impacts in the future, and people with heat-sensitive illnesses.

The islands on which Uncle Pabai and Uncle Paul live, Sabai and Boigu, are extremely low-lying. Climate-related flooding is already affecting whether people can live there.

Importantly, small differences in future emissions scenarios will significantly impact their habitability. Every fraction of a degree of warming will matter.

During the case, climate scientists gave evidence that on the current emissions scenario, the islands are highly likely to be uninhabitable less than 25 years from now.

This will force Torres Strait Islanders to leave, severing them from thousands of years of tradition, fulfilment of their traditional practices (called Ailan Kastom), and connection to country and identity.

The legal claim against the Commonwealth

Uncle Pabai and Uncle Paul argued the Commonwealth government has a duty to protect Torres Strait Islanders from climate change when setting national emissions-reduction targets. They argued the government breached that duty by not setting targets in line with the best available science. This would involve calculating reduction targets by reference to Australia’s share to keep global warming to as close to 1.5 degrees above pre-industrial levels as possible.

Second, they argued the government has a duty to protect property, the fulfilment of their traditional customs, and the health and life of Torres Strait Islanders from climate impacts. They argued the government breached that duty by failing to properly fund the construction of sea walls.

What the Federal Court said

Justice Michael Wigney’s judgement emphasised the existential threat of climate change. It noted Torres Strait Islanders are particularly vulnerable to climate impacts and face a “bleak future” unless urgent action is taken.

But it accepted the government’s argument that setting emissions reductions targets, and allocating funding for protective infrastructure, involves “policy” considerations a court can’t review.

When do governments owe a duty of care to climate vulnerable groups?

Plaintiffs elsewhere in the world have successfully argued that their government owed them a duty of care to protect them from climate harms by lowering emissions. But the argument has had mixed success in Australia.

To establish a legal duty of care, plaintiffs need to show they have some kind of special relationship with the defendant. This relationship arises through factors such as the plaintiff’s vulnerability to a certain harm, and the defendant’s knowledge of, and control over, that harm.

As First Peoples, Uncle Pabai and Uncle Paul argued they have this kind of relationship with the government. They pointed to a range of factors such as the particular vulnerability of the Torres Strait Islanders, and the government’s control over climate harms to them.

Novel duties of care can be imposed on government and public authorities. But Australian courts have sometimes declined to do this where they would have to judge how governments have weighed different policy considerations.

This is partly because it would be too difficult for the court to decide whether the government had met the legal standard of behaviour.

Courts are more willing to find a government owes a duty of care where the government is merely applying a policy, or where it can measure the government’s behaviour against clear standards. But courts have also acknowledged that the distinction between making policy and applying policy is blurry.

Uncle Pabai and Uncle Paul argued the Australian government has committed to the Paris Agreement, and this sets out a clear legal standard of the “best available science”.

The Australian government argued its decisions about climate policy involve complex political priorities that a court shouldn’t review. It argued it shouldn’t be bound by the best available science as a legal standard.

The role of courts in protecting people from climate harm

Today’s decision is a setback for both the climate and Indigenous justice movements. But the situation isn’t as bleak as it may seem.

Across the world, plaintiffs in courts are gaining legal ground on climate accountability. It’s becoming easier to attribute harms to emitters, and to develop standards against which governments can be measured. And courts frequently reject government arguments that their contribution to climate change is minimal. They emphasise that each country must do its share for global collective action to work.

It is a question of when, rather than if, law will adapt to deal with climate impacts. Much like a rising tide breaking against a seawall, the future impact of climate change on things that law already protects is too extreme for the law to resist.

Liz Hicks, Lecturer in Law, The University of Melbourne

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

Climate change has made extreme weather events such as bushfires and floods more frequent and more likely in recent years, and the trend is expected to continue. These events have led to human and animal deaths, harmed physical and mental health, and damaged properties and infrastructure.

Will firsthand experience of these events change how people think and act about climate change, making it seem immediate and local rather than a distant or future problem?

Research so far has offered a mixed picture. Some studies suggest going through extreme weather can make people more likely to believe in climate change, worry about it, support climate policies, and vote for Green parties. But other studies have found no such effects on people’s beliefs, concern, or behaviour.

New research led by Viktoria Cologna at ETH Zurich in Switzerland may help to explain what’s going on. Using data from around the world, the study suggests simple exposure to extreme weather events does not affect people’s view of climate action – but linking those events to climate change can make a big difference.

Global opinion, global weather

The new study, published in Nature Climate Change, looked at the question of extreme weather and climate opinion using two global datasets.

The first is the Trust in Science and Science-related Populism (TISP) survey, which includes responses from more than 70,000 people in 68 countries. It measures public support for climate policies and the extent that people think climate change is behind increases in extreme weather.

The second dataset estimates how much of each country’s population has been affected each year by events such as droughts, floods, heatwaves and storms. These estimates are based on detailed models and historical climate records.

Public support for climate policies

The survey measured public support for climate policy by asking people how much they supported five specific actions to cut carbon emissions. These included raising carbon taxes, improving public transport, using more renewable energy, protecting forests and land, and taxing carbon-heavy foods.

Responses ranged from 1 (not at all) to 3 (very much). On average, support was fairly strong, with an average rating of 2.37 across the five policies. Support was especially high in parts of South Asia, Africa, the Americas and Oceania, but lower in countries such as Russia, Czechia and Ethiopia.

Exposure to extreme weather events

The study found most people around the world have experienced heatwaves and heavy rainfall in recent decades. Wildfires affected fewer people in many European and North American countries, but were more common in parts of Asia, Africa and Latin America.

Cyclones mostly impacted North America and Asia, while droughts affected large populations in Asia, Latin America and Africa. River flooding was widespread across most regions, except Oceania.

Do people in countries with higher exposure to extreme weather events show greater support for climate policies? This study found they don’t.

In most cases, living in a country where more people are exposed to disasters was not reflected in stronger support for climate action.

Wildfires were the only exception. Countries with more wildfire exposure showed slightly higher support, but this link disappeared once factors such as land size and overall climate belief were considered.

In short, just experiencing more disasters does not seem to translate into increased support for mitigation efforts.

Seeing the link between weather and climate change

In the global survey, people were asked how much they think climate change has increased the impact of extreme weather over recent decades. On average, responses were moderately high (3.8 out of 5) suggesting that many people do link recent weather events to climate change.

Such an attribution was especially strong in Latin America, but lower in parts of Africa (such as Congo and Ethiopia) and Northern Europe (such as Finland and Norway).

Crucially, people who more strongly believed climate change had worsened these events were also more likely to support climate policies. In fact, this belief mattered more for policy support than whether they had actually experienced the events firsthand.

What does this study tell us?

While public support for climate policies is relatively high around the world, even more support is needed to introduce stronger, more ambitious measures. It might seem reasonable to expect that feeling the effects of climate change would push people to act, but this study suggests that doesn’t always happen.

Prior research shows less dramatic and chronic events like rainfall or temperature anomalies have less influence on public views than more acute hazards like floods or bushfires. Even then, the influence on beliefs and behaviour tends to be slow and limited.

This study shows climate impacts alone may not change minds. However, it also highlights what may affect public thinking: helping people recognise the link between climate change and extreme weather events.

In countries such as Australia, climate change makes up only about 1% of media coverage. What’s more, most of the coverage focuses on social or political aspects rather than scientific, ecological, or economic impacts.

Many stories about disasters linked to climate change also fail to mention the link, or indeed mention climate change at all. Making these connections clearer may encourage stronger public support for climate action.

Omid Ghasemi, Research Associate in Behavioural Science at the Institute for Climate Risk & Response, UNSW Sydney

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

On her first dedicated scientific voyage to Antarctica in March, the Australian icebreaker RSV Nuyina found the area sea-ice free. Scientists were able to reach places never sampled before.

Over the past four summers, Antarctic sea ice extent has hit new lows.

I’m part of a large group of scientists who set out to explore the consequences of summer sea ice loss after the record lows of 2022 and 2023. Together we rounded up the latest publications, then gathered new evidence using satellites, computer modelling, and robotic ocean sampling devices. Today we can finally reveal what we found.

It’s bad news on many levels, because Antarctic sea ice is vital for the world’s climate and ecosystems. But we need to get a grip on what’s happening – and use this concerning data to prompt faster action on climate change.

What we did and what we found

Our team used a huge range of approaches to study the consequences of sea ice loss.

We used satellites to understand sea ice loss over summer, measuring everything from ice thickness and extent to the length of time each year when sea ice is absent.

Satellite data was also used to calculate how much of the Antarctic coast was exposed to open ocean waves. We were then able to quantify the relationship between sea ice loss and iceberg calving.

Data from free-drifting ocean robots was used to understand how sea ice loss affects the tiny plants that support the marine food web.

Every other kind of available data was then harnessed to explore the full impact of sea ice changes on ecosystems.

Voyage reports from international colleagues came in handy when studying how sea ice loss affected Antarctic resupply missions.

We also used computer models to simulate the impact of dramatic summer sea ice loss on the ocean.

In summary, our extensive research reveals four key consequences of summer sea ice loss in Antarctica.

1. Ocean warming is compounding

Bright white sea ice reflects about 90% of the incoming energy from sunlight, while the darker ocean absorbs about 90%. So if there’s less summer sea ice, the ocean absorbs much more heat.

This means the ocean surface warms more in an extreme low sea ice year, such as 2016 – when everything changed.

Until recently, the Southern Ocean would reset over winter. If there was a summer with low sea ice cover, the ocean would warm a bit. But over winter, the extra heat would shift into the atmosphere.

That’s not working anymore. We know this from measuring sea surface temperatures, but we have also confirmed this relationship using computer models.

What’s happening instead is when summer sea ice is very low, as in 2016, it triggers ocean warming that persists. It takes about three years for the system to fully recover. But recovery is becoming less and less likely, given warming is building from year to year.

2. More icebergs are forming

Sea ice protects Antarctica’s coast from ocean waves.

On average, about a third of the continent’s coastline is exposed over summer. But this is changing. In 2022 and 2023, more than half of the Antarctic coast was exposed.

Our research shows more icebergs break away from Antarctic ice sheets in years with less sea ice. During an average summer, about 100 icebergs break away. Summers with low sea ice produce about twice as many icebergs.

3. Wildlife squeezed off the ice

Many species of seals and penguins rely on sea ice, especially for breeding and moulting.

Entire colonies of emperor penguins experienced “catastrophic breeding failure” in 2022, when sea ice melted before chicks were ready to go to sea.

After giving birth, crabeater seals need large, stable sea ice platforms for 2–3 weeks until their pups are weaned. The ice provides shelter and protection from predators. Less summer sea-ice cover makes large platforms harder to find.

Many seal and penguin species also take refuge on the sea ice when moulting. These species must avoid the icy water while their new feathers or fur grows, or risk dying of hypothermia.

4. Logistical challenges at the end of the world

Low summer sea ice makes it harder for people working in Antarctica. Shrinking summer sea ice will narrow the time window during which Antarctic bases can be resupplied over the ice. These bases may soon need to be resupplied from different locations, or using more difficult methods such as small boats.

No longer safe

Anarctic sea ice began to change rapidly in 2015 and 2016. Since then it has remained well below the long-term average.

The dataset we use relies on measurements from US Department of Defense satellites. Late last month, the department announced it would no longer provide this data to the scientific community. While this has since been delayed to July 31, significant uncertainty remains.

One of the biggest challenges in climate science is gathering and maintaining consistent long-term datasets. Without these, we don’t accurately know how much our climate is changing. Observing the entire Earth is hard enough when we all work together. It’s going to be almost impossible if we don’t share our data.

Recent low sea ice summers present a scientific challenge. The system is currently changing faster than our scientific community can study it.

But vanishing sea ice also presents a challenge to society. The only way to prevent even more drastic changes in the future is to rapidly transition away from fossil fuels and reach net zero emissions.

Edward Doddridge, Senior Research Associate in Physical Oceanography, University of Tasmania

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

The ocean around Antarctica is rapidly getting saltier at the same time as sea ice is retreating at a record pace. Since 2015, the frozen continent has lost sea ice similar to the size of Greenland. That ice hasn’t returned, marking the largest global environmental change during the past decade.

This finding caught us off guard – melting ice typically makes the ocean fresher. But new satellite data shows the opposite is happening, and that’s a big problem. Saltier water at the ocean surface behaves differently than fresher seawater by drawing up heat from the deep ocean and making it harder for sea ice to regrow.

The loss of Antarctic sea ice has global consequences. Less sea ice means less habitat for penguins and other ice-dwelling species. More of the heat stored in the ocean is released into the atmosphere when ice melts, increasing the number and intensity of storms and accelerating global warming. This brings heatwaves on land and melts even more of the Antarctic ice sheet, which raises sea levels globally.

Our new study has revealed that the Southern Ocean is changing, but in a different way to what we expected. We may have passed a tipping point and entered a new state defined by persistent sea ice decline, sustained by a newly discovered feedback loop.

A surprising discovery

Monitoring the Southern Ocean is no small task. It’s one of the most remote and stormy places on Earth, and is covered in darkness for several months a year. Thanks to new European Space Agency satellites and underwater robots which stay below the ocean surface measuring temperature and salinity, we can now observe what is happening in real time.

Our team at the University of Southampton worked with colleagues at the Barcelona Expert Centre and the European Space Agency to develop new algorithms to track ocean surface conditions in polar regions from satellites. By combining satellite observations with data from underwater robots, we built a 15-year picture of changes in ocean salinity, temperature and sea ice.

What we found was astonishing. Around 2015, surface salinity in the Southern Ocean began rising sharply – just as sea ice extent started to crash. This reversal was completely unexpected. For decades, the surface had been getting fresher and colder, helping sea ice expand.

To understand why this matters, it helps to think of the Southern Ocean as a series of layers. Normally, the cold, fresh surface water sits on top of warmer, saltier water deep below. This layering (or stratification, as scientists call it) traps heat in the ocean depths, keeping surface waters cool and helping sea ice to form.

Saltier water is denser and therefore heavier. So, when surface waters become saltier, they sink more readily, stirring the ocean’s layers and allowing heat from the deep to rise. This upward heat flux can melt sea ice from below, even during winter, making it harder for ice to reform. This vertical circulation also draws up more salt from deeper layers, reinforcing the cycle.

A powerful feedback loop is created: more salinity brings more heat to the surface, which melts more ice, which then allows more heat to be absorbed from the Sun. My colleagues and I saw these processes first hand in 2016-2017 with the return of the Maud Rise polynya, which is a gaping hole in the sea ice that is nearly four times the size of Wales and last appeared in the 1970s.

What happens in Antarctica doesn’t stay there

Losing Antarctic sea ice is a planetary problem. Sea ice acts like a giant mirror reflecting sunlight back into space. Without it, more energy stays in the Earth system, speeding up global warming, intensifying storms and driving sea level rise in coastal cities worldwide.

Wildlife also suffers. Emperor penguins rely on sea ice to breed and raise their chicks. Tiny krill – shrimp-like crustaceans which form the foundation of the Antarctic food chain as food for whales and seals – feed on algae that grow beneath the ice. Without that ice, entire ecosystems start to unravel.

What’s happening at the bottom of the world is rippling outward, reshaping weather systems, ocean currents and life on land and sea.

Antarctica is no longer the stable, frozen continent we once believed it to be. It is changing rapidly, and in ways that current climate models didn’t foresee. Until recently, those models assumed a warming world would increase precipitation and ice-melting, freshening surface waters and helping keep Antarctic sea ice relatively stable. That assumption no longer holds.

Our findings show that the salinity of surface water is rising, the ocean’s layered structure is breaking down and sea ice is declining faster than expected. If we don’t update our scientific models, we risk being caught off guard by changes we could have prepared for. Indeed, the ultimate driver of the 2015 salinity increase remains uncertain, underscoring the need for scientists to revise their perspective on the Antarctic system and highlighting the urgency of further research.

We need to keep watching, yet ongoing satellite and ocean monitoring is threatened by funding cuts. This research offers us an early warning signal, a planetary thermometer and a strategic tool for tracking a rapidly shifting climate. Without accurate, continuous data, it will be impossible to adapt to the changes in store.

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Alessandro Silvano, NERC Independent Research Fellow in Oceanography, University of Southampton

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

The number of tourists heading to Antarctica has been skyrocketing. From fewer than 8,000 a year about three decades ago, nearly 125,000 tourists flocked to the icy continent in 2023–24. The trend is likely to continue in the long term.

Unchecked tourism growth in Antarctica risks undermining the very environment that draws visitors. This would be bad for operators and tourists. It would also be bad for Antarctica – and the planet.

Over the past two weeks, the nations that decide what human activities are permitted in Antarctica have convened in Italy. The meeting incorporates discussions by a special working group that aims to address tourism issues.

It’s not easy to manage tourist visitors to a continent beyond any one country’s control. So, how do we stop Antarctica being loved to death? The answer may lie in economics.

Future visitor trends

We recently modelled future visitor trends in Antarctica. A conservative scenario shows by 2033–34, visitor numbers could reach around 285,000. Under the least conservative scenario, numbers could reach 450,000 – however, this figure incorporates pent-up demand from COVID shutdowns that will likely diminish.

The vast majority of the Antarctic tourism industry comprises cruise-ship tourism in the Antarctic Peninsula. A small percentage of visitors travel to the Ross Sea region and parts of the continent’s interior.

Antarctic tourism is managed by an international set of agreements together known as the Antarctic Treaty System, as well as the International Association of Antarctica Tour Operators (IAATO).

The Treaty System is notoriously slow-moving and riven by geopolitics, and IAATO does not have the power to cap visitor numbers.

Pressure on a fragile continent

About two-thirds of Antarctic tourists land on the continent. The visitors can threaten fragile ecosystems by:

• compacting soils
• trampling fragile vegetation
• introducing non-native microbes and plant species
• disturbing breeding colonies of birds and seals.

Even when cruise ships don’t dock, they can cause problems such as air, water and noise pollution – as well as anchoring that can damage the seabed.

Then there’s carbon emissions. Each cruise ship traveller to Antarctica typically produces between 3.2 and 4.1 tonnes of carbon, not including travel to the port of departure. This is similar to the carbon emissions an average person produces in a year.

Global warming caused by carbon emissions is damaging Antarctica. At the Peninsula region, glaciers and ice shelves are retreating and sea ice is shrinking, affecting wildlife and vegetation.

Of course, Antarctic tourism represents only a tiny fraction of overall emissions. However, the industry has a moral obligation to protect the place that maintains it. And tourism in Antarctica can compound damage from climate change, tipping delicate ecosystems into decline.

Some operators use hybrid ships and less polluting fuels, and offset emissions to offer carbon-neutral travel. IAATO has pledged to halve emissions by 2050 – a positive step.

Can economics protect Antarctica?

Market-based tools – such as taxes, cap-and-trade schemes and certification – have been used in environmental management around the world. Research shows these tools could also prevent Antarctic tourist numbers from getting out of control.

One option is requiring visitors to pay a tourism tax. This would help raise revenue to support environmental monitoring and enforcement in Antarctica, as well as fund research.

Such a tax already exists in the small South Asian nation of Bhutan, where each tourist pays a tax of US$100 (A$152) a night. But while a tax might deter the budget-conscious, it probably wouldn’t deter high income, experience-driven tourists.

Alternatively, a cap-and-trade system would create a limited number of Antarctica visitor permits for a fixed period. The initial distribution of permits could be among tourism operators or countries, via negotiation, auction or lottery. Unused permits could then be sold, making them quite valuable.

Caps have been successful at managing tourism impacts elsewhere, such as Lord Howe Island, although there are no trades allowed in that system.

Any cap on tourist numbers in Antarctica, and rules for trading, must be based on evidence about what the environment can handle. But there is a lack of precise data on Antarctica’s carrying capacity. And permit allocations amongst the operators and nations would need to be fair and inclusive.

Alternatively, existing industry standards could be augmented with independent schemes certifying particular practices – for example, reducing carbon footprints. This could be backed by robust monitoring and enforcement to avoid greenwashing.

Looking ahead

Given the complexities of Antarctic governance, our research finds that the most workable solution is a combination of these market-based options, alongside other regulatory measures.

So far, parties to the Antarctic treaty have made very few binding rules for the tourism industry. And some market-based levers will be more acceptable to the parties than others. But doing nothing is not a solution.

The authors would like to acknowledge Valeria Senigaglia, Natalie Stoeckl and Jing Tian and the rest of the team for their contributions to the research upon which this article was based.

Correction: An earlier version of this article said the IAATO’s emissions targets fell short of that set by the International Maritime Organization. This was incorrect.

Darla Hatton MacDonald, Professor of Environmental Economics, University of Tasmania and Elizabeth Leane, Professor of Antarctic Studies, School of Humanities, University of Tasmania

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

At a coastal port in Chittagong, Bangladesh, something remarkable is underway. With support from a US$850 million (£620 million) investment from the World Bank, engineers are building flood-resistant infrastructure that can survive rising seas and stronger storms. A new 3.7-mile-long barrier will protect people, homes, and trade in one of the world’s most climate-vulnerable regions.

Projects like this do more than save lives. They show why investing in climate adaptation is one of the smartest financial opportunities of our time. There are plenty of global conferences where leaders discuss climate change and make big promises. Yet, less than 5.5% of global climate finance actually reaches the countries most at risk. That is not just a failure of fairness. It is a missed chance for real impact.

As the world gathers in Seville, Spain for the fourth international meeting on development financing, the focus must go beyond pledges and shift toward practical, on-the-ground investment in resilience.

At the previous UN climate finance meeting, also held in Seville, leaders focused on fixing how public money flows through global institutions. But just as important is the need to invest in climate adaptation. This means helping people live with the changes already happening, including more floods, longer droughts, rising seas and intense heat.

While mitigation is about stopping climate change getting worse (by switching to clean energy or protecting forests that absorb carbon, for example), adaptation is about coping with the effects we can no longer avoid. It includes building stronger homes, growing more resilient crops, and improving hospitals and schools so they can keep working during extreme weather. Both approaches are necessary, but adaptation often gets less attention. And less money.

Private investors have already committed large sums to clean energy projects. But they have done much less to support communities on the frontlines of climate change. Many of these countries struggle with limited budgets, complex rules for accessing finance, and a lack of support to develop viable projects. So promising ideas often go unfunded.

That is beginning to change. New tools are helping investors take on less risk and back more projects. These include low-interest loans, partnerships between public and private institutions, and guarantees that reduce the risk of failure.

The Green Climate Fund is the largest source of dedicated climate finance for developing countries. By the end of 2023, it had approved US$13.5 billion in funding, rising to US$51.9 billion when co-financing is included. This money helps unlock adaptation efforts that were previously out of reach.

We can already see progress. In Kenya and Ethiopia, farmers are using drought-resistant seeds to grow more food in changing conditions. In the Caribbean, solar energy is powering schools and clinics in remote communities. And in Bangladesh, the new port infrastructure in Chittagong is protecting a vital economic hub while boosting local businesses.

Working with nature

In coastal areas, restoring mangrove forests can reduce the force of incoming storms, protect biodiversity and support fisheries. The Pollination Group, a climate investment firm, is helping turn “nature-based solutions” like these into projects that attract private finance.

In his previous role as the Prince of Wales, King Charles III launched the Natural Capital Investment Alliance, an initiative that aims to mobilise US$10 billion for projects that restore and protect nature while offering solid financial returns. The alliance also helps investors better understand these kinds of opportunities by creating clearer guidance and standards. This supports the Terra Carta, a charter created by King Charles III that offers a roadmap for businesses to align with the needs of both people and the planet by 2030.

Investors who step into these emerging spaces gain more than financial returns. They build long-term relationships with governments and local communities. They help shape future policy. And they create lasting foundations for growth in places that are ready to lead if given the chance.

Adaptation projects also bring real benefits to people. They improve access to clean water, protect food supplies, create jobs, strengthen education and support healthcare systems. For families already facing climate disruption, these changes are not just improvements. They are lifelines.

By creating stable and welcoming environments for responsible investment, governments can accelerate this shift. By simplifying how money is accessed, international institutions can make it easier for good ideas to become funded projects. Philanthropic groups and development agencies can help build local skills and prepare projects for funding. Private investors can bring capital, innovation and experience.

Investing in climate adaptation is no longer just a moral issue. It is a smart, scalable and necessary response to a changing world.

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Ali Serim, Advisor for the Centre of Geopolitics of Global Change, ODI Global

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Bangladesh is known as the land of rivers and flooding, despite almost all of its water originating outside the territory. The fact that 80% of rivers that flow through Bangladesh have their sources in a neighbouring country, can make access to freshwater in Bangladesh fraught. And the country’s fast-growing cities and farms – and the warming global climate – are turning up the pressure.

In a recent analysis, my colleagues and I found that four out of the ten rivers that flow through Bangladesh have failed to meet a set of conditions known as their “safe operating space”, meaning that the flow of water in these rivers is below the minimum necessary to sustain the social-ecological systems that rely on them. These rivers included the Ganges and Old Brahmaputra, as well as Gorai and Halda.

This puts a safe and reliable food and water supply not to mention the livelihoods of millions of fishers, farmers and other people in the region, at risk.

Water flow on the remaining six rivers may be close to a dangerous state too, due to the construction of hydropower dams and reservoirs, as well as booming irrigated agriculture.

The concept of a safe operating space was devised by Stockholm University researchers in 2009 and typically assesses the Earth’s health as a whole by defining boundaries such as climate warming, water use and biodiversity loss which become dangerous to humanity once exceeded. A 2023 update to this research found that six of the nine defined planetary boundaries have been transgressed.

Since the Bangladesh delta is one of the world’s largest and most densely populated (home to around 170 million people), we thought it prudent to apply this thinking to the rivers here. We found that food, fisheries and the world’s largest intertidal mangrove forest, a haven for rich biodiversity, are all under strain from water demand in growing cities such as Dhaka.

The knock-on effects

During all seasons but winter, river flows in the Bangladesh delta have fallen over the past three decades.

Our analysis highlights the limits of existing political solutions. The ability of the Ganges river to support life and society is severely strained, despite the Ganges water sharing treaty between India and Bangladesh, which was signed in 1996.

Rivers in Bangladesh have shaped the economy, environment and culture of South Asia since the dawn of human civilisation here. And humans are not the only species suffering. Hilsha (Tenualosa ilisha), related to the herring, is a fish popular for its flavour and delicate texture. It contributes 12% to national fish production in Bangladesh but has become extinct in the upper reaches of the Ganges due to the reduction of water flow.

Excessive water extraction upstream, primarily through the Farakka barrage, a dam just over the border in the Indian state of West Bengal, has also raised the salinity of the Gorai river. A healthy river flow maintains a liveable balance of salt and freshwater. As river flows have been restricted, salinity has crept up, particularly in coastal regions that are also beset by sea level rise. This damages freshwater fisheries, farm yields and threatens a population of freshwater dolphins in the Ganges.

Low river flows and increasing salinisation now threaten the destruction of the world’s largest mangrove forest, the loss of which would disrupt the regional climate of Bangladesh, India and Nepal. It would also release a lot of stored carbon to the atmosphere, accelerating climate change and the melting of snow and ice in the Himalayan mountain chain.

Resilience to climate change

Solving this problem is no simple task. It will require cooperation across national boundaries and international support to ensure fair treaties capable of managing the rivers sustainably, restoring their associated ecosystems and maintaining river flows within their safe operating spaces.

This is particularly challenging in the Bangladesh delta, which contains rivers that drain many countries, including China, India, Nepal and Pakistan. The political regimes in each country might oppose transboundary negotiations, which could nevertheless resolve conflict over water which is needed to sustain nearly 700 million people.

There have been success stories, however. The Mekong river commission between Cambodia, Laos, Thailand and Vietnam is a useful template for bilateral and multilateral treaties with India and Nepal for the Ganges, and China and Bhutan for the Jamuna river.

Tax-based water sharing can help resolve conflicts and decide water allocation between countries in the river basin. The countries using more water would pay more tax and the revenue would be redistributed among the other countries who share rivers in the treaty. Additionally, water sharing should be based on the historical river flow disregarding existing infrastructure and projections of future changes.

Reducing deforestation, alternating land use and restoring wetlands could enhance resilience to flooding and drought and ensure water security in the Bangladesh delta. Ultimately, to secure a safe operating space for the rivers here is to secure a safe future for society too.

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Md Sarwar Hossain, Senior Lecturer in Environmental Science & Sustainability, University of Glasgow

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Global warming has picked up pace since around 2010, leading to the recent string of record warm years. Why this is happening is still unclear, and among the biggest questions in climate science today. Our new study reveals that reductions in air pollution – particularly in China and east Asia – are a key reason for this faster warming.

Cleanup of sulphur emissions from global shipping has been implicated in past research. But that cleanup only began in 2020, so it’s considered too weak to explain the full extent of this acceleration. Nasa researchers have suggested that changes in clouds could play a role, either through reductions in cloud cover in the tropics or over the North Pacific.

One factor that has not been well quantified, however, is the effect of monumental efforts by countries in east Asia, notably China, to combat air pollution and improve public health through strict air quality policies. There has already been a 75% reduction in east Asian sulphur dioxide emissions since around 2013, and that cleanup effort picked up pace just as global warming began accelerating.

Our study addresses the link between east Asian air quality improvements and global temperature, building on the efforts of eight teams of climate modellers across the world.

We have found that polluted air may have been masking the full effects of global warming. Cleaner air could now be revealing more of the human-induced global warming from greenhouse gases.

In addition to causing millions of premature deaths, air pollution shields the Earth from sunlight and therefore cools the surface. There has been so much air pollution that it has held human-induced warming in check by up to 0.5°C over the last century.

With the cleanup of air pollution, something that’s vital for human health, this artificial sunshade is removed. Since greenhouse gas emissions have kept on increasing, the result is that the Earth’s surface is warming faster than ever before.

Modelling the cleanup

Our team used 160 computer simulations from eight global climate models. This enabled us to better quantify the effects that east Asian air pollution has on global temperature and rainfall patterns. We simulated a cleanup of pollution similar to what has happened in the real world since 2010. We found an extra global warming of around 0.07°C.

While this is a small number compared with the full global warming of around 1.3°C since 1850, it is still enough to explain the recent acceleration in global warming when we take away year-to-year swings in temperature from natural cycles such as El Niño, a climate phenomenon in the Pacific that affects weather patterns globally.

Based on long-term trends, we would have expected around 0.23°C of warming since 2010. However, we actually measured around 0.33°C. While the additional 0.1°C can largely be explained by the east Asian air pollution cleanup, other factors include the change in shipping emissions and the recent accelerated increase in methane concentrations in the atmosphere.

Air pollution causes cooling by reflecting sunlight or by changing the properties of clouds so they reflect more sunlight. The cleanup in east Asian air pollution influences global temperatures because it reduces the shading effect of the pollution over east Asia itself. It also means less pollution is blown across the north Pacific, causing clouds in the east Pacific to reflect less sunlight.

The pattern of these changes across the North Pacific simulated in our models matches that seen in satellite observations. Our models and temperature observations also show relatively strong warming over the North Pacific, downwind from east Asia.

The main source of global warming is still greenhouse gas emissions, and a cleanup of air pollution was both necessary and overdue. This did not cause the additional warming but rather, removed an artificial cooling that has for a time helped shield us from some of the extreme weather and other well-established consequences of climate change.

Global warming will continue for decades. Indeed, our past and future emissions of greenhouse gases will affect the climate for centuries. However, air pollution is quickly removed from the atmosphere, and the recent acceleration in global warming from this particular unmasking may therefore be short-lived.

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Laura Wilcox, Professor, National Centre for Atmospheric Science, University of Reading and Bjørn H. Samset, Senior Researcher in Climate and Atmospheric Sciences, Center for International Climate and Environment Research - Oslo

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Lakes are essential to ecosystems, providing freshwater, supporting biodiversity and offering crucial habitat for fish and other aquatic species.

But a recent study by my colleagues and I shows that lakes around the world are warming, not just at the surface, but deep below as well. Subsurface heatwaves in lakes, defined as extreme periods of high water temperature below the surface, are increasing in frequency, duration and intensity.

These hidden extremes could have serious consequences for lake ecosystems. Despite that, the issue remains largely unmonitored and poorly understood.

Lake heatwaves are similar to those in the atmosphere or ocean. They are prolonged periods of excessive warmth. Most research to date has focused on surface temperatures, where climate change has already caused more frequent and intense heatwaves over recent decades.

These surface events can disrupt the chemical and physical balance of lakes, damage food webs and, in some cases, cause mass fish die-offs.

Aquatic species respond to surface heatwaves in different ways. Some benefit if the warming expands their preferred temperature range. But many others, particularly those already living near their thermal limits, face significant stress.

In lakes that stratify during summer – where warm surface water sits above a cooler bottom layer – some species seek refuge from the heat by migrating to deeper water. But what happens when that deeper refuge is no longer cool?

A closer look beneath the surface

To investigate, we analysed temperature data from tens of thousands of lakes worldwide. These included one-dimensional lake models, high-resolution simulations for the Great Lakes of North America, and local models calibrated to specific lake conditions.

By analysing how temperature varies with depth and time, we identified when and where subsurface waters crossed extreme heat thresholds.

We defined subsurface heatwaves as periods when temperatures at particular depths exceeded their typical seasonal range. We also tracked how these events have changed since 1980, and how they might evolve under different emissions scenarios by the end of this century.

Subsurface heatwaves are already common and they’re becoming more so.

Since 1980, bottom heatwaves (those occurring at the deepest parts of lakes) have increased by an average of more than seven days per decade in frequency, more than two days per decade in duration and they have risen by around 0.2C per decade.

Although these deep-water events tend to be slightly less intense than surface ones, they often last longer.

We also found a rise in “vertically compounding” heatwaves. This is when extreme temperatures happen simultaneously at the surface and bottom of a lake.

These doubled-up events are now happening more than three days per decade more frequently. When they strike, aquatic species can be left with no place to escape the heat.

Even more concerning, the deep-water refuges that once offered shelter during surface heatwaves are shrinking or disappearing altogether. In some lakes, the distance fish need to travel to find cooler water has increased by nearly a metre per decade.

Our simulations suggest that these trends will intensify, especially under high-emission scenarios. By the end of this century, some bottom heatwaves could last for months, with temperature extremes not seen in the historical record.

Why this matters

Lake ecosystems rely on thermal structure. When extreme heat reaches deeper into the water column, it can trigger cascading ecological effects, from shifting fish habitats and altering species distribution, to increased nutrient cycling and algal blooms. It could even affect the release of greenhouse gases like methane from lake bed sediments.

Subsurface heatwaves pose a particular risk to bottom-dwelling species, which may be less mobile or already adapted to cold, stable conditions. The loss of thermal refuges during surface heatwaves also jeopardises species that would otherwise escape to deeper waters.

By ignoring what’s happening below the surface, we risk underestimating the true ecological effects of climate change on freshwater systems.

Our study highlights the urgent need to expand lake monitoring efforts to include subsurface temperatures. While satellites have transformed our understanding of surface warming, they can’t capture what’s happening below.

Future research should examine how different species respond to these deep-water and vertically compounding heatwaves. It should explore how changes in lake thermal structure affect different processes like nutrient cycling and methane production.

For conservation planners, that means incorporating subsurface heatwaves into risk assessments and habitat models. For climate modellers, it means better representing vertical processes in lakes within global Earth system models.

As lakes continue to warm, managing and understanding these hidden heat extremes will be critical to protecting biodiversity and the vital ecosystem services lakes provide.

Iestyn Woolway, Reader and NERC Independent Research Fellow, Bangor University

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More than 180 plants were stolen from a well-loved public park in Nottingham called Arboretum in May 2025. This incident took place just days after volunteers had re-planted flowers and shrubs to repair damage from a previous theft in March. In April 2025, the nearby Forest Recreation Ground community garden was also targeted – roses and crops grown by volunteers were stolen, even a pond went missing.

Plant theft may seem trivial, but environmental and wildlife crime tend to be overlooked. This is precisely one of the reasons why it is on the rise. Research suggests an annual growth rate in environmental crime of 5%-7%, making it the third largest criminal sector in the world.

Globally, environmental crime has been valued at US$70-213 billion (£52-158 billion) annually. As with most crime, its true scale is difficult to estimate as it remains hidden. This is even more true for environmental crime that goes undetected.

Plant thefts in Nottingham where I am based are small in comparison, but they tell the same story of lucrative illicit opportunities for criminals where law enforcement and potential sanctions are low. It’s most likely that people steal local plants to sell on for profit.

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Another reason for overlooking this growing trend in wildlife crime is that perpetrators, as well as much of society, may feel that this is a “victimless crime”. Where plants, animals, watercourses or soil are “the victim”, people don’t feel as strongly because our ethics and value systems generally prioritise fellow humans and do not recognise non-humans as victims.

People may be more likely to care about mammals such as elephants targeted in illegal ivory trade, but environmental crime permeates every community in the UK, as the recent Nottingham cases indicate.

Stolen benefits

As a researcher in environmental sociology, I believe wildlife crime and environmental damage should gain higher priority in terms of public attention, law enforcement and potential sanctions. Not only because of the intrinsic value that non-human nature has in its own right, but because of the value nature brings to us humans.

Parks and green spaces known as “green infrastructure” are central to our wellbeing in cities. They bring environmental and social benefits in terms of air quality, urban heat island effect, surface flooding, carbon storage, biodiversity and health.

After the COVID pandemic, the importance of accessing quality green spaces for our mental and physical wellbeing became even more apparent. Visits to parks can reduce loneliness and anxiety, as well as foster a sense of belonging and community.

This has the potential to benefit the public purse too. Nottingham is currently involved in a national green social prescribing test and learn programme to demonstrate the benefits of nature-based activity.

Public parks are often also significant in terms of cultural heritage. This is not a new discovery. Historically, public parks were introduced in cities to improve living conditions, quality of life and as educational resources. The Arboretum – the city centre park recently targeted by thieves - was the first such public park to open in Nottingham in 1845.

When valued green spaces are the victim of crime, this is not a mere aesthetic problem. Wider social and environmental harms are inflicted upon communities and nature that depend on open green spaces to thrive.

This matters in cities like Nottingham that suffer from high levels of deprivation and poor health outcomes. My own research has shown that while Nottingham is often celebrated for leadership in green initiatives, it suffers from deep-seated social inequality and deprivation that are long-term challenges.

Social inequality is associated with crime and disorder in urban areas that creates a vicious cycle when the crimes target community assets such as public parks. It is beyond doubt that public parks being ransacked will negatively impact the quality of life in Nottingham.

It is likely that these crimes get dismissed as a minor nuisance because “only plants” were stolen, but this attitude serves to mask the broader trend of growing environmental crime and the damage this brings to communities. Unfortunately, this will further contribute to the likelihood of such crimes spreading in future.

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Jenni Cauvain, Senior Lecturer in Sociology, Nottingham Trent University

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Last weekend, a woman was mauled by a lioness at Darling Downs Zoo in Queensland, and lost her arm. The zoo, which keeps nine lions, has been operating for 20 years and had never experienced an incident such as this.

The victim was a relative of the zoo owner, Steve Robinson, who told the media the lions were not aggressive and the lioness was thought to be “just playing”.

Although attacks like this are extremely rare, they are obviously of great concern. The incident should prompt a rethink of our approach to wild animals in captivity, and whether it’s morally acceptable – or safe – to keep them there at all.

Why do zoos exist?

Zoos, aquariums and other settings where wild animals are kept captive exist for two main reasons: human entertainment and profit-making.

Surveys show zoo visitors have a preference for large mammals such as elephants, primates and big cats.

Some animals are more tolerant of captivity conditions and exposure to humans than others. Fish, for example, seem to respond more neutrally to human presence than most other species.

But a recent study found captive animals generally demonstrate abnormal behaviour more often than non-captive ones.

For most wild animals, captivity deprives them of the ability to engage in natural behaviour, which harms their welfare. For example, free-living dolphins and whales have long-range migration patterns which require vast ocean spaces. They are also highly social and display complex communication behaviour.

Some countries have banned keeping dolphins and whales in captivity for entertainment because it causes the animals to suffer sensory deprivation and stress, among other harms.

Captive dolphins were once common in aquariums and marine parks across Australia. But now only one facility, Sea World in Queensland, still breeds dolphins for entertainment.

And earlier this year, the last elephants at Perth Zoo were moved to a 12-hectare habitat in South Australia to improve their welfare.

Another important welfare question is whether the captive animal has “agency” – that is, whether it can make choices as it would in the wild.

Can it choose, for example, which other animals it has relationships with? Or whether it has privacy? Having control over such decisions enhances the quality of life for the captive animal.

It’s important to note that some zoos can deliver positive outcomes for animals. Many play an important conservation role, such as running captive breeding programs for endangered species.

An example is a long-running program across several Australian zoos and other organisations to recover populations of the critically endangered Regent Honeyeater. The program has released more than 400 zoo-bred birds into the wild.

However, such conservation programs do not necessarily need to involve zoos to succeed.

Weighing up the risks

No matter how domesticated they might seem, some wild animals in captivity will always pose a risk to humans. Their behaviour can be unpredictable and, as the recent Queensland example shows, even a “playing” lioness can cause enormous physical harm to people.

Wild animals are called wild for a reason. To be kept in captivity, most animals require training so they can be safely handled. The Darling Downs Zoo incident shows despite this precaution, things can still go wrong.

But humans will, understandably, always be fascinated by other animals, and want to see them up close. So what are the alternatives to zoos?

Open range-zoos, such as the one to which the Perth elephants were moved, can offer a better option for some animals.

Another option is to recreate the zoo experience using technology. Artificial intelligence, virtual reality and augmented reality can be used to create images of animals that look and seem real.

In Australia, examples include Brisbane’s Hologram Zoo and a high-tech puppetry experience touring Australia which replicates a real shark dive.

Overseas, animatronic displays have been created to replace dolphin shows.

Questions about animals kept in captivity require us to consider how much risk to human safety we accept, and the extent to which we prioritise human amusement over animal welfare. In searching for answers, we can start by asking whether we need zoos at all.

Georgette Leah Burns, Associate Professor, Griffith School of Environment and Science, Griffith University

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Since 1970, 73% of global wildlife has been lost, while the world’s population has doubled to 8 billion. Research shows this isn’t a coincidence but that population growth is causing a catastrophic decline in biodiversity.

Yet a turning point in human history is underway. According to UN projections, the number of people in 85 countries will be shrinking by 2050, mostly in Europe and Asia. By 2100, the human population is on course for global decline. Some say this will be good for the environment.

In 2010, Japan became the first Asian country to begin depopulating. South Korea, China and Taiwan are following close behind. In 2014, Italy was the first in southern Europe, followed by Spain, Portugal and others. We call Japan and Italy “depopulation vanguard countries” on account of their role as forerunners for understanding possible consequences in their regions.

Given assumptions that depopulation could help deliver environmental restoration, we have been working with colleagues Yang Li and Taku Fujita to investigate whether Japan is experiencing what we have termed a biodiversity “depopulation dividend” or something else.

Since 2003, hundreds of citizen scientists have been collecting biodiversity data for the Japanese government’s Monitoring Sites 1,000 project. We used 1.5 million recorded species observations from 158 sites.

These were in wooded, agricultural and peri-urban (transitional spaces on outskirts of cities) areas. We compared these observations against changes in local population, land use and surface temperature for periods of five to 20 years.

Our study, published in the journal Nature Sustainability, includes birds, butterflies, fireflies, frogs and 2,922 native and non-native plants. These landscapes have experienced the greatest depopulation since the 1990s.

Due to the size of our database, choice of sites and the positioning of Japan as a depopulation vanguard for north-east Asia, this is one of the largest studies of its kind.

Japan is not Chernobyl

Biodiversity continued to decrease in most of the areas we studied, irrespective of population increase or decrease. Only where the population remains steady is biodiversity more stable. However, the population of these areas is ageing and will decline soon, bringing them in line with the areas already seeing biodiversity loss.

Unlike in Chernobyl, where a sudden crisis caused an almost total evacuation which stimulated startling accounts of wildlife revival, Japan’s population loss has developed gradually. Here, a mosaic pattern of changing land use emerges amid still-functioning communities.

While most farmland remains under cultivation, some falls into disuse or abandonment, some is sold for urban development or transformed into intensively farmed landscapes. This prevents widespread natural succession of plant growth or afforestation (planting of new trees) that would enrich biodiversity.

In these areas, humans are agents of ecosystem sustainability. Traditional farming and seasonal livelihood practices, such as flooding, planting and harvesting of rice fields, orchard and coppice management, and property upkeep, are important for maintaining biodiversity. So depopulation can be destructive to nature. Some species thrive, but these are often non-native ones that present other challenges, such as the drying and choking of formerly wet rice paddy fields by invasive grasses.

Vacant and derelict buildings, underused infrastructure and socio-legal issues (such as complicated inheritance laws and land taxes, lack of local authority administrative capacity, and high demolition and disposal costs) all compound the problem.

Even as the number of akiya (empty, disused or abandoned houses) increases to nearly 15% of the nation’s housing stock, the construction of new dwellings continues remorselessly. In 2024, more than 790,000 were built, due partly to Japan’s changing population distribution and household composition. Alongside these come roads, shopping malls, sports facilities, car parks and Japan’s ubiquitous convenience stores. All in all, wildlife has less space and fewer niches to inhabit, despite there being fewer people.

What can be done?

Data shows deepening depopulation in Japan and north-east Asia. Fertility rates remain low in most developed countries. Immigration provides only a short-term softer landing, as countries currently supplying migrants, such as Vietnam, are also on course for depopulation.

Our research demonstrates that biodiversity recovery needs to be actively managed, especially in depopulating areas. Despite this there are only a few rewilding projects in Japan. To help these develop, local authorities could be given powers to convert disused land into locally managed community conservancies.

Nature depletion is a systemic risk to global economic stability. Ecological risks, such as fish stock declines or deforestation, need better accountability from governments and corporations. Rather than spend on more infrastructure for an ever-dwindling population, for example, Japanese companies could invest in growing local natural forests for carbon credits.

Depopulation is emerging as a 21st-century global megatrend. Handled well, depopulation could help reduce the world’s most pressing environmental problems, including resource and energy use, emissions and waste, and nature conservation. But it needs to be actively managed for those opportunities to be realised.

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Peter Matanle, Senior Lecturer in Japanese Studies, University of Sheffield; Kei Uchida, Associate Professor, Conservation and Biodiversity Management, Tokyo City University, and Masayoshi K. Hiraiwa, Postdoctoral Researcher, Ecology, Faculty of Agriculture, Kindai University

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The greenhouse effect was discovered more than 150 years ago and the first scientific paper linking carbon dioxide levels in the atmosphere with climate change was published in 1896.

But it wasn’t until the 1950s that scientists could definitively detect the effect of human activities on the Earth’s atmosphere.

In 1956, United States scientist Charles Keeling chose Hawaii’s Mauna Loa volcano for the site of a new atmospheric measuring station. It was ideal, located in the middle of the Pacific Ocean and at high altitude away from the confounding influence of population centres.

Data collected by Mauna Loa from 1958 onward let us clearly see the evidence of climate change for the first time. The station samples the air and measures global CO₂ levels. Charles Keeling and his successors used this data to produce the famous Keeling curve – a graph showing carbon dioxide levels increasing year after year.

But this precious record is in peril. US President Donald Trump has decided to defund the observatory recording the data, as well as the widespread US greenhouse gas monitoring network and other climate measuring sites.

We can’t solve the existential problem of climate change if we can’t track the changes. Losing Mauna Loa would be a huge loss to climate science. If it shuts, other observatories such as Australia’s Kennaook/Cape Grim will become even more vital.

What did Mauna Loa show us?

The first year of measurements at Mauna Loa revealed something incredible. For the first time, the clear annual cycle in atmospheric CO₂ was visible. As plants grow in summer, they absorb CO₂ and draw it out of the atmosphere. As they die and decay in winter, the CO₂ returns to the atmosphere. It’s like Earth is breathing.

Most land on Earth is in the Northern Hemisphere, which means this cycle is largely influenced by the northern summer and winter.

It only took a few years of measurements before an even more profound pattern emerged.

Year on year, CO₂ levels in the atmosphere were relentlessly rising. The natural in-out cycle continued, but against a steady increase.

Scientists would later figure out that the ocean and land together were absorbing almost half of the CO₂ produced by humans. But the rest was building up in the atmosphere.

Crucially, isotopic measurements meant scientists could be crystal clear about the origin of the extra carbon dioxide. It was coming from humans, largely through burning fossil fuels.

Mauna Loa has now been collecting data for more than 65 years. The resulting Keeling curve graph is the most iconic demonstration of how human activities are collectively affecting the planet.

When the last of the Baby Boomer generation were being born in the 1960s, CO₂ levels were around 320 parts per million. Now they’re over 420 ppm. That’s a level unseen for at least three million years. The rate of increase far exceeds any natural change in the past 50 million years.

The reason carbon dioxide is so important is that this molecule has special properties. Its ability to trap heat alongside other greenhouse gases means Earth isn’t a frozen rock. If there were no greenhouse gases, Earth would have an average temperature of -18°C, rather than the balmy 14°C under which human civilisation emerged.

The greenhouse effect is essential to life. But if there are too many gases, the planet becomes dangerously hot. That’s what’s happening now – a very sharp increase in gases exceptionally good at trapping heat even at low concentrations.

Keeping our eyes open

It’s not enough to know CO₂ is climbing. Monitoring is essential. That’s because as the planet warms, both the ocean and the land are expected to take up less and less of humanity’s emissions, letting still more carbon accumulate in the air.

Continuous, high-precision monitoring is the only way to spot if and when that happens.

This monitoring provides the vital means to verify whether new climate policies are genuinely influencing the atmospheric CO₂ curve rather than just being touted as effective. Monitoring will also be vital to capture the moment many have been working towards when government policies and new technologies finally slow and eventually stop the increase in CO₂.

The US administration’s plans to defund key climate monitoring systems and roll back green energy initiatives presents a global challenge.

Without these systems, it will be harder to forecast the weather and give seasonal updates. It will also be harder to forecast dangerous extreme weather events.

Scientists in the US and globally have sounded the alarm about what the closure would do to science. This is understandable. Stopping data climate collection is like breaking a thermometer because you don’t like knowing you’ve got a fever.

If the US follows through, other countries will need to carefully reconsider their commitments to gathering and sharing climate data.

Australia has a long record of direct atmospheric CO₂ measurement, which began in 1976 at the Kennaook/Cape Grim Baseline Air Pollution Station in north-west Tasmania. This and other climate observations will only become more valuable if Mauna Loa is lost.

It remains to be seen how Australia’s leaders respond to the US retreat from climate monitoring. Ideally, Australia would not only maintain but strategically expand its monitoring systems of atmosphere, land and oceans.

Correction: the original lead image on this article depicted Hawaii’s Mauna Kea Observatory, not the Mauna Loa Observatory.

Alex Sen Gupta, Associate Professor in Climate Science, UNSW Sydney; Katrin Meissner, Professor and Director of the Climate Change Research Centre, UNSW, UNSW Sydney, and Timothy H. Raupach, Scientia Senior Lecturer, UNSW Sydney

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

The Story Bridge, with its sweeping steel trusses and art deco towers, is a striking sight above the Brisbane River in Queensland. In 2025, it was named the state’s best landmark. But more than an icon, it serves as one of the vital arteries of the state capital, carrying more than 100,000 vehicles daily.

But a recent report revealed serious structural issues in the 85-year-old bridge. These included the deterioration of concrete, corrosion and overloading on pedestrian footpaths.

The findings prompted an urgent closure of the footpath for safety reasons. They also highlighted the urgency of Brisbane City Council’s planned bridge restoration project.

But this example – and far more tragic ones from around the world in recent years – have also sparked a broader conversation about the safety of ageing bridges and other urban infrastructure. A simple, proactive step known as structural health monitoring can help.

A number of collapses

In January 2022, the Fern Hollow Bridge in Pittsburgh, Pennsylvania, in the United States collapsed and injured several people. This collapse was caused by extensive corrosion and the fracturing of a vital steel component. It stemmed from poor maintenance and failure to act on repeated inspection recommendations. These problems were compounded by inadequate inspections and oversight.

Three years earlier, Taiwan’s Nanfang'ao Bridge collapsed. Exposure to damp, salty sea air had severely weakened its suspension cables. Six people beneath the bridge died.

In August 2018, Italy’s Morandi Bridge fell, killing 43 people. The collapse was due to corrosion in pre-stressed concrete and steel tendons. These factors were worsened by inspection and maintenance challenges.

In August 2007, a bridge in the US city of Minneapolis collapsed, killing 13 people and injuring 145. This collapse was primarily due to previously unnoticed problems with the design of the bridge. But it also demonstrated how ageing infrastructure, coupled with increasing loads and ineffective routine visual inspections, can exacerbate inherent weaknesses.

A technology-driven solution

Structural health monitoring is a technology-driven approach to assessing the condition of infrastructure. It can provide near real-time information and enable timely decision-making. This is crucial when it comes to managing ageing structures.

The approach doesn’t rely solely on occasional periodic inspections. Instead it uses sensors, data loggers and analytics platforms to continuously monitor stress, vibration, displacement, temperature and corrosion on critical components.

This approach can significantly improve our understanding of bridge performance compared to traditional assessment models. In one case, it updated a bridge’s estimated fatigue life – the remaining life of the structure before fatigue-induced failure is predicted to occur– from just five years to more than 52 years. This ultimately avoided unnecessary and costly restoration.

Good structural health-monitoring systems can last several decades. They can be integrated with artificial intelligence techniques and bridge information modelling to develop digital twin-based monitoring platforms.

The cost of structural health monitoring systems varies by bridge size and the extent of monitoring required. Some simple systems can cost just a few thousand dollars, while more advanced ones can cost more than A$300,000.

These systems require ongoing operational support – typically 10% to 20% of the installation cost annually – for data management, system maintenance, and informed decision-making.

Additionally, while advanced systems can be costly, scalable structural health monitoring solutions allow authorities to start small and expand over time.

A model for proactive management

The design of structural health monitoring systems has been incorporated into new large-scale bridge designs, such as Sutong Bridge in China and Governor Mario M. Cuomo Bridge in the US.

But perhaps the most compelling example of these systems in action is the Jacques Cartier Bridge in Montreal, Canada.

Opened in 1930, it shares design similarities with Brisbane’s Story Bridge. And, like many ageing structures, it faces its own challenges.

However, authorities managing the Jacques Cartier Bridge have embraced a proactive approach through comprehensive structural health monitoring systems. The bridge has been outfitted with more than 300 sensors.

Acoustic emission monitoring enables early detection of micro-cracking activity, while long-term instrumentation tracks structural deformation and dynamic behaviour across key spans.

Satellite-based radar imagery adds a remote, non-intrusive layer of deformation monitoring, and advanced data analysis ensures that the vast amounts of sensor data are translated into timely, actionable insights.

Together, these technologies demonstrate how a well-integrated structural-health monitoring system can support proactive maintenance, extend the life of ageing infrastructure – and ultimately improve public safety.

A way forward for Brisbane – and beyond

The Story Bridge’s current challenges are serious, but they also present an opportunity.

By investing in the right structural health monitoring system, Brisbane can lead the way in modern infrastructure management – protecting lives, restoring public confidence, preserving heritage and setting a precedent for cities around the world.

As climate change, urban growth, and ageing assets put increasing pressure on our transport networks, smart monitoring is no longer a luxury – it’s a necessity.

Andy Nguyen, Senior Lecturer in Structural Engineering, University of Southern Queensland

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

Have you ever gone to toss something into the recycling bin – a jam jar, a pizza box, a takeaway container encrusted with yesterday’s lunch – and wondered if you’re doing it right? Perhaps you asked yourself: should I scrub the jar with hot water? Scrape the mozzarella off the box? Wash off that palak paneer?

Research shows most Australians believe they are good recyclers. But only 25% of people separate waste correctly and up to 35% of recycling goes to landfill unnecessarily. And one in four Australians tends not to rinse or empty food containers before sending them to the bin.

The problem is not helped by different recycling practices between councils, which causes public confusion.

So just how well does recycling need to be rinsed? What should you do with your plastic lids and pizza boxes? And will robots one day work it all out for us?

The problem of contamination

Mechanical recycling methods – such as shredding and melting – struggle to operate when food and other residues are present.

In fact, one spoiled item might ruin the entire cycling batch. Queensland’s Goondiwindi Regional Council, for example, said nearly a quarter of its kerbside recyclables collected in 2022–23 was contaminated and sent to landfill.

Some councils use “advanced materials recovery” that can tolerate lightly soiled recyclables. These facilities use mechanical and automated sorting processes, including optical sorters and artificial intelligence.

But other councils still rely on human sorting, or basic mechanical systems, which require items to be relatively clean.

Be a tip-top recycler

While local recycling capabilities come into play, as a general rule, rinse containers when you can. As well as avoiding contamination, it helps reduce smells and keep bins clean.

The best pre-cleaning method for recycling depends on the type of packaging.

Paper and cardboard: these items must be clean and dry – no exceptions. Paper and cardboard absorbs contamination more than other materials. So if it gets wet or greasy, it can’t be recycled – though it may be compostable.

So for pizza boxes, for example, recycle the clean parts and bin the parts that are greasy or have food stuck to them.

Unfortunately, traditional cardboard coffee cups are not usually recyclable in Australia. That’s because the plastic lining inside is bonded tightly to the paper, making it difficult to separate during standard paper recycling.

However in some areas, programs such as Simply Cups collect coffee cups and recycle them into sustainable products such as asphalt, concrete and building products.

And in some states, such as South Australia and Western Australia, single-use cups lined with polymer are banned and only compostable cups can be used.

Glass and metals: these items are washed and processed at extremely high temperatures, so can tolerate a bit of residue. But too much residue can contaminate paper and cardboard in the bin. So rinse glass and plastic to remove visible food and empty liquids. Just a quick rinse is enough – there’s no need to scrub or use hot water.

But not all glass and metals can be recycled. Mirrors and light bulbs, for instance, are treated in such a way that they melt at different temperatures to other glass. So check before you chuck.

Plastics: rinse plastics before putting them in the recycling bin. It’s important to know that the numbers 1 to 7 on plastics, inside a recycling symbol, do not necessarily mean the item can be recycled in your area. The number is a code that identifies what plastic the item is made from. Check if your council can recycle that type of plastic.

Complicating matters further is the question of plastic lids. On this, guidelines differ across Australia, so check your local rules.

Some councils recycle plastic coffee-cup lids while others don’t.

Likewise, the rules on plastic bottle lids differ. Some councils allow bottle-lid recycling, but even then, the processes vary. In the Australian Capital Territory, for example, a lid larger than a credit card can be put in the recycling bin, but consumers are asked to remove the lid from the bottle. But Brisbane City Council asks consumers to leave the lids on.

Meanwhile, organisations such as Lids4Kids collect plastic lids and make them into new products.

The future of recycling

Recycling methods are evolving.

Advanced chemical recycling breaks plastic down into its chemical building blocks. It can process plastic types that traditional methods can’t, such as soft plastics, and turn it into valuable new products.

AI and automation are also reshaping recycling, by improving sorting and reducing contamination. And closed-loop washing systems, which filter and reuse water, can clean lightly soiled recyclables.

Other innovations are emerging, too, such as dissolvable packaging and AI-enabled “smart bins” that might one day identify and sort materials – and maybe even tell consumers if items need rinsing!

And goods can also be “upcycled” into higher value products such as “nanomaterials” or hydrogen.

But upcycling still requires clean, well-sorted streams to be viable. And until all these technologies are widespread, each of us must help keep our recycling systems working well.

Pooria Pasbakhsh, Research Fellow in Polymer Upcycling, The University of Melbourne

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

As the world looks for ways to tackle climate change, Australia has invested heavily in green hydrogen.

Green hydrogen is shaping as the best option to strip carbon emissions from some industrial processes, such as iron-making and ammonia production. But making the dream a reality in Australia is proving difficult.

Two recent announcements are a case in point. This month, the Queensland government withdrew financial support for the Central Queensland Hydrogen Hub. It came weeks after energy company Fortescue cut 90 green hydrogen jobs in Queensland and Western Australia.

I led the development of Australia’s National Hydrogen Strategy in 2019, in my previous job as a federal public servant. I also co-authored a Grattan Institute report on how hydrogen could help decarbonise the Australian economy. Here, I explain the main challenges to getting the industry off the ground.

But first, what is green hydrogen?

Hydrogen is the lightest and most abundant element in the universe. It’s usually found as a gas, or bonded to other elements.

It’s used to make products such as fertilisers, explosives and plastics. In future, it may also be a zero-emissions replacement for fossil fuels in industries such as steel and chemicals manufacturing.

Australia currently makes very low volumes of hydrogen using natural gas, which produces greenhouse gas emissions. We are well-placed to produce “green” or zero-emissions hydrogen, through a process powered by renewable energy which releases hydrogen from water.

But creating a large green hydrogen industry won’t be easy. These are the main five challenges.

1. The learning curve is steep

About 15 facilities in Australia are currently producing green hydrogen, all at low volumes – between 8 kilograms and one tonne a day (see chart below).

By contrast, most recently cancelled projects would have produced hundreds of tonnes of green hydrogen daily. The Central Queensland Hydrogen Hub, for example, would initially have produced about 200 tonnes a day, scaling up to 800 tonnes in the 2030s.

The failure of these big projects shows Australia has much to learn about planning, building, commissioning and operating large green hydrogen facilities.

2. Demand is limited

Very little hydrogen is currently used in Australia – around 500,000 tonnes a year. This is less than 1% of national energy consumption.

Most of this hydrogen is produced using natural gas, and is produced on site at existing industrial operations that require hydrogen, such as oil refiners and ammonia plants. Using hydrogen from a different source would require major – and costly – engineering changes at these facilities.

So, how do new green hydrogen producers create demand for their product?

The first option is to convince a company to spend money changing their operations to bring in green hydrogen from outside. This is not an easy prospect. The second is to find big new markets – which leads to the next challenge.

3. The chicken-and-egg problem

Renewable hydrogen isn’t a direct substitute for conventional fuels.

You can’t burn hydrogen in your gas stovetop without changing the pipes in the house and the burners on the stove. Likewise, you can’t use hydrogen as a substitute for coal when making steel without changing the smelting process.

This creates a chicken-and-egg problem. Green hydrogen proponents won’t invest in high-volume production unless there are large users to buy the product. But large users won’t invest in changing their processes unless they are assured of supply.

4. Green hydrogen is expensive

Green hydrogen is much more expensive than conventional hydrogen. And as yet, there’s little evidence buyers are willing pay more for it.

So for green hydrogen to compete with conventional production, it needs government subsidies.

The huge expense is largely due to the electricity used to make green hydrogen – prices of which are currently high.

As renewable energy expands, electricity prices in Australia are expected to fall. But building more large-scale renewable generation in Australia is itself a difficult prospect.

5. Economic and political turmoil

Recent turmoil in global markets has made companies more cautious about investing outside their core business. And global inflation has helped drive up the cost of electricity needed to produce green hydrogen.

Globally, governments have scrambled to keep national economies afloat, which has led to cuts in green hydrogen in several countries.

In Australia, green hydrogen is still key to the Albanese government’s Future Made in Australia policy. And hydrogen has been a rare area of agreement between the two major parties, at both federal and state levels.

But there are signs this is changing. The federal opposition last year fought the government’s hydrogen tax credits, and the withdrawal of support for the Central Queensland Hydrogen Hub came from the Queensland LNP government, which won office in October last year.

What next?

There is a long road ahead if green hydrogen is to help Australia reach its goal of net-zero emissions by 2050.

So what have we learned so far?

Many scrapped projects tried to implement a “hub” model – combining multiple users in one place, which was designed to make it more attractive to suppliers. But this was difficult to co-ordinate, and vulnerable to changing global conditions.

The green hydrogen industry should focus on the most promising uses for its product. For example, if it could successfully make enough green hydrogen to supply ammonia production, it could build on this to eventually support a bigger industry, such as iron-making.

It’s also time to rethink how subsidies are structured, to reflect the fact some sectors are better bets than others. At present, the federal government’s Hydrogen Headstart program and the hydrogen tax credit are agnostic as to how the hydrogen is used, which does little to help demand emerge in the right places.

Finally, political unity must be renewed. Hydrogen projects require a lot of capital, and investors get nervous when an industry does not have bipartisan support.

The hype around green hydrogen in Australia is fading. There are some reasons for hope – but success will require a lot of hard work.

Alison Reeve, Program Director, Energy and Climate Change, Grattan Institute

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

Deep-sea mining promises critical minerals for the energy transition without the problems of mining on land. It also promises to bring wealth to developing nations. But the evidence suggests these promises are false, and mining would harm the environment.

The practice involves scooping up rock-like nodules from vast areas of the sea floor. These potato-sized lumps contain metals and minerals such as zinc, manganese, molybdenum, nickel and rare earth elements.

Technology to mine the deep sea exists, but commercial mining of the deep sea is not happening anywhere in the world. That could soon change. Nations are meeting this month in Kingston, Jamaica, to agree to a mining code. Such a code would make way for mining to begin within the next few years.

On Thursday, Australia’s national science agency, CSIRO, released research into the environmental impacts of deep-sea mining. It aims to promote better environmental management of deep-sea mining, should it proceed.

We have previously challenged the rationale for deep-sea mining, drawing on our expertise in international politics and environmental management. We argue mining the deep sea is harmful and the economic benefits have been overstated. What’s more, the metals and minerals to be mined are not scarce.

The best course of action is a ban on international seabed mining, building on the coalition for a moratorium.

Managing and monitoring environmental harm

Recent advances in technology have made deep-sea mining more feasible. But removing the nodules – which also requires pumping water around – has been shown to damage the seabed and endanger marine life.

CSIRO has developed the first environmental management and monitoring frameworks to protect deep sea ecosystems from mining. It aims to provide “trusted, science-based tools to evaluate the environmental risks and viability of deep-sea mining”.

Scientists from Griffith University, Museums Victoria, the University of the Sunshine Coast, and Earth Sciences New Zealand were also involved in the work.

The Metals Company Australia, a local subsidiary of the Canadian deep-sea mining exploration company, commissioned the research. It involved analysing data from test mining the company carried out in the Pacific Ocean in 2022.

The company has led efforts to expedite deep-sea mining. This includes pushing for the mining code, and exploring commercial mining of the international seabed through approval from the US government.

In a media briefing this week, CSIRO Senior Principal Research Scientist Piers Dunstan said the mining activity substantially affected the sea floor. Some marine life, especially that attached to the nodules, had very little hope of recovery. He said if mining were to go ahead, monitoring would be crucial.

We are sceptical that ecological impacts can be managed even with this new framework. Little is known about life in these deep-water ecosystems. But research shows nodule mining would cause extensive habitat loss and damage.

Do we really need to open the ocean frontier to mining? We argue the answer is no, on three counts.

1. Minerals are not scarce

The minerals required for the energy transition are abundant on land. Known global terrestrial reserves of cobalt, copper, manganese, molybdenum and nickel are enough to meet current production levels for decades – even with growing demand.

There is no compelling reason to extract deep-sea minerals, given the economics of both deep-sea and land-based mining. Deep-sea mining is speculative and inevitably too expensive given such remote, deep operations.

Claims about mineral scarcity are being used to justify attempting to legitimise a new extractive frontier in the deep sea. Opportunistic investors can make money through speculation and attracting government subsidies.

2. Mining at sea will not replace mining on land

Proponents claim deep-sea mining can replace some mining on land. Mining on land has led to social issues including infringing on indigenous and community rights. It also damages the environment.

But deep-sea mining will not necessarily displace, replace or change mining on land. Land-based mining contracts span decades and the companies involved will not abandon ongoing or planned projects. Their activities will continue, even if deep-sea mining begins.

Deep-sea mining also faces many of the same challenges as mining on land, while introducing new problems. The social problems that arise during transport, processing and distribution remain the same.

And sea-based industries are already rife with modern slavery and labour violations, partly because they are notoriously difficult to monitor.

Deep-sea mining does not solve social problems with land-based mining, and adds more challenges.

3. Common heritage of humankind and the Global South

Under the United Nations Convention on the Law of the Sea, the international seabed is the common heritage of humankind. This means the proceeds of deep-sea mining should be distributed fairly among all countries.

Deep-sea mining commercial partnerships between developing countries in the Global South and firms from the North have yet to pay off for the former. There is little indication this pattern will change.

For example, when Canadian company Nautilus went bankrupt in 2019, it saddled Papua New Guinea with millions in debt from a failed domestic deep-sea mining venture.

The Metals Company has partnerships with Nauru and Tonga but the latest deal with the US creates uncertainty about whether their agreements will be honoured.

European investors took control of Blue Minerals Jamaica, originally a Jamaican-owned company, shortly after orchestrating its start up. Any profits would therefore go offshore.

A wise investment?

It is unclear whether deep-sea mining will ever be a good investment.

Multiple large corporate investors have pulled out of the industry, or gone bankrupt. And The Metals Company has received delisting notices from the Nasdaq stock exchange due to poor financial performance.

Given the threat of environmental harm, the evidence suggests deep-sea mining is not worth the risk.

Justin Alger, Associate Professor / Senior Lecturer in Global Environmental Politics, The University of Melbourne; D.G. Webster, Associate Professor, Environmental Studies, Dartmouth College; Jessica Green, Professor, Political Science, University of Toronto; Kate J Neville, Associate Professor of Environmental Politics, University of Toronto; Stacy D VanDeveer, Professor of Global Governance & Human Security , UMass Boston, and Susan M Park, Professor of Global Governance, University of Sydney

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

Green hydrogen is touted by some as the future – a way for Australia to slowly replace its reliance on fossil fuel exports. The energy-dense gas has the potential to reduce emissions in sectors challenging to decarbonise, such as steelmaking and fertiliser manufacturing.

The Albanese government wants it to be a massive new export industry and has laid out a pathway through its National Hydrogen Strategy.

Unfortunately, there’s a real gap between rhetoric and reality. Despite ambitious plans, no green hydrogen project has yet succeeded in Australia. The technology’s most prominent local backer, billionaire miner Twiggy Forrest, has dialled down his ambition. Globally, just 7% of announced green hydrogen projects are up and running.

Economic viability is one problem. But there’s a much larger issue flying under the radar: water. Hitting the 2050 target of 15 million to 30 million tonnes of hydrogen a year would use 7–15% of the amount Australia’s households, farms, mines and black coal power plants use annually. That’s simply not sustainable.

Splitting water

Green hydrogen uses renewable energy to power electrolyser machines, which split water molecules into hydrogen and oxygen.

On the surface, this is an appealing use of clean energy, especially during solar peak periods.

But what the government hasn’t properly accounted for is the water cost for green hydrogen. The strategy states water use is likely to be “considerable but not prohibitive”.

This is questionable. For every kilogram of hydrogen produced through electrolysis, nine litres of water are directly consumed.

That’s not all. The water needed to make hydrogen has to be extremely pure. Salt water has to be desalinated, and even fresh water needs purification. Equipment also needs cooling, which consumes even more water.

All these processes incur substantial indirect water losses, such as the water used for industrial processes and cooling. The volumes used are highly uncertain. They can be up to 20 times greater than the direct water use.

A key input value for the government’s hydrogen strategy modelling is taken from a 2015 report by the Argonne National Energy Laboratory in the United States, which assumes each kilogram of green hydrogen produced requires just over 30 litres of water.

The Australian hydrogen strategy suggests 30 litres per kilogram of hydrogen would cover “all system losses including purification processes and cooling water required”. But it’s not clear if this figure covers other uses of water in making hydrogen, such as water treatment.

How much water would this use?

According to the government’s modelling, making 15 million tonnes would require 740 billion litres of water. That would be about 7% of the 10,450 billion litres used by all of Australia’s households, farms, mines and black coal power plants.

That’s substantial. One and a half Sydney Harbours worth, every year. But it might be a major underestimate. After all, estimates on indirect water use differ widely. The government’s figures are at the very bottom of the range.

For instance, the latest research gives water consumption figures of about 66 litres per kilogram – more than twice as large. Other sources give values between 90 and 300 litres per kilogram of hydrogen – three to ten times higher.

Uncertainty in modelling is normal. But the wide research suggesting much higher water use should give rise to real concern.

If we take a middle-of-the-range figure of 95 litres per kilogram, this would mean that making 15 million tonnes of green hydrogen would use up 22% of the 10,450 billion litres used by households, farms, mines and black coal power plants annually by 2050.

If hydrogen was even thirstier at 310 litres per kilogram, that would translate to 72% of that figure.

These estimates are enormous. Even under the most optimistic scenario, the draw on Australia’s scarce freshwater resources would simply be too much. Where would this water come from? Farmers? Groundwater? Environmental flows from rivers?

As the Queensland Farmers Federation pointed out in its response to the hydrogen strategy, the figures on water use “beg the question if they are in fact sustainable”.

The Water Services Association of Australia has called for much greater attention to the water demands of green hydrogen, which it says are “often seriously underestimated”.

What about saltwater? Australia has no shortage of oceans. The problem here becomes energy and wastewater. Desalination is still very energy intensive. Converting saltwater to fresh also produces large volumes of super-salty brine, which must then be managed as waste.

Which way forward?

Does this mean green hydrogen is a non-starter? Not necessarily. Improved electrolyser technology might offer ways to slash water use, while circular economy approaches such as resource recovery from brine could also reduce losses.

But these concerns about water must be front and centre in future discussions about the shape and size of the industry in Australia.

Madoc Sheehan, Adjunct Associate Professor in Chemical Engineering, James Cook University

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

When flooding strikes, our screens fill with scenes of devastated victims, and men performing heroic dinghy rescues in swollen rivers. But another story often goes untold: how women step in, and step up, to hold their stricken communities together.

Unprecedented floods in the Northern Rivers of New South Wales in 2022 are a case in point. Our research shows female leadership was the hidden backbone of community recovery in the aftermath of the emergency. Women rose to leadership roles, filling crucial gaps left by formal disaster responses. As one woman told us:

I mean there’s some blokes around, I’ve got to give them some credit, but, yeah, I’m amazed … it was always the women saying, what do you need? What can I help with?

And long after the disaster had passed and the media had moved on, women were still there, quietly leading sustained recovery efforts from their homes, community halls and online networks.

But while the labour of men was generally supported and recognised, the complex and difficult work of women was largely overlooked.

The invisible labour of disaster recovery

The NSW Northern Rivers region is a rural area highly prone to climate disaster.

In February and March 2022, the region experienced catastrophic flooding and landslips. About 11,000 homes were inundated. Health care facilities were damaged and disrupted. Emergency services were overwhelmed and many communities were cut off, some for weeks.

In response, the community stepped up in extraordinary ways. Our research explored the particular contribution of women to this effort.

‘No one else was going to do it’

The research involved interviews with people involved in the flood response and recovery. We also examined notes from public events and transcripts from a NSW government inquiry into the floods.

We found that, despite facing immense challenges, women played an essential role in sustaining their communities during and after the crisis.

For example, they coordinated food relief, managed donation hubs, organised volunteers and provided emotional support to neighbours and strangers. As one female interviewee told us:

It was more than about food … people would just come and then we’d just hug them and they’d just cry … the food relief turned into something deeper.

Emergency-management environments are often dominated by men. As a result, female community organisers often felt excluded from formal decision-making. As one woman told us:

every face in the meeting was a white middle-aged guy with a buzz cut. And, and I was like, there is no women. There is no diversity. There was no sense of community or that whole recovery space.

One woman cited the example of a local council celebrating “men in their dinghies” who took part in a flood rescue, while failing to recognise women who collectively contributed many thousands of unpaid hours towards the recovery effort:

here we are with just simply a trillion women doing all of the childcare, all of the cooking, all of the soft labour, literally everything plus being on dinghies … and there’s just nothing for us.

Some women took unpaid leave from work to coordinate recovery activities in their communities, because, as one woman told us, “no one else was going to do it”.

Women’s roles were not limited to unskilled tasks and care work. Women also brought professional skills to the recovery effort, such as event management, IT, nursing, communications, clinical psychology, trauma healing, business management, social work and public health.

Women: there for the long term

We found while men’s involvement in disaster recovery tended to be concentrated on specific short-term rescue and response, women tended to remain active for months or even years.

For example, two years after the flooding disaster, at a gathering of grassroots community-disaster organisers, 87% of names on the contact list were female.

Some women continued to volunteer their labour, while others managed to obtain short-term funding. Whether paid or unpaid, the women experienced overwhelm and felt exhausted by the long-term effort, and some experienced vicarious trauma. However, their sense of community responsibility prevented them from stepping back.

Rethinking who we see as leaders

The research confirms women’s contributions are consistently overlooked during and after a disaster. It reflects a broader trend in Australia, where women’s labour is historically undervalued.

Women’s disaster work – coordinating volunteers, providing emotional care and advocating for their communities – was often unsupported by government and continued long after official agencies left.

Yet, these contributions remained largely invisible.

Three years after the floods, many women in the Northern Rivers are preparing for the next emergency, and women comprise the majority of community resilience groups in the region.

Women must be recognised and supported to ensure the health and wellbeing of disaster-affected communities. The health and wellbeing of these women themselves must also be paramount.

More government and private funding is vital. Where possible, philanthropic community grants should also be expanded.

The recently formed Northern Rivers Community Resilience Alliance involves 50 grassroots groups combining to provide peer support, advocate together, seek joint funding and provide training. Such networks can provide ongoing support to community organisers.

As Earth’s climate becomes more hostile and extreme weather events become more likely, there is an urgent need to support community efforts – and to rethink who we see as leaders in times of disaster. Building resilient communities starts with recognising and resourcing the people doing the work – including local women.

The authors acknowledge Emma Pittaway, Loriana Bethune and Dominica Meade who co-authored the research upon which this article is based.

Rebecca McNaught, Research Fellow, Rural and Remote Health, University of Sydney and Jo Longman, Senior Research Fellow, The University Centre for Rural Health, University of Sydney

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

Almost two-thirds of the world’s population is affected by the monsoon – the annual arrival of intense rains in areas north and south of the Equator. These drenching rains tend to arrive during each hemisphere’s summer.

The East Asian monsoon north of the equator is the best known and best studied, because it affects the largest land area and the most people. But the southern Indo-Australian monsoon is vitally important to northern Australia, Indonesia and Papua New Guinea. To date, it has been studied much less.

To help fill this gap in knowledge, we analysed deep sediment from an unusual lagoon near Darwin in northern Australia. We looked at ancient pollen and chemical isotopes (different versions of the same chemical element) to look about 150,000 years back in time and glimpse changes to the monsoon. When types of pollen change, it tells us the monsoon has changed. Drier conditions favour the emergence of grasslands, while wetter climates favour forests.

Our new research suggests as the world gets hotter, the Indo-Australian monsoon will intensify and northern Australia will get wetter. This finding is consistent with research suggesting the East Asian monsoon could weaken, threatening agriculture and nature in heavily populated countries.

The past held in a single lagoon

To examine how monsoons change over time, researchers drill sediment cores to track changes in pollen and chemical isotopes. For example, changes in hydrogen isotopes indicate changes in the intensity of the monsoon rain.

The problem is, these cores have to come from long-undisturbed lake sediments, because such places provide a continuous record of change.

To reconstruct past changes in monsoon patterns, undisturbed sediments have to be sampled carefully by extracting a thin “core” from the bottom sediments. Once researchers have this precious core, they can examine the changing proportions of pollen, chemical isotopes and other properties. The deeper you drill the core, the farther back in time you can look.

These exacting requirements are one reason the Indo-Australian monsoon is not as well understood as its northern cousin.

Fortunately, we have found one place which has kept a detailed environmental record over a long period: Girraween Lagoon on the outskirts of Darwin in the Northern Territory.

This lagoon was created after a sinkhole formed more than 200,000 years ago. It has contained permanent water ever since, and is slowly filling with sediment and pollen blown in from the surrounding landscape.

The 18-metre core from Girraween’s sediments gave us a 150,000-year record of environmental change in Australia’s northern savannahs.

Dipping into the past

If you walk around Girraween Lagoon today, you’ll see a tall and dense tree canopy with a thick grass understory in the wet season. But it hasn’t always been that way.

During the last ice age 20,000–30,000 years ago, the sea level was much lower and the polar ice caps much larger. As a result, the lagoon was more than 300 kilometres from the coast. At that time, the lagoon was surrounded by an open, grassy savannah with fewer, shorter trees.

About 115,000 years ago (and again 90,000 years ago), Australia was dotted with gigantic inland “megalakes”. At those times, the lagoon expanded into a large, shallow lake surrounded by lush monsoon forest, with almost no grass.

At times, tree cover changed radically. In fact, over one 3,000-year period, the percentage of tree pollen soared from 15% to 95%. That suggests a sweeping change from grassland to dense forest – meaning a switch from drier to wetter climate at a rate too fast to be explained by changes in Earth’s orbit.

Some of these changes are linked to the shifting distance between coastline and lagoon as well as predictable variation in how much solar energy reaches Earth.

A connection to the North Atlantic

Huge ice sheets covered large areas of the Northern Hemisphere during previous ice ages.

Remarkably, the evidence of their melting at the end of previous ice age was there in the sediment core from Girraween Lagoon.

When glacial ice melts rapidly, huge volumes of fresh water flood into the North Atlantic. These rapid pulses are known as Heinrich events. These pulses can shut down the warm Gulf Stream current up the east coast of North America. As a result, the Northern Hemisphere cools and the Southern Hemisphere warms.

Over the last 150,000 years, there have been 14 of these events. We could see evidence of them in the sediment cores. Every gush of fresh water in the Atlantic triggered higher rainfall over northern Australia because of the buildup of heat in the Southern Hemisphere as the Gulf Stream slowed.

What does this mean for the monsoon?

All this suggests the Indo-Australian monsoon will get more intense as the world gets hotter and more ice melts.

That would mean a wetter northern Australia. It could also bring more rainfall to other Australian regions, and neighbouring countries. At this stage, it’s too uncertain to predict what an intensifying monsoon would do to the southern parts of Australia.

We might already be seeing this shift. Weather records since the 1960s show northern Australia getting steadily wetter, and less rain in Australia’s southeast and southwest.

What would this mean for people? Australia’s tropical north is not densely populated, which would reduce the human impact of an intensifying monsoon.

But while our research suggests the Indo-Australian monsoon strengthens during Heinrich events, earlier research has shown the East Asian and other Northern Hemisphere monsoons will weaken. Without reliable monsoonal rains, food and water supplies for billions of people could be at risk.

Corey J. A. Bradshaw, Matthew Flinders Professor of Global Ecology and Node Leader in the ARC Centre of Excellence for Indigenous and Environmental Histories and Futures, Flinders University; Cassandra Rowe, Senior Research Fellow, ARC Centre of Excellence for Indigenous and Environmental Histories and Futures, and College of Science and Engineering, James Cook University, and Michael Bird, JCU Distinguished Professor, ARC Centre of Excellence for Indigenous and Environmental Histories and Futures, James Cook University

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

Scientists have detected pesticides in rivers, lakes and oceans worldwide. So what are these pesticides doing to the fish?

Long before pesticides reach lethal doses, they can disrupt hormones, impair brain function and change fish behaviour. Many of these behaviours are essential for healthy ecosystems.

In a new study, my colleagues and I found that pesticides affect many different behaviours in fish. Overall, the chemical pesticides make fish less sociable and interactive. They spend less time gathering in groups, become less protective of their territory, and make fewer attempts to mate.

Imagine the ocean without the vibrant schools of fish we’ve come to love – only isolated swimmers drifting about. Quietly, ecosystems begin to unravel, long before mass die-offs hit the news.

Fish are living and dying in polluted water

Australia is a major producer and user of pesticides, with more than 11,000 approved chemical products routinely used in agricultural and domestic settings. Remarkably, some of these chemicals remain approved in Australia despite being banned in other regions such as the European Union due to safety concerns.

When a tractor or plane sprays pesticides onto crops, it creates a mist of chemicals in the air to kill crop pests. After heavy rain, these chemicals can flow into roadside drains, filter through soil, and slowly move into rivers, lakes and oceans.

Fish swim in this diluted chemical mixture. They can absorb pesticides through their gills or eat contaminated prey.

At high concentrations, mass fish deaths can result, such as those repeatedly observed in the Menindee Lakes. However, doses in the wild often aren’t lethal and more subtle effects can occur. Scientists call these “sub-lethal” effects.

One commonly investigated sub-lethal effect is a change in behaviour – in other words, a change in the way a fish interacts with its surrounding environment.

Our previous research has found most experiments have looked at the impacts on fish in isolation, measuring things such as how far or how fast they swim when pesticides are present.

But fish aren’t solitary — they form groups, defend territory and find mates. These behaviours keep aquatic ecosystems stable. So this time we studied how pesticides affect these crucial social behaviours.

Pesticide exposure makes fish less social

Our study extracted and analysed data from 37 experiments conducted around the world. Together, these tested the impacts of 31 different pesticides on the social behaviour of 11 different fish species.

The evidence suggests pesticides make fish less social, and this finding is consistent across species. Courtship was the most severely impacted behaviour – the process fish use to find and attract mates. This is particularly alarming because successful courtship is essential for healthy fish populations and ecosystem stability.

Next, we found pesticides such as the herbicide glyphosate, which can disrupt brain function and hormone levels had the strongest impacts on fish social behaviours. This raises important questions about how brain function and hormones drive fish social behaviour, which could be tested by scientists in the future.

For example, scientists could test how much a change in testosterone relates to a change in territory defence. Looking at these relationships between what’s going on inside the body mechanisms and outward behaviour will help us better understand the complex impacts of pesticides.

We also identified gaps in the current studies. Most existing studies focus on a limited number of easy-to-study “model species” such as zebrafish, medaka and guppies. They also often use pesticide dosages and durations that may not reflect real-world realities.

Addressing these gaps by including a range of species and environmentally relevant dosages is crucial to understanding how pesticides affect fish in the wild.

Behaviour is a blind spot in regulation

Regulatory authorities should begin to recognise behaviour as a reliable and important indicator of pesticide safety. This can help them catch pesticide pollution early, before mass deaths occur.

Scientists play a crucial role too. By following the same methods, scientists can produce comparable results. A standardised method then provides regulators the evidence needed to confidently assess pesticide risks.

Together, regulatory authorities and scientists can find a way to use behavioural studies to help inform policy decisions. This will help to prevent mass deaths and catch pesticide impacts early on.

Leave no stone unturned in restoring our waters

Rivers, lakes, oceans and reefs are bearing the brunt of an ever-growing human footprint.

So far, much of the spotlight has focused on reducing carbon emissions and managing overfishing — and rightly so. But there’s another, quieter threat drifting beneath the surface: the chemicals we use.

Pesticides used on farms and in gardens are being detected everywhere, even iconic ecosystems such as the Great Barrier Reef. As we have shown, these pesticides can have disturbing effects even at low concentrations.

Now is the time to cut pesticide use and reduce runoff. Through switching to less toxic chemicals and introducing better regulations, we can reduce the damage. If we act with urgency, we can limit the impacts pesticides have on our planet.

Kyle Morrison, PhD Candidate in Ecology and Evolutionary Biology, UNSW Sydney

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