When winter comes to Antarctica, seals and Adélie penguins leave the freezing shores and head for the edge of the forming sea ice. But emperor penguins stay put.

The existence of emperor penguins seems all but impossible. Their lives revolve around seasons, timing and access to “fast ice” – sea ice connected to the Antarctic coast. Here, the sea ice persists long enough into summer for the penguins to rear their chicks successfully.

But climate change is upending the penguins’ carefully tuned biological cycles. The crucial sea ice they depend on is melting too early, plunging the chicks from some colonies into the sea before they are fully fledged.

In the latest bad news for these penguins, research by the British Antarctic Survey examined satellite images from 2009 to 2024 to assess fast-ice conditions at 16 emperor penguin colonies south of South America. They noted an average 22% fall in numbers across these colonies. That translates to a decrease of 1.6% every year.

This rate of loss is staggering. As the paper’s lead author Peter Fretwell told the ABC, the rate is about 50% worse than even the most pessimistic estimates.

Breeding while it’s freezing

Just like polar bears in the Arctic, emperor penguins are the iconic species threatened by climate change in Antarctica.

Emperor penguins are a highly successful species. They’re the tallest and heaviest penguin alive today. They evolved about one million years ago, and are highly adapted to life in one of Earth’s harshest environments. As of 2009, the emperor penguin population was estimated at just shy of 600,000 birds.

Unfortunately, they are now in real trouble, because their breeding habitat appears to be reducing.

At the beginning of every Antarctic winter, the surface of the ocean begins to freeze and sea ice forms. Over March and April, emperor penguins aggregate into raucous breeding colonies along the coast of the ice continent. They need about nine months to care for their chicks, until the young penguins can go to sea and look after themselves.

The males frequently huddle to keep each other warm and their eggs safe. Meanwhile, the females spend months at sea catching krill, squid and fish, returning in July/August to feed their hungry chicks. When summer finally comes in December, the chicks start to shed their down and grow a dense, waterproof plumage – like a feathery armour against the intensely cold seas off the icy continent.

Breeding locations are a kind of “Goldilocks” zone. When choosing a home, the penguins have to find a place that is safe but not too far from the fast ice edge where they go to start hunting.

The greater the distance they have to travel, the longer it takes to return to their offspring, and the chicks may miss out on meals. But if a colony is too close to the edge of the fast ice, the risk increases that the ice breaks up before the chicks are ready to go to sea. Although fast ice can cover vast areas of the ocean surface, its edge is exposed to the swell of the Southern Ocean.

In recent years, the fast ice in different parts of Antarctica has been breaking up early, before the chicks have moulted into their adult plumage. Without waterproof plumage, chicks perish because the cold water kills quickly. As this happens more often, the size of a colony shrinks.

How bad is it?

We don’t yet know if this rate of loss is happening right across Antarctica. The study only covers a the part of the continent that includes the Antarctic Peninsula and the Weddell Sea.

What we do know is that Antarctica and its unique biodiversity are not immune to the consequences of still-rising global greenhouse gas emissions.

In 2021, emperor penguins were listed as endangered by the United States, because the risk of extinction by century’s end had increased. Australia has not yet listed the emperor penguin as a threatened species.

The new research suggests the future of these iconic birds is not looking good. Until the world gets serious about cutting greenhouse gas emissions, sea ice will retreat – and more chicks will fall into the icy water before they are ready to launch.

Seabird ecologist Dr Barbara Wienecke contributed to this article.

Dana M Bergstrom, Honorary Senior Fellow in Ecology, University of Wollongong

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

South Australian beaches have been awash with foamy, discoloured water and dead marine life for months. The problem hasn’t gone away; it has spread.

Devastating scenes of death and destruction mobilised locals along the Fleurieu Peninsula, Yorke Peninsula and Kangaroo Island. The state government has hosted emergency meetings, most recently with marine and environment experts from around Australia, and issued weekly updates.

Unfortunately, there are few ways to stop the bloom. Scientists had hoped strong westerly winds would break it up and push it out to sea. But so far, the wild weather has just pushed it through the Murray Mouth into the Coorong. And even if the bloom is washed away this winter, it could return in spring.

This bloom represents a stark warning to coastal communities, as well as tourism, seafood and aquaculture industries. It’s a sign of what’s to come, in Australia and around the world, as the oceans warm.

An unprecedented algal bloom

The first sign of trouble came in March this year, when dozens of surfers and beachgoers fell ill. Many reported sore eyes, coughing or trouble breathing.

Water testing soon revealed the cause: a harmful algal bloom of Karenia mikimotoi.

Most people felt better within hours or days of leaving the beach. But marine life of all kinds was washing up dead or dying.

Fish habitat charity OzFish set up a new citizen science project to capture the data, using iNaturalist.

OzFish SA project manager Brad Martin told a public forum the bloom was like an “underwater bushfire”, adding:

It’s suffocating fish, it’s taking the oxygen out of the water and it’s producing toxins.

Photos of dead fish, seahorses, octopuses and rays were already circulating on social media. So OzFish encouraged people to start using iNaturalist, to identify the species and capture the data.

The data shows more than 200 species of marine creatures died, including 100 types of fish and sharks. This includes popular recreational fishing species such as flathead, squid, crabs and rock lobsters.

Almost half the deaths were ray-finned fish species. A quarter were sharks and ray species. Then came soft-bodied “cephalopods” such as cuttlefish and octopus, and crustaceans such as crabs, lobsters and prawns.

Most of these species live on or near the sea floor with small home ranges. As in a bushfire, they have little chance of escape. Other fish that live in the open ocean, such as whiting, snapper and tuna, can swim away.

The culprit

K. mikimotoi is a type of microalgae. It uses sunlight and carbon dioxide to grow and divide, releasing oxygen.

In calm conditions, with plenty of light and warmth, the algal cells divide rapidly. Ideal conditions for algal growth are becoming more common as the climate changes and seas warm.

Algal toxins are known to cause illness and sometimes death in humans, pets and livestock.

K. mikimotoi is lethal to marine life, not humans. But the toxic effects in marine life are complicated and poorly understood.

The algae irritates fish gills, causing cell death and bleeding. It also causes hypoxia, or lack of oxygen in the blood. And when the algae die off, decomposition consumes huge amounts of oxygen – leaving marine life to suffocate.

Scientists now suspect other Karenia species may be involved too, due to the detection of brevetoxins in shellfish. This is the first detection of brevetoxins in Australia.

What can be done?

A marine heatwave is largely to blame. Sea surface temperatures have been 2.5°C warmer than usual since September. Relatively calm conditions, with little wind and small swells, also enabled the bloom to grow. Now it’s a matter of waiting for strong westerly winds to blow it all away.

The latest update shows sea surface temperatures have stabilised. But deeper gulf and shelf waters remain 1–2°C above average for this time of the year.

Climate change is making future blooms more likely. So tackling climate change is one way to help.

Another is minimising the runoff of nutrients into waterways. Microalgae can be found anywhere with enough water, light and nutrients. So reducing pollution can help reduce the risk of algal blooms.

This includes better management of fertiliser on farms and in home gardens. Lower levels of nutrients such as nitrogen and phosphorous will reduce the risk of future blooms in marine and inland waterways.

When it comes to blue-green algae, flushing with freshwater and stirring it up can disperse the colonies and prevent a bloom.

Monitoring is also important. OzFish encourages South Australians to continue providing photo reports via iNaturalist. Any new fish kills should also be reported to the state government.

Microalgae are not all bad

It’s worth remembering life on Earth wouldn’t exist without microalgae. These tiny organisms produced 60% of the oxygen in the atmosphere today, and play an important role in balanced ecosystems.

The algae spirulina is a common dietary supplement. Microalgae are also potentially useful for water recycling, as a renewable biofuel and for capturing and storing greenhouse gases.

Heeding the lessons

Once a harmful algal bloom begins, it will persist for as long as conditions remain suitable.

This bloom already has lasted three months, and there’s no guarantee the end is near.

Recovery will be slow, as shown in the historical record and other parts of the world. And the risk of a repeat event is high.

Further research is needed to keep these ancient organisms in check.

With thanks to OzFish SA project manager Brad Martin, who contributed to this article.

Erin Barrera, PhD Candidate, School of Public Health, University of Adelaide

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

As a teenager in the 1970s, I worked on a typical dairy farm in England. Fifty cows grazed on lush pastures for most of their long lives, each producing about 12 litres of milk daily. They were loved and cared for by two herdsmen.

About 50 years later, I visited a dairy farm in China. There, 30,000 cows lived indoors. Most of these selectively bred animals wore out after two or three years of producing 30–40 litres of milk every day, after which they were unceremoniously killed. The workers rarely had contact with the cows. Instead, they sat in offices, programming machines which managed them.

This speaks to a huge and very recent shift in how we treat animals. Over the last half century, the human population has soared – and so too our demand for meat, milk and many other animal products. As a result livestock populations have ballooned while living conditions for animals permanently kept inside have drastically worsened.

Even as farmed animals have multiplied, populations of wild animals have crashed. The two trends are deeply connected. Humans convert wildlife habitat into pastures and farms, expanding living space for farm animals at the expense of many other animals.

This cannot continue. Humans must reckon with how we treat the myriad other species on the planet, whether we rely on them or not. As I argue in my new open access book, the growing scarcity of animal species should make us grasp our responsibility towards the welfare of all animal species on the planet, not just those in farms.

Efforts to enshrine rights for animals is not enough. The focus has to be on our responsibilities to them, ensuring they lead good lives if in our care – or are left well alone if they are not.

Should we care?

In the last 50 years, two-thirds of all wild animal populations have been lost.

The main cause is habitat loss, as native forest is felled to grow grass for cattle or corn and soya for livestock.

By weight, the world’s farm animals and humans now dwarf the remaining wild animals. Farm animals weigh 630 million tonnes and humans 390 million tonnes, while wild land mammals now weigh just 20 million tonnes and marine mammals 40 million tonnes.

Wildlife numbers have fallen off a cliff across many kingdoms of life. Three quarters of flying insects are gone from monitored areas of Western Europe. One in eight bird species is threatened with extinction worldwide.

On animal welfare, philosophers have long argued one of two positions. The first is known as “utilitarianism”. This approach argues for minimising the bad things in the world and maximising the good things, regardless of who benefits from them, humans or other animals. This theory-heavy approach does little to restore our relationship with wild animals because of the difficulties in deciding what is good and bad for animals.

The second has more to recommend it. This is the view that animals have the right to be looked after well. This approach has also been used to give rights to rivers, nature and even the atmosphere.

But this doesn’t recognise the fact that only humans can attribute such rights to animals, who themselves do not have any concept of “rights”. It also doesn’t tackle the issue that most humans would not accord the same rights to a blue whale and an insect.

A better approach might be to recognise our responsibilities to animals, rather than attribute rights to them.

This would acknowledge the increasing rarity of animal species on Earth and the fact that – as far as we know – they’re unique in the universe. So far, no reliable signs have been found indicating life evolved on any other planets.

Earth formed just over 4.5 billion years ago. Some evidence suggests simple animal life began just 400 million years later.

The evolution of complex multicellular life on earth probably only happened once when a single celled organism – one of the ancient archaea, perhaps – engulfed a bacterium without digesting it. Instead, it found something better: putting it to work as an internal energy factory as the first mitochondrion. After that came life’s great flowering.

But now we’re currently losing between 0.01–0.1% of all species each year. If we use an average species loss rate of 0.05% and assuming human pressures remain similar, life on Earth could have only 2,000 years left.

Do we have responsibility to care for something just because it’s rare? Not always. But life is beautiful. We marvel when we are able to connect with wildlife. Other social animals also appear to derive pleasure from such relationships.

If we destroy wild animal life, we could undermine the natural systems humans depend on. Pollinators are essential for orchards, forests protect topsoil and produce clean drinking water and predators prevent herbivore populations from soaring out of control and destroying crops. As wilder areas shrink, the chance of another animal virus spillover into humans increases.

From small scale to industrial

For almost all of human history, livestock herds were small enough that people could build relationships with the animals they depended on.

But in only a couple of human generations, we’ve turned farm animal production into a factory process with billions of animals.

For centuries, farm animals were walked to market. That, too, has changed. In 2005, I was undertaking research on a livestock ship alongside 80,000 sheep being transported from Australia to the Middle East. Hundreds of sheep die from the stress of these journeys, while many survivors arrive exhausted and terrified.

These changes have made it possible for humans all around the globe to eat meat or dairy products at every meal. But it has come at a real cost to livestock and wild animals.

Correcting this will not be easy. We have to learn to eat fewer animals or preferably none at all, restore habitat for wildlife and curb our consumption of the world’s natural resources.

It’s not too late to restore animal habitat. Rewilding efforts are drawing back long-missing wild animals. There are hopeful signs for farm animal welfare too. The live export of Australian sheep will end in 2028. Battery cage production of eggs is dying out.

These are big issues. But to paraphrase a quote reputedly by Confucius:

The man who asks big questions is a fool for a minute. The man who does not ask, is a fool for life.

Clive Phillips, Adjunct Professor in Animal Welfare, Curtin University

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

More people believe misinformation about electric vehicles than disagree with it and even EV owners tend to believe the myths, our new research shows.

We investigated the prevalence of misinformation about EVs in four countries – Australia, the United States, Germany and Austria. Unfortunately, we found substantial agreement with misinformation across all countries.

People who endorsed false claims about EVs were, not surprisingly, significantly less likely to consider buying one.

Electric vehicles are vital in the fight against climate change. But pervasive misinformation is a significant challenge to the technology’s uptake and has serious implications for the shift away from fossil fuels.

Widespread agreement with false EV claims

We conducted a survey of 4,200 people who did not own an electric vehicle across the four countries. We measured the extent to which they agreed with these nine misleading claims about electric vehicles:

What we found

To tally the results, we looked at participants’ responses for all nine misinformation statements – more than 36,000 responses in all. We then calculated how many of these responses indicated agreement or disagreement.

Of the 36,000 responses, 36% were in agreement with a statement and 23% were in disagreement. A further 24% were undecided and 17% did not know.

Misinformation agreement was highest in Germany and lowest in the US, but the differences between nations were small.

The most widely believed myth was that electric vehicles are more likely to catch fire than petrol cars. Some 43–56% of people agreed with the statement, depending on the country.

Agreement with misinformation was strongly correlated with a lack of support for electric vehicle policies and a lack of intention to buy an EV in future.

A separate part of the research involved 2,100 people in the US, about half of whom owned an electric vehicle. Surprisingly, EV owners did not significantly differ in their agreement with misinformation compared to non-owners. This underscores how embedded the problem has become.

It’s not about education

We also examined the factors that make individuals more susceptible to EV misinformation.

The strongest predictor was people who scored highly on a “conspiracy mentality” – in other words, they believed conspiracies were common in society, they saw the world through a lens of corruption and secret agendas, and distrusted institutions.

People with progressive political and environmental views were less likely to endorse misinformation about EVs.

A person’s scientific knowledge or level of education was not a predictor. This finding aligns with previous research, and suggests the pervasive endorsement of misinformation stems from distrust in institutions and expertise rather than from a lack of education.

Grounds for optimism

We tested whether misinformation could be reduced with two interventions among a different sample of US participants. One group was asked to converse with ChatGPT about their views on EV misinformation. The second was asked to read a traditional EV fact sheet from the US Department of Energy. On a third “control” group, no intervention was tested.

Participants who engaged with either ChatGPT or the fact sheet before we surveyed them showed significantly lower endorsement of EV misinformation compared to the control group. This persisted at a follow-up session ten days after the survey.

Notably, ChatGPT did not produce any misinformation about EVs. These results build upon existing research demonstrating ChatGPT’s potential to reduce endorsement of conspiracy theories.

How to tackle EV misinformation

Our findings show misinformation about electric vehicles has a substantial foothold in Western nations. Susceptibility is not a matter of education or knowledge, but rather stems from distrust of established institutions and expertise.

We also found people who engage with facts about electric vehicles are less likely to endorse misinformation.

This suggests a dual strategy is needed to reduce misinformation about EVs. First, those who deliberately spread misinformation should be held accountable. And second, evidence-based information, including accessible AI tools, can be used to build public resilience against false claims.

Christian Bretter, Senior Research Fellow in Environmental Psychology, The University of Queensland; Matthew Hornsey, Professor, University of Queensland Business School, The University of Queensland, and Samuel Pearson, Post-doctoral Research Fellow, The University of Queensland

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

Ahead of this week’s crucial United Nations ocean conference, federal Environment Minister Murray Watt promised that by 2030, 30% of Australian waters would be “highly protected”.

This is a telling pledge. After all, 52% of Australian waters are now protected following years of rapid expansion. But many are “paper parks” – lines on a map with very little real protection.

Watt is proposing to expand the area under gold-standard protection, meaning fishing, mining and drilling would be banned inside the parks. This is welcome. But it must be done strategically, protecting ecologically representative and high biodiversity areas.

If Watt is serious, he must ensure these upgraded marine parks cover poorly protected habitats important for biodiversity. These include shallow coastal zones, submarine canyons, seamounts and rocky reefs on the continental shelf. It’s not just about protecting 30% of the seas – marine parks must protect the full range of species and habitats in Australia.

Impressive on paper

Australia’s waters cover all five of the world’s climate zones, from the coral reefs of the tropics to the icy shores of Antarctica. At least 33,000 marine species are found in the nation’s marine boundaries – the most on Earth. Australia also has the most endemic marine species.

For more than 30 years, successive federal and state governments in Australia have claimed global leadership roles in conserving ocean areas. Just last year, the Albanese government claimed the latest expansion meant Australia now protected “more ocean than any other country on earth”.

When 196 countries committed to the goal of “30% by 2030” – the effective protection and management of at least 30% of the world’s coastal and marine areas by decade’s end – Australia was already well past that in terms of the size of areas considered marine protected areas.

About 45% of marine waters were protected in 2022, up from 7% in 2002. Now that figure is 52%.

Job done? Not even close. Even as Australia’s marine protected areas have rapidly expanded, marine species populations have shrunk while entire ecosystems hover on the brink.

More than half of Australia’s marine parks allow commercial fishing and mining. The latest large protection around the sub-Antarctic Heard and McDonald Islands doesn’t give strong protection to species-rich areas such as seamounts and undersea canyons.

Losses everywhere

Tasmania’s giant kelp forests once ringed the island state. At least 95% have vanished since the 1990s, wiped out by warmer waters and voracious sea urchins.

Before European settlement, oyster reefs carpeted shallow sea floors in temperate east coast waters. But 99% of these have gone.

Half the Great Barrier Reef’s coral cover died between 1995 and 2017 – a period with only two mass bleaching events. Bleaching has become more regular and more severe since then.

Many marine species are in serious trouble. The most comprehensive assessment to date found populations of 57% of species living on coral, rocky and kelp reefs had fallen between 2011 and 2021. In 2020, a Tasmanian endemic species, the smooth handfish, became the first marine fish officially listed as extinct on the IUCN Red List of Threatened Species.

As the oceans get hotter, coral reefs are forecast to be wiped out. Poor marine water quality is drowning coastal species and ecosystems in sediments, nutrients, chemicals, and pathogens, including in The Great Barrier Reef.

That’s not to say marine park expansion and other government efforts have been worthless. Far from it.

Some whales have rebounded strongly due to the moratorium on commercial whaling. Good management of the southern bluefin tuna led to its removal from the threatened species list last year.

Efforts to phase out gill net fishing are bearing fruit, while water quality has improved a little in the Great Barrier Reef.

But these wins don’t offset an overall rapid decline.

Action needed on climate and improving marine parks

Giving Australia’s marine parks better protection won’t solve the problem of hotter, more acidic oceans due to climate change.

Australia’s current emission target is consistent with a 2°C warming pathway. That level of warming would mean the loss of 99% of the world’s coral reefs.

Australia is one of the world’s biggest producers of coal and liquefied natural gas and still has one of the world’s highest rates of land clearing, accounting for up to 12% of the country’s total emissions in some years.

Protecting life in the seas means Australia must dramatically reduce emissions, end widespread land clearing and halt the approval of new coal and gas projects.

Better protection inside marine parks will stop other major threats, such as seabed mining, gas and oil exploration and fishing.

To date, Australia’s marine parks with high levels of protection are typically in remote areas with minimal human activity threatening biodiversity.

From paper parks to real conservation leadership

For decades, Australian leaders have touted their efforts to protect the seas. It’s now abundantly clear that paper protection isn’t enough.

To arrest the steep decline in marine life, Australia must properly protect its marine areas by preventing fishing and mining in areas important for all marine species, while expanding its highly protected marine parks to save unprotected ecosystems.

Minister Watt’s pledge is welcome. But it must actually prevent damaging human activities such as fishing and oil and gas extraction which are major contributors to the extinction crisis.

Leaders must also focus on sustainable production and consumption of seafood and ramp up their ambition to tackle climate change and marine pollution.

If Australia continues to expand paper parks without doing the hard work of genuine protection, it will set a dangerous precedent.

Carissa Klein, Associate Professor in Conservation Biology, The University of Queensland; Amelia Wenger, Research Fellow in Conservation, The University of Queensland, and James Watson, Professor in Conservation Science, School of the Environment, The University of Queensland

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

Emission control systems in modern cars have slashed air pollutants such as particulate matter and nitrogen oxides.

But these systems face two major challenges: carmakers cheating on pollution tests and owner tampering. Cheating means high-polluting cars can be sold when they shouldn’t be, while tampering can increase some pollutants up to 100 times.

In our new research review, we found the impacts of cheating and tampering on emissions of pollutants are substantial across the globe. For instance, researchers in Spain found almost half the diesel trucks had been tampered with, while the Volkswagen Dieselgate cheating scandal uncovered in 2015 led to an estimated A$60 billion in health costs in the European Union. In California, researchers found one in 12 trucks had a damaged or malfunctioning diesel particulate filter – and these high-emitting trucks contributed 70% of the entire fleet’s emissions of tiny particulate matter.

The solutions? Better detection of tampering, cheating and malfunctioning emission systems – and vigilance to get high polluting cars off the road.

How did we get here?

From the 1950s onwards, smog, air pollution and health issues from car exhausts led many regulators to require carmakers to reduce dangerous air pollutants.

These days, modern combustion-engine cars are complex computer-controlled systems optimised to balance engine performance, durability and emission control. When working properly, new vehicles can reduce air pollutant emissions by 90% or more. However, they can increase carbon dioxide emissions by using slightly more fuel.

But these pollutants can soar if emissions control systems malfunction – or suffer from intentional cheating or tampering.

Cheating and tampering are not new. Cheating was first reported in the 1970s and it’s still happening. Tampering, too, dates back to the 1970s.

Both issues worsen air quality. These excess air pollutants have substantial costs to human health, as they can trigger respiratory conditions and can cause disability and premature death.

While the numbers of electric vehicles are rising, they’re only about 5% of the global fleet – about 60 million compared to about 1.5 billion cars powered by petrol, diesel and gas.

Because cars have relatively long lifespans, many fossil-fuel powered cars will still be in use in 2050, now just 25 years away. Many will be exported from rich countries to developing economies. That means effective pollutant control still matters.

Cheating by manufacturers

It’s well established combustion engine cars produce substantially more emissions and pollutants during real-world driving than they do in regulatory tests.

There are many reasons for this, including natural wear and tear. But one big reason may be cheating.

Authorities in many nations rely on testing to see if a new model is emitting at rates low enough to meet emission standards.

Manufacturers can take advantage of the known quirks of official tests and intentionally alter how their vehicles operate during testing. To do this, they may install a “defeat device”, usually deep in the car’s engine or its computer code.

These devices shift the car to a special low-emissions mode if testing is detected. They’re typically easy for the automaker to install and difficult to detect.

Defeat devices are mainly found in diesel cars and trucks, since diesel emissions control systems are more complicated and expensive than petrol or LPG. Adding an emission control system to meet Euro 6 standards costs about $600 for a petrol car. For diesel, the cost can be three to five times higher.

In 2015, the United States Environmental Protection Agency and the state of California announced Volkswagen had been using a software-based defeat device to make its diesel cars appear substantially cleaner. The scandal drew worldwide attention and cost the company about $50 billion.

For those caught, large fines and mandatory recalls have followed. But this hasn’t been enough to stop the practice.

The way these tests are conducted usually has to be disclosed by law to ensure transparency and make results comparable and repeatable. Unfortunately, having detailed knowledge of the tests makes it easier to cheat.

Tampering by car owners

Tampering is largely done by owners of diesel cars and trucks. Owners can tamper with emission control systems to improve performance, rebel against laws they don’t agree with or avoid extra costs such as Adblue, a liquid needed to reduce nitrogen oxides emissions from diesel trucks.

Tampering is usually illegal. But that hasn’t stopped the production of aftermarket tampering devices, such as software which deactivates emission control systems. It’s not necessarily illegal to sell these devices, but it is illegal to install and use them.

In the road freight sector, the use of aftermarket tampering by vehicle owners also acts as an unfair economic advantage by undercutting responsible and law-abiding operators.

What should be done?

Combustion engine cars and trucks will be on the world’s roads for decades to come.

Ensuring they run as cleanly as possible over their lifetime will require independent and in-service emissions testing. Authorities will also need to focus on enforcement.

Creating an internationally agreed test protocol for the detection of defeat devices will also be necessary.

Combating tampering by owners as well as malfunctioning emissions systems will require better detection efforts, either through on-road emissions testing or during a car service.

One approach would be to add telemetry to the onboard diagnostics systems now common in modern cars. Telemetry radio transponders can report emissions problems to the owner and relevant authorities, who can then act.

Shifting to EVs offers the most robust and cost-effective way to combat fraud and cut exhaust pollutants and carbon emissions from road transport. But this will take decades. Authorities need to ensure diesel and petrol vehicles run as cleanly as possible until they can be retired.

Robin Smit, Adjunct Professor of Transport, University of Technology Sydney and Alberto Ayala, Adjunct Professor of Mechanical Engineering, West Virginia University

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

President Donald Trump is trying to unravel the signature climate policy of his predecessor Joe Biden, the Inflation Reduction Act, as part of a sweeping bid to dismantle the United States’ climate ambition.

The Inflation Reduction Act, or IRA, is a A$530 billion suite of measures that aims to turbocharge clean energy investment and slash emissions in the US. Once hailed as a game-changer for the global clean energy transition, it set in train a fierce international competition for renewable energy investment.

But the policy is now hanging by a thread, after the US House of Representatives last month narrowly passed a bill to repeal many of its clean energy measures.

Should the bill pass the Senate, billions of dollars in renewables investment once destined for the US could be looking for a new home. Now is the time for the Albanese government to woo investors with a bolder program of climate action in Australia.

What is the Inflation Reduction Act?

The Inflation Reduction Act passed US Congress in 2022. It legislated billions of dollars in tax credits for solar panels, wind turbines, batteries and geothermal plants, among other technologies.

It included around A$13 billion in rebates for Americans to electrify their homes, tax credits of almost A$11,000 to electrify their cars, and billions more to establish a “green bank” and target agricultural emissions.

The money flowed. Last year, almost A$420 billion was invested in the manufacture and deployment of clean energy – double that in 2021, the year before the legislation passed.

Even in the first quarter of this year, under a Trump presidency, A$103 billion was invested in clean energy tech – an increase on the first quarter results of 2024. Electric vehicle manufacturing projects, especially batteries, were standout performers.

But then came the proposed repeal. The Trump administration wants to gut tax credits for clean energy technologies. The measures passed the House of Representatives and must now clear the US Senate, where the Republicans have a margin of three votes.

Initial modelling suggests the bill, if passed, could derail clean energy manufacturing in the US – including in Republican states where new projects were planned.

The potential economic damage has sparked concern even among Trump’s own troops. Some Republicans last week reportedly urged the scaling back of the cuts, despite voting for the bill in the House.

Opportunities for Australia

After the IRA was enacted, many countries followed the US’ lead – including Australia’s Albanese government, which legislated the A$22.7 billion Future Made in Australia package.

So how will Trump’s unravelling of the policy affect the rest of the world?

The economic impacts are still being modelled. Some studies suggest the US could cede A$123 billion in investment to other countries.

The US axing of tax credits for battery and solar technology paves the way for nations such as China and South Korea to capitalise – given, for example, they already dominate battery manufacturing.

Australia should be doing its utmost to attract investors that no longer see the US as an option. Our existing policies are a start, but they are not sufficient.

In February this year, Labor increased the investment capacity of the Clean Energy Finance Corporation – Australia’s “green bank” – by A$2 billion. But more will be needed if the government is serious about crowding-in private investment in low-emission technologies exiting the US.

The government would also be wise to remove incentives that increase fossil fuel use. This includes the diesel fuel rebate, which encourages the use of diesel-powered trucks on mine sites. Fortescue Metals this week announced a push for the subsidy to be wound back – potentially providing the political opening Labor needs.

What about nuclear?

Trump has also promised a “nuclear renaissance”, signing four executive orders designed to reinvigorate the US nuclear energy industry.

But those measures are likely to fail, just as Trump’s 2016 promise to revive the coal industry never eventuated.

In fact, his cuts to the Loan Programs Office – which helps finance new energy projects including nuclear – threaten to undermine the viability of new nuclear plants. The office has been the guarantor for every new US nuclear plant this century, bar one.

If the US is struggling to scale up its existing nuclear industry, this does not bode well for the technology’s hopes in Australia. Here, the prospect of a nuclear energy policy still appears alive in the Coalition party room, even though the technology remains politically unpopular, and the economics don’t stack up.

What’s next?

Predicting US climate and energy policy is a fool’s errand, given the potential IRA repeal, flip-flopping tariff announcements and daily social media tirades from Trump, including a social media bust-up with former ally Elon Musk over the merits of the repeal itself.

Stepping back from the politics, we cannot ignore the climate harms flowing from a walk-back on US climate action.

The US is the world’s second-largest emitter of greenhouse gases. As climate change reaches new extremes, the policy vacuum created by Donald Trump must urgently be filled by the rest of the world.

Christian Downie, Professor, Australian National University

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

For decades, scientists have known that platypuses and echidnas – Australia’s unique egg-laying mammals – have another developmental quirk: they don’t use the same genetic toolkit as other mammals to develop male and female embryos.

What’s more, just how they do it has been a mystery. Until now.

In a recent study published in Genome Biology, our research team has found strong evidence that monotreme sex comes down to a single gene – one that’s much more like what we see in some fish and amphibians than other mammals.

The search for the secret of monotreme sex

The Australian platypus and echidna are monotremes, the most ancient living group of mammals. These unique creatures are famously the only mammals to lay eggs, and they also have other reptile-like features.

Humans and many other mammal species have two sex-determining chromosomes, X and Y. An embryo with an XX pair of chromosomes will develop as female, while an XY pair leads to a male embryo.

In many mammals, the process that makes an embryo develop as male is triggered by a gene called SRY on the male Y chromosome. However, the SRY gene in monotremes has never been found.

About 20 years ago, it was discovered that monotremes have an entirely different system that uses multiple X and Y chromosomes. Scientists assumed the Y chromosomes must still hold a gene that determined sex, but very little was known about what it might be.

In 2008 a full genome sequence of a platypus was published, which was a step in the right direction. However, the genome was from a female so it had no information about Y chromosomes.

By 2021, a new and improved platypus genome and a first echidna genome included sequences of multiple Y chromosomes. A gene emerged as the frontrunner for the role of sex determination in monotremes: the anti-Muellerian hormone (or AMH), which is involved in the sexual development in many animals.

A 100-million-year-old change

Our new research provides the first real evidence that an adapted version of AMH found on one of the monotreme Y chromosomes (dubbed AMHY) is the sex determination gene in monotremes.

We showed that changes in the AMH gene long ago, early in the evolution of monotremes, could explain how AMHY arose and took on a role in male sexual development.

This event would have set the stage for the evolution of the novel sex chromosome system in the ancestor of today’s platypus and echidna, about 100 million years ago when the AMH gene on the XY chromosomes embarked on separated paths.

We showed that although the AMHY gene has changed significantly from the original AMH gene (AMHX), it has retained its essential features. Importantly, we could show for the first time that AMHY is turned on in the right tissue and at the right time to direct development of the testes during male development, which was an important missing piece of the puzzle.

A first for mammals

Unlike the other mammal sex determination genes, which act directly on the DNA to switch on other genes that lead to male development, AMHY is a hormone. It does not interact with DNA, but instead acts at the surface of cells to turn genes on or off.

There is growing evidence that AMHY also plays a role in sex determination in a number of fish and amphibian species. However, AMHY in monotremes would be the first known example of a hormone playing a sex-determining role in mammals.

What’s next? Our ongoing research investigate in detail how AMHX and AMHY work differently in monotremes compared to other mammals.

The work discussed in this article was carried out by researchers from the University of Adelaide, the University of Melbourne, the University of Queensland, Monash University and Currumbin Wildlife Sanctuary.

Linda Shearwin, Researcher, Comparative Genome Biology Laboratory, University of Adelaide and Frank Grützner, Professor, School of Biological Sciences, University of Adelaide

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Over the past 50 years, global aquaculture including fish, mussel and seaweed farms has grown dramatically. Almost half of the world’s wild-caught fish is used to produce fishmeal and oils that feed farmed fish.

Mussel farming provides a more sustainable alternative protein source for human diets, because mussels filter feed on plankton and do not have to be fed wild-caught fish. Mussel farming also takes some pressure off the need for so much industrial agriculture and fish farming, and could therefore help reduce greenhouse gas emissions of food production – in line with the UK’s goal to reach net zero by 2050.

Most mussel farms are typically located in sheltered bays but as space to grow mussels inshore is limited, there isn’t always room to grow mussels at scale.

Some coastal mussel farms can damage the environment as the mussel waste accumulates and can deplete oxygen in sediments, which in turn affects the animals that live in and on the seabed. As a result, offshore mussel farming (growing and harvesting mussels far from the coast) is becoming increasingly attractive.

In Lyme Bay on the south coast of England, the UK’s first offshore mussel farm has been in operation since 2013. This farm has a licensed area of 6 square miles (15.4km²) and is located 2-6 miles away from the coast. To grow the mussels, the farmers deploy long ropes that are anchored to the seabed and kept afloat using large buoys.

Local science, global stories. This article is part of a series, Secrets of the Sea, exploring how marine scientists are developing climate solutions. In collaboration with the BBC, Anna Turns travels around the West Country coastline to meet ocean experts making exciting discoveries beneath the waves.

Blue mussels (Mytilus edulis) naturally settle on these ropes. Hands-on input is minimal – the farmers need only distribute small mussels around the farm so they have space to naturally grow to the desired size, before they are harvested after 12-to-18 months. This farm is now producing more than 2,000 tonnes of high-quality, rope-grown mussels in a fully offshore marine environment.

The Lyme Bay mussel farm, managed by family-run company Offshore Shellfish Ltd, was the first in Europe to be certified for best aquaculture practices by the Global Aquaculture Alliance. Its infrastructure creates physical habitat for marine species such as fish and crabs to feed, breed and shelter. The rope farm structure also prevents destructive fishing such as trawling and dredging in the area.

Our team of marine researchers have been monitoring marine life in and around this mussel farm since before the first ropes were deployed in 2013 – with the help of the local fishing community. We use their boats as research vessels to monitor how the farm’s biodiversity has changed in the past decade.

We use a range of non-destructive, remote underwater video cameras and more traditional sampling techniques to count animals that live on the mussel ropes, on the seabed and in the water column inside the farm, as well as at reference sites to the east and west of the farm.

Before the first ropes were deployed, the habitat had been degraded from years of destructive fishing, so our early observations didn’t detect much marine life. That has changed over the life of the farm, and we now see significantly increased productivity and greater biodiversity.

Over many years, our studies have shown how some mussels from the farm have fallen to the seabed and regenerated lost shell reefs. The farm has also boosted populations of crabs, lobsters, scallops, starfish, fish, conger eels, sharks and rays.

Our team’s Defra-funded Ropes to Reefs project builds on this annual monitoring to help us understand the potential conservation benefits of the mussel farm. We are also studying how the farm affects the nearby Lyme Bay marine protected area, and recording any “spillover effect” as commercial fish breeding within the farm move out into local fishing grounds.

We use cutting-edge technology such as acoustic telemetry and an echosounder to tag and track lobsters, thornback rays and small-spotted catsharks, and measure the total amount of fish to better understand why and when species use the farm.

This new data will enable us to calculate the full value of the Lyme Bay mussel farm to species of both conservation and commercial importance. Our findings to date show that offshore aquaculture farms like this can have positive effects on the surrounding marine ecosystem.

By creating structure and excluding the damaging effects of bottom-towed fishing, offshore mussel farms can restore degraded fishing grounds and provide a sustainable and healthy source of marine protein.

As demand for mussels increases, offshore mussel farming and other types of shellfish farming can help improve the UK’s food security and economic resilience, and enhance its seafood industry, while contributing to marine conservation and net zero goals.

Listen to episode three of Secrets of the Sea here on BBC Sounds, presented by Anna Turns for The Conversation.

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Emma Sheehan, Associate Professor of Marine Ecology, University of Plymouth and Llucia Mascorda-Cabre, Postdoctoral Researcher, Applied Marine Ecosystem Research Unit, University of Plymouth

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

As Australian cities heat up and dry out, street trees are emerging as frontline defenders of urban liveability.

Street trees make city life more bearable during heatwaves. They also improve human health and wellbeing, filter pollutants and support biodiversity.

But as climate change intensifies droughts and dials up more extreme heat, can urban forests survive in a hotter, drier future?

To find out, we studied how ten of Australia’s most common non-native street trees grow and tolerate drought across seven cities. The familiar species we chose are the well-loved jacaranda and widely planted London plane tree as well as box elder, European nettle tree, honey locust, sweetgum, southern magnolia, callery pear, black locust and Chinese elm.

Unexpectedly, our new research shows several species tolerate drought better than predicted, including jacaranda and London plane. Some even put on growth spurts during droughts of unprecedented duration and heat. But others showed greater sensitivity than we had anticipated, including honey locust and black locust.

As cities plan for a hotter future, our research will help urban planners choose the toughest, most resilient street trees.

What did we do?

Street trees cool cities both through their shade and by giving off water through transpiration. These effects can lower local temperatures by several degrees, which helps offset the extra heat trapped by roads, rooftops and hard surfaces.

But the trees we rely on for cooling are vulnerable to mounting pressures from climate change. Drought, heatwaves and limited soil and water availability in cities can all threaten tree health, growth and survival.

To test how these species were coping, we chose more then 570 street trees in Adelaide, Melbourne and Sydney, as well as Mildura in regional Victoria, Mandurah south of Perth and Parramatta and Penrith in Western Sydney.

We extracted small cores of wood from the trunk, in a process that leaves the tree alive and largely unaffected. The oldest tree we sampled was a 70-year-old southern magnolia in Sydney.

Growth rings in these cores let us reconstruct their growth histories and assess how they responded both to long-term climate patterns and extreme events such as the Black Summer of 2019–20 and the Millennium Drought from 1997–2009.

How resilient are these trees?

What we found was both reassuring and surprising.

Across all seven cities, the fastest average growth for all species was recorded in Mildura in northern Victoria. Overall, the slowest growth was found in the warmest location – Penrith.

Some species behaved predictably. The black locust grew faster in cooler, wetter cities such as Melbourne, as expected, while honey locust and Chinese elms grew more slowly in hotter cities.

But others defied expectations. Species such as London plane and southern magnolia showed consistent growth trends across cities despite the difference in heat, while others varied depending on local conditions.

Crucially, the growth records showed many street trees responded positively to wetter conditions during the warmest months, most likely due to the longer growing season and increased access to water.

Surprisingly, species such as box elder and Callery pear actually increased their growth during the very hot periods over the Black Summer of 2019–20 as well as during wetter La Niña periods in 2021–22. This suggests these species have adapted to warm urban environments – or that care and watering was provided.

What happened during drought?

During drought, street trees generally demonstrated strong resistance. This means they maintained their growth during dry periods.

But their resilience – measured by their ability to bounce back to pre-drought growth rates – was often limited, especially in drier cities.

While many street trees can withstand short-term stress, this suggests repeated or prolonged droughts can still take a toll on their long-term health.

Interestingly, species identified as vulnerable in climate models did not always show greater sensitivity to drought or climate extremes in our real-world study.

Why? Local conditions and species-level characteristics such as leaf size, wood density and water use strategy may play a significant role in determining which individual trees will thrive as the climate changes.

We also know care provided by council staff or local residents is extremely useful. When trees are irrigated during stressful conditions, they can help get the tree through tough times.

Why no eucalypts?

During their growing season each year, many northern hemisphere trees produce growth rings. These rings make it possible to reliably reconstruct their growth histories using our methods.

But most eucalypts don’t form clear annual growth rings. This is why we didn’t include spotted gums and other common eucalypts seen on city streets.

Eucalypts tend to grow whenever conditions are favourable rather than being constrained by a strict annual cycle. Only a few native species reliably produce datable annual rings, such as snow gums and alpine ash. This is because they live in cold, high elevation areas, where winter consistently limits growth each year. These conditions aren’t found in any major Australian city.

What does this mean for city planners?

Our research shows that species selection matters a great deal.

Some street trees such as jacarandas, London plane and the European nettle tree can thrive even under extreme heat and drought, while honey locust and Chinese elms are more sensitive to local conditions.

Authorities can maximise the benefits of urban forests and reduce tree decline or loss by choosing resilient species and matching them to the specific climate of each city or neighbourhood.

As climate extremes become more common, even resilient species may face new challenges.

Planting and maintaining diverse, climate-adapted urban forests will help ensure our cities remain liveable, healthy, and green in the decades to come.

Manuel Esperon-Rodriguez, Senior Lecturer in Ecology, Western Sydney University; Mark G Tjoelker, Professor of Ecology and Associate Director, Hawkesbury Institute for the Environment, Western Sydney University; Matthew Brookhouse, Senior Lecturer in Ecology, Australian National University, and Sally Power, Professor of Ecology, Western Sydney University

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

Australia’s dairy industry is in the middle of a crisis, fuelled by an almost perfect storm of challenges.

Climate change and extreme weather have been battering farmlands and impacting animal productivity, creating mounting financial strains and mental health struggles for many farmers.

Meanwhile, beyond the farm gate, consumer tastes are shifting to a range of dairy substitutes. Interest and investment in alternative dairy proteins is accelerating.

Earlier this month, industry figures warned consumers to prepare for price rises amid expected shortages of milk, butter and cheese. Already mired in uncertainty, the dairy industry is now being forced to confront some tough questions about its future head on.

Dairy under pressure

Dairy is Australia’s third-largest rural industry. It produces more than A$6 billion worth of milk each year, and directly employs more than 30,000 people.

But the sector has been under sustained pressure. This year alone, repeated extreme weather events have affected key dairy-producing regions in southern and eastern parts of Australia.

In New South Wales, dairy farmers face increased pressure from floods. In May, many regions had their monthly rainfall records broken – some by huge margins.

In Victoria, drought and water shortages are worsening. Tasmania, too, continues to endure some of the driest conditions in more than a century.

Conditions have prompted many farmers to sell down their cattle numbers to conserve feed and water.

All of this heavily impacts farm productivity. Agriculture has long been predicated on our ability to predict climate conditions and grow food or rear animals according to the cycles of nature.

As climate change disrupts weather patterns, this makes both short and long-term planning for the sector a growing challenge.

High costs, low profits

Climate change isn’t the only test. The industry has also been grappling with productivity and profitability concerns.

At the farm level, dairy farmers are feeling the impacts of high operating costs. Compared to other types of farming (such as sheep or beef), dairy farms require more plant, machinery and equipment capital, mostly in the form of specialised milking machinery.

The price of milk also has many farmers concerned. The modest increase in farmgate milk prices – just announced by dairy companies for the start of the next financial year – left many farmers disappointed. Some say the increase isn’t enough to cover rising operating costs.

Zooming out, there are concerns about a lack of family succession planning for dairy farms. Many young people are wary of taking on such burdens, and the total number of Australian dairy farms has been in steady decline – from more than 6,000 in 2015 to just 4,163 in 2023.

What’s the solution?

Is there a way to make the dairy industry more productive, profitable and sustainable? Australian Dairy Farmers is the national policy and advocacy group supporting the profitability and sustainability of the sector.

In the lead up to this year’s federal election, the group called for $399 million in government investment to address what it said were key priorities. These included:

• investment in on-farm technologies to improve efficiencies
• funding for water security
• upskilling programs for farmers
• support for succession planning.

However, as the industry struggles to grapple with a changing climate, financial strain and mental health pressures, there should also be pathways for incumbent farmers to transition, either to farming dairy differently (such as by reducing herd sizes) or exiting out of dairy farming and into something else.

Dairy without the cows

The push to make dairy production more sustainable and efficient faces its own competition. A number of techniques in development promise dairy products without the cows, through cellular agriculture – and more specifically, “precision fermentation”.

Australian company Eden Brew, in partnership with dairy giant Norco, has plans to produce and commercialise precision fermentation dairy proteins.

And last year, Australian company All G secured approval to sell precision fermentation lactoferrin (a key dairy ingredient in baby formula) in China – another animal-free milk product.

It is important to note that cost and scalability for cellular agriculture remains a challenge.

Nonetheless, Australia’s rapidly growing non-dairy milk market – soy, oat, and so on – is now worth over $600 million annually. This reflects the global shift towards plant-based options driven by health, environmental, and ethical concerns.

Is there a win-win outcome?

Is there a possible future where more funding is given to produce milk at scale through precision fermentation while we also look after incumbent dairy workers, farms and the rural sector at large to diversify or leave the sector altogether?

Some believe this future is possible. This is what researchers call “protein pluralism” – a market where traditional and alternative proteins coexist. Long-term planning from both the dairy industry and government would be needed.

Remember, while techniques like precision fermentation offer the promise of animal-free dairy products, their benefits are largely yet to materialise. How they will ultimately benefit the whole of society remains speculative.

What we can do now

For this reason, some scholars have argued we should prioritise actions that can be taken now. This includes support for practices such as agroecology, which seek to address injustice and inequity in food systems to help empower primary food producers.

A recent study found Australian dairy farmers were interested in financial and technical advice to make decisions about where they take their business in future.

Despite growing recognition of the challenges facing the dairy sector, responses from government and alternative dairy remain uneven. A more coordinated approach is needed for affected farmers, helping them adapt or diversify with guidance from government and industry experts.

Milena Bojovic, Lecturer, Sustainability and Environment, University of Technology Sydney

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The international space industry is on a growth trajectory, but new research shows a rapid increase in rocket launches would damage the ozone layer.

Several hundred rockets are launched globally each year by a mix of commercial companies and nation-state space programmes. These take place at around 20 sites, almost all in the northern hemisphere, with the most prolific launch rates currently from the United States, China, New Zealand and Russia.

Our latest research explores the tipping point when launching more rockets will begin to cause problems. Our findings show that once rates reach 2,000 launches a year – about a ten-fold increase on last year – the current healing of the ozone layer slows down.

We argue that with care, we can avoid this future. The economic benefits of industry growth can be realised, but it will take a collaborative effort.

Rocket launches thin the ozone layer

The ozone layer protects life on Earth from harmful solar ultraviolet (UV) rays. It is slowly healing from the effects of chlorofluorocarbons and other damaging chemicals emitted last century, thanks to global cooperative agreements under the Montreal Protocol.

Gases and particulates emitted by rockets as they punch through the atmosphere are known to thin the ozone layer. So far, they don’t cause appreciable ozone depletion, as relatively few launches take place each year.

However, launches are steadily increasing. In 2019, there were 102 launches. By 2024, that increased to 258 worldwide. There are expected to be even more in 2025. At multiple sites worldwide, the launch industry projects impressive levels of future growth.

For US-based launches, a three-fold increase in the number of rockets launched in 2023 is expected as soon as 2028.

One driver of this growth is the effort to build out satellite constellations to tens of thousands of units, positioned low in Earth’s orbit. These require many launches to create and are happening in several nations, run by a number of companies.

Once in place, these constellations require ongoing launches to keep them supplied with active satellites.

Potential delay in ozone recovery

To figure out how future launches could affect the ozone layer, we first built a database of ozone-depleting chemicals emitted by rockets currently in use. We then fed this database into a model of Earth’s atmosphere and climate, and simulated atmospheric composition under several scenarios of higher rates of rocket launches.

We found that with around 2,000 launches worldwide each year, the ozone layer thins by up to 3%. Due to atmospheric transport of rocket-emitted chemicals, we saw the largest ozone losses over Antarctica, even though most launches are taking place in the northern hemisphere.

Fortunately, the ozone losses are small. We wouldn’t expect to see catastrophic damage to humans or ecosystems. However, the losses are significant given global efforts underway to heal the ozone layer. The global abundance of ozone is still around 2% lower than before the onset of losses caused by chlorofluorocarbons.

Future ozone losses are not locked in

Encouragingly, we found no significant ozone loss in a scenario of more modest rates of around 900 launches per year. However, this is for the types of rockets that are in use right now around the world.

We focus on current launch vehicles because it is uncertain when the new and massive rockets currently in development will enter use. But these larger rockets often require far more fuel, which creates more emissions at each launch.

Rocket propellant choices make a big difference to the atmosphere. We found fuels emitting chlorine-containing chemicals or black carbon particulates have the largest effects on the ozone layer. Reducing use of these fuels as launch rates increase is key to supporting an ongoing recovery of the ozone layer.

Re-entering spacecraft and satellite debris can also cause damage. However, the global scientific community doesn’t yet fully understand the chemistry around re-entry. Our work provides a realistic “floor” for the lowest level of damage that will occur.

But it is important to remember that these effects are not locked in. It is entirely possible to create a launch industry where we avoid harmful effects, but that would require reducing use of chlorine-containing fuels, minimising black carbon emissions by new rockets and monitoring emissions.

It will take keen effort and enthusiasm from industry and regulators, working together with scientists. But this needs to start now, not after the damage is done.

Laura Revell, Associate Professor in Atmospheric Chemistry, University of Canterbury and Michele Bannister, Senior Lecturer in Astronomy, School of Physical and Chemical Sciences Te Kura Matū, University of Canterbury

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