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Australia’s 2022 federal election was seen as the climate election. But this time round, climate policy has so far taken a back seat as the major parties focus on cost-of-living issues.

Despite this, climate change remains an ever-present threat. Last year was the world’s hottest on record and extreme weather is lashing Queensland. But there are hints of progress. Australia’s emissions have begun to fall and the main power grid is now 40% renewable.

So before Australians head to the polls on May 3, it’s worth closely examining the climate policies of the two major parties. What are they offering on cutting emissions, preparing for climate-boosted disasters and future-proofing our energy systems? And where are the gaps?

Energy transition - Tony Wood, Grattan Institute

Cost-of-living pressures, escalating damage from climate change and global policy uncertainty mean no election issue is more important than transforming Australia’s economy to achieve net zero. But our energy supply must be reliable and affordable. What should the next government prioritise?

There is great pressure to deliver power bill relief. But the next government’s priority should be reducing how much a household spends on energy, rather than trying to bring down the price of electricity. Far better to give financial support for battery storage and better home insulation, to slash how much power consumers need to buy from the grid.

The Liberal-led Senate inquiry has just found supporting home electrification will also help with cost of living pressures.

The electricity rebates on offer from Labor and the temporary cut to fuel excise from the Coalition aren’t enough.

Federal and state governments must maintain their support and investment in the new transmission lines necessary to support new renewable generation and storage.

Labor needs to do more to meet its 2030 target of reaching 82% renewables in the main grid. Currently, the figure is around 40%. The Coalition’s plan to slow down renewables, keep coal going longer and burn more gas while pushing for a nuclear future carries alarmingly high risks on reliability, cost and environmental grounds.

Gas shortfalls are looming for Australia’s southeast in the next few winters and the price of gas remains stubbornly high. Labor does not yet have a workable solution to either issue, while the Coalition has an idea – more and therefore cheaper gas – but no clarity on how its plan to keep more gas for domestic use would work in practice.

So far, we have been offered superficially appealing ideas. The field is wide open for a leader to deliver a compelling vision and credible plan for Australia’s net-zero future.

Climate adaptation – Johanna Nalau, Griffith University

You would think adapting to climate change would be high on the election agenda. Southeast Queensland just weathered its first cyclone in 50 years, estimated to have caused A$1.2 billion in damage, while outback Queensland is enduring the worst flooding in 50 years.

But so far, there’s little to see on adaptation.

Both major parties have committed to building a weather radar in western Queensland, following local outcry. While welcome, it’s a knee-jerk response rather than good forward planning.

By 2060, damage from climate change will cost Australia $73 billion a year under a low emissions scenario, according to a Deloitte report. The next federal government should invest more in disaster preparation rather than throwing money at recovery. It’s cheaper, for one thing – longer term, there are significant savings by investing in more resilient infrastructure before damage occurs.

Being prepared requires having enough public servants in disaster management to do the work. The Coalition has promised to cut 41,000 jobs from the federal public service, and has not yet said where the cuts would be made.

While in office, Labor has been developing a National Adaptation Plan to shape preparations and a National Climate Risk Assessment to gather evidence of the main climate risks for Australia and ways to adapt.

Regardless of who takes power, these will be useful roadmaps to manage extreme weather, damage to agriculture and intensified droughts, floods and fires. Making sure climate-exposed groups such as farmers get necessary assistance to weather worse disasters, and manage new risks and challenges stemming from climate change, is not a partisan issue. Such plans will help direct investment towards adaptation methods that work at scale.

New National Science Priorities are helpful too, especially the focus on new technologies able to sustainably meet Australia’s food and water needs in a changing climate.

Emission reduction – Madeline Taylor, Macquarie University

Emission reduction has so far been a footnote for the major parties. In terms of the wider energy transition, both parties are expected to announce policies to encourage household battery uptake and there’s a bipartisan focus on speeding up energy planning approvals.

But there is a clear divide in where the major parties’ policies will lead Australia on its net-zero journey.

Labor’s policies largely continue its approach in government, including bringing more clean power and storage into the grid within the Capacity Investment Scheme and building new transmission lines under the Rewiring Australia Plan.

These policies are leading to lower emissions from the power sector. Last year, total emissions fell by 0.6%. Labor’s Future Made in Australia policies give incentives to produce critical minerals, green steel, and green manufacturing. Such policies should help Australia gain market share in the trade of low-carbon products.

From January 1 this year, Labor’s new laws require some large companies to disclose emissions from operations. This is positive, giving investors essential data to make decisions. From their second reporting period, companies will have to disclose Scope 3 emissions as well – those from their supply chains. The laws will cover some companies where measuring emissions upstream is incredibly tricky, including agriculture. Coalition senators issued a dissenting report pointing this out. The Coalition has now vowed to scrap these rules.

The Coalition has not committed to Labor’s target of cutting emissions 43% by 2030. Their flagship plan to go nuclear will likely mean pushing out emissions reduction goals given the likely 2040s completion timeframe for large-scale nuclear generation, unless small modular reactors become viable.

On gas, there’s virtually bipartisan support. The Coalition promise to reserve more gas for domestic use is a response to looming shortfalls on the east coast. Labor has also approved more coal and gas projects largely for export, though Australian coal and gas burned overseas aren’t counted domestically.

Opposition Leader Peter Dutton has promised to include gas in Labor’s renewable-oriented Capacity Investment Scheme and has floated relaxing the Safeguard Mechanism on heavy emitters. The Coalition has vowed to cancel plans for three offshore wind projects and are very critical of green hydrogen funding.

Both parties will likely introduce emission reduction measures, but a Coalition government would be less stringent. Scrapping corporate emissions reporting entirely would be a misstep, because accurate measurement of emissions are essential for attracting green investment and reducing climate risks.

Johanna Nalau, Senior Lecturer, Climate Adaptation, Griffith University; Madeline Taylor, Associate Professor of Energy Law, Macquarie University, and Tony Wood, Program Director, Energy, Grattan Institute

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

Australia is a place of great natural beauty, home to many species found nowhere else on Earth. But it’s also particularly vulnerable to introduced animals, diseases and weeds. Habitat destruction, pollution and climate change make matters worse. To conserve what’s special, we need far greater care.

Unfortunately, successive federal governments have failed to protect nature. Australia now has more than 2,000 threatened species and “ecological communities” – groups of native species that live together and interact. This threatened list is growing at an alarming rate.

The Albanese government came to power in 2022 promising to reform the nation’s nature laws, following a scathing review of the laws. But it has failed to do so.

If re-elected, Labor has vowed to complete its reforms and introduce a federal Environment Protection Agency, in some other form.

The Coalition has not made such a commitment. Instead, it refers to “genuine conservation”, balancing the environment and the economy. They’ve also promised to cut “green tape” for industry.

But scientific evidence suggests much more is required to protect Australia’s natural wonders.

Fighting invaders

Labor has made a welcome commitment of more than A$100 million to counter “highly pathogenic avian influenza”. This virulent strain of bird flu is likely to kill millions of native birds and other wildlife.

The government also provided much-needed funding for a network of safe havens for threatened mammals. These safe-havens exclude cats, foxes and other invasive species.

But much more needs to be done. Funding is urgently needed to eradicate red imported fire ants, before eradication becomes impossible. Other election commitments to look for include:

• increased biosecurity funding, to prevent new incursions
• long-term investment in eradicating major pests and weeds from key sites
• support for research into new tools to control invasive species such as feral cats, for which no broad-scale solution is currently possible
• no reversal or weakening of policies aimed at curbing invasive pests such as feral horses in national parks
• new laws to ensure threat abatement plans must be implemented
• adequate funds to manage invasive species across the expanded protected areas system to meet the key global commitment to nature conservation
• national coordination and leadership to stop the indiscriminate use of poisons that can spread through ecosystems and food-chains, killing non-target animals such as owls, quolls, Tasmanian devils, reptiles and frogs.

Stopping land clearing and habitat destruction

The states are largely responsible for controlling land clearing. But when land clearing affects “matters of national environmental significance” such as a nationally listed threatened species or ecological community, it becomes a federal matter.

Such proposals are supposed to be referred to the federal environment minister for assessment under the Environment Protection and Biodiversity Conservation (EPBC) Act.

But most habitat destruction is never referred. And if it is, it’s mostly deemed “not a controlled action”. That means no further consideration is required and the development can proceed.

Only about 1.5% of the hundreds of thousands of hectares of land cleared in Australia every year is fully assessed under the EPBC Act.

This means our threatened species and ecological communities are suffering a “death by a thousand cuts”.

How do we fix this? A starting point is to introduce “national environmental standards” of the kind envisaged in the 2020 review of the EPBC Act by Professor Graeme Samuel.

A strong Environment Protection Agency could ensure impacts on biodiversity are appropriately assessed and accounted for.

Protecting threatened species

For Australia to turn around its extinction crisis, prospective elected representatives and governments must firmly commit to the following actions.

Stronger environmental law and enforcement is essential for tackling biodiveristy decline and extinction. This should include what’s known as a “climate trigger”, which means any proposal likely to produce a significant amount of greenhouse gases would have to be assessed under the EPBC Act.

This is necessary because climate change is among the greatest threats to biodiversity. But the federal environment minister is currently not legally bound to consider – or authorised to refuse – project proposals based on their greenhouse gas emissions. In an attempt to pass the EPBC reforms in the Senate last year, the Greens agreed to postpone their demand for a climate trigger.

Key threats to species, including habitat destruction, invasive species, climate change, and pollution, must be prevented or reduced. Aligning government policies and priorities to ensure environmental goals aren’t undermined by economic and development interests is essential.

A large increase in environmental spending – to at least 1% of the federal budget – is vital. It would ensure sufficient support for conservation progress and meeting legal requirements of the EPBC Act, including listing threatened species and designing and implementing recovery plans when required.

Show nature the money!

Neither major party has committed to substantial increases in environmental spending in line with what experts suggest is urgently needed.

Without such increased investment Australia’s conservation record will almost certainly continue to deteriorate. The loss of nature hurts us all. For example, most invasive species not only affect biodiversity; they have major economic costs to productivity.

Whoever forms Australia’s next government, we urge elected leaders to act on the wishes of 96% of surveyed Australians calling for more action to conserve nature. 

Euan Ritchie, Professor in Wildlife Ecology and Conservation, School of Life & Environmental Sciences, Deakin University; John Woinarski, Professor of Conservation Biology, Charles Darwin University, and Martine Maron, Professor of Environmental Management, The University of Queensland

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

Street trees usually grow in appalling soils, have little space for their roots, are rarely watered and often get aggressively trimmed by road authorities or utility companies.

If they do get established, many street trees suffer damage from vehicles, have to live in wind tunnels or are forced to grow in the permanent shade of large buildings.

But despite everything we throw at them, many street trees don’t just survive, they thrive. So let’s meet one of these heroic species: the yellow gum, (Eucalyptus leucoxylon).

Pretty but tough

Yellow gum is widely planted across southeastern and eastern Australia as a street tree. In some suburbs and towns, it is so common that people think it is a native tree (in fact it is from South Australia, Victoria or southwest New South Wales).

It is not to be confused with yellow box (Eucalyptus melliodora), a different eucalypt altogether.

Yellow gum has been widely planted because it meets many of the demands we place on urban trees.

It grows well in different soils and climates, and has very attractive red, white or pink flowers.

It’s called yellow gum in Victoria and parts of NSW, but is often known as blue gum in SA.

The common names can be confusing, but yellow gum refers to its pale yellow wood and bark patches, while blue gum refers to its leaves.

Many specimens develop dense, low, spreading canopies, which offer lovely shade and help cool our cities down.

And importantly, it doesn’t grow too big. It is typically a medium to small woodland tree, usually between 13 and 16 metres high (but it can grow higher in the wild).

Different bird and insect species feed on the trees some feeding on flowers and fruits and others on the foliage.

Natural populations of yellow gum occur in coastal and inland SA, in the southwest corner of NSW and in the western half of Victoria from the Murray River to the coast.

There are several subspecies, too, and debate rages in botanical and horticultural circles about whether some of them deserve to be recognised as their own species.

Yellow gum is also tolerant of wind and salt spray, and can withstand waterlogged soils. They stood up to the millennium drought conditions well.

Many arborists think the yellow gum has the potential to do well in many parts of Australia as the climate changes. Research has shown, for example, that some individual yellow gum trees regulate their water use better (when compared to other individuals in the species, and when compared to other eucalypts).

Like many eucalypts, yellow gum possesses lots of dormant buds and a lignotuber (a swelling at the base of the trunk containing dormant buds and carbohydrate). This means it copes well with pruning and will respond especially well to targeted formative pruning when young.

This can help reduce the risk of problems such as what’s known as “co-dominant stems” (when two main stems grow from a single point of origin, instead of one tall, straight trunk) and rubbing or crossing branches.

Not everyone’s favourite

Not everybody likes the yellow gum, and for some good reasons.

Some yellow gums are multi-stemmed, while others have twisted and curving trunks; some have both. These are not the characteristics many local governments want in street trees; many want to see straight trunks and dense canopies.

These problems can be so annoying that some council arborists no longer recommend planting yellow gums.

But these issues are due to poor tree selection and propagation. In the past, yellow gum seed was not carefully sourced from the best trees with the most suitable characteristics, and so inferior specimens have prospered.

With the right investment of time and money into tree selection, these problems can be overcome.

Ticking most of the boxes

All in all, yellow gum can be a very fine and useful urban tree.

The species grows well and if superior stock is used, the trees develop with straight and attractive trunks and wide, dense canopies.

They are typically medium-sized trees, do well in tough street conditions or in smaller domestic front and back yards.

They tick most, if not all, of the boxes for a good urban street tree.

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

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

The greater bilby (Macrotis lagotis) is one of Australia’s most iconic yet at-risk animals — and the last surviving bilby species. Once found across 70% of Australia, its range has contracted by more than 80% since European colonisation.

Today, these nocturnal marsupials, still culturally significant to many Indigenous peoples, are restricted to remote deserts. They face an ongoing threat of extinction.

Local elders, Indigenous rangers and scientists hold valuable knowledge about bilby populations, the threats they face, and strategies needed to sustain them into the future.

Our new study, published today in Conservation Science and Practice, reveals how collaboration between scientists and Indigenous land managers can help yield new and vital information.

In the field, we used two methods – one based on Warlpiri knowledge and one based on standard scientific protocols – to locate bilbies and collect scat (poo) samples in the North Tanami Indigenous Protected Area in the Northern Territory.

By drawing on Warlpiri tracking expertise and Western scientific methods, we uncovered crucial information on bilby populations that could help conserve these rare creatures.

Understanding bilby numbers is important – but hard

Bilbies turn over tonnes of soil each year, helping to improve soil health, help seeds germinate and enhance water infiltration. Their deep, complex burrows also provide shelter for other species.

They’re crucial to the health of desert ecosystems; protecting bilbies means protecting the web of life they support.

To do this, we need to know more about:

• how many bilbies there are
• how they respond to land management techniques such as planned burning
• how they respond to threats such as feral predators.

Yet, bilbies are notoriously difficult to monitor directly via live capture. They’re nocturnal, shy and solitary. And they inhabit vast landscapes, making it very hard to estimate population numbers.

Luckily, the tracks, diggings and scats bilbies leave behind provide ample clues. DNA from scat (if it can be found) can be used to estimate how many bilbies are present in a particular area.

Systematic ecological surveys, often used to monitor wildlife, can be rigid and expensive, especially in remote regions.

We need flexible methods that align with local knowledge and the practical realities of monitoring bilbies on Country.

A new approach to monitor and manage bilbies

We tested two methods of locating bilby scat for DNA analysis.

The first was systematic sampling. This is a standard scientific approach where fixed lengths of land were walked multiple times to collect scat.

This ensures sampling effort is even over the search area and comparable across sites. However, like most species, bilby distribution is patchy, and this approach can lead to researchers missing important signs.

The second method was targeted sampling, guided by Warlpiri knowledge, to search in areas most likely to yield results.

This allowed the search team to focus on areas where bilbies were active or predicted to be active based on knowledge of their habits and food sources.

Altogether, we collected more than 1,000 scat samples. In the lab, we extracted DNA from these samples to identify individual bilbies. These data, combined with the location of samples, allowed us to estimate the size of the bilby population.

We then compared estimates that would have been derived if we had only done systematic or targeted sampling, or both, to assess their strengths and limitations for monitoring bilby populations.

What we found

We identified 20 bilbies from the scats collected during systematic surveys and 26 – six more – from targeted surveys. At least 16 individual bilbies were detected by both methods. In total, we confirmed 32 unique bilbies in the study area.

When it came to population estimates – which consider how many repeat captures occur and where – combining data from both types of surveys produced the most accurate estimates with the least effort.

Targeted sampling tended to overestimate population size because it focused on areas of high activity. Systematic sampling was more precise but required greater effort.

Combining both approaches provided the most reliable estimates while saving time.

What this means for conservation

Our research highlights how collaboration that includes different ways of knowing can improve conservation.

By adapting standard on-ground survey techniques to include Warlpiri methods for tracking bilbies, we produced better data and supported local capacity for bilby monitoring.

Elders also had opportunities to share tracking skills with younger people, helping keep cultural knowledge alive.

Conservation programs often rely on standardised ecological monitoring protocols – in other words, doing things much the same way no matter where you’re working.

While these protocols provide consistency, they are rigid and don’t always yield the best results. They also fail to incorporate local knowledge crucial for managing species like the bilby.

Our approach shows how integrating diverse ways of working can deliver more inclusive and effective outcomes, without compromising data reliability.

A path forward

Bilbies face ongoing threats including:

• introduced predators (particularly foxes)
• habitat degradation and
• inappropriate fire regimes.

Their future depends on collaborative efforts that draw on scientific and Indigenous and local knowledges.

This study provides an example of how such partnerships can work – not just for bilbies, but for other species and ecosystems.

As Australia confronts biodiversity loss, this research underscores the importance of listening to those who know Country best.

By valuing and respecting local expertise, we can build a stronger future for bilbies and the landscapes that are their home.

Hayley Geyle, Ecologist, Charles Darwin University; Cathy Robinson, Principal Research Scientist, CSIRO; Christine Schlesinger, Associate Professor in Environmental Science, Charles Darwin University, and Helen Wilson, Lead Ranger, North Tanami Rangers, Indigenous Knowledge

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

As I sprinted across the flower-rich meadow on the eastern coast of Cyprus, I could barely see my car. The air was full of tiny black dots, pelting like bullets past me. I hauled open the car door and breathed a sigh of relief once inside. I was surrounded by millions of flies, amid the most incredible migration event I have ever seen.

The migration cameras my team and I use to monitor these insects counted nearly 6,000 flies per metre per minute. Being hit by a fly travelling over 25mph (helped by the wind) hurts enough to make you want shelter quickly.

All of these flies had just travelled at least 60 miles (100km) across open sea from the Middle East to Cyprus. This journey forms part of their springtime migration towards northern Europe.

Butterflies and dragonflies are well-known insect migrants, but not because they’re the most numerous. That title is given to the flies. I have studied all of the insects migrating through Cyprus and the Pyrenees on the France-Spain border. Flies make up nearly 90% of all migrants. Yet they have been consistently overlooked by scientists and their ecological contribution has been hugely underappreciated.

My colleagues and I set out to change this. We have spent months collecting written sources that mentioned fly migration from anywhere in the world. Our findings, now published in Biological Reviews, could change our perception of flies forever. Previously, nobody really knew the extent to which flies migrated, yet they are the most numerous and most ecologically important of all terrestrial migrants.

Fly migration has been part of written human history for millennia. In the book of Exodus, when the pharoah of Egypt didn’t let Moses’s people go, God sent a plague of flies to change his mind. Then God removed flies from the land until “not a fly remained”. This last biblical quote is key.

If these flies had been misidentified mayflies coming out of the river Nile, which are known to amass in huge numbers, their exhausted bodies would have remained for days. Because they all disappeared without a trace, this suggests a huge migration of flies. Egypt is on an important fly migration route. So perhaps fly migration was significant enough to be the subject of divine intervention.

Flies migrate to reproduce, moving to exploit seasonal food resources. All over the world, it’s mostly females that migrate. They have been recorded migrating through mountain passes high in the Himalayas, on ships hundreds of miles out to sea in the Gulf of Mexico and in their millions migrating through western Europe. Amazingly, while on fieldwork in the Maldives, I saw Forcipomyia midges use their soft foot hairs to stick to dragonfly wings to hitch a lift over the Indian Ocean.

Vital roles

Flies are so important to the planet and to us. No other group of terrestrial migrants (including vertebrates such as mammals) are as ecologically diverse as flies. More than half (62%) of all migrating flies, including hoverflies, are pollinators. Without them, food crop production would decline.

As they migrate, flies transport and disperse pollen between flowers. This could help plants adapt to climate change by maintaining genetic diversity.

Many migratory fly species (34%) are decomposers, ensuring the planet isn’t covered in rotting carcasses and animal dung. One study showed that the larvae of just 50 houseflies (Musca domestica), – the very ecologically similar and equally abundant autumn housefly Musca autumnalis migrate south through the Pyrenees in their millions – can decompose up to 444kg of pig manure.

The ecological roles of flies are not all positive, though. My latest study shows that monoculture crops provide lots of food for some migratory fly species (18%) that have subsequently become crop pests. Some (16%) carry diseases, such as mosquitoes that migrate huge distances and bring diseases such as malaria.

But migratory flies have an overwhelmingly positive impact on the planet. Hoverfly larvae eat trillions of aphids each year in southern England. Insect migration is already known to be the most important way that the nutrients plants need to grow are moved across the land and flies make up the majority of the insects that transport the nutrients.

The movement and subsequent death of trillions of migrating flies, whose bodies contain elements, such as phosphorous and nitrogen which plants need to grow, could be vital to soil health of the soils too. Migratory birds have been noted feeding on and moving at the same time as migratory flies, perhaps using them as fuel for their journeys.

We’re only just waking up to the significance of flies. Hopefully, it’s not too late to protect them. One German study found that the number of aphid-eating migratory hoverflies declined by 97% over the last 50 years. Fewer aphid-eating hoverflies means more crop-eating aphids and also fewer pollinators. So that’s a terrifying statistic that could have drastic consequences.

A sunrise of hope exists, however. These brilliant migratory flies have so many young that if we improve landscape connectivity, reduce pesticide usage and provide suitable habitat, they can bounce back really quickly. We need these flies as much as we need the air we breathe. So next time you see a fly up against your window, open it and let it out. It has a long way to go and such important work to do.

Don’t have time to read about climate change as much as you’d like?
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Will Hawkes, Insect Migration Researcher, College of Life and Environmental Science, University of Exeter

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

There are roughly a trillion species of microorganisms on Earth – the vast majority of which are bacteria.

Bacteria consist of a single cell. They do not have bones and are not like big animals that leave clear signs in the geological record, which thankful palaeontologists can study many millions of years later.

This has made it very hard for scientists to establish a timeline of their early evolution. But with the help of machine learning, we have been able to fill in many of the details. Our new research, published today in Science, also reveals some bacteria developed the ability to use oxygen long before Earth became saturated with it roughly 2.4 billion years ago.

A monumental event in Earth’s history

About 4.5 billion years ago, the Moon formed. Violently. A Mars-size object collided with Earth, turning its surface into molten rock. If life existed before this cataclysm, it was probably destroyed.

After that, the current ancestors of all living beings appeared: single-celled microbes. For the first 80% of life’s history, Earth was inhabited solely by these microbes.

Nothing in biology makes sense except in the light of evolution, as evolutionary biologist Theodosius Dobzhansky famously said in 1973. But how did the evolution of life proceed through the early history of Earth?

Comparing DNA sequences from the wonderful diversity of life we see today can tell us how different groups relate to each other. For instance, we humans are more closely related to mushrooms than we are to apple trees. Likewise, such comparisons can tell us how different groups of bacteria are related to each other.

But comparison of DNA sequences can only take us so far. DNA comparisons do not say when in Earth’s history evolutionary events took place. At one point in time, an organism reproduced two offspring. One of them gave rise to mushrooms, the other to humans (and lots of other species too). But when exactly did that organism live? How many years ago?

One thing geology teaches us about is the existence of another monumental event in the history of Earth, 2.4 billion years ago. At that time, the atmosphere of the Earth changed dramatically. A group of bacteria called the cyanobacteria invented a trick that would alter the story of life forever: photosynthesis.

Harvesting energy from the sun powered their cells. But it also generated an inconvenient waste product, oxygen gas.

Over the course of millions of years, oxygen in the atmosphere slowly accumulated. Before this “Great Oxidation Event”, Earth contained almost no oxygen, so life was not ready for it. In fact, to uninitiated bacteria, oxygen is a poisonous gas, and so its release into the atmosphere probably caused a mass extinction. The surviving bacteria either evolved to use oxygen, or retreated into the recesses of the planet where it doesn’t penetrate.

The bacterial tree of life

The Great Oxidation Event is especially interesting for us not only because of its impact in the history of life, but also because it can be given a clear date. We know it happened around 2.4 billion years ago – and we also know most bacteria that adapted to oxygen had to live after this event. We used this information to layer on dates to the bacterial tree of life.

We started by training an artificial intelligence (AI) model to predict whether a bacteria lives with oxygen or not from the genes it has. Many bacteria we see today use oxygen, such as cyanobacteria and others that live in the ocean. But many do not, such as the bacteria that live in our gut.

As far as machine learning tasks go, this one was quite straightforward. The chemical power of oxygen markedly changes a bacteria’s genome because a cell’s metabolism becomes organised around oxygen use, and so there are many clues in the data.

We then applied our machine learning models to predict which bacteria used oxygen in the past. This was possible because modern techniques allow us to estimate not only how the species we see today are related, but also which genes each ancestor carried in its genome.

A surprising twist

By using the planet-wide geological event of the Great Oxidation Event effectively as a “fossil” calibration point, our approach produced a detailed timeline of bacterial evolution.

Combining results from geology, paleontology, phylogenetics and machine learning, we were able to refine the timing of bacterial evolution significantly.

Our results also revealed a surprising twist: some bacterial lineages capable of using oxygen existed roughly 900 million years before the Great Oxidation Event. This suggests these bacteria evolved the ability to use oxygen even when atmospheric oxygen was scarce.

Remarkably, our findings indicated that cyanobacteria actually evolved the ability to use oxygen before they developed photosynthesis.

This framework not only reshapes our understanding of bacterial evolutionary history but also illustrates how life’s capabilities evolved in response to Earth’s changing environments.

Ben Woodcroft, Associate Professor of Microbial Informatics, Queensland University of Technology and Adrián A. Davín, Postdoctoral Fellow, Department of Biology, Swiss Federal Institute of Technology Zurich

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

Opposition Leader Peter Dutton would withdraw Australia’s bid to co-host next year’s global climate summit if the Coalition wins the federal election.

Australia has lobbied hard for the right to host the talks, known as COP31, in conjunction with Pacific nations. Australia has emerged as a leading contender, and has the backing of most countries in its United Nations grouping, including the United Kingdom, France, Germany, Canada and New Zealand.

However, Dutton on Sunday described the idea of hosting the UN climate conference as “not something we are supporting — it is madness”. He also falsely claimed it would cost Australia “tens of billions” of dollars to host the event.

Australia would reap big benefits by hosting the high-profile global talks. It would likely attract considerable investment in renewables and clean energy export industries, and strengthen Australia’s national security during a time of increasing geo-strategic competition in the Pacific. To pull out now would be a costly move.

Decison deferred until June

The decision on who will host COP31 in 2026 was expected at last year’s summit in Azerbaijan. But it was deferred until June this year – after Australia’s next federal election.

Hosting rights are shared between five UN country groupings on a rotational basis. The final decision is made by consensus.

Australia’s bid to host with Pacific nations has considerable support. But Turkey, the only other country in the running to host COP31, has so far resisted lobbying efforts to persuade it to drop out.

An economic boost for Australia

Hosting the UN climate talks is a massive economic opportunity for Australia.

COP31 would be one of the biggest diplomatic summits Australia has ever hosted. Tens of thousands of people could be expected for a fortnight of negotiations, with satellite events held across the nation and the Pacific.

Adelaide is in the box seat to play host. The South Australian government estimated hosting the UN talks could generate more than A$500 million for the state. But economic benefits would be much wider, and longer-lasting, than tourism receipts from those attending. The talks are a chance to attract investment for Australia’s energy transition and for clean energy industries of the future, including critical minerals and green iron.

The UK government’s assessment of the value of hosting the UN climate summit in Glasgow in 2021 found the net economic benefit was double that spent – around A$1 billion. That includes benefits from trade deals and foreign investment. With abundant critical minerals, and excellent wind and solar resources, Australia has even more to gain.

Hosting the world’s largest climate summit is a chance to attract the investment needed to replace ageing and unreliable coal-fired power stations. According to the Clean Energy Investor Group, which represents the capital behind large-scale renewables, more than 70% of the investment in clean energy comes from international sources.

Dutton says he plans to replace coal with nuclear power (and to rely on gas until nuclear plants are built decades from now). The Coalition’s nuclear plan would require hundreds of billions of dollars of taxpayer support.

Securing our place in the Pacific

Working with Pacific nations to address climate change is key to Australian national security.

Australia aims to be the security partner of choice for Pacific island countries. And Pacific island countries are crystal clear: climate change is their “single greatest threat”.

In 2022, Solomon Islands signed a security deal with China, which raised the prospect of a potential Chinese naval base in Australia’s maritime approaches. Foreign Minister Penny Wong – who was in opposition at the time – described it as the worst foreign policy blunder in the Pacific since the end of WWII.

The Albanese government has looked to cement Australia’s place in the Pacific by working with island nations to address climate change. In July 2022, Albanese joined Pacific leaders to declare a Pacific climate emergency and launched bid to co-host a UN climate summit with Pacific nations. In 2023, Australia signed a climate migration deal with Tuvalu that also prevents Tuvalu from pursuing a security deal with China.

Pacific leaders have welcomed Australia’s plans to host the UN climate talks and have agreed to work together to advocate for the joint bid. Walking away now could do real damage to Australian strategy in the region.

Embracing our clean energy future

Hosting COP31 is a chance to set up Australia’s economy of tomorrow, signalling the shift from fossil fuel heavyweight to clean energy superpower.

Australia is leading the clean energy transition. This is a story to tell the world. One in three households have rooftop solar. Already 40% of the main national power grid is powered by wind, solar and storage. We are on track for 80% renewables by 2030.

South Australia is moving even faster, set for 100% clean electricity by 2027. Hosting COP31 in the state is also a chance to showcase clean energy export industries, especially plans to produce green iron and green steel at the Whyalla steelworks.

Australia is the world’s largest exporter of raw iron ore, but is well positioned to export more-valuable, and lower-polluting, green iron to major economies in our region. The potential export value of green iron is estimated to be $295 billion a year, or three times the current value of iron ore exports.

More broadly, our clean energy exports – including green metals, green fertilisers and green fuels – could be worth six to eight times more than our fossil fuel exports.

Walking away from the chance to host the world and showcase our clean energy future would be costly indeed.

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

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

When Brisbane was awarded the 2032 Olympic and Paralympic Games, it came with a widely publicised landmark promise: the world’s first “climate-positive” games.

The International Olympic Committee had already announced all games would be climate-positive from 2030. It said this meant the games would be required to “go beyond” the previous obligation of reducing carbon emissions directly related to their operations and offsetting or otherwise “compensating” for the rest.

In other words, achieving net-zero was no longer sufficient. Now each organising committee would be legally required to remove more carbon from the atmosphere than the games emit. This is in keeping with the most widely cited definition of climate-positive.

Both Paris 2024 and Los Angeles 2028 made voluntary pledges. But Brisbane 2032 was the first contractually required to be climate-positive. This was enshrined in the original 2021 Olympic Host Contract, an agreement between the IOC, the State of Queensland, Brisbane City Council and the Australian Olympic Committee.

But the host contract has quietly changed since. All references to “climate-positive” have been replaced with weaker terminology. The move was not publicly announced. This fits a broader pattern of Olympic Games promising big on sustainability before weakening or abandoning commitments over time.

A quiet retreat from climate positive

Research by my team has shown the climate-positive announcement sparked great hope for the future of Brisbane as a regenerative city. We saw Brisbane 2032 as a once-in-a-lifetime opportunity to radically shift away from the ongoing systemic issues underlying urban development.

This vision to embrace genuinely sustainable city design centred on fostering circular economies and net positive development. It would have aligned urban development with ecological stewardship. Beyond just mitigating environmental harm, the games could have set a new standard for sustainability by becoming a catalyst to actively regenerate the natural environment.

Yet, on December 7 2023, the International Olympic Committee (IOC) initiated an addendum to the host contract. It effectively downgraded the games’ sustainability obligations.

It was signed by Brisbane City Council, the State of Queensland, the Australian Olympic Committee and the IOC between April and May 2024.

Asked about these amendments, the IOC replied it “took the decision to no longer use the term ‘climate-positive’ when referring to its climate commitments”.

But the IOC maintains that: “The requirements underpinning this term, however, and our ambition to address the climate crisis, have not changed”.

It said the terminology was changed to ensure that communications “are transparent and easily understood; that they focus on the actions implemented to reduce carbon emissions; and that they are aligned with best practice and current regulations, as well as the principle of continual improvement”.

Similarly, a Brisbane 2032 spokesperson told The Conversation the language was changed:

to ensure we are communicating in a transparent and easily understood manner, following advice from the International Olympic Committee and recommendations of the United Nations and European Union Green Claims Directive, made in 2023.

Brisbane 2032 will continue to plan, as we always have, to deliver a Games that focus on specific measures to deliver a more sustainable Games.

But the new wording commits Brisbane 2032 to merely “aiming at removing more carbon from the atmosphere than what the Games project emits”.

Crucially, this is no longer binding. The new language makes carbon removal an optional goal rather than a contractual requirement.

Aiming high, yet falling short

Olympic Games have adopted increasingly ambitious sustainability rhetoric. Yet, action in the real world typically falls short.

In our ongoing research with the Politecnico di Torino, Italy, we analysed sustainability commitments since the 2006 Winter Olympics in Turin. We found they often change over time. Initial promises are either watered down or abandoned altogether due to political, financial, and logistical pressures.

Construction activities for the Winter Olympic Games 2014 in Sochi, Russia, irreversibly damaged the Western Caucasus – a UNESCO World Heritage Site. Rio 2016 failed to clean up Guanabara Bay, despite its original pledge to reduce pollutants by 80%. Rio also caused large-scale deforestation and wetland destruction. Ancient forests were cleared for PyeongChang 2018 ski slopes.

Our research found a persistent gap between sustainability rhetoric and reality. Brisbane 2032 fits this pattern as the original promise of hosting climate-positive games is at risk of reverting to business as usual.

Victoria Park controversy

In 2021, a KPMG report for the Queensland government analysed the potential economic, social and environmental benefits of the Brisbane 2032 games.

It said the government was proposing to deliver the climate-positive commitment required to host the 2032 games through a range of initiatives. This included “repurposing and upgrading existing infrastructure with enhanced green star credentials”.

But plans for the Olympic stadium have changed a great deal since then. Plans to upgrade the Brisbane Cricket Ground, commonly known as the Gabba, have been replaced by a new stadium to be built in Victoria Park.

Victoria Park is Brisbane’s largest remaining inner-city green space. It is known to Indigenous peoples as Barrambin (the windy place). It is listed on the Queensland Heritage Register due to its great cultural significance.

Page 90 of the Olympic Host Contract prohibits permanent construction “in statutory nature areas, cultural protected areas and World Heritage sites”.

Local community groups and environmental advocates have vowed to fight plans for a Victoria Park stadium. This may include a legal challenge.

What next?

The climate-positive commitment has been downgraded to an unenforceable aspiration. A new Olympic stadium has been announced in direct violation of the host contract. Will Brisbane 2032 still leave a green legacy?

Greater transparency and public accountability are needed. Otherwise, the original plan may fall short of the positive legacy it aspired to, before the Olympics even begin.

Marcus Foth, Professor of Urban Informatics, Queensland University of Technology

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

The future of Australia’s key climate policy is uncertain after Opposition Leader Peter Dutton said a Coalition government would review the measure, known as the “safeguard mechanism”, which is designed to limit emissions from Australia’s largest industrial polluters.

According to the Australian Financial Review, if the Coalition wins office it will consider relaxing the policy, as part of its plan to increase domestic gas supplies.

Evidence suggests weakening the mechanism would be a mistake. In fact, it could be argued the policy does not go far enough to force polluting companies to curb their emissions.

Both major parties now accept Australia must reach net-zero emissions by 2050. This bipartisan agreement should make one thing clear: winding back the safeguard mechanism would be reckless policy.

What’s the safeguard mechanism again?

The safeguard mechanism began under the Coalition government in 2016. It now applies to 219 large polluting facilities that emit more than 100,000 tonnes of greenhouse gases a year. These facilities are in sectors such as electricity, mining, gas, manufacturing, waste and transport. Together, they produce just under one-third of Australia’s emissions.

Under the policy’s original design, companies were purportedly required to keep their emissions below a certain cap, and buy carbon credits to offset any emissions over the cap. However, loopholes meant the cap was weakly enforced.

This meant greenhouse gas pollution from the facilities actually increased – rising from 131.3 million tonnes to 138.7 million tonnes in the first six years of the policy.

Labor strengthened the safeguard mechanism after it won office, by setting a hard cap for industrial emissions. The Coalition voted against the reforms.

Dutton has since labelled the safeguard mechanism a “carbon tax” – a claim that has been debunked. Some members of the Coalition reportedly believe the policy makes manufacturers globally uncompetitive.

Now, according to media reports, a Coalition government would review the safeguard mechanism with a view to weakening it, in a bid to bolster business and increase gas supply.

Why the safeguard mechanism should be left alone

Weakening the safeguard mechanism would lead to several problems.

First, it would mean large facilities, including new coal and gas projects, would be permitted to operate without meaningful limits on their pollution. This threatens Australia’s international climate obligations.

Second, if polluters were no longer required to buy carbon offsets, this would disrupt Australia’s carbon market.

As the Clean Energy Regulator notes, the safeguard mechanism is the “dominant source” of demand for Australian carbon credits.

In the first quarter of 2024, about 1.2 million carbon-credit units were purchased by parties wanting to offset their emissions. The vast majority were purchased by companies meeting compliance obligations under the safeguard mechanism or similar state rules.

If companies are no longer required to buy offsets, or they buy fewer offsets, this would hurt those who sell carbon credits.

Carbon credits are earned by organisations and individuals who abate carbon – through measures such as tree planting or retaining vegetation. The activities are often carried out by farmers and other landholders, including Indigenous organisations. Indigenous-led carbon projects have delivered jobs, cultural renewal and environmental benefits.

The safeguard mechanism, together with the government pledge to reach net-zero emissions by 2050, also provides certainty for the operators of polluting facilities. Many in the business sector have called for the policy to remain unchanged.

And finally, winding back the safeguard mechanism would send a troubling signal to the world: that Australia is stepping back from climate action.

Now is not the time to abdicate our responsibilities on climate change. Atmospheric carbon dioxide levels have risen dramatically since 1960. This increase is driving global warming and climate change, leading to extreme weather events which will only worsen.

A hard-won policy

The safeguard mechanism has not had time to deliver meaningful outcomes. And it is far from perfect – but it is hard-won, and Australia needs it.

The 2023 reforms to the mechanism were designed to support trade-exposed industries, while encouraging companies to invest in emissions reduction.

Undoing this mechanism would risk our climate goals. It would leave the government limited means to curb pollution from Australia’s largest emitters, and muddy the roadmap to net-zero. It would also create uncertainty for all carbon market participants, including the polluting facilities themselves.

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

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

The small Queensland town of Eromanga bills itself as Australia’s town furthest from the sea. But this week, an ocean of freshwater arrived.

Monsoon-like weather has hit the normally arid Channel Country of inland Queensland. Some towns have had two years’ worth of rain in a couple of days. These flat grazing lands now resemble an inland sea.

One New South Wales man is still missing and dozens of people have been evacuated. Others are preparing to be cut off, potentially for weeks. And graziers are reporting major livestock losses – more than 100,000 and climbing. In some areas, the flooding is worse than 1974, the wettest year on record in Australia.

Why so much rain? Tropical, water-laden air has been brought far inland from the oceans to the north and east. This can happen under normal climate variability. But our ocean temperatures are the highest on record, which supercharges the water cycle.

In coming weeks, this huge volume of water will wend its way through the channels perhaps 600 km to fill Kati Thanda-Lake Eyre, the ephemeral lake which appears in the northern reaches of South Australia. It’s likely this will be a Lake Eyre for the ages.

In the first three months of the year, deadly record-breaking floods hit northern Queensland before Cyclone Alfred tracked unusually far south and made landfall in southeast Queensland, bringing widespread winds and rains and leaving expensive repair bills. Now the rain has come inland.

Why so much rain in arid areas?

Some meteorologists have dubbed this event a pseudo-monsoon. That’s because the normal Australian monsoon doesn’t reach this far south – the torrential rains of the monsoonal wet season tend to fall closer to the northern coasts.

Because the Arafura and Timor Seas to the north are unusually warm, evaporation rates have shot up. Once in the air, this water vapour makes for very humid conditions. These air masses are even more humid than normal tropical air, because they have flowed down from the equator. Many Queenslanders can vouch for the intense humidity.

But there’s a second factor at work. At present, Australia’s climate is influenced by a positive Southern Annular Mode. This means the belt of intense westerly winds blowing across the Southern Ocean has been pushed further south, causing a ripple effect which can lead to more summer rain in Australia’s southeast, up to inland Queensland. This natural climate driver has meant easterly winds have blown uninterrupted from as far away as Fiji, carrying yet more humid air inland.

These two streams of converging humid tropical air were driven up into the cooler heights of the atmosphere by upper and surface low pressure troughs, triggering torrential rain over wide areas of the outback

While these humid air masses have now dumped most of their water, more rain is coming in the aftermath of the short-lived Cyclone Dianne off northwest Australia. These rains won’t be as intense but may drive more flood peaks over already saturated catchments.

This is why it has been so wet in what is normally an exceptionally dry part of Australia.

What is this doing to the Channel Country?

Many Australians have never been to the remote Channel Country. It’s a striking landscape, marked by ancient, braided river channels.

Even for an area known for drought-flood cycles, the rainfall totals are extreme. This is a very rare event.

People who live there have to be resilient and self-sufficient. But farmers and graziers are bracing for awful losses of livestock. Livestock can drown in floodwaters, but a common fate is succumbing to pneumonia after spending too long in water. After the water moves down the channels, it will leave behind notoriously boggy and sticky mud. This can be lethal to livestock and native animals, which can find themselves unable to move.

Where will the water go next?

Little of these temporary inland seas will ever reach the ocean.

Some of the rain has fallen in the catchment of the Darling River, where it will flow down and meet the Murray. The Darling is often filled by summer rains, while the Murray gets more water from autumn and winter rains. This water will eventually reach the Southern Ocean.

But most of the rain fell further inland. The waters snaking through the channels will head south, flowing slowly along the flat ground for weeks until it crosses the South Australian border and begins to fill up Kati Thanda-Lake Eyre. Here, the waters will stop, more than 300 km from the nearest ocean at Port Augusta, and fill what is normally a huge, salty depression and Australia’s lowest point, 15 metres below sea level.

When Kati Thanda-Lake Eyre fills, it creates an extraordinary spectacle. Millions of brine shrimp will hatch from eggs in the dry soil. This sudden abundance will draw waterbirds in their millions, while fish carried in the floodwaters will spawn and eat the shrimp. Then there are the remarkable shield shrimps, hibernating inland crabs and salt-adapted hardyhead fish.

The rain event will send enough water to keep Lake Eyre full for many months and it usually takes up to two years for it to dry out again. We can expect to see a huge lake form – the size of a small European country. Birdwatchers and biologists will flock to the area to see the sight of a temporary sea in the desert.

Eventually, the intense sun of the outback will evaporate every last drop of the floodwaters, leaving behind salted ground and shrimp eggs for the next big rains.

As the climate keeps warming, we can expect to see more sudden torrential rain dumps like this one, followed by periods of rapid drying.

Steve Turton, Adjunct Professor of Environmental Geography, CQUniversity Australia

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

The damage climate change will inflict on the world’s economy is likely to have been massively underestimated, according to new research by my colleagues and I which accounts for the full global reach of extreme weather and its aftermath.

To date, projections of how climate change will affect global gross domestic product (GDP) have broadly suggested mild to moderate harm. This in part has led to a lack of urgency in national efforts to reduce greenhouse gas emissions.

However, these models often contain a fundamental flaw – they assume a national economy is affected only by weather in that country. Any impacts from weather events elsewhere, such as how flooding in one country affects the food supply to another, are not incorporated into the models.

Our new research sought to fix this. After including the global repercussions of extreme weather into our models, the predicted harm to global GDP became far worse than previously thought – affecting the lives of people in every country on Earth.

Weather shocks everywhere, all at once

Global warming affects economies in many ways.

The most obvious is damage from extreme weather. Droughts can cause poor harvests, while storms and floods can cause widespread destruction and disrupt the supply of goods. Recent research has also shown heatwaves, aggravated by climate change, have contributed to food inflation.

Heat also makes workers less productive. It affects human health, and disease transmission, and can cause mass migration and conflict.

Most prior research predicts that even extreme warming of 4°C will have only mild negative impacts on the global economy by the end of the century – between 7% and 23%.

Such modelling is usually based on the effects of weather shocks in the past. However, these shocks have typically been confined to a local or regional scale, and balanced out by conditions elsewhere.

For example, in the past, South America might have been in drought, but other parts of the world were getting good rainfall. So, South America could rely on imports of agricultural products from other countries to fill domestic shortfalls and prevent spikes in food prices.

But future climate change will increase the risk of weather shocks occurring simultaneously across countries and more persistently over time. This will disrupt the networks producing and delivering goods, compromise trade and limit the extent to which countries can help each other.

International trade is fundamental to the global economic production. So, our research examined how a country’s future economic growth would be influenced by weather conditions everywhere else in the world.

What did we find?

One thing was immediately clear: a warm year across the planet causes lower global growth.

We corrected three leading models to account for the effects of global weather on national economies, then averaged out their results. Our analysis focused on global GDP per capita – in other words, the world’s economic output divided by its population.

We found if the Earth warms by more than 3°C by the end of the century, the estimated harm to the global economy jumped from an average of 11% (under previous modelling assumptions) to 40% (under our modelling assumptions). This level of damage could devastate livelihoods in large parts of the world.

Previous models have asserted economies in cold parts of the world, such as Russia and Northern Europe, will benefit from warmer global temperatures. However, we found the impact on the global economy was so large, all countries will be badly affected.

Costs vs benefits

Reducing emissions leads to short-term economic costs. These must be balanced against the long-term benefits of avoiding dangerous climate change.

Recent economic modelling has suggested this balance would be struck by reducing emissions at a rate that allows Earth to heat by 2.7°C.

This is close to Earth’s current warming trajectory. But it is far higher than the goals of the Paris Agreement, and global warming limits recommended by climate scientists. It is also based on the flawed assumptions discussed above.

Under our new research, the optimal amount of global warming, balancing short-term costs with long-term benefits, is 1.7°C – a figure broadly consistent with the Paris Agreement’s most ambitious target.

Changing course

Our new research shows previous forecasts of how such warming will affect the global economy have been far too optimistic. It adds to other recent evidence suggesting the economic impacts of climate change has been badly underestimated.

Clearly, Earth’s current emissions trajectory risks our future and that of our children. The sooner humanity grasps the calamities in store under severe climate change, the sooner we can change course to avoid it.

Timothy Neal, Senior lecturer in Economics / Institute for Climate Risk and Response, UNSW Sydney

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