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The world’s hottest years over the past decade have coincided with stagnant economic productivity, rising prices and geopolitical instability.

Is this just coincidence or has the current level of climate change been one of the drivers? Climate change is often framed as a problem for the future. But how much economic damage has today’s current level of ~1.35°C of warming already caused?

To answer that question, we analysed the effects of climate change to date on the New South Wales economy. The results were released today as part of a Net Zero Commission report.

We estimate climate change has already caused median losses of around 18% (probability range 4–33%) to the NSW economy, the biggest economic jurisdiction in the country. At a median 18% loss, that translates to about A$21,300 per person on average in yearly income.

We show that it’s not local bushfires or flooding that are driving the majority of damage, but changing global weather that in turn affects our cost of living.

Imagine a world without climate change

Studies typically project the global economic damage that climate change will do by 2050 or 2100.

Some influential estimates have suggested climate damage would be fairly small. But our recent research and work by others shows the economic damage coming down the pipeline could be more than four times larger than previously thought.

Our research question for this report was different: “What would the NSW economy look like today if historical emissions of greenhouse gases had not caused climate change?”

This requires a thought experiment: imagining a past where we burn fossil fuels at the historical rate, but the additional carbon dioxide and other atmospheric gases do not cause changes to temperature or rainfall patterns.

Answering this question will allow us to understand the economic losses we have already endured from historical climate change.

How we did it

First, we collected data on historical economic growth and weather across the world over the past 70 years. We then modelled how weather changes (or shocks) impacted economic growth over this period. There is significant debate on how to do this, so we adopted a variety of approaches.

Then we had to plausibly guess at how the weather would have evolved in the past four decades without climate change. To create this hypothetical weather series, we simply removed any trend found in the weather data which we ascribe to human-caused climate change. This works because there is no evidence natural causes have contributed to the upward trend in temperatures.

Finally, we compared economic growth rates predicted by the models under the observed and under the hypothetical weather conditions. The contrast between the total economic production of the NSW economy in the two scenarios is the economic cost of historical climate change for a given year.

What we found

We estimate the median economic loss for NSW in 2024 was 18%. There is significant uncertainty in this figure, with the lower estimates around 4% and the higher around 33%.

The median loss figure of 18% translates into an average of $21,288 in losses per person in yearly income (in 2023–2024 dollar values). In other words, the model finds that if historical warming had not occurred then people living in NSW would each have $21,288 more dollars, on average, in their pockets every year. This amount is large enough to meaningfully improve the quality of life of the state’s average household.

The models suggest the primary mechanism through which this loss has occurred is the rise in the global average temperature. When people think about losses associated with climate change in NSW, they might consider how climate change exacerbated the bushfires of 2019–20, or the floods that followed. The damages they caused are, of course, real and significant.

However, the economic models suggest the majority of the damage has come from shifts in weather globally. Given the interconnectedness of modern economies through trade and global supply chains, it is reasonable to assume that climate shocks to supply chains affect the whole globe.

How we think about climate change

When pollsters ask Australian voters what issues they care about, “climate change” is often listed as one issue among many. Voters are asked to assess how important climate change is to them relative to the cost of living, public health, interest rates, secure employment, and other important things.

Presenting issues in this way reinforces a common misconception that they are independent, and that one can be prioritised over the other.

To the contrary, there is now good evidence that climate change is strongly related to economic outcomes, which in turn drive the cost of living, interest rates, investment in in health and education and the labour market.

It’s time to stop thinking of climate change as “merely” an environmental issue, which can be discarded when economic times are tough. Instead, we should recognise what it really is: a current and ongoing threat to our standard of living.

Timothy Neal, Senior lecturer in Economics and the Institute for Climate Risk and Response, UNSW Sydney and Ben Newell, Professor of Cognitive Psychology and Director of the Institute for Climate Risk and Response, UNSW Sydney

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

Picture sea ice in your mind. You probably imagine brilliant white, snow-covered floes floating on the surface of the ocean, home to penguins in the south of the globe or polar bears in the north.

But our new research shows Antarctic sea ice can turn into rafts of rotting floes (the free-floating pieces of ice) or an icy green slush when it interacts with waves in the stormiest ocean on the planet.

We now know the wave-driven processes that cause the surface of the sea ice to melt are a “missing link” in understanding what’s driving the increasing Antarctic sea ice melt each summer.

These processes can dramatically increase the rate the ice melts, with major implications for the global climate and Antarctic marine ecosystems.

Our planetary heartbeat

Each year, the sea ice that hugs the coast of Antarctica expands from 3 million square kilometres in summer to 19 million square kilometres in winter, stretching far north into the Southern Ocean. As the sun rises and the temperatures increase, it retreats again.

This remarkable seasonal change is like a heartbeat within our planet’s climate system, moderating global temperatures, driving ocean circulation and forming a unique habitat for a plethora of living organisms, all adapted to its seasonal rhythms.

The annual summer sea ice melt is particularly remarkable because it occurs over only three months. But even the most sophisticated climate models underestimate the rapid rate of sea ice retreat each summer.

How do waves melt sea ice?

Until now, the waves travelling from the ice-free ocean into the area covered in sea ice had only been studied for their role in breaking up ice floes. We knew these smaller floes were prone to melting around their sides and bottoms as the ocean was heated by the sun as summer progressed.

But this is not the full story.

We now know waves also flood over ice floes, washing away the bright snow cover that shields the underlying ice from sunlight and creating ponds of seawater on the floe surfaces.

Due to their reduced brightness, the snow-free ice and these “wave ponds” absorb substantially more solar heat than snow-covered ice, and this melts the ice from the top down. Moreover, the snow-free ice and wave ponds are oases in which algae thrive, turning the ice and ponds green and absorbing even more heat from the sun.

The waves also pulverise the floes into small fragments and slush. Under the right conditions, the combination of wave flooding, algal greening and pulverisation turns the sea ice cover into a slushy mixture, resembling a green soup.

We estimate that flooding, ponding and pulverisation can increase summer-time ice thinning by over 4 centimetres per day. Algal greening can add an additional 1 centimetre of thinning per day. These are extraordinary accelerators of ice melt, considering that most Antarctic sea ice is less than 1 metre thick at the end of winter.

Waves are also generated deep within the Antarctic sea-ice region by winds blowing over large openings in the ice cover. In this way, wave melt processes eat away at the ice cover from within, as well as from the edge throughout summer.

Feedbacks could trigger further melt

Our ice melt estimates are significant, yet they are likely underestimates. They do not account for amplifications to melting caused by so-called “positive feedbacks”.

For example, the ice darkening caused by waves removing the snow, ponding and pulverisation substantially increases the amount of sunlight absorbed by the ice. This causes additional surface and interior melting, which further reduces the ice brightness. And this causes more vertical melting, and so on, in an amplifying cycle.

We propose that this positive feedback is strengthened by algal greening that further darkens the ice, leading to further absorption of sunlight and melting.

Exactly how much these feedbacks would cause further ice melt is tricky to quantify, so we have left this as an exciting future research challenge.

Ponds at both poles

The Antarctic “wave ponds” we have observed are the seawater equivalent of “melt ponds”. These form extensively across Arctic sea ice in summer from pooling snow meltwater.

These freshwater melt ponds have been intensively studied and integrated into climate models, because of their important role in the rapid decline in the coverage and thickness of Arctic sea ice over recent decades.

Unlike melt ponds, seawater wave ponds occur year-round. Although they only occur in regions where sea ice interacts with ocean waves, this encompasses a large proportion of Antarctic sea ice over the course of a year.

The future of Antarctic sea ice

The effects of wave melt, greening and associated feedbacks are likely to intensify on sea ice around Antarctica over coming decades. Climate change is predicted to increase wind speeds and wave heights across the polar Southern Ocean.

This disruption of the annual sea ice cycle and further sea ice loss has serious consequences for global climate and marine ecosystems.

We need further observations using autonomous camera systems on icebreakers and modelling research to better understand these wave processes and their overall influence on Antarctica’s sea ice cycle.

These advances are vital to understanding the causes of recent dramatic sea-ice losses around Antarctica, and promise vital insights about the future of the icy south and our Earth system.

Luke Bennetts, Professor of Applied Mathematics, The University of Melbourne; Bonnie Light, Physicist, University of Washington; Petteri Uotila, Professor, University of Helsinki; Philip Reid, Scientist, Australian Bureau of Meteorology, and Rob Massom, Leader, Sea Ice Section, Antarctic Climate Program, Australian Antarctic Division

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

Trees take carbon dioxide from the air and turn it into wood, storing it for decades. This is why Australian authorities have made forest regeneration eligible for carbon credits.

The largest carbon farming scheme is known as human-induced regeneration. Here, land owners and managers support forests to return on once-forested land. Every tonne of carbon dioxide soaked up by regrowing trees is worth one Australian carbon credit, about A$37.50.

The scheme has around 42 million hectares of land on its books. But only a third of this area is eligible for carbon credits, as the land has to be assessed as likely to regenerate into forest under changed management.

In recent years, some projects have come under fire. Researchers have suggested there’s not enough regeneration or that regeneration would have happened anyway. But independent assessment of these claims suggest these concerns are overblown.

As someone responsible for formally reviewing almost 100 of these projects since 2023, I have visited many sites and verified the data. Overall, I found these projects were being managed well – and forests are regrowing.

How does carbon farming work?

Under the rules, the area can’t have been forested for at least a decade before the project starts. It must have a high likelihood of becoming forested and richer in carbon through regeneration.

If left alone, trees will naturally regrow unless something stops them. Grazing by livestock, feral animals and sometimes native animals is the biggest barrier.

Many regeneration projects are in semi-arid areas with limited water. If water is made freely available for livestock, it can lead to surging numbers of kangaroos, wallabies and other native animals that eat regenerating saplings. This is why one method of limiting grazing is removing artificial watering points.

Fencing is another method. Australian and international researchers have found trees and vegetation on degraded land usually regenerate better when behind fences, though not always.

Does it work?

Australian authorities define a forest as an area dominated by trees over two metres tall, with existing or potential taller trees covering 20% or more of the area.

Participants have to prove forests of local tree species exist in the surrounding area, show the land can support forest and that there are sources of seeds. They also have to show evidence the area could be considered forest 20 years or so after the project begins.

Before carbon farmers can earn credits, the evidence they supply is audited and reviewed by teams of independent experts.

As one of these experts, I have reviewed a great deal of evidence and been on site when data was collected by independent ecologists to confirm how accurate tree cover estimates are. They’re not perfect. But they are very good.

If regeneration is too slow or fails, the area can be removed from the scheme. To date, about 6% of the land considered likely to regenerate has been taken off the scheme. Put another way, that means forests are actually regrowing on 94% of the land considered likely to regenerate.

Is criticism warranted?

Prominent critics have questioned the link between stopping grazing and regenerating forest. If this critique was accurate, it would mean there was no permanent boost to forests by ending grazing.

They argue instead in favour of only giving carbon credits to projects where trees are actively planted on previously cleared land.

The problem is, planting is relatively expensive and can be limited in scope. Planting also requires great care in tree species selection and genetics.

By contrast, removing pressure and allowing forests to naturally regenerate avoids these issues. Natural regeneration can also work in areas where planting and tree management would be expensive.

The critics used national-scale maps of woody vegetation to argue tree cover on some projects was falling short.

But as other experts have pointed out, these criticisms don’t stack up. The maps and models they rely on underestimate tree cover, compared to local and precise data gathered by aircraft with high-resolution scanning lasers.

When regeneration areas are independently assessed using similar gold standard methods, almost all show clear signs of regenerating forest.

Where does this leave us?

Worldwide, there are very real and well documented problems with carbon credit schemes intended to protect or restore forests.

This is why it’s important to scrutinise Australia’s human-induced regeneration scheme and others like it. But not all criticisms are valid.

The good news is, gold standard data gathered by participants cross-checked with regular on the ground audits and reviews show the scheme is largely working.

Regeneration can be slow, even after livestock have been removed. Some heavily degraded areas may not regenerate at all. But overall, it is leading to more forests and more carbon stored.

Under Australia’s carbon credit rules, all methods of producing credits expire after ten years. As a result, the human-induced regeneration scheme closed to new participants in 2023. Policymakers are working on new nature-based solutions to store carbon and boost wildlife on privately managed land.

But for the foreseeable future, forests will quietly regrow on huge tracts of land – and their successes and failures will be tracked and measured to make sure Australia has more trees than it would have otherwise.

Cris Brack, Associate Professor, Forest Measurement and Management, Fenner School of Environment and Society, Australian National University

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

We’ve all been there: just as you’re about to fall asleep, you notice a huntsman spider on the ceiling. Or you walk into your kitchen and find a long trail of ants snaking into your pantry.

Given there are an estimated 10 quintillion individual insects alive on Earth at any one time, it’s no surprise they sometimes find their way into our homes. In fact, the average Australian shares their home with around 100 different insect and spider species.

But the reality is most of these tiny housemates won’t hurt us, and you really don’t need to kill them. In fact, many perform helpful jobs such as catching flies and mosquitoes, or tidying up crumbs.

So, what can you do instead?

Starting with spiders

Remember: many spiders in your home are harmless.

Common spider housemates include:

• huntsman spiders (Sparassidae sp)
• black and brown house spiders (Badumna sp) and
• daddy long-legs spiders (Pholcus phalangioides).

They’re big and speedy, but huntsmen are gentle giants that rarely bite and their venom can’t hurt humans. They are naturally timid animals that will usually try to avoid us big, scary humans.

Black and brown house spiders live in messy webs often on screen doors or in corners. They are sometimes mistaken for funnel-web spiders, and while their venom can cause unpleasant symptoms such as nausea and swelling, they are generally timid and rarely bite.

Daddy long-legs spiders are the source of an urban legend claiming they are the most venomous spider in Australia, but have jaws too weak to break human skin. This is false; there’s no evidence these lovely spiders have venom capable of harming a human.

There have been no confirmed deaths from a spider bite in Australia in nearly 50 years, partly due to the introduction of effective antivenom and partly because most spiders are very reluctant to bite.

In fact, you are far more likely to be killed by a dog, cow or kangaroo than by a spider.

Even redbacks are shy and non-aggressive and will often play dead rather than bite; most bites occur when the spider is accidentally squeezed, such as when moving a pot plant or putting on a shoe. Although their venom can make us unwell, no one has died from a redback bite since antivenom was introduced in 1956.

While a bite from a Sydney funnel web spider (Atrax robustus) should always be treated as a medical emergency, effective antivenom treatments mean no one has died from a funnel-web bite since 1981.

What about ants and flies?

Most ants in the house are harmless. They are likely scavenging for food, looking for water, or may even be passing through on their way to somewhere else.

Having said that, sometimes it’s hard to figure out what they’re doing. I have a trail of ants that runs up my shower wall – I have no idea what they are doing or why they are there. They’re just part of the family now.

Some people worry insects can spread disease. Yes, cockroaches, ants and flies can potentially transfer bacteria from one surface to another but this is rarely a problem in our homes since a single fly touchdown is unlikely to transfer enough bacteria to cause issues. Our homes also don’t typically have rotting food or faeces lying around where insects can touch it and spread germs elsewhere.

What should I do about them?

In many cases, you don’t have to do anything; the bug or spider in your house is likely harmless and won’t cause problems.

And growing evidence suggests at least some insects, including crickets, can experience pain or pain-like states.

While scientists still debate exactly what insects experience, it’s increasingly clear insects and spiders are far more behaviourally and neurologically complex than once assumed.

Is it really worth causing suffering to an animal that has done nothing wrong other than share your space?

Instead, consider simply capturing the animal in a container and sliding a piece of cardboard or plastic underneath before releasing it outside.

If you live with a phobia, perhaps you could ask a friend or neighbour to do it for you.

To make your home less attractive to insects and spiders, you can:

• cover food sources, including pet food
• clean up any spilled foods, crumbs or food residues
• store loose food in sealed containers to prevent pantry moths and grain beetles
• make sure your bin seals properly when closed
• ensure your windows have well-fitting fly screens.

Only if everything else fails — or if the spider or insect is genuinely dangerous, which is rare — should lethal control such as pesticides or squishing be considered.

Remember: household insecticides are not necessarily harmless. Some studies have linked insecticide exposure to a range of health concerns (particularly in children).

Learning to live with them

The minibeasts in our homes are fascinating to watch and can provide a source of entertainment and education.

Kids (and adults!) can learn a lot about nature, ecology and science from watching insects and spiders at home. In fact, keeping and observing an insect has even been used as a successful form of therapy for children.

It’s OK to be scared of insects and spiders, but perhaps we should approach it the same way we approach fear of dogs or other furry animals: not through killing but by acknowledging the fear and working towards managing it.

Tanya Latty, Associate Professor in Entomology, University of Sydney

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

It’s surprising how easy it is to see a koala every day in Australia’s major cities.

The cute, grey marsupial can be found on t-shirts, hanging off people’s bags and pencils, and decorating any decent souvenir shop. But seeing a real koala in the wild has become increasingly tricky in some parts of the country. The iconic marsupial is now listed as endangered in Queensland, New South Wales and the Australian Capital Territory.

But koalas have been in a similar situation before.

As my new study published in the journal Molecular Biology and Evolution shows, koalas experienced a population crash about 100,000 years ago. This finding rewrites our understanding of the genetic history of koalas in Australia – and overturns previous theories about what caused their decline in ancient times.

Turning to the genome

Fossil records of koalas are extremely rare. This makes it difficult to estimate how many koalas were present in the past.

Instead, genomes provide important clues about their evolutionary history. The genome acts as a historical record. It preserves genetic information from ancestral populations that can be used to determine their population size.

Previous genomic studies of koalas have estimated koalas experienced a major population decline roughly 40,000 years ago. This was shortly after the arrival of humans in Australia, suggesting this may have been a contributing factor.

Yet the impact of human arrival on Australian fauna is hotly debated. Some researchers use it to explain the widespread extinction of megafauna during this period.

My new study challenges this theory.

Pushing the timeline back 60,000 years

My colleagues and I set out to construct the first estimate of the koala mutation rate. This is simply the number of mutations that appear in each generation.

Estimating the historical population sizes that have shaped mutation patterns in the genome relies heavily on knowing how often new mutations arise. The problem is that each species has its own unique mutation rate.

To estimate the mutation rate in koalas, we sequenced the genomes of 12 koalas from three families, comprising seven parents and five offspring. This allowed us to count the number of new mutations over each generation.

The whole koala genome has about 3.4 billion sites where changes could occur. We found only 25 mutations per offspring. That’s the equivalent of searching for 25 wrong letters scattered across more than 1,000 copies of The Lord of the Rings trilogy.

We then applied this mutation rate to 457 koala genomes sampled across their entire range. This allowed us to investigate how koala populations have changed over time – including when their numbers crashed.

We found koala population declines occurred around 100,000 years ago – well before humans arrived in Australia. This effectively rules out humans as a cause of the population crash.

Although the mutation rate is a fundamental evolutionary concept, we surprisingly have very few estimates for Australian species. Our estimate is the first from Diprotodontia, the marsupial order which also includes wombats, kangaroos and possums.

Previous studies estimating historical population sizes in koalas have had to rely on mutation rate estimates from distantly related placental mammals such as humans and mice. Applying the koala mutation rate has rewritten the genetic timeline for koalas.

So, what caused the crash?

The koala population crash 100,000 years ago matches a period of intense environmental change across Australia.

The Pleistocene (2.5 million to 11,700 years ago) saw repeated glacial periods, characterised by cold and dry conditions, as well as repeated interglacial periods, characterised by warmer and wetter conditions.

As Australia became drier, the expansion of the Nullarbor Plain established a vast semi-arid shrubland across southern Australia, shrinking suitable koala habitat and separating eastern and western koala populations.

Unfortunately, the population west of the Nullarbor Plain (which was recently described as a distinct species from the modern koala) went extinct around 28,000 years ago.

Although eastern populations were restricted to a small patch of forest on the east coast, they persisted through harsh glacial conditions. Over the last 17,000 years, as conditions became warmer and wetter, they expanded and formed the five genetic groups that are now distributed along the east coast of Australia.

Given our results, we’re now curious to see if other Australian species, including the closest relatives of extinct megafauna, also experienced population declines before humans arrived.

Koalas are back to hard times

Koalas are once again experiencing population declines across Australia.

One similarity between modern and ancient declines is they are both largely driven by reductions in the amount of suitable habitat. The ancient decline was driven by global glacial cycles – an unavoidable result of Earth’s orbit.

However, recent declines have generated a similar bottleneck over a much shorter time window, due to the historical and continued removal of suitable koala habitat. This is made worse by other threats such as hunting, disease, vehicle strikes, feral dog attacks and bushfires.

Fortunately, most koala populations have only recently started losing genetic diversity, and rapid population recovery can prevent further loss and inbreeding.

Hopefully the eastern koala will persist once again.

Toby Kovacs, PhD Candidate, School of Life and Environmental Sciences, University of Sydney

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

When a whale dies, a very special natural phenomenon can come alive. The carcass might float at the surface for some time, attracting sharks and other predators. As it becomes weathered it may start to sink, falling through the water until it eventually settles on the seafloor where deep sea scavengers feast upon it.

The scientific record of “whale falls” is sparse and fragmentary. But a team of researchers, led by Xiaotong Peng from the Chinese Academy of Sciences, has discovered a vast and ancient whale necropolis in the Diamantina Zone in the southeastern Indian Ocean.

The site, described in a new paper published in Nature, dates back more than five million years and is one of the deepest known whale fall ecosystems in the world.

A whale-sized find in the middle of the ocean

During a special dive mission in February 2023 using a submersible called the Fendouzhe, the team of scientists discovered extensive whale skeletons and fossils partially buried in sediment on the seafloor.

Following the initial discovery, the team made 32 more dives to the seafloor over the next month, mapping the extent of the necropolis.

It stretched roughly 1,200 kilometres along the seafloor at depths of between 4,200 and 7,000 metres. It contained 476 whale fossils as well as five active whale falls.

These active whale falls were teeming with many strange-looking creatures, including jellyfish, brittle stars and bone-boring worms – many of which may be new to science, according to the researchers.

From the 43 fossils the team recovered, they identified five beaked-whale species, including the Andrews’ beaked whale (Mesoplodon bowdoini) and the strap-toothed whale (Mesoplodon layardii) which are known to inhabit the region, and one species of baleen whale – the sei whale (Balaenoptera borealis).

The largest find was a dead Antarctic minke whale, five metres in length, which the team identified from its distinct ear bone shape, as well as genetic analysis. The team also identified a new whale species – Pterocetus diamantinae – which is now extinct.

Isotopic dating, where scientists use the decay of radioactive isotopes, revealed that the oldest fossils from the site are about 5.3 million years old.

The high concentration of whale remains in the region raises the question of how exactly this graveyard was formed. The authors suggest the reason probably has to do with the V-shaped topography of the Diamantina Zone which funnels carcasses onto the seafloor, plus the fact that many deep-diving beaked whale species are known to inhabit this part of the ocean.

A reminder of how little we know

This work deepens our our understanding of whale falls and the incredible ecosystems they support. It also deepens our understanding of beaked whales – usually offshore species which routinely dive up to 1 kilometre and hold their breath for more than an hour.

The finding of five million-year-old fossils provide an evolutionary window into the history of beaked whales from the Pliocene epoch to the present day.

This research is also a humbling reminder of how little we know of the deep sea – and how when we look for something, we may just find it, and so much more.

Vanessa Pirotta, Postdoctoral Researcher and Wildlife Scientist, Macquarie University

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

The Australian government has launched its largest-ever lawsuit, suing American chemical giant 3M and its local subsidiary. The government is seeking A$2 billion in damages for the past and future cost of investigating and managing “forever chemicals” contamination from firefighting foams on almost 30 Defence sites.

The government alleges the company withheld internal testing that showed these foams did significant environmental damage. 3M has vowed to defend itself.

What’s interesting is the scope. State-owned facilities, such as public water utilities, are unlikely to be included. The case also avoids any mention of possible impacts on human health. This is at least in part because the impacts of forever chemicals are a live topic of scientific debate and inquiry.

What is the case based on?

Forever chemicals are properly known as PFAS, or per- and polyfluoroalkyl substances. They are also known as “forever chemicals” because they take a very long time to break down in the environment.

The Commonwealth case focuses on the use of PFAS-containing firefighting foams manufactured by 3M and used on Defence bases from the 1970s until the mid 2000s. These aqueous film-forming foams have been slowly phased out in Australia.

Several communities near affected Defence facilities have sued the Commonwealth, with class actions and other claims amounting to around $400 million in legal settlements.

Until now, the government hasn’t sought to recover these costs, but is doing so now to remediate the sites, pay out class actions and cover future remediation.

While full court documents are not yet public, multiple government statements and the court file suggest the claim is mainly based on the Australian Consumer Law.

The Commonwealth may argue 3M engaged in misleading or deceptive conduct by failing to disclose what it knew about the environmental risks of these firefighting foams.

In the United States, many state attorneys-general have sought to recover clean-up and monitoring costs from manufacturers allegedly promoting PFAS products as safe, despite knowing their risks.

How likely is a settlement?

While both sides appear to have adopted a firm public position committing to the case, this isn’t guaranteed. Large lawsuits like this frequently reach a settlement before trial.

This is because reaching a settlement allows parties to agree on compensation without a judicial finding of liability.

Australian courts encourage alternative dispute resolution, which can enable settlements and reduce costs and uncertainty, while allowing defendants to avoid formal findings of wrongdoing. Class actions against Defence have all settled before trial.

In the US, municipal governments and water authorities sued 3M and other PFAS manufacturers for selling products they knew would contaminate the environment, seeking payments to “help clean up the mess that they created”. These claims became part of a larger case.

In response, 3M agreed to pay about A$14 billion (US$10 billion) to assist with testing and treatment costs while denying liability.

Settlements have also been reached in personal injury litigation, including one against another manufacturer, DuPont, worth A$953 (US$670) million across 3,550 claims.

What’s in and what’s out of the case?

The proceedings have been framed as an effort to recover past and future costs from almost 30 Defence sites.

Yet PFAS contamination isn’t limited to these sites. Other sites of concern include state-operated firefighting facilities, industrial sites and public water supplies. This case is unlikely to directly address those locations.

It’s not clear whether any funds recovered would support measures sought by affected communities, such as routine blood testing or long-term medical monitoring. Residents of Katherine in the Northern Territory have questioned whether any potential settlement would compensate losses not covered by earlier class actions. Many civilian and military firefighters exposed to these PFAS foams for decades have not been involved in compensation schemes or major litigation.

Notably, the case doesn’t mention any possible effects on human health. Assistant Minister for Defence Peter Khalil has cited advice from health authorities that evidence of health impacts from forever chemicals remains limited.

In 2023, the cancer agency of the World Health Organization found one forever chemical, PFOA, was carcinogenic. But there are many different types of PFAS. The WHO is now conducting a systematic review of key PFAS compounds and health outcomes, such as cancer and reproductive toxicity.

The PFAS class actions against Defence similarly excluded personal injury claims, focusing instead on property, business and cultural losses. Even so, evidence about possible health effects was raised because contamination affected property values.

It will be interesting to see whether the Commonwealth can separate environmental contamination from health concerns, while maintaining its position that evidence of human health impacts remains limited.

What’s next?

If the lawsuit goes to a trial and the government succeeds in its claim, it would likely open the door to further claims against 3M by fire services, water suppliers and other affected groups.

This could also happen if the claim is settled out of court.

Regardless of the result, more legal action and advocacy is likely from communities affected by PFAS around Australia.

Cameron Holley, Professor, UNSW Law & Justice and UNSW Institute for Climate Risk & Response, UNSW Sydney and Carley Bartlett, Postdoctoral Research Associate in Law and Justice, UNSW Sydney

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

Summer heatwaves are currently receiving a lot of attention in Europe because they now cause more deaths than floods or storms.

But winters are also warming. While they are generally less deadly, they influence and disrupt human and natural systems in many subtle ways.

Aotearoa New Zealand has experienced a particularly warm start to this winter, with record high June temperatures in the capital and warm conditions across the country.

Many will welcome the unseasonably warm weather, but milder winters have a range of impacts, especially for plants and insects.

Extra winter growth, but loss of carbon

In forests, warmer temperatures can extend the growing season of trees.

Usually, many trees are dormant during winter as conditions are too cold for growth. But our ongoing measurements of kauri tree growth in Auckland indicate trees have continued to grow throughout recent winters.

One might assume a longer growing season would increase carbon uptake and storage in trees. However, overall carbon changes are actually negative because warmer temperatures also increase respiration, which returns more carbon to the atmosphere.

In Aotearoa, few plant species lose their leaves in winter. But according to traditional Māori knowledge (mātauranga Māori), flowering time has changed and fruit biomass has declined with warming in forests of the central North Island since the 1950s.

This has had a negative impact on the numbers, breeding rates and health of kererū (native wood pigeons) and has reduced nutrient cycling in the soil.

Risk of new invasions

Insects are also very sensitive to winter temperatures.

Like trees, many insects have a dormant period during colder months. Some insects from warmer climates have established as pests in Aotearoa, but they usually struggle to survive cold conditions. As winters warm, the numbers of species able to get through the cold season is increasing.

For instance, in temperate climates such as in New Zealand, wasp colonies have a strong seasonal cycle. Wasp numbers increase during spring after the queen emerges from overwintering and lays eggs. The workers expand the colony during summer but when temperatures drop in autumn, most of them die off.

However, in warmer conditions, sightings of winter-active workers have increased in Aotearoa. This means a warming climate will likely lead to higher wasp numbers and increased ecological and economic impacts.

There are a range of other invertebrate pests that may become more problematic in natural systems, plantation forests and agricultural and horticultural settings as winters warm. This includes rising numbers of parasites of sheep and cattle, more insect pests in plantation forests, increased risk of overwintering of the Queensland fruit fly and bigger range sizes for mosquitoes and ant and cattle ticks.

Shrinking alpine refuge

New invasive plant species from subtropical regions may also be able to establish or expand their ranges and shift into the alpine zone.

Similarly, the upward expansion of invasive mammals will reduce the availability of refuge areas for native birds, including the endangered rock wren.

Known as “thermal squeeze”, the movement of rats and stoats to higher elevations reduces the availability of safe spaces for large alpine birds such as the kea, exacerbating the risk of extinction.

The alpine zone is especially vulnerable to winter warming because plants and animals living there are highly adapted to the specific environmental conditions and are often poorly prepared for invasive predators or competitors.

Horticultural winners and losers

In the horticulture industry, cold winter nights are important as a trigger for spring flowering. Economically important fruits such as apples, avocados and kiwifruit may not flower well and have poor-quality fruit under future climates.

Potatoes and onions are also sensitive to warming conditions because heat stress reduces the quality of tubers and produces smaller bulbs, causing lower yields of both crops.

Plant breeding and gene technologies offer opportunities to develop fruits and vegetables that are better prepared for a warmer world.

And there is some good news in other areas, including that flea infestations are predicted to decline in regions where warming is associated with drying. There may also be opportunities for the establishment of new crops, such as bananas.

As the climate continues to warm, there is more to learn about the impacts and options for adaptation in Aotearoa. Research needs to focus on finding solutions for native species and primary industries because healthy ecosystems are essential for a healthy economy and thriving communities.

Cate Macinnis-Ng, Professor in Biological Sciences, University of Auckland, Waipapa Taumata Rau

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

Most of us think of espresso as a hot, high-pressure ritual. Finely ground coffee goes into a machine, boiling water is forced through it, and in about 30 seconds we get a concentrated shot with crema, aroma, bitterness, body and caffeine.

As someone from Colombia, I like to think coffee is in my blood – and I’m proud to come from a country known for producing some of the best coffee beans in the world.

So perhaps that’s why I have spent a lot of time in my laboratory with my team asking a simple question: does espresso really need hot water?

Our new research suggests the answer may be no.

Low energy, full strength

We have developed what we call an ultrasonic espresso: a room-temperature brewing process that uses high-frequency sound waves to extract the flavour, oils, aroma and caffeine from coffee grounds. The result is an espresso-strength coffee made in under three minutes, but needing far less energy than the conventional method.

Saving up to 75% of energy by not heating the water is a minor benefit for home users or small coffee shops. But for companies making ready-to-drink coffee products at industrial scale, it could be very significant indeed.

A concentrated room-temperature coffee could be used directly in bottled drinks, milk-based beverages or cold coffee products. It can also be shipped as a concentrate and diluted later. This would reduce not only energy use, but potentially processing time as well.

Ultrasound replaces heat

The key to the new process is ultrasound. These are sound waves above the range of human hearing.

In our system, a small metal device called a transducer presses against the side of a traditional espresso basket and makes it vibrate rapidly. Those vibrations move through the water and coffee grounds.

This creates a phenomenon known as acoustic cavitation. Tiny bubbles form and collapse in the liquid.

When these bubbles collapse near coffee particles, they produce microscopic jets and forces that act a little like scrubbing brushes. They pit and fracture the surface of the coffee grounds, helping flavour compounds, oils and caffeine move into the water much faster than they normally would at room temperature.

In other words, ultrasound helps us replace heat with mechanical energy.

Water, grind and time

This is not the same as cold brew. Cold brew is usually made by steeping coffee in cold water for 12 to 24 hours. It tends to be smooth, mellow and much less concentrated than espresso. In earlier work, we used ultrasound to speed up cold brew dramatically.

But the challenge in this project was different: could we produce something with the strength, body and intensity of espresso, without heating the water?

To do that, we adjusted several variables. Brew ratio was one of the most important: how much water we used for each gram of coffee. Too much water and the drink becomes diluted; too little and extraction becomes difficult.

Grind size also mattered. Finer grounds allowed us to extract flavour more rapidly. Finally, we tested how long the ultrasound should be applied. We found the sweet spot was about two-and-a-half to three minutes.

The taste test

Of course, making a concentrated coffee in the laboratory is one thing. The real test is whether people want to drink it.

So we ran a blind evaluation with around 100 regular coffee drinkers. They were not trained judges; they were everyday consumers who drink coffee at least once a week.

We served them four coffees in identical cups: traditional espresso, ultrasound-brewed espresso, traditional filter coffee and ultrasound-brewed filter coffee. All were freshly prepared, cooled to the same temperature and presented in random order.

For the espresso samples, participants could not reliably tell the traditional and ultrasonic versions apart. There were no significant differences in aroma, flavour, bitterness or overall liking. For filter coffee, the ultrasound version was actually preferred overall, with participants rating its bitterness more pleasantly.

Those results show espresso may not need to begin with hot water after all. By using sound waves to shake the coffee grounds, we were able to create the same richness, body and intensity, but with far less energy.

Francisco Trujillo, Senior Lecturer, School of Chemical Engineering, UNSW Sydney

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

We’re used to a lot of different natural things falling out of the sky. These can include snow, rain, and sometimes even frogs (yes, really). All of these relate to weather phenomena.

Far more exotic things fall from the sky that are not related to weather. Earth is pelted by about 14 tons of micrometeorites each day. And larger meteorite falls also happen daily, which are visible as fireballs that streak across the night sky.

When an asteroid collides with Earth, it can trigger even stranger debris. Tektites are glassy droplets that form by melting during a meteorite impact, and are then ejected hundreds to thousands of kilometres away from the impact site. The Australasian tektite field that formed some 790,000 years ago from an unknown impact and might cover 10–30% of Earth’s surface is the most famous example.

In a new study published in the journal Meteoritics and Planetary Science, we describe the discovery of a previously unknown 4km-diameter meteorite impact crater in the Eastern Goldfields of Western Australia.

A gold band points the way

The impact site is near the town of Ora Banda (Spanish for “gold band”), a historic gold mining district about 50km north of Kalgoorlie.

For now we’ve named the site the “Ora Banda impact structure”, given its proximity to the historic mining district. However, the region has a much longer history of First Nations culture, and we’re currently working with collaborators at the Goldfields Aboriginal Language Centre on establishing an Indigenous name for the site.

The impact site is interesting for a number of reasons. Ora Banda is one of the few impact craters on Earth whose target rocks – meaning, all rocks in the area affected by the impact – are ancient greenstones, which are metamorphosed volcanic rocks like basalt.

Greenstones are valuable to the economy of Australia because in some places they contain gold. The Ora Banda impact was accidentally discovered during exploration drilling for gold.

The ‘smoking gun’ evidence for impact

If you find a site you suspect might be an impact crater, the scientific process to confirm that’s indeed the case involves documenting what’s known as diagnostic evidence.

Diagnostic impact evidence – the “smoking gun” of an impact – is that which is found nowhere else. It can include either evidence of the space rock itself, or unique high-pressure shock wave damage in the target rocks.

The first evidence for impact we found at Ora Banda was shatter cones – distinctive conical features in rocks that record the passage of the shock wave. We found a few shatter cones in rubbly outcrops at the surface, and we also found some in the drill cores.

The discovery of shatter cones nailed it – we knew then this spot had to be an ancient impact site.

However, we set out to look for more evidence in order to further support our new impact hypothesis and learn more about the event. So, we went back to the cores.

Unusual rocks

The Ora Banda drill cores contained a range of different rock types. At the top was a sequence of clay-rich sediments – these washed into the crater after it formed. At the bottom were rocks that had a different story to tell: impact breccias.

Breccia is a name for any rock that’s been broken up into smaller fragments and has a matrix of smaller particles that “glue” it all together. Breccias are commonly found at impact craters, because the high-energy shock waves can cause rocks to instantly shatter.

Not surprisingly, there are different types of impact breccias, depending on what they contain.

A breccia is “monomict” if it consists of just one rock type, or “polymict” if it contains pieces of different rocks. Polymict breccias provide strong evidence of mixing, as if the rocks were thrown together in a blender. Both breccia types occur in the Ora Banda cores.

If breccia contains glassy melt particles along with other bits of rock, we call that “suevite”. The glassy bits provide key evidence for an even stranger part of the impact process.

They hint that molten material was thrown up into the sky when the meteorite smashed into Earth. While flying in the air, the molten particles turned to glass before landing back into the newly formed crater, resulting in a layer of suevite breccia.

But that’s not all. We found two additional types of microscopic “smoking gun” impact evidence in the breccia.

The first was shocked quartz grains, deformed in a way that’s unique to meteorite impacts. The second was meteorite residue in the glass. This happens because the meteorite vaporises and partly dissolves within the glassy melt particles.

With the discovery of shatter cones, shocked quartz, and extra-terrestrial meteorite residue, our hypothesis that the Ora Banda structure is an impact crater was confirmed.

Raining gold?

Glass and shocked minerals wasn’t all we found in the Ora Banda breccias. Some also contained small nuggets of gold.

This means that during the impact event, when all the shocked rock fragments and glass were thrown up into the sky, gold particles were also raining back down onto the surface, into the newly formed breccia deposits. That’s not something typically found in impact craters, and it shows how unique this geologic setting is.

With Ora Banda, and the recently discovered Ilkurlka and Miralga structures, there are now 34 confirmed meteorite impact craters across Australia. They range in age from a few thousand years old, to the 2.2 billion-year-old Yarrabubba structure.

Some, like the iconic Wolfe Creek (Kandimalal) crater, are youthful and well preserved. Most others, including Ora Banda, are older and eroded to the point that a circular crater is no longer visible.

Aaron J. Cavosie, Senior Lecturer, School of Earth and Planetary Sciences, Curtin University and Raiza R. Quintero, Assistant Professor, Department of Geology, University of Puerto Rico - Mayagüez

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

If you’ve ever stood on a Victorian beach and felt the wind from the Southern Ocean, you’ll know this is not a gentle force. Whipped up across thousands of kilometres of cold ocean, these winds are relentless and powerful.

More than that – they’re one of Australia’s most valuable untapped sources of energy. Australia has many windfarms, but all of them have been built on land.

The stronger, more reliable winds blowing over oceans now turn truly enormous turbines in nations from Denmark to China. Offshore wind would work particularly well in Victoria. The state government wants large windfarms built out at sea to replace the remaining coal plants.

But will these strong winds keep blowing as reliably under climate change? Our recent research is reassuring. Despite small drops in wind strength, the winds will remain strong and reliable over the next 30-50 years.

What’s so good about offshore wind?

Offshore wind farms produce power more reliably than onshore wind or solar. They can produce a great deal of power and require minimal land. This is why offshore wind has been seen as a good fit for Australia.

Coupled with big batteries and transmission lines, offshore wind could contribute significantly to the energy transition.

Victoria has most at stake. For decades it has relied on brown coal and gas. But its gas supplies are depleting fast and ageing coal plants in the Gippsland region will not be replaced with more coal. Instead, the state wants to tap Gippsland’s offshore wind resources, which rank among the world’s best.

Despite the interest, the offshore wind sector has been slow to start. Political and economic headwinds have led some projects to be cancelled. But the sector looks set to finally begin in August, when Victoria will host the nation’s first offshore auction with a goal of securing 2 gigawatts of capacity.

Victoria is not alone. Offshore wind zones have been declared along Australia’s entire southern and western coastline, including Victoria, South Australia, Tasmania and parts of New South Wales and Western Australia.

Will the winds stay strong?

As the climate changes, wind patterns are likely to change too.

The powerful westerly winds of the Southern Ocean are forecast to be gradually pushed closer to Antarctica. Wind speeds across southern mainland Australia could drop by up to 5% by the end of the century.

If wind speeds drop too much, it could pose a problem for offshore wind. Weaker winds would mean less electricity can be generated, potentially making projects less viable and slowing the energy transition.

An offshore windfarm commissioned today will operate for 25–30 years. That means it will still be operating mid-century, when climate change is likely to have intensified.

To find out what climate change will mean for offshore wind, we worked with climate scientists and offshore wind researchers to simulate winds 30-50 years from now using seven high-resolution regional climate models.

We projected future wind speeds at the ocean surface and offshore wind energy production across Australia’s existing offshore wind zones under two scenarios – ambitious climate action limiting global warming to around 1.8°C and continued fossil fuel dependence driving warming to roughly 3.6°C by 2100.

We validated our projections against the best available records of historical wind speeds, which date back several decades. This is because it’s not just about whether wind speeds change, but whether they will change more than the natural variability offshore wind farms can already cope with.

What we found was broadly reassuring. Yes, the winds are likely to weaken over the next 30 to 50 years. But the changes are minor, falling 0.1% to 2.6% on average. That’s within the bounds of natural variability. Unlike projections of future rainfall or temperature, our findings hold across both emissions scenarios. This suggests offshore winds will remain strong and reliable overall.

While reassuring, one area is likely to see a larger drop. Under the high emissions scenario, wind speeds are likely to fall up to 20% over winter in Western Australia’s offshore wind zones near Bunbury.

Good news for offshore wind?

It’s good news that average wind speeds across Australia’s offshore wind zones are not likely to change significantly.

Our research is not the whole story, however. We didn’t model whether extreme winds or strong swell conditions will become more likely. These events can stop windfarms from operating, damage infrastructure and shorten the window of time when turbines can be installed and maintained.

To give offshore wind developers full certainty, it will be important to study what climate change will do to these extreme events.

Alberto Meucci, Research Fellow in Oceanography, The University of Melbourne; Guisela Grossmann-Matheson, Research Fellow in Oceanography, The University of Melbourne, and Shiaohuey Chow, Associate Professor in Geotechnical Engineering, The University of Melbourne

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

Following the devastating Northern Rivers floods in New South Wales in 2022, roughly 14,000 truckloads of water-damaged materials were sent to landfill.

The flood exposed many things, including our unimaginative approach to managing waste. As immediate recovery moved into reconstruction, we saw an opportunity to manage this flood-damaged material differently.

We proposed an alternative to traditional house demolition. It was piloted on two flood-damaged houses in Lismore, using a “circular” model that could reuse materials and eliminate waste.

As well offering potential economic benefits for the local community, our report found it had considerable social and environmental value.

Why did homes get demolished?

In the aftermath of the floods, many NSW homes were significantly damaged and still lay in the path of future floods. In response, the NSW government introduced a buy-back scheme for eligible homes in flood-prone areas.

Part of this program involved demolishing homes, with the materials discarded in landfill or used for low-value recycling, such as woodchipping and burning. Yet the homes contained valuable materials, such as hardwood timbers.

Losing these homes was traumatic for the local community and an unnecessary loss of valuable resources. So the NSW Reconstruction Authority, Living Lab Northern Rivers, and the University of Technology Sydney (UTS) explored how to recover a material that is extremely difficult to source today – old growth timber.

The colonial hunger for hardwood

The first wave of European colonisation of the Northern Rivers included groups known as “cedar getters”. These timber cutters arrived in search of highly-prized rainforest hardwoods.

Much of this timber was transported to Australian cities or as far away as Europe. It was also used to construct buildings and homes for local communities.

Premium old growth timbers extracted from the area included red cedar (Toona ciliata), spotted gum (Corymbia maculata), tallowwood (Eucalyptus microcorys), rosewood (Didymocheton fraserianus) and blackbutt (Eucalyptus pilularis).

This is not your ordinary hardware-variety timber. Prized hardwood rainforest timber is dense, strong, durable and resistant to rot and insects.

The circular timber project

In early 2024, the Circular Timber project developed an alternative to traditional demolition, which offers very little opportunity for recovering materials.

The current system for demolishing homes is this: large-scale machines level structures and excavators scoop materials into dump trucks, which transport them to distant landfill. Sometimes, materials are recovered, but the vast majority are broken into small pieces, trucked away and buried.

We wanted to establish a “circular” system that reused materials and eliminated waste. This cannot be achieved by a single entity – multiple partners needed to collaborate. In this case, the local community, educators, businesses and government agencies collaborated to establish a pilot where timber from uninhabitable homes could be recovered and reused.

The local community was invited to make prototypes as proof that these premium timbers could be salvaged into new objects. Buy-in from the community was immediate – the materials in these homes represented a link to the region’s history and culture.

Two homes acquired by the government authority were deconstructed, with their recovered materials made available to local timber makers, builders, artists, architects and designers. The salvaged timber was transformed into a dining table, a community shed, and other designed objects.

How it happened

Moving from home demolition to deconstruction represented a significant challenge. There are Australian standards for demolishing a building, but no guidelines for deconstructing exist (yet).

This project developed a considered approach to dismantling the homes. Care was taken in site preparation, materials identification and disassembly to ensure as much of the timber was recovered as possible.

Although deconstructing, recovering and reusing house materials requires more time, there were significant local and global benefits. For example, salvaging timber reduces carbon emissions, significantly reduces waste sent to landfill, and has a smaller carbon footprint than using virgin timber.

There are also economic and social benefits. This was a Northern Rivers community with a long history of seeing lives turned upside down by catastrophic floods. They responded positively to retaining the physical, cultural, and historical value of the past built into these homes.

Homes hold many values

Between 2019 and 2025, there were 214,483 approvals granted nationwide for knock-down-and-rebuild applications in Australia, with the management of waste material left to the discretion of the owner and demolition contractor.

A standard Australian house can include salvageable materials such as hardwood timber, premium timbers, pressed metal ceilings or Federation red bricks.

Shifting our approach from demolition to deconstruction could open up new opportunities. Not only could it create jobs, but it could reduce the need for virgin materials and protect our environment.

This project reminds us that value should not only be assessed in economic terms but also in relation to our environment and communities. This program showed deconstructing homes can be embraced as a way to transform waste into a valuable resource.

Berto Pandolfo, Associate Professor, Product Design, University of Technology Sydney; Angelique Milojevic, Design Researcher, University of Technology Sydney, and Dan Etheridge, Director, The Living Lab Northern Rivers, Office of Pro Vice Chancellor (Research and Education Impact), Southern Cross University

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

It may seem like it’s impossible to find a car park on the street.

As a recent Grattan Institute report makes clear, Australia actually has an oversupply of parking, both on streets and in parking lots. Across five of the state capitals, most postcodes have more on-street spaces than there are registered cars.

That’s great for drivers, given most on-street parking outside the inner city is free and has no time limit. Many spaces are used by locals with a driveway or garage who find it more convenient to park on the street.

The problem is, abundant street parking comes at a cost. Streets jammed with parked cars look bad – and remove space for bikes, e-bikes and scooters.

Is it too late to change course? No.

The rise and rise of kerbside parking

If you look back at the street designs by 19th-century planning pioneers, you immediately notice something very different from today’s city streets.

Back then, there was no kerbside parking. Streets were largely shared spaces, where walkers, horse coaches, trams and early bicycles mingled. Of course, this was when motor vehicles were just emerging.

As car ownership surged in the 1920s and ‘30s, city centres began to struggle with parking shortages, double parking and endless cruising for spaces. The problem was summed up by Nebraska journalist Henry Allen Brainerd in a letter to his city newspaper:

What a pity that the builders of large business blocks could not have looked ahead at the time of building and seen the need for parking space in the larger cities of the world.

Since then, many cities around the world have heeded that advice, requiring parking spaces to be provided everywhere – along city streets, in suburbs, under apartment blocks and in parking lots.

What’s wrong with kerbside parking?

Many people see kerbside parking as a simple fact of life. But it was a choice, and it comes with real costs.

For one, parked cars look bad. A pretty street loses appeal if there are endless lines of parked cars. There’s a reason real estate ads don’t include cars. People find it stressful or boring to be in monotonous streetscapes characterised by heavy traffic and parking.

Road space is limited. Drivers are using a public road to park their private cars.

Worse still, kerbside parking makes it much harder for other types of transport to share the road. In recent years, there’s been huge growth in micromobility – think bikes, e-bikes and scooters.

But the road space available hasn’t changed much. Too often, riders are forced onto skinny bike lanes that end abruptly, or have to try and ride in the narrow space between parked cars and moving vehicles.

As micromobility booms, the pressure on scarce road space will only intensify as riders demand wider segregated paths. The only way this could happen in densely populated areas is if there was less kerbside parking.

Could we really reduce kerbside parking?

What would happen if authorities banned on-street parking? Given the oversupply of parking, most drivers would be able to park off-street, such as at shopping centres, offices and parking lots. These would need better sharing arrangements.

With road space freed up, it would be possible to make many streets much more pleasant – and include safe two-way paths for riders.

In areas where these lanes aren’t needed, the freed-up space could be used for trees and plants to help cool cities and soak up rain. Other options include EV charging stations and expanding outdoor dining, as many areas did during the COVID years.

In practice, a ban on kerbside parking couldn’t be universal. Some spaces would have to be reserved for people with disabilities, emergency services, deliveries, ride-hailing and car-sharing.

But would it be political suicide?

There’s almost always a backlash when authorities try to wind back kerbside parking.

Resistance usually comes from drivers, residents and business owners, who worry that less on-street parking will lead to more traffic, less business and even a drop in property prices.

The opposite is true. When high streets are made more friendly to bikes and other forms of micromobility, businesses generally make more money, not less, and property values can go up. People who prefer driving or have no alternative also benefit from less traffic, making it more likely they can visit the business.

Overseas examples show it can be done

In many European nations, authorities have worked to make streets less centred on cars and parking.

Established models of reducing car parking include Woonerven (living streets) and Fietsstraten (cycling streets) in the Netherlands, as well as car-free or car-lite neighbourhoods such as Vauban in Germany and Hammarby Sjöstad in Sweden. If cars are permitted at all, they are treated as guests.

Even in the car-friendly United States, there are examples such as as Culdesac Tempe near Phoenix, a car-free development without kerbside or household parking. My colleagues and I have dubbed this “Robin Hood planning” – taking from cars and giving to people.

If this is possible in the US – the land of automobility – it should be possible in Australia.

Dorina Pojani, Associate Professor in Urban Planning, The University of Queensland

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

Around 13,000 years ago, as the world was emerging from the grip of the last ice age, much of the North Atlantic region plunged back into near-glacial conditions.

Sea ice expanded across the North Atlantic, reaching as far south as the Shetland Islands. Glaciers began to regrow in the Scottish Highlands, while winter temperatures across Europe and North America plummeted. Yet off the coast of Atlantic Canada, the ocean did the opposite.

In our new study, published in the journal Nature Communications, we found evidence that waters off Nova Scotia, Canada, warmed as the Gulf Stream shifted hundreds of kilometres northward, while deep circulation also changed.

It is the first direct evidence that this vital current responded in such a way during a period of abrupt climate change that rearranged Atlantic Ocean circulation.

The finding lends support to the climate models that predict a similar northward shift in the future if the Atlantic Meridional Overturning Circulation (Amoc) weakens – a trend that has probably already begun.

Why the Gulf Stream matters

The Gulf Stream transports warm tropical waters northwards along the eastern coast of North America before turning north-east towards Europe. In doing so, it forms part of the Amoc, a vast system of ocean currents that redistributes heat, nutrients and carbon around the Atlantic Ocean. Consequently, the Amoc plays a major role in regulating the climate. In particular, the northern arm of the Gulf Stream helps keep western Europe much milder than other regions at similar latitudes.

Scientists are increasingly concerned about the future of this circulation system. As the climate warms and extra freshwater (from melting ice) enters the North Atlantic, surface waters become less dense and therefore less able to sink. Most climate models project that these changes weaken the Amoc. Observations suggest that this weakening has already begun, but it is predicted to weaken much more as the 21st century progresses. However, direct evidence showing how the system responds to such major disruptions remains relatively limited.

To answer that question, paleoceanographers like us turn to the past.

A natural experiment from the end of the last ice age

The Younger Dryas was one of the most dramatic episodes of abrupt climate change in Earth’s recent history. As the planet emerged from the last ice age, warming trends across much of the North Atlantic region abruptly reversed. European summer temperatures declined by around 4°C–8°C in less than a century, while Greenland cooled by up to 10°C within just a few decades. The effects rippled far beyond the North Atlantic, weakening monsoon systems across Africa and Asia.

To understand how the ocean responded, we analysed sediment extracted from the seabed off Nova Scotia. Microscopic fossil shells and sediment grains preserved within this marine mud can reveal what the sea would have been like at the time it formed. We then reconstructed changes in both surface and deep Atlantic circulation before, during, and after the Younger Dryas.

An unexpected warming signal

What we found surprised us. While Greenland and much of the subpolar North Atlantic cooled rapidly, waters off Atlantic Canada warmed instead, by as much as 4°C–5°C.

The most likely explanation is that the Gulf Stream migrated northwards, bringing warm subtropical waters closer to the Canadian coastline.

Previous climate-model simulations had predicted that a weakening of one of the Amoc’s deep currents could trigger exactly this response. Until now, however, there had been little direct geological evidence that it had happened before.

Our study provides real-world evidence for a process that climate models have long proposed. That matters because it shows that large reorganisations of Atlantic circulation are not just theoretical possibilities – they have happened before.

What can the past tell us about the future?

No past climate event is a perfect analogue for modern climate change. The Younger Dryas occurred under very different conditions from today. Massive ice sheets still covered much of Canada and Scandinavia, and the sea level was tens of metres lower than at present.

Nevertheless, the physical links connecting the different components of the North Atlantic circulation system are likely to be the same.

Our study does not suggest that the Amoc completely collapsed during the Younger Dryas, nor does it tell us whether such a collapse is likely in the future. Instead, it reveals a more nuanced picture in which various components of the North Atlantic circulation system changed in different ways. Rather than producing a uniform response, this reorganisation created a patchwork of warming and cooling across the North Atlantic.

Similar patterns have also emerged over the last 150 years, with a relative “warming hole” developing in the ocean south of Greenland while regions closer to the Gulf Stream have warmed more rapidly. Our findings provide real-world evidence that these contrasting patterns are closely linked to changes in ocean circulation.

Looking to the future, scientists are concerned that continued human-caused warming could trigger major changes in North Atlantic circulation, leading to shifts in ocean temperature patterns, which would disrupt weather and climate across the globe. Examining how the Atlantic behaved 13,000 years ago can help us recognise the warning signs of major changes before they happen again.

Critically, our study suggests that such reorganisations can unfold over about a century, with individual components of the circulation changing within just a few decades – within a human lifetime.

By showing how different parts of the Atlantic circulation interacted during a past episode of abrupt climate change, our findings provide an important benchmark for testing climate models. The deeper understanding we have gained into how the interconnected Atlantic system behaves will also help us with the very challenging task of developing early-warning systems for future circulation changes and potential climate tipping points.

Alice Carter-Champion, Researcher, Paleoceanography, Royal Holloway, University of London; Fangjingcheng Zhu, PhD Candidate, Paleoceanography, University of Southampton, and Jack Wharton, Postdoctoral Research Fellow in Paleoceanography, UCL

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

One argument often used to quell concerns about the rising energy and resource demand of data centres is that artificial intelligence (AI) models will need less in the future as they improve and become more efficient.

But this seemingly logical thinking is a trap, according to a new United Nations report that quantifies the environmental costs of AI.

The report estimates that by 2030, AI’s energy use could double to consume 3% of the world’s electricity, produce emissions to equal the UK and deplete more water for cooling than the annual drinking water need of the global population.

It also anticipates the use of AI will follow an economic principle known as the “Jevons paradox”, which predicts that when technological improvements increase the efficiency of a resource, it leads to a rise, rather than a fall, in the total consumption of that resource.

The paradox is named after economist William Stanley Jevons who observed this effect with the use of coal in 19th-century England. Efficiency gains did not reduce overall consumption. Instead, the lower costs resulted in expanded use and higher overall demand.

As AI models become cheaper and more attractive, the report expects this to encourage new uses and higher volumes of use, eroding and possibly erasing any savings from efficiency advances.

To avoid falling into this trap, it lays out a roadmap for responsible AI use based on guiding principles of transparency, efficiency by design, equity and justice, lifecycle responsibility, global cooperation and sustainable use.

The scale of the problem

Last year, data centres already consumed as much electricity as Saudi Arabia, which ranks as the world’s 11th largest electricity consumer.

If electricity use doubles as projected by 2030, the associated carbon footprint would require 6.7 billion trees grown over ten years to offset this demand.

Data centres would also require 9.3 trillion litres of water and land nearly ten times the size of Mexico City.

Beyond resource use, the report also underscores the structural inequity at the heart of the AI boom, with only 32 nations hosting AI-specific cloud infrastructure and 90% of that capacity located in the US and China.

It warns of a widening digital divide between nations that build and control AI systems and those that consume them, with the latter often bearing a disproportionate environmental burden caused by mineral extraction and e-waste.

Responsible AI use

Two main forces shape AI’s operational footprint: how much we use it and how we use it.

This involves all tasks AI models perform, from text and code generation to image and video. Each of these tasks requires different levels of computational effort.

The model choice also matters as each AI system performs these task with distinct energy and environmental costs.

The report argues responsible AI requires full value-chain governance, from mineral sourcing to recycling and safe disposal.

It calls for a twinning of capability and environmental stewardship – thinking about both what AI can do for us and the protection of the natural environment.

This would mean making environmental disclosures a routine part of AI development, at both the model and task level, and incorporating projected AI demand in climate and energy planning.

Responsible AI is crucial as countries are promoting and adopting AI across government and the public sector.

In Aotearoa New Zealand, the government has launched a national AI strategy and a public service AI framework.

While the framework was informed by the OECD’s values-based AI principles, including inclusive and sustainable development, there is no requirement for environmental disclosures and no regulator compiling energy use or emissions.

Likewise in Australia, improving public services is part of the national AI plan. For example, the National Film and Sound Archive of Australia has created Bowerbird, a machine learning-enabled mass audio and video transcription engine, to document material. The Department of Veteran’s Affairs has developed a proof-of-concept tool to see whether AI can help speed up the processing of claims.

Both countries take a deliberate “light touch” and principles-based regulatory approach to AI. But this approach risks overlooking the growing environmental cost of AI that can’t be solved by improving it.

The natural environment is foundational to the economy, culture and wellbeing. It should be at the centre of our thinking. It’s time to rethink the AI innovation playbook and shift focus toward a sustainable tech future.

Amanda Turnbull-McRae, Senior Lecturer in Law, University of Waikato

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

Australia’s data centre rush now rivals the mining boom. OpenAI chief executive Sam Altman last week said Australia could become a “data centre capital of the world”.

This would come at an environmental cost. Water use is a common concern. One report estimates AI centres could use billions of litres of water a year.

But what do the numbers say? Based on the value derived per megalitre, data centres look less threatening and more likely to be a highly economically productive use of water.

The bigger problems are energy and location. As a new report suggests, electricity demand from data centres could outstrip clean power from renewables and lead to new gas plants.

Before committing fully, we need granular detail on how much water and energy these centres use.

What value do we get from water?

In the 2023–24 financial year, Australian industries consumed about 17.6 million megalitres of water – about 30 times the water in Sydney Harbour.

Of this, agriculture, forestry and fishing consumed about two-thirds of the total – nearly 11.8 million ML. This water was used to produce goods valued at A$54.6 billion – roughly $4,600 for every megalitre consumed.

Compare this to “other industries”, the category covering data centres. A megalitre of water in this sector was valued at $2.3 million – 500 times more value than if used on a farm.

How much water do data centres use?

We can only make a rough estimate on water use due to a lack of clear data.

Research shows data centres need about 25ML of water per megawatt of capacity. Australia has about 300 data centres with about 1.3 gigawatts of operating capacity. Using these figures, Australia’s current data centres would use 15,000–35,000ML a year. That would be a fraction of 1% of the water used nationwide – close to a rounding error.

There are three caveats.

First, credible estimates of water use vary widely.

Second, most estimates – including this article – only count water used directly for cooling. Data centres can be remarkably frugal with this water and getting more efficient.

But data centres indirectly use substantially more in the water used to produce the electricity powering them. Coal, gas and hydro plants all need water.

Third, proposed new data centres are much, much larger than existing ones. Some are seeking between 5ML and 40ML a day.

Sydney is set for huge growth in AI data centres.

If all 41 in the pipeline or under assessment are built, they would directly use 15–20% of Sydney’s water supply within a decade.

Sydney would bear the strain on water supplies in return for an upfront economic benefit from construction and some ongoing jobs. But the economy wide $116 billion boost to GDP from AI adoption by all industries over the next ten years would be spread nationally.

It would make sense to locate data centres where water is more abundant and cheaper.

Energy is a bigger concern than water

At present, data centres use just over 2% of the electricity on the National Electricity Market.

This would almost triple to 6% within four years, according to Australian Energy Market Operator forecasts. The Clean Energy Finance Corporation estimates the figure could be 11% within a decade.

Energy use isn’t inherently bad. What matters is whether increasing demand will be met by renewables – or gas.

We need better data – on data centres

We can’t manage what we don’t measure. Data centres are a textbook example of a data gap impeding good policy.

The Australian Bureau of Statistics rolls data centres into a broader category.

This means we can’t access detailed statistics on how much water or energy data centres use. Nor how much they add to the national accounts.

The federal government has introduced new expectations on water use and efficiency for data centre operators. That’s something. But it’s not the same as a national picture that fits with existing official statistics. Only one data centre meets the new national water-efficiency rating.

Surprisingly, Australia’s National AI Plan has little focus on water and energy. State and federal water ministers have named data centres as an emerging threat to water security. A Senate inquiry is in progress.

We need to track water use better

Australia’s water accounts measure how much water every industry uses. But they don’t track how much water is lost to evaporation or value all water used. Water supply and sewerage are bundled together in even the most detailed view of the national accounts, meaning neither can be seen clearly.

So while data centres appear to be a high-value use of water, we can’t confirm it.

There are signs of change. Australia uses the international System of Environmental-Economic Accounting to track water use. This is being rewritten now, in part to address these issues. The national accounts have also begun treating damage to nature as a cost of production. Both shifts matter, no longer treating the environment as free lunch.

To finish the job, authorities will have to properly value all the water used by industries and disentangle data centre data from other industries. This would turn a noisy debate into a measurable one.

Time to keep tabs on AI

Based on the data we do have, we can say Australia’s data centre boom is neither the water villain some fear nor the cost-free miracle its promoters describe.

Instead, it looks like a high-value industry arriving at record speed which is relatively light on water use and fairly heavy on energy.

With better data in hand, the numbers – not the headlines – should decide where the next megalitre and the next megawatt should go.

Michael Vardon, Associate Professor of Environmental Accounting, Australian National University

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

New polling this week put One Nation ahead of Labor in the primary vote for the first time, as the party’s latest policy announcements signal greater political ambition.

One Nation recently unveiled its new oil and gas policy at the Australian Energy Producers Conference in Adelaide. It promises “vastly greater returns” to an electorate “rightly unhappy” with the distribution of Australia’s natural resources.

While One Nation’s gas policy is not entirely new, the party’s growing prominence means announcements will attract greater scrutiny.

So, what is the party proposing?

Embracing government intervention

The Norway-style gas proposal is One Nation’s first substantial intervention in current tax and energy policy debates. It’s a marked shift away from the social and migration issues that have long defined the party.

Norway heavily taxes its oil and gas extraction profits. It reinvests the wealth into the world’s largest sovereign fund to spent on social initiatives.

Echoing the Trump administration’s willingness to buy into resource and technology companies, One Nation’s announcement reflects a broader embrace of economic interventionism: where a government actively modifies a free-market economy.

The announcement shows a stark differentiation between One Nation and The Liberal Party on the economy. And it comes at a time when the parties have increasingly overlapped on issues like migration.

Liberal frontbencher James Paterson attacked the policy as socialist. He described it as “borrowed from Venezuela and Hugo Chávez”.

One Nation’s policy

Despite the splashy announcement, One Nation’s gas policy was not entirely new.

Hanson has pointed to a Norway-style sovereign wealth fund as a model for gas revenue policy since at least 2017. Senator Hanson has also frequently attacked parliament for being “hostage” to multinationals resource companies operating in Australia.

In announcing the policy, Senator Hanson committed One Nation to encouraging more gas and oil exploration and production. Hanson also said taxpayers should get a “fair share” on profits from Australian resources.

Key elements of the policy include replacing the current Petroleum Resource Rent Tax, which places a 40% tax on the profits related to the extraction of petroleum, gas and condensate.

Instead, One Nation would give the government the option to take a 30% stake in future drilling projects, with profits directed into a new sovereign wealth fund.

It’s not the first time this has been suggested. Back in May 2017, Hanson proposed One Nation adopt a system of royalties paid on production, saying such a scheme would raise up to $10 billion per year.

Tapping into public grievance

One Nation’s position sets it apart from both major parties.

Labor and the Coalition hold sharply differing views on energy and Net Zero.

But the two parties share common ground on one point: neither supports increased taxation measures on the gas industry, particularly amid global uncertainty caused by the US-Israel war with Iran.

With its policy, One Nation is tapping into real public grievance. Others, such as The Australia Institute, the Greens, and Independent senator David Pocock have spent years pointing out the same basic unfairness: Australia exports vast quantities of gas, companies profit enormously, and the taxpayer gets very little in return.

But the timing of One Nation’s announcement deserves closer scrutiny. It was not made to a general audience but a gathering of energy industry heavyweights. Reports suggest the announced version was softened after consultations with industry representatives.

Pushing back at the ‘green agenda’

Far-right parties have a distinctive approach to energy policy – they simultaneously cast multinationals as “elites” who take wealth from ordinary people, while advocating for gas drilling expansion themselves.

Hanson has adopted US President Donald Trump’s slogan – “drill, baby, drill” – to spruik her party’s approach to fossil fuels. And she has called on the Labor government to push their “climate change bedwetters” to the side, and expand oil and gas exploration in the interest of energy security.

One Nation blames environmental reforms for triggering an energy crisis, which it claims has cost everyday Australians. Ending net zero is, accordingly, a “massive part” of One Nation’s gas policy, which they claim will safeguard fuel security.

Hanson has described One Nation’s policy as “partnering with the oil and gas industry, rather than treating it as the enemy”.

Internal tensions

This policy debate risks exposing potential tensions between the federal and state branches of One Nation.

Efforts by the South Australian Labor government to repeal a ten-year moratorium on fracking in the south east of the state were blocked by the newly elected One Nation MPs and Liberal Opposition.

The inconsistency between the federal party’s pledge to expand gas exploration and the state branch’s efforts to block it have created headaches for their leader. Hanson distanced herself, dismissing it as a decision for the state branch.

Heading into the next election, One Nation wants contrast with the Liberals on economic interventionism, while setting itself apart from Labor, the Greens and the independents on climate and environmental policy. It is calculated decision from a party that senses its moment.

Emily Foley, Postdoctoral research fellow, Flinders University; University of Canberra; Jordan McSwiney, Senior research fellow, University of Canberra, and Kurt Sengul, Research fellow, Far-Right Communication, Macquarie University

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

When most people imagine scientists discovering new species, they probably still picture an expedition into the unknown.

A naturalist travels somewhere remote, perhaps on a wooden ship, and traipses through the jungle to encounter an animal or plant never before described by science. The intrepid explorer brings back specimens or observations to a museum, where they can be compared, named and described.

There is some truth to this stereotype. Between 1854 and 1862, scientist Alfred Russel Wallace travelled through the Malay Archipelago, discovering animals and insects unknown to Western science. This led him to the theory of evolution by natural selection, contemporaneously with Charles Darwin.

Antarctica had its own era of discovery. In 1840, scientists on a French expedition encountered what we now know as Adélie penguins. Imagine seeing penguins for the first time: strange black-and-white birds waddling over the ice, sliding on their bellies, leaping from freezing seas.

Of course, “discovery” is a loaded word. Many animals and plants described by Western science were already known to Indigenous peoples and local communities. What changed was their entry into the formal scientific naming system – the global process by which species are compared, classified and recognised.

Today, scientists are still finding new life in remote places and hidden inside the DNA of animals we thought we already knew.

We still explore unknown worlds

Scientists still discover species this way: by probing Earth’s nooks and crannies and travelling to remote places to study what lives there.

Last year, I was onboard the scientific vessel R/V Falkor (too) in Antarctica’s Weddell Sea, where one scientific team was searching for seafloor methane seeps.

These are not just geological curiosities. Methane seeps create unusual habitats that harbour strange communities of life fuelled not by sunlight, but by chemicals rising from below. Scientists have already found new microbial diversity at Antarctica’s first known active methane seep.

Not all hard-to-reach worlds are underwater. In Papua New Guinea’s Southern Fold Mountains, camera traps captured a shy, ground-dwelling bird slipping through rugged limestone forest. Scientists described it as a new species in 2025, the hooded jewel-babbler.

But there is another kind of discovery happening too.

Hidden species in familiar animals

Some species are not hidden because they live at the bottom of the sea or deep in a mountain forest. They are hiding in plain sight.

Gentoo penguins are a good example. With their bright orange bills and comic waddle, they are familiar to anyone who has visited Antarctica. To most observers, they are simply “gentoos”.

But our new research shows gentoo penguins are not one widespread species, but four. Our 2020 study first showed major genetic and physical differences between gentoo penguins from different islands.

Now, using whole genomes – the complete set of genetic instructions inside an animal – and ecological modelling, we found these penguins are not just separated by distance, but have adapted to different Southern Ocean worlds.

Learning to see in higher resolution

Discoveries like this are often called “hidden” species. They look very similar to their relatives, but if we study their DNA, body measurements, behaviour and ecology, it’s clear they are separate species.

Species discovery has always depended on the tools available. Early naturalists relied on what they could collect: feathers, skins, eggs and bones. These museum collections are like time machines and remain incredibly important.

Today, whole genomes tell us if animals have different coding. Ecological models show whether animals live in different environmental conditions. Mathematical approaches test whether groups are evolving independently.

In other words, we are learning to see biodiversity in higher resolution.

This sharper view is changing how we understand familiar animals. For a long time, giraffes were considered one species, but genetics suggests they are four. My own work on forest birds in Madagascar found a new species of Newtonia bird.

The Tapanuli orangutan is a powerful example. This Indonesian great ape from Sumatra was described as a new species in 2017, based on genomic, anatomical and behavioural evidence. It was extraordinary to recognise a new great ape in the 21st century, and sobering to realise fewer than 800 may remain.

Again and again, the message is the same. The natural world is more complex than we know. And sometimes, by the time we recognise that complexity, a species may already be in deep trouble.

Why names matter

Taxonomy – the science of naming and classifying life – can sound like an old-fashioned labelling exercise. But it’s how we map life on Earth.

Conservation laws, threatened species lists and monitoring programs usually work at the species level. If several species are mistakenly treated as one, a declining species can be hidden inside a larger group that looks secure.

As we stand at the precipice of Earth’s sixth mass extinction, this has never been more important.

Recognising hidden biodiversity does not solve conservation problems by itself. But it helps us ask better questions. Which species are increasing? Which are declining? Which have not been counted for decades?

These questions are urgent, because we are racing to understand biodiversity while climate change and habitat loss reshape life on Earth.

Even now, in an age of satellites and genome sequencing, Earth still has secrets. Not only in the most remote places, but in the first animals we learn to recognise as children: penguins, giraffes, orangutans.

The closer we look, the more life reveals itself. Our task now is to keep looking and protect the richness that was there all along.

Jane Younger, Senior Lecturer in Southern Ocean Vertebrate Ecology, Institute for Marine and Antarctic Studies, University of Tasmania

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

Everyone has a storm story – whether it’s that time you just escaped a downpour, or the hailstorm that wrote off your car. Even though hailstorms are relatively rare, they cause significant damages. Two new studies shed light on how hail might change as the world warms.

In our study, published today in Nature Climate Change, we show that hail conditions may move towards the poles with global warming and shift a bit from summer to winter. This could lead to more hailstorms in places such as northern Europe, Canada, southeastern Australia and New Zealand’s South Island.

Another new study led by Shiyi Zhang at Peking University shows that hail may also become more damaging.

Hailstorms are costly. In Australia in 2025, hail in New South Wales and Queensland caused A$1.9b in insurance claims, and in recent years severe storms have caused enormous losses globally.

Severe storm costs are increasing. Much of this increase is because people and assets are more exposed to storms as populations increase and cities expand.

But is climate change also playing a role?

How does hail form?

To get hail you need a thunderstorm, and to get a thunderstorm you need an updraught. Updraughts form when buoyant air rises in a localised area. They bring up water vapour, which condenses into clouds made of tiny water droplets.

Inside a storm those drops hit each other, and if it’s cold enough, liquid drops freeze onto ice particles, growing them into hailstones.

For hail to affect us at ground level, a strong updraught needs to keep hailstones aloft for long enough to grow, and the hailstones must then survive melting as they fall to Earth’s surface.

Wind shear, or shifts in wind with height, increases storm severity by moving falling rain and hail away from the updraught, so the updraught is not inhibited and can grow stronger.

Buoyancy and wind shear form the basic atmospheric “ingredients” required for hail.

How might climate change affect hailstorms?

Climate change is warming the atmosphere and adding moisture to it. Moisture is the fuel for storms, and a warmer atmosphere is more likely to make strong updraughts that can support larger hail.

A warmer atmosphere also melts falling hail faster, which might make hailstones shrink or melt away before they reach the ground. So, these two changes work against each other.

According to past research, the broad expectation of climate change’s impact on hail is that it will bring less frequent hail, but the hailstones will be larger when hail does happen. That’s because more melting would mean smaller hail reaches the ground less often, but stronger updraughts would enable larger hailstones.

However, these changes vary regionally, depending on variations in the delicate balance between hailstorm ingredient changes.

Global climate models generally can’t tell us about individual storms, let alone hailstones – think of a low-resolution image that only shows the broad picture but no details.

So, instead of looking at hail directly, our study examined how the ingredients for hailstorms change. Because the exact relationships between ingredients and hail risk remain unclear, we used several so-called “proxy” relationships, including one that we previously developed for Australia and the wide range of weather regimes here.

New global projections for hail frequency

We applied three proxies to outputs from eight climate models to look at a range of possible future warming scenarios.

First, the proxies and models agree that in the warming scenarios hail-prone conditions are shifting toward the poles – decreasing across mid-latitudes in the southern hemisphere, and increasing in mid-high latitudes, particularly in the northern hemisphere.

We project more frequent hail conditions in northern Europe, Canada and the northwestern US, southeastern Australia, and the South Island of New Zealand; and less frequent hail conditions in northern Australia, most of Africa, southern India and southeastern China.

Second, our results predict less frequent hail conditions in summer and more in winter. That means winter crops like wheat may see increasing risk, while risk may decrease for summer crops like maize. If climate change shifts arable regions closer to the poles, these crops may be subjected to increased hail frequency there.

Third, the different proxies don’t always agree, particularly in the tropics where some show increases and others decreases. These disagreements highlight the difficulties in estimating changes in hail environments and how that connects to whether hail happens.

Less frequent, but more damaging

What about the severity of hail when it occurs? Zhang and colleagues took a different approach to ours. They applied a model of hailstone growth and melting to climate simulations, to examine possible hail sizes and changes in potential damage they might cause.

Their new global simulations overall predict more large hailstones and fewer small ones. This result is in line with previous reasoning – a warmer atmosphere can melt smaller hailstones away but produce larger hail through stronger updraughts.

Like ours, their study shows regional differences in changes. Both studies show increasing hail risk with increased frequency and hail damage potential in the mid-high latitude northern hemisphere and southeastern South America.

In sub-tropical regions of Africa and northern South America, both studies show decreasing hail risk. In southeast US, mid-northern Africa, southern India, and northeastern Australia, we project decreasing frequency while Zhang and colleagues project increasing damage potential.

These two studies point to increasing risk from hail damage in a warming world, even though the details of where this will be experienced are still not clear. The more warming occurs, the more this risk will increase.

Quickly reducing greenhouse gas emissions is the surest way to blunt the most damaging effects of climate change.

Timothy H. Raupach, Scientia Senior Lecturer, Institute for Climate Risk and Response, UNSW Sydney and Steven Sherwood, Professor of Atmospheric Sciences, Climate Change Research Centre, UNSW Sydney

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

When you picture a cave, you probably think of an environment devoid of life. But for most caves on Earth, this couldn’t be further from the truth.

Caves are remarkably good at supporting life. Underground air temperature and humidity levels are usually consistent. For vulnerable species unable to tolerate fluctuations above ground, caves are a haven. This is why ecologists think of caves as evolutionary time capsules. They preserve troglofauna – small animals living mostly or entirely within caves – that might have otherwise died out during ancient climate change events.

Australian caves are home to many such species, ranging from blind fishes, to blind eels, and even blind wasps.

Perhaps the weirdest are cave crickets. Cave crickets are spindly, spider-like insects very different to your average backyard cricket. They can’t chirp and are flightless. Because they can’t travel long distances, all of Australia’s species are endemic – that is, they’re found nowhere else.

When the pioneering entomologist Aola Richards retired in the 1980s, it was thought Australia only harboured 23 cave cricket species and knowledge of these creatures languished. But in our recent research, we found three new species – with more to come. One was named to honour Richards, and another uses Gundungurra language in a first for Western scientific naming.

Underground room service

The long legs and antennae of cave crickets mean that some people mistake them for spiders, but these animals are harmless.

As their common name suggests, cave crickets thrive in cool, dark and humid environments such as caves.

These crickets also play a critical ecological role in cave ecosystems – by leaving them. When night falls, these savvy scavengers leave the cave entrance and venture above ground to forage for food, chomping on vegetation, other insects and whatever they can get their six legs on.

Food is in short supply in caves. This is why cave crickets are so vital – they can be prey for other species, while the nutrients they bring back and poo out act as a crucial top-up for other species, such as bats. They’re essentially cave room service.

How we found and named three new species

Despite the uniqueness of Australia’s cave crickets, research has been minimal since the late Aola Richards retired. Richards was responsible for naming almost all cave cricket species in Australia and New Zealand.

We had a hunch there were more to find which hadn’t yet been described, based on our fieldwork and observations by citizen scientists.

We worked with experienced cavers to collect crickets from the entrances of caves and abandoned mineshafts in Victoria and New South Wales.

In the lab, we examined dozens of specimens in detail. By comparing their physical characteristics with species already known to science, we were able to find three different types of cave cricket in the Speleotettix genus.

To make sure our identification was correct, we sequenced their DNA and compared it to known species. All three were distinct. Tiny differences in the base pairs of their DNA – often referred to as the building blocks of life – provide a reliable way of determining when one species is distinct from another.

Finding a name

Naming a species might sound simple. In reality, it’s a long and complicated process with important implications for conserving our native species. Without a formal name, species aren’t eligible for protection under Australia’s environmental laws - effectively rendering them invisible.

We chose the names Speleotettix aolae, S. binoomea, and S. palaga.

The first species was named to acknowledge Richards’ huge contribution to our knowledge of cave crickets. In fact, several specimens of S. aolae were collected by Richards more than 60 years ago. These museum specimens proved essential in understanding where the new species were found.

Speleotettix aolae and S. palaga were collected from caves and mineshafts in Victoria, while S. binoomea is from the World Heritage-listed Jenolan Caves and surrounding cave systems in NSW.

First Gundungurra word in a species name

The Gundungurra people are the Traditional Custodians of the Jenolan Caves.

We named the species found in these and surrounding caves Speleotettix binoomea. Binoomea means “dark places” in Gundungurra, and is used by the Gundungurra people to refer to the Jenolan Caves. To select the name, we worked with Gundungurra Elder Aunty Sharyn Halls and the Jenolan Caves Reserve Trust.

The choice of name recognises the deep cultural link between this species, the Jenolan Caves, and their Traditional Custodians.

To our knowledge, this is the first time a Gundungurra word has been used in the the Western scientific naming process.

Thousands of Australian species still without names

Australia and New Zealand are home to an estimated 225,000 species of insects.

Most of these are sorely understudied. In fact, only a third of our insect fauna has been formally named, and many are entirely unknown to science. That is, we estimate they should exist but a lack of study means they’ve never even been collected, let alone named.

Today, fewer than 30 Australian cave cricket species have been formally described. Our field collections and genetic analyses suggest the true number is at least double this amount.

The first step to protect a species is to describe it and name it. Once a species has a formal name, scientists and authorities can assess their risk of extinction and work to protect them.

Caves have long been a refuge, but this isn’t guaranteed. As the climate changes, drier, hotter conditions will intrude into caves. That could pose an existential threat to cave crickets and other cave dwellers, many of which can quickly dry out.

We hope this research will revive interest in Australia’s cave crickets and represents a crucial first step towards protecting these strange animals.

Perry G. Beasley-Hall, Postdoctoral Fellow in Entomology, Adelaide University and Brock A. Hedges, Research Affiliate in Ecology, Adelaide University

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

The most destructive wildfire season on record in Europe was in 2025, with more than one million hectares burned and tens of thousands of people displaced by fires across the continent.

For people in Ireland and Britain, the type of destructive wildfires that ravage southern Europe each summer can seem like a distant problem. But these fires are not confined to the dry Mediterranean landscapes of Spain, Portugal and Greece. In recent years, they have started to extend into regions more commonly associated with rain-soaked hills and bogs.

In 2026, this trend has continued with major wildfires breaking out across Scotland, Northern Ireland and Ireland.

As fires spread across the Highlands and Moray in Scotland this April, public warnings focused heavily on dry weather, campfires and accidental ignitions. In Northern Ireland, cautions were issued as firefighters battled several large gorse fires across the Mourne Mountains and other upland ares.

Similar warnings were issued nationally in Ireland over the Easter bank holiday weekend, when the public was urged to avoid lighting fires or bringing barbecues into the countryside. The threat of wildfires is only expected to ramp up this summer as temperatures rise further.

These are important messages. But focusing only on how fires start risks missing a slower and less visible transformation already unfolding across many upland landscapes. The real wildfire story in places like Ireland and Scotland is not just about climate or how fires start. It is also about how rural upland landscapes themselves are changing.

Changing farming styles

Recent research explores how decades of agricultural policy reform under the EU’s common agricultural policy, alongside falling farming populations and declining active land management, are reshaping vegetation patterns across Ireland’s uplands.

Historically, many upland landscapes were actively managed through livestock grazing, cutting and controlled patch burning. These practices helped maintain open landscapes and reduced the build-up of highly flammable vegetation.

But that balance has shifted. Reduced grazing pressure and changing land management practices are contributing to the expansion of highly flammable vegetation such as gorse, heather and purple moor grass.

While lower grazing pressure can bring biodiversity benefits and support natural regeneration, it can also increase the amount and proliferation of flammable vegetation across the landscape, known as fuel loads and fuel continuity. In practice, this means larger and more connected stretches of vegetation that allow fires to spread more rapidly and across greater distances.

This is especially concerning in upland areas where the average age of people working on farms is rising, and active land management is declining. Rural depopulation and labour shortages mean fewer people are available to manage what is known as commonages in Ireland and common grazing in Scotland. That means less maintenance of grazing systems and a reduction in the small, controlled vegetation burns that historically decreased wildfire risk by clearing vegetation and creating firebreaks. As one upland farmer in County Kerry recently described it to me: “It’s a bomb waiting to go off.”

Increasing flammability

Climate change is intensifying these risks. Hotter, drier conditions increase the likelihood that vegetation will dry out, increasing flammability. But climate alone does not explain why some landscapes burn more severely than others.

Wildfire risk is also shaped by what is growing on the land, how landscapes are managed, and whether fuel loads are reduced or allowed to accumulate over time. Experts responding to the recent Scottish fires also highlighted the role of vegetation build-up, prolonged dry conditions and changing land management in shaping fire behaviour, warning that historically wetter regions may face increasing wildfire risks in the future.

Similar patterns have already emerged across parts of southern Europe, where rural depopulation and land abandonment have contributed to increasingly severe wildfire regimes.

Recent research from Italy has shown abandoned land, declining grazing and reduced active land management have contributed to fuel accumulation, and to the build-up of dense, continuous vegetation – conditions associated with increasingly large and severe wildfires. While the climates and landscapes of Ireland and Scotland differ from the Mediterranean, similar long-term changes are beginning to emerge here.

This creates a difficult tension for policymakers and conservationists. Reduced grazing pressure and natural regeneration can support biodiversity recovery in upland systems. Yet these same changes may also increase wildfire risk where vegetation becomes dense, continuous and unmanaged. The challenge is therefore not choosing between farming or conservation, but finding ways to support landscapes that can sustain biodiversity, rural livelihoods and wildfire resilience together.

Wildfire risk in Ireland and Scotland can no longer be understood simply as a problem of careless ignitions or extreme weather. It runs much deeper than that. It is increasingly tied to long-term changes in how upland landscapes are farmed, governed and managed.

If future policy is serious about reducing wildfire risk, it must look beyond seasonal warnings and begin addressing the deeper forces reshaping our uplands.

Will Hayes, Postdoctoral Research Associate in Fire Governance, Royal Holloway, University of London

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

In December 2025, Indonesia quietly abandoned plans to close the Cirebon-1 coal power plant.

This was no ordinary power plant. Cirebon-1 was supposed to be the centrepiece of a US$21.4 billion (£16.5bn) international deal backed by the US, UK, Japan and the EU to help Indonesia end coal use.

Indonesia’s so-called Just Energy Transition Partnership, or Jet-P, was launched at a G20 summit in Bali in 2022. Similar deals have been struck with South Africa, Vietnam and Senegal. They are widely regarded as the most ambitious attempt at getting international climate finance to end coal use in populous, coal-dependent middle-income countries.

The UK government once touted the Jet-Ps as “a template on how to support just transition around the world”. This refers to efforts to ensure that the phase-out of fossil fuels and phase-in of low-carbon technologies is fair, inclusive and reflects the demands of workers and affected communities.

But if this approach cannot retire a single plant in Indonesia, the world’s fourth largest coal consumer, there is reason to question whether the model itself works. Our research suggests these partnerships are better understood as a cautionary tale.

Investors needed

The idea underpinning the Jet-Ps is elegant in theory: use public money from rich countries to attract private investment for renewable energy projects and closing down coal plants.

Grants from governments and low-cost loans supposedly reduce the risk enough to bring in billions more from banks and asset managers. The public money “unlocks” the private money, and together they fund an energy transition that benefits the public through cleaner air, reliable energy and reduced climate risk. Win, win.

But across all four Jet-P countries, the private money has yet to materialise at the scale envisioned. In Indonesia, as of early 2025, only around US$1.1 billion of public money had been disbursed. But the country’s plan for decarbonising electricity estimates it needs US$97 billion in investment by 2030 – a cavernous gap.

More troubling still is the lack of consolidated financial reporting for the Jet-P funds. Fifty separate funding packages within the Indonesian Jet-P, all with their own financial instruments and accounting frameworks, make it all but impossible to track how much money has been spent.

As international climate law expert Lukas Bogner has argued, this kind of finance creates complex bureaucratic layers that recipient countries must navigate.

Why investors haven’t shut coal plants

Decommissioning a coal plant is not like building a new one. It means buying out existing contracts, compensating investors for lost future profits, and renegotiating complex legal agreements.

Even then, the electricity the plant provided still needs to be replaced. This requires further investment in generation systems that may not yet exist. Investors have little appetite for any of this, and the costs fall primarily on the state.

In fact, the supposed unlocking of private investment with public money raises a perennial tendency: private capital moves where returns are highest and risks lowest.

Investors in London and New York, for example, demand high returns from middle-income economies like Indonesia, yet baulk at complex regulatory environments, state-owned electricity companies, powerful coal interests and mounting sovereign debt burdens. Public money can make some projects more attractive, but will not remove the supposed political and economic risks investors see in countries like Indonesia.

The Jet-P also means loading Indonesia with more debt. Of the US$21.4 billion now pledged, only 2.6% comes in the form of interest-free grants. Most Jet-P finance would arrive as commercially-priced loans which Indonesia must eventually repay.

In other words, Indonesia is being asked to borrow more to decommission coal assets that currently generate government revenue and employment. At the same time, it will have to purchase renewable electricity from the privatised companies that would replace them.

In the words of one of our interviewees, the Indonesian state is expected to “pay twice” – once to close the old system, and again to buy power from the new one. Trade unions in Indonesia have been blunt about what this means in practice. Under the Jet-P model, they warn electricity will no longer be treated as a public good, but as a commodity that ordinary Indonesians will pay more for.

The Jet-P model can also weaken the same state institutions needed to manage the energy transition. Countries that have managed rapid clean-energy booms, from China to Vietnam, have done so through strong state-owned enterprises, clear industrial strategies, and the ability to direct investment and discipline business.

The Jet-Ps, by contrast, are designed around a diminished role for the state and a central role for private capital. This happens through regulatory reform, the creation of new private markets, or through investor-friendly technologies.

In the case of Indonesia, this “de-risking” agenda explains the pressure to break up the national electricity company and sell off its assets – a prospect fiercely resisted by trade unions, civil society, and even wealthy groups who profit from the existing system.

A broken model?

International climate finance remains important. Rich countries must still fund energy transitions in the global south. But the Indonesian Jet-P suggests that relying on private investors to deliver coal phase-outs may be the wrong model.

Alternatives do exist, from proposals for much larger grant-based financing to the Bridgetown Initiative proposed by Barbados’s prime minister, Mia Mottley, which would use International Monetary Fund resources to support climate investment. More radical proposals call for publicly-owned, worker-led transitions. But so far, these ideas have made little progress.

Our research suggests just transitions are more likely when governments receive direct grants that help them retain the capacity to shape their own energy systems, and to support domestic industries through green industrialisation.

The failure to decommission Cirebon-1 matters beyond Indonesia. It suggests the world’s flagship model for financing the end of fossil fuels isn’t working. And the longer it takes to admit that, the harder the transition becomes – for Indonesia, and for everyone.

Freddie Daley, Research Associate, Centre for Global Political Economy, University of Sussex and Charlie Lawrie, Postdoctoral associate, University of Sussex

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

When you think of Antarctica, you might imagine a stark, other-worldly continent of endless, white ice. The only sound being the wind, punctuated by the crack of a glacier calving in the distance.

This image may have been true more than 30 years ago but is certainly not the case anymore. In January, I met online with colleagues who are working on a science project at the UK’s Rothera research station. Rothera is on the West Antarctic peninsula, one of the many front lines of climate change. It had been raining. Again. I carried out my PhD research at Rothera, spending three southern hemisphere summers there from 2004-06, and I don’t remember it ever raining properly while I was there. Certainly not for days on end. Now it’s becoming a regular occurrence.

Over the past few years, Antarctica has been experiencing more extreme warm weather, often triggered by “atmospheric rivers” of warm air from nearer the equator. These extreme environmental events are associated with anomalies in precipitation (rainfall and snow) as well as melting at the surface of the ice sheet and floating ice shelves. These changes have knock-on effects for marine ecosystems, from shifting the timing and nature of algal blooms that support food webs to the disruption of breeding cycles of zooplankton, seabirds and marine mammals.

Extreme events can be short and sharp, or – more concerningly – could result in persistent or irreversible changes to a system that is already under stress. Those distant glaciers that calved, booming into the sea could retreat so far that they form rivers, fundamentally and irreversibly changing the interaction between ice and ocean. And they are now breaking records: in March 2022, the French-Italian station at Concordia, near the South Pole, recorded temperatures of -11.5°C; cold, yes, but almost 40°C warmer than expected.

There’s a greater need than ever to understand how climate change in Antarctica will have global consequences. We urgently need more data with better coverage in order to make more robust predictions of sea-level rise and risks to natural resources, which will impact societies globally.

On the plus side, there are ongoing international efforts to bring together polar scientists over the next few years to decide how best to work together to help protect Antarctica.

However, as a new paper published by my colleagues and I in Nature Communications Earth & Environment discusses, the increasing frequency and severity of extreme weather makes Antarctic research more important but also more challenging.

The impact of extreme environmental events in Antarctica is leading to severe consequences for those who are trying to carry out and support the scientific studies we need. It’s only going to get harder to transport people and equipment to Antarctica, as warming and surface melt cause airstrips to collapse or subside, and shifting ice dynamics will play havoc with shipping routes.

Research stations will also increasingly suffer from subsidence, putting both peoples lives and laboratories at risk.

Remote stations and camps out on the ice sheet will be challenging and potentially dangerous to access, because rainfall and melting ice will get harder to predict. Access issues will affect the health and safety of Antarctic scientists, as medical evacuations will take longer. Extreme weather will add pressure to the wellbeing and mental health of scientists and support staff.

Looking to the future

Where will this leave us in the scientific research community? One fortunate and timely aspect is that emerging technologies will be able to support research into the future. We have new autonomous systems such as gliders, floats and submarines that operate underwater, plus uncrewed aerial vehicles and drones on the surface of the ocean and in the air.

These robots are not only safer in uncertain and changing conditions but also lower carbon, because they are light and can run on batteries. They can provide us with the measurements and samples needed for us to address key scientific questions ahead of us.

We are also experiencing a revolution in how we combine together our observations, large-scale information from satellites, and models. Near real-time models of the ocean, called digital twins, allow us to upscale observations to the global scale as well as support more efficient field observations.

Antarctica remains a fundamental component of Earth’s system. Scientists need to work together internationally to unlock its secrets to understand how and when it will change in the future.

Katharine Hendry, Honorary Associate Professor, School of Earth Sciences, University of Bristol; British Antarctic Survey

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

After another spell of wet weather along Australia’s east coast, with storms, heavy rain and flash flooding across Sydney and parts of New South Wales, it is natural to ask whether our cities are shaping the rainfall that descends upon them.

This matters because most people now live in cities. If urbanisation changes rainfall, even slightly, the effects can reach large populations through flooding, stormwater design, water supply and infrastructure planning.

Satellite data have consistently shown that many cities experience more rain events than the countryside around them. The usual explanation is that cities themselves are involved: urban heat, rougher surfaces, aerosols and changed land cover can all affect how storms develop and where rain falls.

Our new study, published in Environmental Research Letters, asks a related question: how much of this data reflects real changes in rainfall, and how much depends on how we observe it?

Why we need satellites

Understanding rainfall over cities is hard.

Rain gauges accurately measure rainfall at a specific location, but are irregularly distributed and cannot fully capture how rain varies across a large city. Climate models can simulate urban weather in detail, but kilometre-scale simulations across many cities and decades remain computationally expensive.

Satellite observations help fill this gap.

NASA’s Integrated Multi satellite Retrievals for GPM, known as IMERG, provides near-global rainfall estimates at high resolution, and is now widely used for studying rainfall over cities.

What the satellite data shows

We examined IMERG rainfall data across 15 of the world’s largest cities, including Sydney and Melbourne. The cities span different climates and geographic settings, including both coastal and inland regions.

A clear pattern emerged. Rain events occurred more often over urban areas than over nearby rural ones. The strongest signal was not that every storm became stronger, but that satellites counted more hours in which it was raining over cities. Individual events over urban centres often dropped less water than those in surrounding areas.

In other words, the main urban signal in IMERG is more frequent rain, not heavier rain.

Different sensors, different stories

Modern satellite rainfall data combines both infrared and microwave observations.

Infrared sensors estimate rainfall indirectly from the temperature at the top of clouds. They provide broad coverage, but can miss light, shallow or warm rain because these can occur even when the tops of the clouds are not very cold.

Microwave satellites fly in low orbit and detect signals more directly linked to raindrops and ice inside clouds, making them particularly useful for identifying whether rain is actually occurring.

When we separated the IMERG data by observation type, the urban signal mainly came from microwave observations, while infrared estimates showed no urban pattern.

This does not mean the microwave signal is wrong, but it raises a potential problem for long-term studies: microwave observations have changed over time. New satellites have been launched and older ones retired, and across the cities we studied, microwave sampling frequency happened almost twice as often by 2023 as it had in 2001.

This matters because the more often a microwave sensor passes overhead, the more rain events it can detect. A light shower missed in 2002 could now be caught by one of several satellites passing within the hour.

Testing the artefact

To test whether this changing sampling affects observed rainfall trends, we compared the microwave and non-microwave with long-term averages. This meant we could separate out the result of changing satellite sampling from the actual changes in weather.

Changes in microwave sampling explained up to about 20% of the long-term rainfall trends across the 15 cities. For rainfall frequency, cities such as Lagos, London, Melbourne, Beijing, Berlin, Mexico City and Paris showed areas where more than 40% of the apparent trend could be linked to the changing observing system.

The satellites did not create the whole urban rainfall pattern. After accounting for sampling effects, the urban signal remained, but the long-term trend became smaller. So we think it really is raining more often over cities, but perhaps not as much as we thought.

Moving forward

For Sydney, we also compared IMERG with CMORPH, another satellite product, and with Bureau of Meteorology rain gauges. CMORPH showed a similar urban pattern, though the two products are not fully independent because they use overlapping microwave observations.

The gauges are a more independent check, but with too few stations outside the urban core, in Sydney and most cities, the true magnitude cannot yet be confirmed on the ground.

Satellite rainfall data is now used everywhere, in climate science, flood risk, agriculture, insurance and water planning. In many regions it is the only consistent rainfall record over large areas. Our results are a caution: part of an apparent trend can come from the changing observing system rather than real change.

As for why cities get more frequent rain, the likeliest explanations are familiar: urban heat that lifts air, rougher surfaces that nudge winds upward, and aerosols that alter cloud droplets. The signal is real. The task now is measuring it properly.

Shankar Sharma, PhD student, Climate Change Research Centre, UNSW Sydney; Andy Pitman, Director of the ARC Centre of Excellence for Climate Extremes, UNSW Sydney, and Jason Evans, Professor, Climate Change Research Centre, UNSW Sydney

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

Cities around the world are planting more trees to cope with rising urban heat. But our research shows trees alone are often not enough. In some cases, the wrong kind of greening can even make streets feel less comfortable on a hot day.

We compared field measurements from Melbourne, Munich and Hong Kong to test how different kinds of urban planting changed the heat people experience outdoors.

The results showed layered vegetation – where trees are combined with shrubs and ground cover – often cooled cities more effectively than trees alone. We also found local climate and street design strongly shaped whether greening worked well.

These findings matter because urban greening is no longer just about aesthetics. As cities spend billions adapting to extreme heat, planting design may matter as much as planting quantity.

Cities are getting hotter

Cities trap heat. Roads, buildings and asphalt absorb solar energy during the day and slowly release it back into the air, especially at night.

This “urban heat island” effect, combined with climate change, is making heatwaves more intense and more dangerous in our cities.

Trees are one of the most popular responses because they provide shade and reduce the amount of heat absorbed by surrounding surfaces. But outdoor comfort depends on more than air temperature alone.

People experience heat through sunlight, reflected heat, humidity and airflow. A shaded street can still feel uncomfortable if humidity is high or if wind cannot move through the space.

That is why a “one-size fits all” greening strategy can fail. A planting design that works well in Melbourne may behave very differently in Hong Kong or Munich.

What we found

To better understand how urban vegetation affects heat stress, we did field measurements in three cities with different climates: temperate Melbourne, cooler Munich and humid subtropical Hong Kong.

Rather than relying only on computer models, we measured real conditions in streets and green spaces during summer.

We compared open urban spaces (with no plantings), sites with trees only, and layered planting (which means trees, shrubs and ground cover together).

Importantly, we did not just measure air temperature. We also measured “mean radiant temperature”, which captures the heat radiating from roads, walls and other surfaces onto the human body.

In Melbourne, street trees reduced radiant heat absorbed by pedestrians by more than 18°C, compared with open streets. Even where air temperatures changed only slightly, shaded streets felt substantially cooler.

Munich showed the strongest benefits from layered planting. There, streets and green spaces containing trees, shrubs and ground cover reduced afternoon heat stress by almost 8°C compared with more open spaces.

Hong Kong also benefited from vegetation, especially through shade created by overlapping tree canopies. But the results there were more mixed because the humid climate changed how cooling worked (more on that later).

Across all three cities, one finding stood out: vegetation structure matters.

Combining trees with shrubs and ground cover often performed better than trees alone, but the benefits depended on how the planting interacted with the local environment.

Why some greening can fail

The study showed that more vegetation is not automatically better.

In Hong Kong, dense vegetation sometimes increased humidity enough to reduce some of the cooling benefit. Plants release water vapour into the air through transpiration, which can help to cool dry climates. But in already humid cities, extra moisture can make outdoor spaces feel sticky and uncomfortable because sweat evaporates less efficiently.

In some Munich streets, dense vegetation reduced airflow through narrow urban corridors, trapping warm air and slowing the movement of vehicle pollution away from pedestrians.

These findings highlight why cities cannot rely on generic canopy targets copied from elsewhere. Climate, street width and airflow all shape whether vegetation improves comfort or creates unintended side effects.

Designing cooler cities

The solution is not to stop planting trees. It is to design urban greening more carefully.

Cities need planting strategies tailored to local conditions rather than universal greening formulas. In parks and open green spaces, layered vegetation can provide strong cooling while also supporting biodiversity. In dense streets, planners may need to balance shade with ventilation.

The findings also suggest cities should move beyond measuring success through tree numbers alone. The arrangement, density and type of vegetation matter just as much as canopy cover.

Designing for local conditions

Our research shows urban vegetation can reduce heat stress, but the benefits depend on how and where cities plant it.

Melbourne demonstrated the strong cooling effect of street trees on radiant heat, Munich showed the added value of layered vegetation, and Hong Kong revealed how dense planting can sometimes backfire in humid conditions.

Cities need climate-smart green spaces designed for local conditions, airflow and human comfort to remain liveable as temperatures rise.

Mohammad A Rahman, Senior Lecturer in Urban Horticulture, The University of Melbourne

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

Climate change is exacerbating rainfall, flooding and sea-level rises in coastal and low lying areas. During the past few years, disastrous floods have swept through Lismore in New South Wales, Northern Queensland, and the Great Ocean Road in Victoria. Large waves have pounded beaches, causing erosion in Byron Bay and Wamberal Beach in NSW and Lancelin, Western Australia.

With climate change likely to accelerate extreme weather in Australia, planned or managed retreat – moving people and infrastructure away from these areas – will grow only more important.

But planned retreat often provokes intense backlash from Australian communities on the front line of climate change. Councils and state governments are generally reticent to have this conversation with communities.

My research, published earlier this year, shows why planned retreat can become emotional – and divisive and how planners and communities can tackle it.

The take-home message? Talking to people from both sides of the debate can help a lot.

What does planned retreat involve?

Planned or managed retreat can involve relocation of people, houses and infrastructure. It can also mean restricting development in risky areas.

A successful example of relocation occurred after an “inland tsunami” flash flood destroyed homes and lives in Grantham, Queensland, in 2011. After the disaster, the town was moved out of harm’s way in a collaboration between state, local governments and communities.

However, planned retreat often provokes fear and anger – especially among residents in vulnerable areas – over the effect on private property.

There was community backlash in the NSW Lake Macquarie City Council area in 2012, when the council included “retreat” among a suite of options it was considering to manage rising seas and flooding in low lying areas.

Fearful and angry property owners voiced concern this would drive down property prices and drive up insurance.

Another example involved a recent draft plan by the Commonwealth and Western Australian governments, which included eventual relocation for residents of Home Island and West Island in the remote Cocos Keeling Islands, about 2,750 kilometres northwest of Perth.

Residents of this low-lying island community were angry at what they saw as a threat to their culture and human rights.

Similarly, Torres Strait Islanders find being forced to abandon their home a painful injustice.

Community frustration

If communities want to relocate out of harm’s way, they need somewhere to live.

After catastrophic flooding in the NSW town of Lismore in 2022, thousands of people were left homeless. Over 1,700 homes were damaged.

Two years after the flood, the NSW state government purchased 497 damaged properties in Lismore, as part of an effort to move residents from these areas.

But many in the community expressed frustration with the slow pace of the process, and lack of affordable housing in the region.

If retreat becomes a taboo topic, planners and residents have limited options.

Residents of Lancelin, Western Australia, have lost coastal walkways due to erosion, which has also threatened a popular hotel.

Yet more than 900 people signed a petition against planned retreat.

In NSW’s Wamberal Beach, retreat has become so politically unpalatable, state and local governments agreed to progress designs for a multi-million dollar seawall to protect waterfront properties from erosion. (It is yet to be built.)

Lessons from research

My research looked at planned retreat in the context of climate change.

In 2019, after the NSW Central Coast Council proposed retreat in coastal areas (in areas such Gosford and Woy Woy) for public consultation, I interviewed residents; climate, environmental and property activists; and council and state adaptation planners.

I found similar resistance to planned retreat from homeowners, property investors, real estate agents and residents.

Many people were worried a planned retreat would make insurance more expensive and drive down property values. They also feared planned retreat would threaten the entire existence of their community.

However, climate activists were afraid people would be stuck with properties they could no longer live in. One person joked about being able to go fishing from his lounge room by 2050. These people wanted a public discussion about planned retreat.

Groups on both sides expressed fear and outrage to get their point across. Faced with hostility, the council became reticent to talk to the community.

Not surprisingly, the discussion about planned retreat soon collapsed.

Talking to warring factions

Once the shouting dies down, my research shows both sides of the debate share common views.

People told me the community should talk about what was fair, and the pros and cons of buybacks and relocation.

Overall, during interviews they voiced hope for collaboration, belonging and survival.

This can help provide a road map for planned retreat in Australia. My research shows we need to:

• air grievances

• find areas of agreement between warring factions

• allow affected people and planners to debate what’s fair for individuals and communities

• acknowledge emotions are part of the process.

For decades, researchers have argued climate change adaptation is a collaborative and community-driven project.

However, recent cases suggest that planned retreat is becoming a divisive issue affecting vulnerable residents. Even the Australian government’s recent National Climate Risk Assessment acknowledged the growing risk sea level rises pose to social cohesion.

We can look to communities for answers. Planned retreat can be tense and emotional – but it can also represent a reset and an opportunity for hope.

Anne Maree Kreller, Research, Australian Centre for Culture, Environment, Society and Space, University of Wollongong

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

From July 1, many Australians can choose something that once sounded absurd: free electricity in the middle of the day. The federal government’s opt-in Solar Sharer Offer will give three hours of free power to households with smart meters in New South Wales, South Australia and southeast Queensland. Victoria’s separate scheme will launch in October.

Free power sounds like a giveaway. It isn’t. It’s meant to encourage people to use more electricity during the hours when solar power flows into the grid. The real aim is to get people to shift the use of water heaters, pool pumps, air-conditioning and electric vehicle charging to the middle of the day. At other times, power prices will be slightly more expensive.

The main challenge for Australia’s power systems is no longer how to meet peak demand in the evening. We now have to use or manage the floods of very cheap solar during the sunniest hours when there’s more supply than demand. If this imbalance isn’t managed, electricity voltage and frequency can move outside safe limits, equipment can trip, and the risk of outages rises.

The scheme makes sense. But there are still questions about its fairness. Electrified households will benefit most, while renters and other groups may benefit less.

The challenge of solar abundance

About one in three Australian homes now has solar. At times, this power source can supply 50% of total demand on Australia’s biggest power grid, the National Energy Market. Wholesale prices have regularly gone negative in recent quarters.

In big solar states such as South Australia, solar can supply more power than the state can use. Surplus power is exported, stored in batteries or curtailed – wasted.

The Solar Sharer Offer is meant to make better use of these floods of solar power.

This financial year, the three hours of free power will be 11am to 2pm daily in NSW and southeast Queensland and 12 to 3pm in South Australia. Australia’s energy regulator chose these times to match when solar output is highest, and network and wholesale costs are lowest. This may change year by year.

The reason the scheme isn’t national is because it’s tied to the Default Market Offer — a regulated safety net plan for electricity customers – which only applies in NSW, SA and southeast Queensland.

Who will benefit most?

Ensuring fair access has been a constant challenge for household clean-energy schemes. People who own their homes and have access to capital are usually better placed to benefit. This scheme has the same issue.

It’s easy to picture the ideal customer for three hours of free power – a homeowner with a smart meter, flexible hot water, electric vehicle, home battery and the ability to choose when power-hungry appliances run.

That’s great for them. But what about everyone else? For instance, you have to have a smart meter to be eligible. Only about 60% of households have one.

The harder question is whether this offer is fair for other households.

Renters, apartment residents and people on embedded networks in retirement villages, caravan parks or shopping centres face another barrier. If they opt in without being able to make good use of the free power, they could actually be worse off due to the higher prices at other times. These concerns were raised during the consultation process.

Making it fairer

The government is aware of these issues. The free power period is capped at 24 kilowatt hours a day, enough to cover several large daytime loads such as hot water, dishwashing, laundry, air-conditioning or part-charging of an EV.

The cap matters because offering electricity for free still incurs costs for energy retailers. To recover the missed revenue during the free window, retailers will boost other usage charges. Capping free power at 24 kWh a day limits how much high-consumption households can use at zero price, which limits how much revenue has to be recovered from usage at other times of day.

More needs to be done to ensure it’s fair. A key step is unglamorous but effective: helping households heat water during the day. Heating water takes a lot of power. Electric hot-water systems are often on controlled-load tariffs designed for overnight operation. A South Australian trial moved close to 50% of water heating from night to day with little reported inconvenience.

Where safe and practical, retailers and network businesses could shift the time these systems charge to the middle of the day. Governments could help rentals and apartment residents by supporting the use of timers, smart controllers and efficient heat-pump hot-water systems. The same logic applies to other flexible loads.

The free lunch is real. The question is who gets a seat at the table.

Saman Gorji, Associate Professor, Renewable Energy and Electrical Engineering, Deakin University and Alireza Ganjovi, Researcher, Energy Systems and Applied Physics, Deakin University

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

Australia’s biggest industrial gas users pump out about 5% of our greenhouse gas emissions. To have any chance of reaching our emissions targets, Australia need to reduce its heavy reliance on fossil gas.

But to make this possible, we need to produce supplies of green hydrogen – made with renewable energy – and biomethane. On current trends, we won’t have enough.

Despite allocating billions of dollars to support green hydrogen, Australia’s policies don’t seem to be working.

The risk is many large factories will either miss their emissions reduction targets by huge margins, or shut down. To prevent this, the federal government needs to foster these crucial green gas industries.

What’s the problem?

The use of gas in Australia has already peaked in all sectors. In our new report, my co-authors and I show:

• the use of gas for electricity generation has fallen 11% since 2014
• gas use in manufacturing has been falling since the early 2000s
• LNG exports also likely peaked in 2022.

As Australia continues its transition towards a “net zero” energy system by 2050, all of its gas emissions will need to cease.

Industrial gas users burn gas as a fuel for high-heat processes, such as refining alumina or manufacturing, as well as using the gas molecules to manufacture chemical products, like ammonia.

Food processors, beer brewers and other industrial gas users who need less intense heat can avoid emissions by electrifying. As the technology improves, a growing share of high-heat industrial users, such as mineral processors, will also be able to take this route.

But a small and critical group of industrial gas users will not be able to easily reduce their gas use. For now, the very high-temperature heat they rely on still needs a burnable fuel. And chemical producers who use gas as a feedstock for its molecules need a renewable substitute.

What is ‘green’ gas?

This is where renewable gases – green hydrogen and biomethane – come in.

Green hydrogen is made by running zero-emissions electricity through water. It can replace gas for high-temperature heat or as a feedstock to make ammonia, which is needed for fertilisers and explosives.

Biomethane is chemically the same as natural gas, but made from waste, such as landfill, sewage and agricultural waste. Because its carbon was only recently absorbed from the atmosphere by plants, it counts as near-zero emissions.

The government has set big targets for renewable gas production – 60 petajoules of green hydrogen and 10 petajoules of biomethane by 2030. But across Australia, as of 2025 we only make 0.1 petajoules of green hydrogen and 0.1 petajoules of biomethane.

To reach the targets, green hydrogen production would need to grow six hundredfold and biomethane one hundredfold in the next four years.

We’re not on track

Other countries have rapidly grown their renewable gas industries from a small base.

Italy had no biomethane industry in 2018. It now produces more than 28 petajoules a year. But Australia’s policies don’t seem to be working.

Australia has allocated A$2.25 billion to help support green hydrogen production, but only two projects have been funded and neither are operational. Several other major projects have been cancelled.

Part of the problem is that the government has tried to skip too many steps. The government has poured money into large projects and offered ongoing revenue support before any large buyers exist.

Biomethane has not received as much support, with only $60 million in grants for three projects. More funding has been announced, but it is still not proportionate to the level of ambition.

Support green gas producers

In our report, we set out the steps the federal government could take to bring Australia’s renewable gas policies up to speed.

Australia needs to improve support for producers and give them certainty that they will have paying customers. For hydrogen, funding should begin by supporting existing users of hydrogen to switch to green hydrogen, because they already have the equipment and the know-how to use hydrogen.

Currently the funding is in the form of tax credits, which only benefit companies profitably selling hydrogen. Instead, support should be restructured to make up the difference between the cost of using green hydrogen and the cost of using carbon-heavy methods of production.

For biomethane, the government should assess whether the sector should be given strategic priority support as part of the Future Made in Australia scheme.

Drive up demand

Australia should introduce a national renewable gas “obligation”, under which large gas users would have to purchase certificates proving a portion of the gas they were using was zero-emissions.

This would drive up demand and prices, creating a revenue stream for renewable gas producers. New South Wales and Victoria already plan to implement renewable gas targets. Instead of state-based approaches, the federal government should introduce a national target and obligation.

In the short term, requiring big gas users to consume a collective 1 petajoule of biomethane would only cost about $15 million.

It would be a small impost if it were spread across all large gas users, and it would be transformational for renewable gas producers.

There’s not a moment to waste. If we’re serious about both our emissions reduction targets and our manufacturing capacity, we need far more renewable gases than Australia is on track to produce. And we need them very soon.

Ben Jefferson, Associate, Grattan Institute

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

Last year, we noted early signs of recovery in Australia’s high country, following the reduction of feral horse numbers.

These had dropped from 17,000 in 2023 to around 3,000 in 2024 across Kosciuszko National Park, thanks to the management efforts of NSW National Parks staff and contractors.

But horse numbers are already bouncing back. The latest survey data estimate between 6,476 and 16,411 horses now roam the national park.

So, what happened?

A mild summer

The answer is simple. If feral horse eradication is impossible — or politically and legally off the table — then continuous management of horse numbers is essential.

With no aerial culling within the national park in 2025, two factors likely contributed to this rapid rebound.

First, horses move. Control efforts have largely focused on remote parts of Kosciuszko National Park, away from people, trails and roads. Once resident herds in these areas have been culled, horses from surrounding regions – particularly adjacent state forests – likely moved in.

Second, horses breed. After a mild summer with significant rainfall across the high country, most mares will have bred. During Autumn fieldwork, we observed large numbers of foals accompanying herds throughout the region.

A numbers game

If numbers aren’t rapidly reduced again, things will only get worse, both for the fragile alpine environment and the horses themselves. With winter conditions imminent, many horses will struggle to maintain condition as snow covers grazing areas and energy reserves are depleted.

Ironically, some of the strongest opposition to culling overlooks these very real animal welfare consequences. Leaving horse populations unmanaged may ultimately result in prolonged suffering from starvation and exposure, compared with humane control conducted by trained professionals.

Forecast El Niño conditions may further compound these pressures, with drought likely to persist through spring and summer. As water and food become scarce, horses will likely concentrate around creeks, wetlands, alpine bogs, fens and meadows. These are precisely the alpine ecosystems most vulnerable to trampling, grazing and erosion.

And this is where hard-fought gains will be rapidly lost. Banks will become eroded, clear waters fouled and our fabled high plains replaced by overgrazed paddocks.

A long-term effort

We don’t need to look far to see what happens when a population of feral animals goes unchecked. Great Keppel Island, for example, is overrun with a thousand or more feral goats, denuding dune and forcing increasingly exasperated locals to erect fences around their properties

As with horses in Kosciuszko, political hesitancy and delayed action on Great Keppel have allowed ecological damage to escalate while management becomes increasingly difficult and expensive.

New South Wales Environment Minister, Penny Sharpe, recently said the latest Kosciuszko feral horse numbers confirmed the need for “continued management”, required to meet the target of reducing feral horse numbers to 3,000 by mid-2027.

But where did that target come from? It’s a holdover from the repealed Kosciuszko Wild Horse Heritage Act and, when even basic population growth models are applied, the implications become clear. Maintaining a population of 3,000 horses would still require the removal of well over 1,000 animals every two years — indefinitely.

In other words, there is no “set and forget” solution. If horse populations are to remain capped, ongoing culling will be necessary in perpetuity.

Alternative solutions?

Some have suggested that instead of culling, rehoming and fertility control should be used. While many Australians might like the idea of a “brumby” or two grazing in the back paddock, the number of landholders willing and able to care for these animals is far smaller.

Even retired racehorses struggle to find suitable long-term homes once their racing careers end, highlighting the practical limitations of large-scale rehoming programs.

Likewise, although various fertility control options have been suggested, vaccines, intra-uterine devices or surgical sterilisation are all invasive procedures for which horses need to be caught and sedated. These may be effective to maintain a small herd in an easily accessible area. But previous assessments have warned such an approach must be carried out in concert with large scale culling efforts.

Population dynamics vs politics

We don’t have to look far to find other examples of how invasive species management could be improved. In 2016, then New Zealand Prime Minister John Key introduced a bold plan to rid Aotearoa of all introduced predators in the next 30 years.

Predator Free 2050 is the first national-scale initiative to reduce the impacts of introduced predators, capitalising on the invention of new technologies including real-time automated species identification to trap targeted species and mobilising neighbourhoods across the country to join the effort.

Australia faces a different set of challenges — larger landscapes, divided jurisdictions and deeply entrenched cultural and political debates around invasive species management.

But the broader lesson remains the same: meaningful conservation outcomes require long-term commitment, clear targets and the willingness to act before ecological problems become too difficult to reverse.

David M Watson, Professor in Ecology, Charles Sturt University and Patrick Finnerty, Postdoctoral Research Fellow in Conservation and Wildlife Management, University of Sydney

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

For a quarter century, Australia’s environment laws were widely regarded as not fit for purpose. In 2020, a scathing review by Professor Graeme Samuel found the Environment Protection and Biodiversity (EPBC) Act was ineffective and unfit for future environmental challenges.

On the last Parliamentary sitting day of 2025, Labor passed its long-awaited reforms to Australia’s nature laws following a deal with the Greens. According to Environment Minister Murray Watt, these reforms would deliver tangible benefits for the environment and “protect what is precious”.

Now the dust has settled on getting the legislation passed, conservationists want to know if they will work.

The big questions is whether two proposed “environmental standards”, a centrepiece in the new laws, are up to the task.

What are environmental standards?

Previously, the EPBC Act required the decision-maker to tick procedural boxes, but this did not necessarily result in an outcome that protected the environment.

For example, while the Department of Environment could access information about the impacts of development on the black-throated finch, it merely needs to “have regard” to this. There was no obligation to reject a project, or impose conditions, even if the projected impacts on the finch would be severe.

To address this, Professor Samuel called for new national environmental standards. These universal requirements would guide the outcomes of environmental decision-making across the country.

For example, his suggested standard for threatened species included the outcome that they would be “protected, managed and recovered over time”. Decisions would have to be consistent with these standards with rare exception, only justifiable in the public interest. Rather than box-ticking, this would require decisions to promote good outcomes for nature.

Although Labor committed to environmental standards in 2022, passing the reforms proved challenging. It took three years, an election, a new Environment Minister, and a slew of compromises, to secure the deal.

What is the government proposing?

Two draft standards have released, and are open for consultation. One is for Matters of National Environmental Significance (MNES), a term in the EPBC Act that includes World Heritage areas, migratory species and the Great Barrier Reef National Park.

The other is for environmental offsets – actions taken to counterbalance the unavoidable negative impacts of a project on the environment.

At first blush, the draft standards contain the components urged by Professor Samuel, including objectives and outcomes. For example, the MNES Standard has an objective that habitat be protected, conserved, and restored.

However, clauses buried in both of the standards render these outcomes and objectives effectively useless. These clauses state that as long as the minister makes a decision consistent with another part of the standard (called the “principles”), the outcomes and objectives are deemed to be met.

These legal technicalities can be confusing. But the reality is that if the standards are signed off in their current form, we will be back to box-ticking as the key focus of environmental decision-making.

These new standards also include a narrow focus on “irreplaceable” habitat. For species that are recognised as threatened, habitat that is “irreplaceable” and necessary for them to remain “viable in the wild” should be protected.

While this framing sounds like what Professor Samuel envisaged, the narrow definition of “irreplaceable” means only the rarest and most fragile habitats will be covered.

This is at odds with the federal government’s previous commitment to “no new extinctions”. Avoiding a species becoming extinct requires habitat to be protected before things get to breaking point.

Weak constraints on state power

The weak standards are especially concerning given the federal government is steaming ahead with plans to pass approval powers to the states and territories. The Commonwealth has an important oversight role in environmental regulation and, although rare, it has stepped in on occasion to stop the most destructive projects, like the proposed Toondah Harbour development.

Under the reformed laws, the standards are supposed to act as a crucial guardrail on state power. The minister cannot devolve powers to a state unless satisfied that its environmental approval frameworks are consistent with federal standards. Unless robust environmental standards are developed, this constraint on state power will be fairly weak.

Environment Minister Murray Watt promised the EPBC reforms would deliver tangible benefits for the environment. Unfortunately, the draft standards offer little guarantee.

Justine Bell-James, Professor, TC Beirne School of Law, The University of Queensland

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

When major new climate change scenarios are released, there’s always strong interest. These scenarios lay out what our future climate will look like, depending on how fast we act to cut emissions.

But what was surprising about the seven new scenarios announced last week was that United States President Donald Trump took an interest.

Why? Because a high-emissions scenario – known as RCP8.5 and its successor SSP5-8.5 – had been removed. Under these worst-case scenarios, nations would make no effort to cut emissions and expand fossil fuel use. By 2100, carbon dioxide levels would almost triple, to 1,135 parts per million and the world would be around 4.5°C hotter than the pre-industrial period.

The climate scientists responsible for laying out the range of possible futures removed the RCP8.5 scenarios for a very good reason. Although often slow and incomplete, our efforts to tackle climate change have made a tangible difference. We have averted the worst climate future once thought possible.

The job is far from done. Emissions are at record highs and global warming is speeding up.

But the removal of this high-emissions scenario isn’t, as Trump and other climate sceptics have claimed, a sign of failed modelling, or that climate change was a hoax. It’s a sign the expansion of solar, wind, electric vehicles and batteries have slowed emissions growth.

How are these scenarios made?

Many climate impacts are becoming evident after about 1.4°C of warming – the level we’re roughly at now.

Because this period of extremely rapid climate change is due to human activities, it means we also have the opportunity to shape the future.

What will this look like? Will the world keep heating up, or will rapid action cut emissions and bring warming to a halt? The answer will make a big difference to the future humanity faces.

Predicting anything is difficult. But a group of scientists has created scenarios representing a range of possible climate futures.

Because the future is not set, scientists lay out a range of possible pathways for our future greenhouse gas emissions. They base them on what’s happened so far and what might happen in politics and technology over coming decades.

Then they select the emissions pathways deemed most plausible and then sample a range of different futures which are more or less optimistic about our fossil fuel use.

Scientific groups around the world then model these scenarios in depth using different climate models to ensure there’s a large amount of data available at global, regional and local levels.

These scenarios aren’t ranked by how likely they are. All are considered to be plausible futures. The huge range of temperature outcomes – approaching 2°C between the most and least optimistic scenarios by 2100 – points to how much of the future is in our hands.

Why the fuss about RCP8.5?

The two previous releases included two closely related scenarios – RCP8.5 and SSP5-8.5 respectively.

Here, “8.5” refers to radiative forcing – the level of extra heat (in watts) trapped per square metre by 2100.

In these worst-case scenarios, the world sharply boosts fossil fuel use. Unsurprisingly, this leads to very high amounts of global warming. Scientists have long argued over whether this was plausible in the first place.

None of the new scenarios are as pessimistic as RCP8.5/SSP5-8.5. The worst possible scenario now envisions high emissions leading to warming of around 3.5°C by 2100. That would still be very, very bad.

Sceptics acting in bad faith

Climate sceptics leapt on the removal of RCP8.5 as a sign the projections were wrong. These attacks were not made in good faith, but to cast doubt on climate science.

A clear eyed assessment is that RCP8.5 was removed because climate action is starting to work.

But while the worst outcome has been averted, we have also missed the window for the best future climate.

The new scenarios have no pathway as optimistic as the lowest emissions scenario from the last round of major climate projections. That scenario – SSP1-1.9 – envisaged strong climate action and rapid cuts to emissions, leading to global warming peaking at around 1.5°C.

Because global emissions haven’t yet begun to fall, the most optimistic new pathway would lead to warming peaking at about 1.9°C.

While we will definitely now pass 1.5°C, the hope is to only temporarily overshoot that level of warming while working to draw carbon dioxide back out of the atmosphere to get back to 1.5°C.

Our current emissions trajectory is somewhere in the middle – below the high emissions path but well above the most optimistic scenario. Based on current policies and countries’ actions, we’re looking at around 2.6°C warming by 2100.

You might wonder why we need to keep redoing these climate scenarios.

One reason: facts change on the ground. Solar keeps rolling out far faster than expected, but fracking has opened up large new fossil fuel deposits. Political shifts make climate action more or less likely.

Another is because our climate models are continually improving. The better the models get, the more accurate and detailed our projections of sea level rise and other climate impacts can be.

Yes, this is progress

Taking RCP8.5 off the table is a sign of progress – we’ve avoided the worst-case scenario. But we have also missed the best case future.

The next five years could play out in many different ways, leading to better or worse future climates. We must understand and prepare for what we’re facing – and double down on our efforts to create the best future possible.

Andrew King, ARC Future Fellow and Associate Professor in Climate Science, ARC Centre of Excellence for 21st Century Weather, The University of Melbourne

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

Mining giant BHP has come under fire for spending hundreds of millions of dollars on new diesel trucks in the Pilbara, despite promising a transition to electric trucks in its climate strategy.

Like other mining companies, BHP’s diesel-driven fleet is eligible for fuel tax credits on diesel. The company’s controversial decision to shelve its plans raises the pressing issue of the diesel fuel rebate.

This rebate began as targeted support for a struggling agricultural sector in the 1980s, but has morphed into an almost $5 billion subsidy for some of the nation’s most profitable corporations.

So, what is the diesel fuel rebate? And is this fossil fuel subsidy still fit for purpose?

Why do we have a diesel rebate?

Since federation in 1901, diesel and petroleum products imported into Australia have been subject to import taxes. Since 1929, tax collected from the petrol pump has been earmarked to build and maintain the nation’s road network.

Australia’s diesel fuel rebate scheme was introduced in 1982. The Fuel Tax Credits Scheme, as it’s officially known, was designed to cushion farmers from rising fuel costs.

Farm and mine businesses buying diesel for off-road uses like tractors, harvesters and irrigation pumps could claim a rebate. At the time, Australia’s mining sector was far smaller.

Now, 44 years later, the rebate scheme still allows businesses like agriculture and mining to claim back the federal fuel tax paid on diesel used in eligible machinery, equipment and heavy vehicles.

Today, the mining industry receives about half of the diesel rebate.

Diesel up, petrol down

Since 2010, Australia’s consumption of liquid fuel has changed dramatically, with official statistics showing falling petrol demand and rising diesel use over the past decade. Petrol use has gradually declined as vehicle efficiency has improved. In contrast, diesel consumption has nearly doubled.

This surge in diesel consumption reflects Australia’s growth in freight, heavy vehicles and, particularly, mining. The diesel rebate scheme is now one of Australia’s largest fossil fuel subsidies, alongside tax concessions for aviation fuel and a range of support measures for coal and gas production, with recent analysis putting its annual cost at around $11.2 billion by 2026–27.

Mining is by far the largest beneficiary, claiming about $5 billion a year in diesel rebates according to one analysis. This includes roughly $1.5 billion for coal mining alone. Agriculture receives only a fraction of the total.

What began as support for farmers using off-road fuel has become a standing subsidy for Australia’s most profitable miners.

Meanwhile, aviation fuel pays little excise – about 3 cents per litre – to fund the Civil Aviation Safety Authority. This compares to a fuel excise rate of 52c per litre on petrol and diesel, which the Australian government halved on April 1 this year in response to fuel price spikes from the US-Israeli war in Iran.

Since 1992, the formal link between petrol and diesel excise and road funding has ended, with fuel tax now flowing into general revenue rather than a dedicated roads fund. The rebate was originally justified on fairness grounds – off‑road users were not meant to subsidise public roads – but once fuel tax stopped being a dedicated roads charge, that logic largely evaporated.

Fuel tax cuts in response to war

The May 2026 federal budget fuel package was worth more than $10 billion, centred on a permanent government-owned fuel reserve.

These are reminders Australia’s fuel security problem is immediate, not theoretical. The government’s response has been to buy and store more fuel, rather than reduce our structural dependence on imported oil and support a shift to electrification and renewable energy.

Australia’s fuel rebate entrenches higher diesel use. But the “we need more fuel” argument ignores the fact Australia’s economy is decisively decoupling from fossil energy consumption.

Uncoupling from oil is not a theoretical future possibility – it is slowly happening. Oil consumption in particular has plateaued since the early 2000s, even as GDP has roughly doubled. If Australia wants to meet its emissions-reduction commitments, it should hasten the shift away from fossil oil, not maintain a subsidy for it.

A fair share of resources

Australia has long failed to gain a fair share of revenue from our finite mineral wealth. Our petroleum resource rent tax is notoriously weak.

Mining companies argue tougher taxes will drive investment offshore. But Australia has some of the world’s highest-grade iron ore, coal and critical minerals. A tax regime would have to be extraordinarily high to make extraction unprofitable.

We are now in the fourth major oil crisis.

Unlike the others, this one arrives with cheaper renewable alternatives readily available. Wind, solar, batteries and electric vehicles are now cheaper than fossil alternatives and faster to deploy.

During a fuel crisis, we should scrutinise where our finite tax revenues are directed. The fuel rebate was designed mostly for farmers, when the mining industry was a fraction of its current size.

Does the policy need to return to its original aim? Or is a new form of road user tax required?

Whatever the mechanism, it makes sense to direct revenue towards electrification, not lock in another decade of diesel dependence.

Response from BHP:

In a statement, a spokesperson for BHP said it has net zero goal for reducing its scope 1 and 2 greenhouse gas emissions to net zero by 2050.

Despite this progress, many of the technologies the resources industry will need to achieve net zero are not yet ready to be deployed, BHP said.

“For example, no Australian mining operation is currently utilising critical 240-ton battery-electric haul trucks as the technology is not advanced enough to scale to an operational fleet,” the spokesperson said.

BHP is partnering with equipment producers to run trials of battery-electric equipment, including two 240-ton battery electric haul trucks, on a BHP site in the Pilbara, and four battery-electric locomotives which we plan to commence trialling in coming months.

Ray Wills, Adjunct Professor, The University of Western Australia and Peter Newman, Professor of Sustainability, Curtin University

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

The red pipefish (Notiocampus ruber) is a rare relative of seahorses and seadragons found only in Australia.

While the species occurs across southern Australia from Western Australia to New South Wales, its incredible camouflage means until now only one person had ever photographed it in the wild.

In Gamay (Botany Bay) it has been observed hiding among feathery red algae, but elsewhere the red pipefish has been recorded on rocky reefs. Its colour and slender body allow it to disappear almost completely against its surroundings.

For decades, scientists have wondered how these elusive creatures carry their eggs. Our new photographs and research, published in the Journal of Fish Biology, finally provide an answer.

A lucky sighting

One of us (Andrew) regularly dives the popular Sydney sites The Leap and The Steps at Kurnell, Gamay (Botany Bay), where he documents seahorses, pygmy pipehorses, seadragons and other related sealife.

Andrew had briefly seen a red pipefish twice before. However, he struck gold when he spotted one at Kurnell in April 2021. He kept tabs on this individual, spotting it almost weekly until January 2022.

During that time it was joined by two more red pipefish. When all three were sighted in November 2021, one was a brooding male carrying eggs on his trunk.

Tails or trunks?

While pipefishes and seahorses are famous for male pregnancy, the family is split by how the males carry their young. Many pipefish – and all seahorses – are “tail brooders”, carrying eggs on the tail in pouches.

Another group of pipefish, the “trunk brooders”, carry eggs exposed directly on the belly. However, scientists have suspected the red pipefish was a tail brooder since 1979 based on the structure of its body. However, without a living male to study the theory remained unproven.

Andrew’s photographs from his November 2021 dives at Kurnell finally provided the proof. They clearly show a male carrying large eggs attached directly to the belly – confirming the species as a trunk-brooder and placing it in an ancient group of pipefishes that lack pouches entirely.

Interestingly, the data suggest this Australian fish may be a long-lost relative of species found as far away as the North Atlantic, despite the vast geographical separation.

Finding such a rare fish in the well-dived waters of Gamay is a reminder that major biological secrets are still hiding in plain sight.

Andrew Trevor-Jones, Technical Officer, Australian Museum and Graham Short, Research Associate, Australian Museum

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

Mosquito repellents are key to protect ourselves from mosquito bites and the pathogens they might carry. The most widely used active ingredient in insect repellents is N,N-diethyl-meta-toluamide, commonly known as DEET.

Highly effective, long-lasting (approximately five hours) and cheap to make, DEET is a gold-standard insect repellent. But even though it was developed more than 80 years ago, there are important gaps in our understanding of how DEET actually works.

A new paper in the Journal of Experimental Biology led by Claudio Lazzari from the University of Tours, France, now shows mosquitoes can be conditioned to be attracted to DEET.

This provides an important piece of the puzzle in our understanding of how DEET works, and hints that this important mozzie repellent could have a vulnerability.

A vital tool that’s not fully understood

Insect repellents are a major method of protection against mosquito-borne diseases including malaria, dengue, chikungunya, Ross River virus, Japanese encephalitis virus and more. Many of these diseases are expanding on a global scale due to travel, urbanisation and climate change.

Female mosquitoes transmit parasites and viruses when they feed on vertebrate blood, which they need to provide proteins for egg development. To find their next blood meal, mosquitoes are strongly attracted to odours and physical cues emitted by warm-blooded “hosts”, including humans.

These include carbon dioxide we exhale, lactic acid in our sweat, and a complex combination of other chemicals that varies between people. Mosquitoes detect all these with sensory organs located in their antennae, proboscis (the pointy mouth part they use to suck blood) and the maxillary palps that flank it.

DEET has been in widespread commercial use since the 1950s, but there’s a lot of scientific debate over how exactly it works as a mozzie repellent. Is it blocking the odour of the host, is it toxic to the mosquito, or something else?

In 2008, groundbreaking research showed DEET blocks the response of sensory neurons to host odours in mosquitoes and vinegar flies. This means DEET is likely “confusing” the mosquito rather than repelling it. A couple of years later, scientists found a small portion of mosquitoes exposed to DEET are insensitive to it, and it’s a heritable trait.

This means mosquitoes do have a physiological response to DEET. But there are also signs some of the mozzie reactions are behavioural. In one study, mosquitoes exposed to DEET were less sensitive to it if exposed again within three hours. This hints they can temporarily get used to the chemical.

What did the new study find?

The new study shows it’s possible to condition mosquitoes to bite more if they’re repeatedly exposed to DEET during a blood meal. Not only does this tell us more about how it repels mosquitoes, but it raises the prospect mosquitoes may actually be attracted towards DEET in some cases.

First, the researchers developed a behavioural test. They kept mosquitoes in tiny cages and moved a food target (a warm bag of blood) towards them, recording proboscis movements when they sensed the target. This was the “biting attempt response”.

To test things further, the team ran a classical conditioning experiment. Mosquitoes were run through one of five “training programs” exposing them to various combinations of an unconditioned stimulus (heat), a conditioned stimulus (short exposure to DEET in a plume of air) and a reward (a short opportunity to feed on blood).

Here’s where it gets surprising. The mosquitoes whose training program included a squirt of DEET while they were already feeding on blood, afterwards had a significantly higher biting response when exposed to DEET again.

If the mosquitoes were exposed to DEET before being offered the blood bag, none of them tried to bite it.

Then, one of the researchers boldly offered her hands up for testing. One of the hands was treated with DEET. About 50% of the mosquitoes who went through the DEET-blood meal training program tried to bite the hand coated in DEET. By contrast, 100% of untrained mozzies avoided the hand covered in DEET and went for the clean one instead.

What does all this mean?

It’s well established mosquitoes can learn and retain information. What they learn about hosts and their environment can in turn have an impact on disease transmission.

This study indicates DEET doesn’t just affect mosquitoes physiologically. There’s a cognitive response as well, which could be an important part of how it works.

The authors raise the possibility – if the concentration of DEET is not high enough to repel mosquitoes but they still sense it during a blood meal, would these mosquitoes then be more likely to bite people who smell of DEET?

It’s important to note the study happened in highly controlled lab conditions, and the training program the mozzies underwent may not reflect everyday scenarios. Future studies should try and come up with test conditions that better represent real-world situations to see if these results hold up.

At a time when mosquito-borne diseases are on the rise, DEET still provides highly effective protection. What this study contributes is an improved understanding of how DEET works – and how we might improve insect repellents in the future.

Leon Hugo, Adjunct Associate Professor, Mosquito Control Laboratory, QIMR Berghofer Medical Research Institute

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

Renewables and energy storage were pitched as a way to drive down power prices. But the hidden costs of the clean energy transition mean lower prices haven’t fully eventuated.

That’s why this week’s news power prices will fall by up to 10% have been gratefully received by the government – and consumers. The falls are real, though they do not apply everywhere.

There are important caveats. The cheaper power will directly apply to customers on the default market offer, the safety net power plan overseen by the Australian Energy Regulator. Fewer than 10% of consumers are on this offer.

Despite this, the decision by the Australian Energy Regulator will be influential. Just as banks tend to follow a Reserve Bank decision on interest rates, energy retailers tend to be guided by the prices set under the default market offer.

Why are prices falling? Solar, wind and batteries can provide power more cheaply than fossil fuels, and renewables have reached as high as 50% in Australia’s main grid. They could have driven retail prices down further if not offset by the rising costs of new transmission lines.

What drives power prices?

The power savings are uneven. In South East Queensland, retail power prices will fall by 10.7% and in New South Wales by up to 7.7%. In South Australia, some customers will have a small price rise of 1.4%. Small businesses will see larger falls – as much as 20.9% in NSW.

In Victoria, which has its own separate default offer, retail prices will fall 5%.

The average power bill for an Australian household is around A$2,000 a year. The actual cost of wholesale power accounts for 30–40% of the bill. Network costs – the cost of getting the power to the consumer – make up another 40%. The remaining amount is due to environmental and retailer costs.

In recent years, the cost of producing wholesale power has dropped. This is because more wind and solar farms have come online, while grid-scale batteries are pushing gas power out of the grid at times.

This means there’s less reliance on coal and gas. The role of gas is key, as this fossil fuel has become more expensive. It tends to be used only when demand is very high. At these times, gas acts as a price-setter for the energy market and the price it sets is high. So, other things being equal, less reliance on gas means lower prices.

Network costs have mostly increased, in a range of 5–10%. The key contributor has been the cost of building new transmission lines, and damage from extreme weather has also added costs in Queensland. Inflation adds extra cost to big projects.

What’s next?

This dynamic is likely to continue for some time. We can expect wholesale prices to keep falling, or at least not rise. We may also see network prices rising more sharply, given community pushback against some new transmission projects and slow progress. Without new transmission lines, many renewable projects won’t be viable.

In the next few years, more Australian households will have smart meters installed. In NSW, SA, the Australian Capital Territory and Queensland, rollout is meant to be complete by 2030. Western Australia and Tasmania have their own programs and Victoria’s rollout was completed more than a decade ago.

Smart meters make it possible for power retailers to charge customers different rates at different times. This encourages people to use more power when it’s cheap to produce, and less during peak times such as evenings.

These time-of-use tariffs will become increasingly important. For the first time, the energy regulator included both flat tariffs and time-of-use tariffs in its default market offer. Over time, and with further market reforms, we can expect to see more people take up time-of-use tariffs.

We can also expect big batteries to flex their muscle in the grid, outcompeting gas peaking plants and keeping wholesale prices lower. The influence of these batteries is beginning to show, and it is accelerating.

Household batteries, too, may play a role. The government’s hugely popular household battery incentive scheme will let people with solar store power at home, and use it during peak times instead of relying on expensive grid power.

In the messy middle

We are in the middle of reshaping the electricity grid.

The 20th-century model was built around peak demand – the handful of times a year when huge demand required standby plants to fire up and produce power at high cost. That’s now changing. Gas will go from providing perhaps 20% of Australia’s electricity to as low as 5%. It will be needed as a backup during low wind or sun days for some time.

But the big unknown is new transmission – the missing piece of the clean energy transition. Until this is done, we will keep seeing lower wholesale costs offset by higher network costs. But when it is complete, network costs, too, should fall.

Tony Wood, Senior Fellow in Energy and Climate Change, Grattan Institute

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

“Biodegradable” has become one of the most reassuring words in modern packaging. It appears on coffee cups, shopping bags and food containers, implying a promise: this product is better for the environment because nature will eventually take care of it.

However, biodegradability is not a simple yes-or-no property. It exists in shades, which we can measure.

Biodegradation is a complex process. Microbes and molecules present in an environment such as soil attack a material and digest it, much like what happens to food in our gut.

A material is typically defined as biodegradable if it is digested “well” by the environment in which it is placed. The more mass the material loses during digestion, and the more carbon dioxide it produces, the more biodegradable it is.

Different environments digest materials in different ways. Temperature, sunlight, oxygen, moisture and microbial diversity all influence how quickly materials degrade.

Even the most rigorous testing cannot fully capture the complexity of the real world – but it can help guide our choices.

Biodegradability is relative

In the lab we can simulate environments such as landfill, home compost bins and industrial compost facilities. If we understand in which settings a material breaks down better, we can tell the consumer how to best dispose of it and prevent pollution and other issues.

A material that decomposes quickly in an industrial composting facility may persist for years in the ocean or landfill.

Industrial composting systems maintain elevated temperatures, controlled aeration and consistent moisture. Hot, moist and oxygen-rich conditions generally aid biodegradation but they are not easy to come by in a backyard compost bin.

Home compost systems are typically cooler and more variable. The result: a material certified for industrial composting may not break down effectively at home.

Take polylactic acid (PLA), a biodegradable material generally considered to be a greener alternative to common plastics (like PET). PLA can biodegrade effectively in an industrial composting system. With temperatures above 60°C and controlled moisture, oxygen and microbial activity, microbes can convert PLA into carbon dioxide, water and biomass in just a few days.

Outside these conditions, the story changes. If PLA ends up in landfill, decomposition can be slow because oxygen is limited. In rivers or marine environments, it may persist for years and act as a raft for “alien” species. In your compost bin or worm farm it might disappear in a few months.

Time for standards

There are many ways to measure biodegradability. One common series of tests, OECD 301 assesses “ready biodegradability” in different environments as a material’s ability to biodegrade around 60% within 28 days under controlled conditions.

Industrially compostable materials are tested under very specific conditions. Standards such as EN 13432, used in Europe, assess whether packaging can successfully break down in industrial composting facilities.

To meet the standard, at least 90% of the material must biodegrade into carbon dioxide, water and biomass within six months. These tests typically involve elevated temperatures, controlled aeration, and moisture.

Most biodegradable plastic materials do not disappear cleanly. Instead, they fragment into progressively smaller particles before fully breaking down. During this period, the fragments will continue interacting with organisms and ecosystems.

Compost bins too can get indigestion

Biodegradability standards are helpful for consumers and waste regulators. Nevertheless, they are limited. They often do not test how much of any given material a specific disposal system can sustain at any one time.

This is an important parameter to take into account. Take food waste. When large quantities of food lie in landfill without oxygen, they generate methane, a greenhouse gas far more potent than carbon dioxide over short timescales.

Other biodegradable materials are no different and can throw out the balance of an ecosystem such as your compost bin, if added in excessive quantities.

Introducing certain materials to a compost bin might also cause certain microbes to thrive and others to suffer, sometimes with unintended consequences, such as making your compost bin smell bad.

In the future, biodegradability tests will likely be paired with ecotoxicity assessments, to help us understand whether a material breaks down safely and without generating harmful byproducts or microbial imbalances.

What can we do?

Few of us have an industrial composting facility nearby to take care of biodegradable materials. Industrially compostable products such as coffee cups often end up sent to landfill alongside conventional waste.

This does not mean individuals are powerless or that biodegradable materials are inherently bad.

You can start by checking local council guidance and choosing products certified for the systems available in your area, or your compost bin.

Ask yourself:

• is this product home compostable or only industrially compostable?

• is there infrastructure locally that can process it?

• has it been independently certified?

As for industrially compostable coffee cups, check that you can return cups to participating cafes. They should not be placed in standard recycling bins or food and organics bins as they are considered contaminants. If unsure, place them in a bin destined for landfill.

Ultimately, the most sustainable option remains a reusable washable cup.

These may seem like small actions but they help push packaging design and waste systems toward greater transparency and accountability.

Moving beyond simple labels

As consumers, we want to make educated choices about their purchases and how they can be disposed of.

For now, we have simple labels. In the future, we will hopefully have more complete information about how materials degrade in industrial composting facilities, home compost bins, soil, freshwater, sea water and landfill sites.

Biodegradable materials offer clear advantages over highly persistent materials, but the term “biodegradable” should not be mistaken for environmentally harmless.

Let’s just remember that a biodegradable material released in the wrong place, at the wrong scale, or under the wrong conditions may behave not very differently from a non-biodegradable material.

Understanding the shades of biodegradability moves the conversation beyond simplistic labels. Nature can break many things down, eventually. The more important question is whether it can do so without getting indigestion.

Martin Zaki, Associate Research Fellow in Biomaterials, Deakin University and Alessandra Sutti, Associate Professor, Institute for Frontier Materials, Deakin University

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

Imagine walking into a double-brick house on a scorching 40°C summer day – it feels cool almost straight away. Now imagine stepping into a corrugated tin shed – it feels like an oven. The difference is simple: some materials slow heat down, while others let it rush through.

Soil works in a similar way. Soil in fully functioning condition can act as a thermal buffer: a giant shock absorber for temperature. It holds water and organic matter such as leaf litter, and slows sharp changes in temperature.

But when soil becomes dry, bare or damaged, that protection weakens. During heatwaves, the roots of crop plants may be sitting in rapidly heating soil.

Our new research shows Australia has “thermal gaps” in large areas. A thermal gap is the difference between a soil’s natural ability to absorb heat and keep temperatures steady, and what it is actually doing now after years of farming, land use change and a warming climate. In some areas, especially across southeastern and central Australia, soils are no longer protecting plants from heat as well as they could.

This matters because soil is not just dirt under our feet. It is a buffer against climate change. Soil controls how heat and moisture move between the land and the atmosphere. When soil loses its buffering power, ground temperatures can rise more quickly.

This can reduce plant growth, lower crop and pasture production, and even affect local weather and climate over large areas.

What we did and what we found

To understand where this is happening, we created the first continent-wide map of Australia’s soil thermal buffering capacity.

In other words, we mapped how well different soils can slow heat and keep ground temperatures stable.

We compared each soil’s natural potential with its current condition. This helps show where soil buffering is strong, where it has weakened, and where it may have changed for better or worse.

The results show a clear contrast between soil types.

Clay-rich soils can hold more water and behave more like the double-brick house. They warm and cool slowly, which helps keep roots in a steadier environment.

Iron-rich red and yellow soils in parts of northern Australia, known as Kandosols, also showed good natural capacity and good current condition in our study. These landscapes are still working well as soil heat buffers.

But this does not mean every Kandosol is the same. Soil condition, ground cover, moisture and management still matter.

Sandy soils tell a different story. They naturally hold far less water. When ground cover is low, they lose water faster. Under a hot sun, they behave more like the tin shed. They heat quickly and offer plants much less protection.

That’s why the difference between “just dry” and “hot and dry” is so important. Once dry or degraded soils lose moisture, the sun’s energy heats the ground directly. Roots can become stressed, soil life slows down and crops may decline before the problem is obvious above ground.

This is one reason flash droughts are so dangerous. A flash drought can develop in days or weeks when high temperatures, dry winds and low soil moisture arrive together.

One 2025 global study found flash droughts linked with extreme heat are more severe and take longer to recover from than flash droughts without extreme heat.

For farmers, trouble may already be building below the surface before normal weather warnings capture the full risk.

The good news

The good news is that soil can regain some of its lost heat protection. We can help “re-insulate” the ground with practical farming methods.

One is called “stubble retention”, which means leaving old crop stalks and leaves on the field after harvest rather than burning or removing them.

This layer shades the soil and slows water loss.

Another method, called “cover cropping”, involved growing plants mainly to protect and feed the soil (not necessarily to harvest them). Cover crops keep living roots in the ground, reduce bare soil and add organic matter.

Studies overseas show why this matters. In the US state of Missouri, fields kept covered with plants held more moisture than bare fields. In North Dakota, bare soil was much hotter near the surface than soil protected by barley residue or cover crops.

These methods do not make heatwaves disappear, but they can reduce the stress heat places on soils and crops. Cooler, moister soils may also help surrounding vegetation dry out more slowly, although this is only one part of reducing bushfire risk.

The next step

Our national map is a starting point. It shows where soils may be losing their ability to buffer heat. The next step is to test that risk on real farms.

That means pairing the map with local sensors, such as soil-temperature and soil-moisture probes buried near plant roots. These sensors can show when the soil is drying and how quickly it is heating, and when roots may be coming under stress.

Farm trials can then test which actions work best in different soil types, such as keeping stubble, planting cover crops, adjusting irrigation or reducing grazing pressure.

The results could be turned into simple tools for farmers, such as paddock maps, heat-risk alerts or irrigation guides.

Asking “how dry is the soil?” is no longer enough. We must go further by asking “how fast will this soil heat up once it dries?”

That question matters for irrigation, grazing, crop planning and drought warnings.

If farmers can see heat stress building below the surface, they may be able to act earlier. They can protect ground cover, adjust irrigation, reduce grazing pressure or harvest sooner before the damage becomes obvious above ground.

Soil is one of Australia’s hidden climate defences. Healthy soil stores water, slows heat and protects roots. Damaged soil loses that shield.

By understanding and closing the thermal gap, we can give farms, landscapes and rural communities a better chance in a hotter, drier future.

Amin Sharififar, Postdoctoral researcher in soil security, University of Sydney

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

When we think of marine life, we usually picture colourful coral reefs or dense seaweed forests filled with fish and other critters. The ocean that comes to mind is the one touched by sunlight.

However, most of the ocean is not like that. By volume, roughly 95% of the ocean consists of the permanently dark, cold deep sea. Despite such hostile conditions though, there is life in the ocean’s abyss.

Deep-sea marine sponges are among the organisms that live in these mysterious dark waters. They form “gardens” that are among the largest ecosystems on the planet, some spanning thousands of square kilometres on the ocean floor. They act as ecosystem engineers, providing habitats to many other organisms living on the seafloor.

Individual sponges can also pump and filter thousands of litres of water every day through their bodies. The nutrients they release support other organisms. Yet we know remarkably little about how sponges survive, let alone thrive, in the inhospitable environment of the deep-sea.

Symbiosis with microbes is an important part of how marine sponges live. We’ve been studying deep-sea sponges to better understand life in the ocean’s depths. So far, we’ve found some sponges are packed with microorganisms that use energy from chemical reactions.

This is called chemosynthesis and is commonly found in other deep-sea organisms, such as mussels and tubeworms living in hydrothermal vents – deep-sea “hot springs”.

Our new study, published today in the journal Microbiome, shows sponges and their microbial partners also use a second strategy to make a living in the deep sea.

Two strategies, one sponge

All living organisms produce waste. Just like humans produce urine, many sponges produce ammonia as one of their waste products.

In this study, we analysed the Calyx species of deep-sea sponges from a depth of 830 metres.

About 16% of their microbial partners use the familiar chemosynthesis process. With ammonia as the energy source, they use carbon dioxide dissolved in the water to build biomass – it’s a bit like plants growing through photosynthesis from sunlight, but in the dark.

In well-lit shallow waters, many sponges and corals have photosynthetic microbes that help them build biomass from carbon dioxide. Our findings show that in the dark depths of the ocean, sponges have microbial partners that use ammonia instead of light for the same process.

The remaining 84% of microbial partners are where it gets really interesting. Instead of chemosynthesis these microbes use heterotrophy, which means consuming organic matter to generate energy and biomass (like the vast majority of animals, humans are also heterotrophs).

The problem here is that there’s little organic matter in the deep sea. Whatever falls down from the surface waters, such as dead plankton and algae, gets stripped by bacteria and small crustaceans of anything easily digestible as it sinks through the water column.

So, the little amount of organic matter that reaches the seafloor is generally poor food for the sponge itself. But, as we discovered, not necessarily for its microbial partners.

It turns out the heterotrophic microbes in Calyx sponges have lots of enzymes specialised in breaking down complex compounds, such as xylan and pectin, which make up the hard-to-digest cell walls of algae.

Feeding on these algal skeletons would allow the microbes to thrive and to transform organic molecules into nutrients their sponge host can use.

Protecting what we don’t yet understand

Our study shows that sponges and their microbial partners are complex, biogeochemical reactors. They use and recycle ammonia “urine”, carbon dioxide and hard-to-digest organics to generate biomass.

The biomass can then support the growth of other organisms, such as brittle stars and fish, in turn supporting the broader community of animals living on the dark seafloor.

Unfortunately, these ecosystems are under pressure from human activities. Deep-sea trawling physically destroys sponge gardens. Deep-sea mining, now being actively pursued for rare metals used in batteries and electronics, threatens to disrupt the deep-sea habitat in ways that might take centuries to recover.

The United Nations has recognised deep-sea sponge gardens as vulnerable marine ecosystems, a formal acknowledgement of both their ecological importance and their fragility. But recognition alone is not enough.

If we destroy these habitats before we fully understand their role in carbon transformation, then we may lose a critical piece of Earth’s carbon cycle before fully realising it was there.

Alessandro N. Garritano, Postdoctoral Research Associate, Faculty of Science, University of Sydney; UNSW Sydney and Torsten Thomas, Professor in Microbiology, UNSW Sydney

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

Diesel is critical to Australia. Any supply disruption has immediate and widespread consequences, given Australia imports almost 80% of its liquid fuels. As the energy shocks of the Iran war ripple out, Australia’s leaders have scrambled to shore up supplies of fuel – especially diesel and aviation fuel.

Disruptions to fuel supplies have happened before, such as in 2008 and 2022. This disruption won’t be the last.

What should policymakers do? One option is to ramp up local production of biofuels made not from crude oil but from natural oils such as canola, animal fats – or algae.

As algae researchers, we believe these humble organisms are worth exploring. Making biodiesel and sustainable aviation fuel from these fast growing organisms can be done with much less land than other crops. Technological advances mean the fuel could scale up.

Many biofuels come with trade-offs

Biofuels have gained traction worldwide as efforts to reduce dependence on fossil fuels and meet climate targets accelerate.

The Australian biofuel sector is relatively small. Farmers exported about 6 million tonnes of canola in 2023–24 to be turned into biofuels overseas.

The Australian government last year announced A$1.1 billion in incentives to boost low-carbon fuels such as biofuels.

Biofuels from corn, soybean, canola and palm oil have boosted fuel security in some nations. Brazil produces 22% of its own transport fuel from biofuels, while biofuels account for 6% of the fuel used in the United States.

The problem is, biofuels often come at an environmental cost. A third of all US corn is used to make ethanol for fuel.

What’s so good about algae?

The type we’re interested in are microalgae, single-celled organisms, not macroalgae such as kelp and other types of seaweed.

These small organisms can grow exceptionally rapidly and hold high concentrations of oils. Many microalgae species can double their weight every day. Nannochloropsis and Chlorella are the two main types used to make oil.

Traditionally, algae was grown in large, shallow outdoor pools called “raceways”. They’re now increasingly grown in high-efficiency algae bioreactors.

Algae can be processed using proven technologies such as hydrothermal liquefaction to produce biodiesel able to be used in existing trucks and machinery. It can also produce sustainable aviation fuel.

Compared to crop-based biofuels, algae has several advantages. It doesn’t compete with food production and it can be grown on non-arable land or in industrial facilities. Some species can grow in saltwater or even treat wastewater while using it for growth. If algal facilities are located near heavy industry, carbon emissions can be captured and used for algal growth in a form of carbon storage.

Algal fuels needs much less land than conventional biofuels. A hectare of algae can yield more than 58,000 litres of oil per year. By contrast, a hectare of corn produces just 172 litres.

What are the barriers?

Interest in algal fuel dates back many decades. Oil shocks in the 1970s and 1990s drove significant research into algae-based fuels. But when oil prices fell, algal biofuels were no longer cost-competitive.

Since the 1990s, technologies have matured and policy settings become more favourable. Efforts to reduce fossil fuel use have put an implicit or explicit price on carbon. Mandates to increase output of sustainable aviation fuel are emerging in the European Union.

Fossil fuel price shocks in 2022 and 2026 have nudged authorities to seriously explore alternatives. Sovereign fuel security has become a strategic priority. Both the United Arab Emirates and the US are exploring algal fuels as a long-term strategic asset.

Algae for Australia?

Australia would be well placed to explore the potential of algal fuels. It has plenty of non-arable land, abundant sunlight and some of the world’s best algae research capabilities. Plus, it depends very heavily on imported diesel and aviation fuel.

Our research group and many others have been systematically working to overcome previous limitations of algal biofuels. We now know how to produce high-quality algal fuels and scale up production at costs low enough to challenge fuels derived from crude oil.

The first step would be to invest in pilot projects to prove the technology can work at scale under real-world conditions. Overseas, similar pilots have been set up next to industry to test the use of carbon capture, or alongside research partners.

If this is successful, the next step would be to build facilities in regional locations where fossil diesel is in demand and expensive to transport – and where algae can offer a dual benefit by treating wastewater or capturing carbon.

Over time, the versatile technology could be expanded, as algae can produce not only biodiesel but also other useful products such as edible protein for animal feed and biochar, highly porous charcoal able to soak up pollutants such as heavy metals.

Algae deserves our attention

Many previous efforts to scale up biofuels have run into problems over environmental impact or cost.

It’s important to be sceptical of claims of the next big thing. But it’s also important not to overlook the potential of humble technologies such as making fuel from algae.

As leaders look for ways to bolster fuel security, algae deserves a closer look.

Peter Ralph, Distinguished Professor of Marine Biology and Executive Director of the Climate Change Cluster, University of Technology Sydney; Alexandra Thomson, Industry Engagement Manager, Climate Change Cluster, University of Technology Sydney, and Martin Lloyd, Strategic Lead, Research Translation, University of Technology Sydney

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

Rice feeds more than half the world. From terraced paddies in Southeast Asia to irrigated fields in China and India, it underpins daily meals for billions of people.

But the same flooded soils that help rice thrive also create ideal conditions for microbes that release climate-warming gases.

In a new study, our team of environment and agriculture scientists found that greenhouse gas emissions from rice paddies have nearly doubled globally since the 1960s, averaging about 1.1 billion tons of carbon dioxide-equivalent emissions per year in the 2010s. That’s roughly equal to the annual emissions of 239 million cars.

This makes rice-growing the largest emissions source in agriculture outside of livestock, and rice demand is expected to keep rising.

Farmers have ways to reduce their rice crops’ emissions without lowering their yields. If every grower used the best currently available “climate-smart” options, we found that global rice emissions could be reduced by about 10% by midcentury. However, greater reductions are needed to slow climate change, which would require developing additional, more effective strategies.

Why rice emissions have increased

Rice emissions have risen for two reasons: the expansion of rice cultivation area and the intensification of management practices.

Just over half of the global increase is from the expansion of rice-growing areas. In Africa, for example, the rice-growing area has roughly doubled since the 1960s, helping drive a twofold rise in methane emissions in the region.

At the same time, rice farmers are using more fertilizers and organic amendments, such as straw and manure, planting more productive rice varieties and growing the plants closer together. The result is more rice but also more greenhouse gas emissions.

We found that one practice in particular – leaving rice stalks in the field after harvest and then plowing them into the soil to improve soil fertility – was responsible for about 18% of rice’s increase in overall net emissions since the 1960s. The reason: It increases the organic matter in the soil, which microbes then decompose, creating more methane emissions.

Rising global temperatures further accelerate microbial activity in the soils, meaning even more emissions.

Fertilizer is another major contributor to emissions. Use of synthetic nitrogen increased by about 76% after 2000, boosting nitrous oxide – another powerful greenhouse gas. It contributed about 9% of the increase in total global net emissions from human activities.

Irrigation practices also affect emissions. In the past, irrigated rice paddies were kept flooded throughout the growing season, resulting in constant greenhouse gas emissions produced by microbes that thrive in the wet environment. Over the past two decades, however, more farmers have used intermittent flooding – draining their fields periodically.

This change has lowered methane emissions compared with keeping the paddies continuously flooded. However, we found a slight increase in nitrogen oxide emissions as soils cycled between wet and dry, which induces microbes to transform nitrogen in organic matter into nitrogen oxide gases, particularly nitrous oxide.

Climate impact of rice production

Putting a full climate price tag on rice production is harder than measuring one greenhouse gas at a time.

Rice paddies emit methane and nitrous oxide from wet or flooded soils. They also remove carbon dioxide from the atmosphere as rice grows, and they lose carbon from their soils between crop seasons.

A credible global estimate requires consistently accounting for different gases and soil carbon changes, as well as the uncertainty involved in tracking data across space and time.

To do that, we combined three approaches:

• An ecosystem computer model allowed us to simulate crop growth, water conditions and soil processes to estimate changes in methane, nitrous oxide and soil carbon together.

• An artificial intelligence-powered machine learning model improved estimates where measurements were sparse to cover all rice regions in the world.

• And a meta-analysis of more than 1,200 field experiment sites provided direct evidence of how practices such as irrigation, fertilizer use and management of crop residue affect emissions.

Together, they allowed us to quantify emissions from 1961 to 2020, determine what drove those emissions, and test the potential of mitigation techniques under future climate conditions.

What works and doesn’t for climate mitigation

There are ways to reduce emissions from rice production without sacrificing yield.

Our study found that reducing fertilizer use and residue applications, managing irrigation to allow dry periods in between flooded ones and reducing tillage could, together, reduce global greenhouse gas emissions from rice by about 10% by midcentury.

We were surprised to find that replacing chemical fertilizers with more organic choices is not always better from a greenhouse gas perspective, although it is valued in organic farming.

Maintaining moderate amounts of straw and other crop residue in the field can help boost soil fertility, but too much can increase methane emissions and accelerate the loss of carbon from the soil. Another option is to convert part of the residue into biochar – burning it under low-oxygen conditions before mixing it into flooded soils. Biochar can help stabilize soil carbon and reduce methane emissions.

Improving water management can be a powerful tool for reducing emissions. Periodically draining fields reduces methane production, though it may slightly raise nitrous oxide emissions. This strategy is particularly effective in regions with reliable irrigation infrastructure, including large parts of Asia.

Managing fertilizer use is also an effective mitigation strategy, particularly in highly fertilized systems, including parts of China and South Asia. Excess nitrogen increases nitrous oxide without a clear increase in crop yields and increases water pollution. Reducing overapplication of nitrogen reduces emissions and water pollution, and it saves farmers money in the process.

The effects of tilling, the practice of plowing the soil between crop seasons, have large regional differences. Reducing tilling is often promoted as climate-friendly, but we found that it does not always minimize net emissions in flooded systems. In rice fields in temperate zones, including much of the U.S. and China, cooler conditions can limit methane production, allowing the soil carbon benefits of reduced tilling to outweigh the methane risk. In warmer, persistently flooded systems, however, low-oxygen conditions can boost microbial activity, increasing methane production and accelerating soil carbon loss.

Overall, we found that no single practice works everywhere. Each region will need to assess the most effective practices for reducing emissions.

A climate ceiling for rice production

The bottom line is both hopeful and sobering: Targeted sets of optimized practices can deliver meaningful emission reductions without losing rice yields, but the total global possible reduction is modest.

To reduce emissions further will require better guidance to help farmers determine the best levels of organic amendments, such as straw or biochar, and new approaches that can reduce emissions without undermining rice production.

Hanqin Tian, Director and Institute Professor, Center for Earth System Science and Global Sustainability, Boston College; Jingting Zhang, Research Scientist at the Center for Earth System Science and Global Sustainability, Boston College; Pep Canadell, Chief Research Scientist, CSIRO Environment; Executive Director, Global Carbon Project, CSIRO, and Shufen (Susan) Pan, Associate Professor of Environmental Science, Boston College

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

Electric vehicles (EVs) are no longer a niche technology. Australians are buying them in growing numbers as petrol prices bite and the federal government continues its tax exemption until 2029.

The challenge now is to build the supporting charging infrastructure.

Fast and ultrafast chargers, which recharge a typical EV in 10–15 minutes, have proven to be commercially attractive, with the number of these chargers growing by 22% in 2025. This is because drivers will pay a premium to recharge quickly while travelling.

But they aren’t appropriate for everyday use. They’re too expensive, and place stress on EV batteries and the grid. They also risk aggravating metro-regional divisions, with regional communities hosting infrastructure that serves the needs of city travellers and not locals.

So, what’s the answer? Our new research crunched the data from 27,000 kerbside charging sessions and made it public in an effort to find out.

A kerbside revolution

For EVs to truly go mainstream, Australia needs more public “kerbside” chargers. These can be microwave-sized boxes mounted to power poles or slightly larger boxes fixed to the kerb. These offer affordable, reliable and convenient recharging in 2–8 hours (depending on the charger and EV).

They are needed for apartment residents and renters without access to private off-street charging, as well as EV drivers who need to charge between trips.

While the need for more kerbside chargers is widely agreed, there is fierce debate about who should deploy them. Electricity distribution companies are lobbying to do so – they would add the cost to all consumer electricity bills. Private operators oppose this because they want to protect their market share.

The federal government is proposing this way forward: $40 million in taxpayer funding, electricity distributor funding through consumer bills, and private investment.

This proposal would allow private investors to cherrypick sites that are expected to be profitable, such as where EV uptake is already high and many residents live in apartments. Other kerbside charging sites would be developed by electricity distribution companies.

In the scramble for position, one question risks being overlooked: what serves the public interest best?

What we need to do

Our new research addresses this question with three guiding principles, and open access data and analysis.

It finds kerbside charging must be delivered in a way that is fast, fair and adaptable in the future.

Rapid EV adoption brings associated advantages in terms of pollution, health, fuel security and economic benefits.

A fair uptake of kerbside charging would see all members of society share in its benefits, not just the predominantly wealthy recipients of the federal government’s current Fringe Benefits Tax subsidies.

Australia’s 20 million domestic cars – and almost all heavier vehicles – will eventually be electric, so we need to prepare for this. And we need to avoid the kind of hiccups Australia experienced when the grid wasn’t ready for millions of rooftop solar systems.

Kerbside charging is profitable

Our research team at UNSW, in partnership with Waverley, Woollahra and Randwick Councils in New South Wales, has processed and made public data from 27,000 kerbside charging sessions.

Our most significant finding is that some kerbside charging sites are quite profitable, but there are not enough of them. And they are not profitable enough to make kerbside networks commercially profitable overall.

This level of profitability is consistent with kerbside charging being public infrastructure – providing an essential service at affordable rates.

What about current proposals?

We analysed the federal proposal, which would to let private investors choose the most attractive sites while the rest were developed through electricity distribution companies. We found there was a risk this would increase long-term costs for electricity customers.

This is because profitable sites would not cross-subsidise unprofitable – but still important – sites. And this might outweigh the benefits of having private investment cover some of the costs otherwise carried by taxpayers and electricity customers.

On the other hand, a proposal that distribution companies should recover the cost of charging hardware from electricity customers and not charge EV drivers for access is, we believe, too generous. It places an unfair burden on all electricity customers.

A better way

There are other approaches that might be more fair.

For example, distributors could use a combination of taxpayer subsidies and charging EV drivers a modest fee for use. This would only be feasible if their charger networks included profitable sites.

In general, it is fairer to get funding from the broad and progressive tax system than from all customers’ electricity bills – especially because electricity distribution companies are split between city and country areas.

One way to deliver fast and fair deployments is involve local councils. Their role has been largely overlooked in federal and distributor proposals. But their insights are invaluable for selecting sites that will be well used. And their planning expertise is fundamental to creating high-quality charging sites.

How to balance the costs and benefits of the much-needed kerbside charging expansion across EV drivers, taxpayers and electricity customers is a challenge for governments and regulators. They must focus on delivering public benefit that makes the EV transition fast, fair and adaptable.

Bjorn Sturmberg, Senior Research Fellow, Collaboration on Energy and Environmental Markets, UNSW Sydney

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

Roughly 500 million years ago, a strange event in the evolution of life on Earth seems to have taken place.

The known fossil record from this time, which falls within the Cambrian period, contains a missing chapter. Palaeontologists refer to it as the “Furongian gap”. And it’s striking because there is an explosion of biodiversity within the fossil record both immediately before and after it.

This decline has been considered evidence for a real biological crisis – one driven by environmental instability, changing ocean chemistry, cooling climates, a lack of oxygen in ancient seas, or a combination of these factors.

Our new study, published in the journal BMC Biology, provides new evidence for an alternative idea. The Furongian may not represent a true collapse in biodiversity, but rather a gap in where scientists have looked and what kinds of rocks have been studied.

It’s a reminder of how incomplete our understanding of Earth’s history remains.

A rare group of fossils

We describe a new 500-million-year-old arthropod from Québec, Canada. Arthropods are animals with exoskeletons – that is, skeletons on the exterior of their bodies.

The fossil belongs to a rare group of early arthropods related to the lineage leading to spiders and scorpions. Importantly, it comes from a geological setting that scientists have not previously recognised as being notable for preserving fossils at this time in Earth’s history.

The fossil itself is named Magnicornaspis garwoodi. The animal belongs to the corcoraniids – an enigmatic group of early arthropods that have broad head shields, segmented bodies, and defensive spines.

Corcoraniids remain exceptionally rare globally. Only a handful of species are known from the Cambrian and Ordovician periods.

Our specimen is unique for its two large forward-projecting spines extending from the head. These exaggerated spines distinguish the species from previously known relatives. They suggest defensive adaptations within the group evolved earlier than previously recognised.

Sitting in a museum drawer for decades

The specimen was originally collected in 1962 during geological mapping near Sainte-Anne-de-la-Pocatière in Québec. It came from mudstones within the Rivière-du-Loup Formation. This formation was deposited in relatively deep marine slope environments during the late Cambrian.

This represents quieter offshore conditions where fine mud settled through the water column. These rocks have received relatively little palaeontological attention, making them ideal for reassessment.

The specimen sat largely overlooked within the collections of the Smithsonian National Museum of Natural History in Washington DC for decades. This highlights one of the most important aspects of palaeontology: major discoveries do not always emerge directly from fieldwork.

Museum collections contain enormous quantities of under-studied material collected during geological surveys and expeditions over the past century. Revisiting these collections with modern techniques can fundamentally reshape understanding of ancient ecosystems.

More treasures awaiting discovery

Our discovery adds to a growing body of evidence that challenges the notion of a barren late Cambrian world.

Studies from China and Sweden have documented other well-preserved fossils from about 497–485 million years ago.

Together, these discoveries suggest ecosystems may have remained diverse and ecologically complex during this time.

The new Québec fossil expands this picture geographically. Our specimen demonstrates the ancient Appalachian margin of eastern Laurentia, the ancient continent that included much of present-day North America and Greenland, was a site of excellent fossil preservation.

This broadens the known distribution of soft-bodied fossil preservation during the interval. It also hints that comparable deposits may await discovery elsewhere.

The Furongian gap therefore may not represent a biological collapse at all. Instead, it may partly reflect an “anthropogenic bias” in the fossil record – a distortion introduced by where humans have searched, collected, and studied fossils.

Each newly discovered Furongian exceptional fossil site narrows this supposed gap. They reveal increasingly sophisticated ecosystems thriving during the late Cambrian.

Entire groups of organisms – and possibly even ecosystems – may still await discovery within museum drawers or poorly studied rock formations. The late Cambrian lasted millions of years across vast ancient oceans. Yet only a tiny fraction of its environments have been systematically explored for soft-bodied preservation.

The next major fossil discovery may not come from a newly discovered outcrop in a remote desert. It may already exist, inside a museum cabinet, collected decades ago and waiting for someone to recognise its significance.

Russell Dean Christopher Bicknell, Post-doctoral researcher in Palaeobiology, Flinders University and Julien Kimmig, Head of Palaeontology Division at the Natural History Museum Karlsruhe

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

Along the California coast, from Bodega Bay to Morro Bay, commercial fishing boats have started pulling in salmon for the first time in three years, and local salmon are once again appearing on restaurant menus and in seafood markets across the state.

California’s commercial ocean salmon fishery began reopening in May 2026 for the first time since a population crash led to a three-year closure.

But while the reopening, happening in phases and with limits, is welcome news, it does not mean the underlying problems have been solved.

The Pacific Fisheries Management Council, established by Congress to oversee West Coast fisheries, closed the salmon fishery in 2023 after populations of fall-run Chinook salmon collapsed to critically low levels, down 85% from the average population before 2005.

The immediate cause of the latest closure was the extreme drought from 2020-2022 that devastated salmon survival as river levels fell and the water heated up. But more than drought pushed the fishery to the brink. The underlying system of water management, hatchery practices and habitat loss have also eroded the salmon population’s ability to quickly recover from difficult years.

We study changing fish ecology in California. The state has the knowledge to create a more resilient system that can help salmon better withstand California’s increasing climate whiplash. But without significant changes in three key areas, we believe today’s good news for salmon could be short-lived once again.

California’s changing salmon population

The Sacramento-San Joaquin Basin once hosted one of the most productive salmon habitats in the U.S. Salmon depend on cold water for reproduction and a productive ocean for adult growth. California provided both in abundance, with spawning streams fed by snowmelt and ocean productivity boosted by seasonal upwelling of nutrients along the coast.

California’s rich mosaic of spawning streams, floodplains and tidal wetlands supported different age classes and migrational timings, making the fish population diverse enough to survive the state’s droughts and other environmental fluctuations.

Much of that stabilizing diversity has been lost over the decades. Massive dams now block access to historic spawning habitat. Rivers have become disconnected from floodplains. Water diversions for farmland alter the timing and temperature of river flows.

The loss of ecological complexity, along with a salmon population that is increasingly raised in hatcheries, resulting in less diversity in both genetics and behavior, has allowed a pattern of boom-bust cycles that can leave the fishery struggling during droughts and marine heat waves.

These population fluctuations have worsened over time. Population crashes caused fishery closures in 2008-2009 and again in 2023-2025. Avoiding a repeating pattern of closures requires restoring the ability of salmon populations and their interconnected network of habitats to withstand droughts, heat waves and other environmental shocks without collapsing.

Managing water

One of the biggest opportunities for salmon recovery lies in smarter management of California’s water resources.

Salmon evolved in rivers with seasonal pulses of cold water from snowmelt and winter storms. Today, dams and reservoirs tightly control those flows to deliver water to cities and agriculture. But scientists now understand much more about how the timing and temperature of water releases affect salmon survival.

Juvenile salmon survive best when rivers receive periodic “pulse flows,” or temporary increases in water that help young fish migrate downstream. Cold-water releases can also help prevent rivers from heating up to lethal temperatures during critical spawning, rearing and migration periods.

The infrastructure to create these pulse flows already exists in many watersheds where dams control the water flow. The challenge is managing water flows to meet the needs of both salmon and people.

Researchers have developed forecasting models that combine snowpack, temperature and river-flow data to help water and fisheries managers identify when targeted water releases could provide the greatest ecological benefit.

Rethinking hatcheries

California hatcheries release millions of young salmon every year. Without them, the reopening would not be possible.

But hatcheries can also unintentionally reduce the diversity that helps make salmon populations resilient to environmental changes.

Hatcheries have historically focused on maximizing the number of fish produced. But they tend to release fish of a similar size over a narrow time range, making the success of each group more vulnerable if they face poor river and ocean conditions.

In some cases, hatcheries have bypassed overheated rivers and trucked fish to the ocean, releasing them directly into San Francisco Bay. This approach can mean more fish survive to breeding age, but those fish are less able to find their way back to traditional spawning grounds.

Hatcheries can also cause harm to natural populations through competition, disease and by reducing genetic variation in the population. However, if they employ careful genetic management, they can preserve more of the natural diversity found in wild salmon populations. This includes changing hatchery practices to avoid unintentionally favoring fish that thrive under hatchery conditions but struggle in the wild.

Restoring habitat

Loss of spawning and rearing habitat is one of the biggest long-term challenges for California salmon.

Dams have blocked access to vast areas of historical spawning habitat. The recent removal of dams on the Klamath River represents one of the largest river restoration projects for salmon habitat in U.S. history.

While dam removal is effective, it can also be costly, time consuming and politically contentious. Other approaches to getting salmon above dams, such as creating fish passages and trucking operations, can also help restore access to historical spawning habitat.

Reconnecting rivers, many of which have been restricted by levees, to seasonal floodplains can dramatically improve growth and survival for juvenile salmon and increase their resilience to climate change.

Floodplains act like productive nurseries, providing a food-rich habitat where young fish can grow rapidly before migrating to the sea. Modifying flood-control structures to allow rivers to spread out during parts of the year can help the salmon population. Winter-flooded rice fields can also serve as seasonal habitat for juvenile salmon. Young salmon raised on these flooded fields grow faster than fish confined to river channels, suggesting that agricultural landscapes could be large-scale opportunities for floodplain restoration.

Coordinating solutions

The reopening of California’s commercial salmon fishery is good news for coastal communities, but coordinated management is needed to strengthen California’s salmon system long term.

These solutions do not recreate the California of 200 years ago, but combined they can rebuild some of the ecological complexity that salmon need to survive in a rapidly changing climate. Importantly, all these solutions, from water to hatcheries to habitat, need to be applied together in order for salmon to complete their complex life cycle. Any single action in isolation, benefiting just one life stage, is unlikely to work.

The benefit is a thriving salmon fishery into the future.

Eric Palkovacs, Professor of Ecology and Evolutionary Biology, University of California, Santa Cruz and Steven T. Lindley, Researcher in Fish Ecology, University of California, Santa Cruz

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

There is not yet much research on the effects of heatwaves on bees. What little there is focuses on super extremes of weather that would kill an adult bee.

However, my new research with colleagues shows that UK populations of solitary bees may be much more sensitive than previously thought to the kinds of extreme weather we are now seeing regularly.

To find out what happens to bees during hot weather, my team recreated the three-day UK heatwave of July 2022. We subjected a group of developing larvae of red mason bees to three days where temperatures peaked daily at 40°C.

Red mason bees are common solitary bees found in UK gardens, and are important pollinators of apples and other fruits. At the same time, a control group experienced normal July temperatures for Hull, where the study was conducted, peaking daily at about 25°C.

After that, we treated both groups identically and allowed them to spin their cocoons and hibernate as normal. Nine months later, all the bees emerged fine, so it appeared initially that the heatwave had had no effect.

But this was before we dissected the bees to look at their reproductive health.

Staggeringly, in males from the heatwave group, sperm activity had dropped by half compared with the control group, and sperm counts by one third. In females, there was a 15% reduction in both the size and the number of developing eggs.

The heatwave had wrecked their fertility, especially in males.

Reduction of sperm motility in bees during heatwave

These numbers are shocking because they suggest solitary bee populations are much more sensitive to weather extremes than we thought, and that this should be factored into calculations of the broader effects of climate change. While bees did not die outright, their fertility was severely affected.

This means that a heatwave one year could lead to a drastic drop in the number of bees the following year, and therefore less efficient pollination for key crops like apples, cherries and oilseed rape.

This would leave commercial fruit growers even more reliant on temporarily renting honeybee hives, commonly called “hire-a-hive” schemes, to combat pollination deficits. This is at a time when research increasingly shows that wild bees, whose services come for free, are better pollinators than honeybees.

What else happens in heatwaves?

In honeybees and bumblebees, living together as a group is the key to withstanding weather extremes. With their social hives, honeybees can flexibly respond to periods of heavy rainfall and strong winds by rapidly reallocating the tasks that worker bees perform – switching from nest maintenance to foraging, for example.

Honeybees and bumblebees are also able to respond to temperature changes. They maintain their nests within strict temperature limits, with some workers switching to becoming living radiators when temperatures drop, buzzing their wing muscles to produce heat that keeps the brood at the ideal growing temperature.

Bumblebee nests begin with a single queen hibernating over winter and then working alone to build up her brood. New research is revealing secrets of their resilience: for example, hibernating bumblebee queens can survive underwater for up to a week when their nest is flooded.

However, honeybees and bumblebees are not most bees.

Unlike honeybees and bumblebees, most bees are solitary, which means they don’t have social nestmates to help them when times get tough – they work entirely on their own. Nests of these solitary bees are at the mercy of the elements, so solitary bees are much more vulnerable to climate change than social bees.

Of course, heatwaves are not the only threats to bees. They have an array of other nightmares to cope with, including pesticides, diseases, nutritional stress and loss of habitat.

The priority now is to investigate how bees affected by heatwaves also cope with these other problems. Our lab heads up a government-funded study looking at how climate change affects the nutritional needs of growing wild bees, and how parent bees respond to these needs.

Excitingly, we are beginning to see patterns indicating that growing bees require different balances of nutrients when they are reared at different temperatures. We are now testing whether bee mothers are sensitive to these requirements, and can adjust the pollen they gather to compensate.

Extreme hot weather is becoming more prevalent, even in cooler countries. These studies show that severe weather, while not necessarily killing bees outright, has the ability to seriously damage the bee population – with long-term consequences for pollination as well as the human food chain.

James Gilbert, Senior Lecturer in Zoology, University of Hull

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

America’s bees and beekeepers are losing a valuable ally just when they need its help most.

The U.S. Department of Agriculture plans to soon close the Beltsville Agricultural Research Center, a 6,500-acre agricultural research station in Maryland that is home to the nation’s premier bee research and disease diagnosis hub, the Beltsville Bee Research Lab.

The closure comes at a critical moment for bees. In winter 2025, many beekeepers lost over half their operations as pesticide-resistant varroa mites spread, bringing deadly viruses. The losses have led to low honey production, and soaring fuel costs have made shipping bees cross-country for agricultural pollination increasingly expensive, further stressing the industry.

During my 14 years researching bees and beekeepers, and in writing my new book, “Bitter Honey: Big Ag’s Threat to Bees and the Fight to Save Them,” I’ve seen beekeepers frequently turn to the USDA bee labs for support during crises like this. Because honey bees contribute roughly US$15 billion to U.S. crop production – native and managed bees pollinate more than 130 crops – these labs help stabilize the nation’s food system.

Today, that scientific support system is at risk, just as beekeepers face their greatest challenges and native bee populations continue to decline.

Why the Beltsville Bee Lab matters

USDA’s bee researchers have served beekeepers for over 130 years, including nearly 90 years at the Beltsville station. One of the Beltsville Bee Lab’s standout services is its bee disease diagnostic service, where beekeepers can send samples for analysis free of charge.

Since the early 2000s, Beltsville researchers have helped beekeepers respond to varroa mites – a primary driver of high colony losses each year. Now, the lab is helping them prepare for a deadlier mite that is infesting honey bees in Asia, Tropilaelaps mercedesae, or “tropi” mites – by developing detection and response protocols that beekeepers can use to protect their colonies.

While the Beltsville Bee Lab supports beekeepers nationwide, it’s located in a prime farming and beekeeping region. Its closure would leave a critical research gap in the Northeast, where beekeepers help pollinate cranberries, squash, blueberries and other crops.

Its location has also allowed researchers to conduct extensive studies on winter colony losses, research that would be difficult to replicate at the remaining USDA bee labs, which are primarily located in more temperate climates.

Hidden costs of bee lab closures

The USDA states that it will decommission the entire Beltsville Agricultural Research Center because building maintenance and renovations would cost an estimated $500 million. But closing the lab could cost beekeepers, farmers and consumers far more.

For example, in winter 2025, beekeepers experienced their highest losses in U.S. history. Many opened their colonies in January that year and found that more than 60% of their colonies had died – nearly 1.7 million colonies nationwide. Beekeepers contacted Beltsville, and researchers quickly flew out to test affected colonies for pesticide residues, diseases and varroa mites, data that could help guide beekeepers’ treatment response.

A few weeks later, as the lab’s scientists were working on the crisis, the Trump administration fired probationary researchers and staff at the bee labs, along with thousands of other employees across the USDA. The Beltsville team was hobbled, and the remaining staff restricted from communicating with beekeepers.

Because of the communication lockdown, it took nearly six months for researchers to deliver their findings. By then, the season was over and beekeepers had been forced to navigate the crisis on their own.

The loss of bee colonies ultimately cost beekeepers an estimated $600 million in lost honey production, pollination income and colony replacement costs – far more than the one-time projected costs to modernize the entire Beltsville Agricultural Research Center.

These losses can hit consumer pocketbooks too.

When beekeepers lose nearly half their operations, they often need to charge farmers more for pollination services to stay afloat. Those added costs can ripple through the food system and affect what everyone pays for the fruits, vegetables and nuts that depend on pollinators.

More cuts planned to US pollinator research

The Beltsville Bee Lab closure is not an isolated case. The administration has proposed eliminating the U.S. Geological Survey’s Ecosystems Mission Area, a move that could defund the USGS Bee Lab, an essential resource for research on native bees.

It also plans to decommission 16 USGS research centers nationwide, including the Northern Prairie Wildlife Research Center in North Dakota, the highest honey-producing state in the nation. For decades, beekeepers have brought colonies to forage on grasslands in the region. Researchers have been tracking how the shift from grasslands to crops has affected honey bee health and beekeeper revenue.

The U.S. Forest Service also faces widespread cuts, including the planned closure of 57 of its 77 research stations throughout the United States. Since the Forest Service manages over 193 million acres of federal lands that support native plants and pollinators, those closures could affect crucial pollinator habitat as well.

These closures risk a severe brain drain.

When the first Trump administration moved the USDA Economic Research Service from Washington to Kansas City, Missouri, in 2019, the agency lost over 75% of its experienced research staff. A recent survey suggests that history may repeat itself. If the reorganization goes through, farmers and beekeepers will lose experts with decades of institutional and technical knowledge.

The Beltsville Bee Lab is a key part of the often-unappreciated federal research infrastructure that supports the health of pollinators and the nation’s food supply.

If the USDA and the USGS move forward with their plans to close bee labs and research sites, the result could be slower responses to bee threats, weaker tracking of native bee populations and diminished pollinator habitat for bees – all of which raise costs and risks for beekeepers, farmers and everyone who depends on the food system.

Jennie L. Durant, Research Affiliate in Human Ecology, University of California, Davis

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

When rivers degrade, pests spread or drought hits crops, nature sends a bill.

Yet it’s one rarely itemised on any balance sheet, because nature’s contribution to business remains genuinely hard to quantify.

One major obstacle is data. Businesses rarely disclose their precise operating locations, while detailed ecological information that can be linked to specific firms is scarce in most countries.

This is despite healthy ecosystems underpinning large parts of the economy, from agriculture and forestry to tourism and food production. As the US economist Herman Daly famously put it, the economy is “a wholly owned subsidiary of the environment, not the reverse”.

As part of a growing body of global research now trying to put hard numbers on what nature actually contributes to the economy, we looked at New Zealand’s case.

Our newly completed research turned up a compelling finding: firms operating in areas with richer biodiversity are measurably more productive.

Measuring nature’s value

We chose New Zealand because it publishes detailed sets of business and environmental data. That allowed us to compare company performance with local ecological conditions across different regions.

We combined measures of sales and employment with biodiversity indicators – including river health, drought risk, land use and invasive species – used as part of international reporting obligations.

We also drew on the Cobb-Douglas economic model – commonly used to estimate how labour and investment drive economic output – to help get a clearer picture of nature’s economic contribution as a factor of production.

We found businesses operating in areas with healthier ecosystems tended to generate higher sales and profits.

Across more than 117,000 observations spanning 2009 to 2022, a 1% increase in natural capital was associated with sales about 0.13% higher and profits about 0.15% higher on average. The relationship remained consistent across multiple measures of biodiversity and ecosystem health.

We also found a trade-off. Areas with more roads, buildings and commercial activity tended to have lower biodiversity scores but higher sales. In other words, businesses can still grow while degrading nature – but may lose some of the productivity benefits healthy ecosystems provide.

When green policy boosts productivity

We also tested whether major environmental policies changed this relationship.

One was New Zealand’s Predator Free 2050 programme. The other was a broader package of reforms introduced from 2017, including freshwater rules, tree-planting incentives, restrictions on offshore oil and gas exploration, limits on single-use plastics and the Zero Carbon Act.

Because these policies targeted ecosystems rather than directly subsidising firms, they helped us test whether improvements in nature were linked to changes in business performance.

We found the relationship between healthy ecosystems and business performance became even stronger following both interventions, with the productivity effect associated with 1% more natural capital increasing business performance by a further 0.05%. The effect was strongest in the year immediately afterwards.

This suggests investment in ecological restoration and protection can generate economic benefits beyond the environmental sector itself.

The strongest effects appeared in agriculture and forestry, where business outcomes are closely tied to the health of surrounding ecosystems.

Farms and forestry operations in less intensively developed areas – with lower population density and less infrastructure – showed markedly stronger productivity gains linked to natural capital.

In these primary industry regions, a 1% increase in natural capital was associated with sales that were additionally higher by 0.71% to 0.81% above the economy-wide average.

This is unsurprising. Healthy soils, clean water, fewer pests and intact native vegetation can support food and fibre production while lowering costs.

The benefits were also evident in service industries, construction and retail, although spread more evenly across a broader range of ecological factors.

An unseen benefit

These New Zealand insights are important for the growing global effort to better understand the economic value of nature. Globally, the services ecosystems provide to business are estimated to be worth trillions of dollars annually.

While new frameworks such as the international Taskforce on Nature-related Financial Disclosures are beginning to emerge, hard evidence linking ecological conditions to firm-level productivity has remained limited.

Our study suggests biodiversity is not simply an environmental concern. Differences in ecosystem health across regions and industries are associated with measurable differences in business performance.

Businesses should view the natural environment as a productive asset every bit as real as machinery or labour, not just background scenery.

And for policymakers – particularly in countries reliant on primary industries, such as New Zealand and Australia – ecological investment and economic productivity shouldn’t be taken as opposing goals.

Nature, it turns out, has been doing more economic work than some have given it credit for.

Paul Griffin, Distinguished Emeritus Professor of Management, University of California, Davis and Martien Lubberink, Associate Professor of Accounting and Capital, Te Herenga Waka — Victoria University of Wellington

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

Increasingly, the world’s oceans are telling us our climate system may be changing faster and more dramatically than expected.

These new insights are made using a vast global network of instruments – from drifting floats and moored buoys to research vessels and underwater gliders – that quietly and continuously feed data to scientists.

Known as the Global Ocean Observing System (GOOS), it provides the fine-grained data that scientists need to detect changes, test climate models and refine projections of future risk.

But now there is rising concern this system itself is at risk – just when the world needs it most.

The hidden system behind modern forecasting

The GOOS is often described as a form of climate monitoring – but it is much more than that. It can best be understood as a network of complementary observing systems, each designed to capture different parts of the ocean in different ways.

Some 4000 autonomous Argo robotic floats sink every ten days down to 2000m depth, before rising to the surface to transmit temperature and salinity profiles to ground stations via satellite.

Underwater gliders target eddies, coastal currents and continental margins where floats cannot go. Elephant seals fitted with sensors collect data beneath polar sea ice in regions no other instrument can easily reach.

Each of these platforms answer questions the others cannot. And ocean observations collected by them now underpin many of the forecasting systems that modern societies rely on every day.

That includes the numerical weather models used to generate daily forecasts, which continuously ingest ocean data to predict evolving weather conditions, as well as newer artificial intelligence-based forecasting systems.

The same is true for hurricane and cyclone forecasts, as well as seasonal forecasting used to anticipate drought, harvests and energy demand. Marine heatwave warnings, sea-level projections and efforts to understand major current systems also rely on sustained long-term observations beneath the ocean surface.

These observations are key for monitoring El Niño climate patterns – including a major event already underway and likely to peak late this year – and major current systems such as the Atlantic Meridional Overturning Circulation.

While satellites can measure surface conditions, they still cannot directly observe the deeper waters where heat accumulates, currents reorganise and the precursors of future weather are already forming.

In short, the GOOS underpins everything from tomorrow’s storm warnings to next century’s climate adaptation plans.

Yet our newly published analysis suggests the system delivering those observations is far more fragile than most people realise.

We found that if observations from a single major contributor, the United States, were withdrawn from GOOS, errors in estimates of how fast the ocean is warming would jump by 163% – worse than randomly losing 80% of all global ocean data.

The reason is largely geographical: US instruments cover every ocean basin and fill critical gaps no other nation currently monitors.

And this is no theoretical concern. Proposed cuts to the National Oceanic and Atmospheric Administration (NOAA) and the National Science Foundation in the United States now threaten exactly this contribution.

Elsewhere, observing systems are also under growing strain, with European programmes facing mounting funding pressure.

In China, scientists and policymakers are trying to build a more resilient national observing effort – but without the resources currently required to fully support it.

A resource the world can’t afford to lose

The total annual cost of operating the GOOS – across all platforms and personnel worldwide – is on the order of US$1.1 billion (about NZ$1.8 billion).

If that sounds expensive, consider that a single major hurricane season can cost the United States hundreds of billions of dollars, while marine heatwaves have already collapsed fisheries and triggered mass coral bleaching around the world.

Compared with the economic damage linked to ocean-driven extreme weather and climate disruption, ocean observation is one of the highest-return public investments available.

The international scientific conference OceanObs'29, to be held in China in three years’ time, will be an opportunity to negotiate a more balanced global observing system – one better aligned with today’s economic realities and maritime interests.

It should also encourage greater scientific cooperation among countries, helping ensure complementary observing networks collectively cover as much of the global ocean as possible.

Maintaining that coverage requires constant renewal.

Argo floats typically last four to five years before their batteries fail. This means they must continually be deployed to prevent gaps emerging across the oceans.

New Zealand plays a surprisingly important role here. Since 2004, the research vessel Kaharoa has helped deploy more than 1,100 Argo floats for international partners across the Pacific and Southern Ocean.

This demonstrates that even smaller countries can use their institutions, expertise and maritime interest to make important contributions.

At the same time, if any one component of the GOOS is removed because of political decisions made in the US or elsewhere, the whole system’s ability to deliver reliable information would degrade.

That would require a rebuild of the system which would prove much more difficult and expensive than the cost of sustaining it today.

More importantly, it could leave the world flying blind into the most consequential transformation of the planet’s climate in human history.

The author acknowledges the contributions of Sabrina Speich, John P. Abraham and Lijing Cheng to this article. 

Kevin Trenberth, Distinguished Scholar, NCAR; Affiliate Faculty, University of Auckland, Waipapa Taumata Rau

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

Natural geological processes have been regulating Earth’s climate for millions of years.

Accelerated versions of these processes are now being promoted as technologies to draw down carbon from the atmosphere – and some are rapidly moving from concept to real-world deployments.

Two such technologies are known as enhanced weathering, which speeds up the chemical breakdown of certain rocks, and ocean alkalinity enhancement, which increases the ocean’s natural ability to remove carbon dioxide from the air.

Startups backed by tech companies including Google and Microsoft are already applying these technologies in field trials. Investment in the sector is rising rapidly, with large-scale trials underway and carbon credits beginning to appear on voluntary markets.

But as our new assessment published in Science highlights, some estimates of carbon removal through these technologies may be too optimistic.

Current models assume carbon captured on land or in coastal waters will reliably make its way into long-term storage in the ocean. However, these models don’t replicate all Earth processes.

In reality, part of the engineered capture of carbon can be reversed as water moves through soils, rivers, estuaries and coastal environments. Dissolved elements can become trapped again in new minerals such as clays, reducing how much carbon ultimately remains stored over long timescales.

The true additional carbon removed from the atmosphere may be smaller than headline estimates suggest.

How enhanced weathering is supposed to work

Enhanced weathering works by accelerating chemical reactions that already occur naturally between rocks, water and carbon dioxide.

When rainwater mixes with carbon dioxide held in the atmosphere and soil, it forms an acid that slowly dissolves rocks that contain the minerals calcium and magnesium. This includes volcanic rocks such as basalt and ultramafic rocks such as dunite.

In nature, the dissolved minerals increase the capactiy of water to store carbon dioxide and these chemical products can then be transported by rivers to the ocean, where the carbon may remain stored for thousands of years.

Enhanced weathering attempts to speed up this natural process. Finely crushed rocks and minerals are spread across landscapes such as agricultural soils, increasing the surface area available for reactions.

Ocean alkalinity enhancement uses similar principles, but aims to increase the ocean’s ability to absorb and store atmospheric carbon dioxide directly.

Carbon losses along the way

Many enhanced weathering assessments assume that once minerals dissolve, the resulting alkalinity and carbon will eventually make their way into the ocean for long-term storage.

However, different materials dissolve at different rates. Climate, rainfall, soil chemistry and biological activity also influence how quickly reactions occur. This means carbon removal can vary enormously between environments.

Earth systems also contain many opportunities for the flow of carbon to weaken before it ever reaches the open ocean.

As alkalinity moves through the environment, dissolved elements released during weathering can become trapped again in new minerals. These reactions can consume alkalinity and reduce the amount of carbon ultimately stored long term.

These challenges are not limited to enhanced weathering on land. Ocean alkalinity enhancement may also experience losses as dissolved elements interact with sediments and seawater chemistry, recycling alkalinity back into solid minerals before it contributes to long-term storage.

The challenge of durable carbon removal

In natural systems, weathering, transport and mineral formation are tightly linked parts of a much larger Earth-system cycle.

While naturally occurring warm and wet environments may accelerate weathering, using a rapid-dissolution model to replicate this does not necessarily guarantee durable carbon storage.

There is also another problem: some enhanced weathering and alkalinity approaches may interfere with natural carbon removal pathways that would have occurred anyway.

For example, increasing alkalinity in one part of the Earth system may reduce natural dissolution or weathering processes elsewhere. This means the amount of truly additional carbon removed from the atmosphere may be smaller.

Many field trials focus on changes occurring at the application site itself, but much of the long-term carbon storage depends on what happens downstream – across entire catchments, rivers and coastal oceans.

As enhanced weathering and ocean alkalinity enhancement move toward larger-scale deployment, the central question is how much carbon remains removed from the atmosphere over decades to centuries – and whether that removal is truly additional.

None of this means these technologies don’t contribute to climate mitigation.

The challenge is whether Earth systems can keep the captured carbon stored or whether we are simply moving carbon across time and space instead of durably removing it from the atmosphere.

New Zealand may offer an opportunity to better understand these questions because volcanic rocks, high rainfall and strong land-to-sea connectivity create ideal conditions for tracking how alkalinity and carbon move through the Earth system.

If these approaches are going to play a major role in future carbon removal strategies – and generate carbon credits at global scale – we need to understand not only how quickly minerals dissolve, but whether carbon is stored durably without weakening natural carbon removal pathways at the same time.

Terry Isson, Senior Lecturer in Marine Science, University of Waikato

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