Koalas need their booster shots too. Here’s a way to beat chlamydia with just 1 capture and less trauma

Chlamydia is a major threat to koala populations across Australia. This bacterial disease infects between 20% and 90% of individuals in koala populations. It’s a major cause of the rapid decline of many wild populations, particularly in South-East Queensland and northern New South Wales.

Our group at Queensland University of Technology (QUT) has developed two vaccines to target chlamydial infections. One of these vaccines, now being trialled in collaboration with Dr Michael Pyne and his staff at Currumbin Wildlife Hospital, has recently had some outstanding results in a wild koala population on the Gold Coast. This population had been declining rapidly due to high rates of the disease.

Two years into the five-year trial, we have seen more than 25 joeys born to vaccinated females. The program involved vaccinating, collaring and releasing 10-20% of young animals each year. All joeys and mums were chlamydia-free. In addition, 11 out of 13 young males vaccinated remain negative at 12–24 months after vaccination.

Like most vaccines, however, this vaccine requires two shots, 30 days apart. This means wild animals must be held in captivity for a month, which many don’t like, or released and recaptured for the booster dose. This is both expensive and traumatic for the animals.

It was during a chat over coffee a few years ago that we first pondered the question, “Could we develop a delayed-release vaccine implant that is given at the same time as the first vaccine and releases the booster vaccine dose 30 days later?”

Why vaccination is the best approach

Chlamydia is spread by direct physical contact between koalas. Symptoms include blindness, urinary tract infections (wet bottom), infertility in females and sperm damage in males.

While antibiotics can be used to treat the eye disease, they cannot be used to treat infertility. This is because antibiotics can destroy the gut bacteria essential for koalas to digest their food, eucalypt leaves.

The vaccine is the best option and is also very safe. We detected no adverse side-effects across multiple studies. The only complication is the need for a booster shot.

So are implants a solution? Our recent research suggests the answer is yes, at least in a sheep model. We have now received a grant from the federal Saving Koalas Fund to develop this implant technology for a koala vaccine against the Chlamydia bacterium.

In our sheep trial of a first-generation implant, animals that received the primary vaccination by injection plus a booster implant developed immune T cell numbers equivalent to animals receiving two vaccinations by injection, together with slightly reduced antibody levels.

How does the implant work?

The implant is a polymer tube developed by the QUT team. It borrows from technology already used by the group for making polymer scaffolds to support tissue growth. The team screened a range of biodegradable polymers for ones that would degrade over just a few weeks. They also had to be flexible enough to not break prematurely when implanted beneath the skin.

Manufacturing the polymer pellets into tubes allows the booster vaccine to be filled into the tube. It’s similar in size to the human Implanon contraceptive implant.

When the koala is injected with the first dose, the implant is also inserted under the skin. This starts a process of slow degradation of the implant until the walls of the tube fail and the vaccine is released as a burst. What is left of the implant dissolves as chemicals naturally found in the body.

What’s the next step?

To scale up the implants we are working with a company in the United States to develop methods to manufacture thousands of implants at once. Our federal funding will allow us to fine-tune a second-generation implant to deliver the chlamydia vaccine to koalas. We will test it for safety in sheep and then evaluate the implant in captive-bred koalas at Currumbin Wildlife Sanctuary.

Our ultimate aim is to be able to capture a wild koala once only and test it for chlamydia. This would be done using a rapid test we have developed. The test can be done in the back of a 4WD vehicle and takes 20–30 minutes.

If the koala is chlamydia-free, we would then vaccinate with the implant and release the animal back into the wild.

Kenneth W Beagley, Professor of Immunology, Queensland University of Technology and Tim Dargaville, Professor of Polymer Chemistry, Queensland University of Technology

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

Tim Flannery’s message to all: rise up and become a climate leader – be the change we need so desperately

As humanity hurtles towards a climate catastrophe, the debate has shifted – from the science to solutions. We know we need to reduce our greenhouse gas emissions. But progress has been painfully slow.

It’s clear the world is lacking climate leadership. So what makes a great climate leader and why are we not seeing more of them?

For two years now I’ve been on a journey, a quest if you like, to find good climate leaders. This is the subject of my new documentary, Climate Changers with director Johan Gabrielsson.

Missed opportunities and wasted time

Saul Griffith is an engineer who wants to “electrify everything”. The co-founder of non-profit group Rewiring Australia decried the “dearth of political leadership” when he told us:

We haven’t had any head of state, of any major nation, positively and proactively engage on climate as an emergency, as an opportunity […] we haven’t had a Churchill or Roosevelt or John F Kennedy ‘let’s go to the moon’ that says: ‘here’s a threat, here’s an opportunity, here’s a vision for how we collectively get there’.

If we’d been on the right emissions reduction trajectory a decade ago, we’d have more time to deal with the problem. But we’ve wasted ten years.

Over that period, probably 20% of all of the carbon pollution we’ve ever put into the atmosphere has been emitted.

A lot of money was made creating those emissions, and that has only benefited a few. But of course the consequences of the emissions will stay with humanity for many, many, many generations.

A different style of leadership

Unfortunately, modern Western politics doesn’t select for great leaders. But there are a few scattered about.

One such example is Matt Kean in New South Wales. In 2020, as state energy minister and treasurer during the Liberal Berejiklian government, he managed to get the Nationals, the Liberals, Labor and the Greens all supporting the same bill, on addressing climate change through clean energy. In my opinion, that is true leadership.

As Kean told us:

What you’ve got to do if you’re going to try and solve the challenge is find those areas of common ground. […] it was about finding the big things that everyone could agree on and designing policy that brought everyone together. And I think that was the key to our success.

Climate leadership requires humility. It requires listening to your political antagonists as well as your allies.

That sort of leadership is rare in our political system. And yet you see it in Indigenous communities and in the Pacific nations where I’ve done a lot of work over the years, that sort of leadership is much more common. Because people understand they need to be consultative. And transparent.

West Papuan activist and human rights lawyer, Frederika Korain, and Solomon Island Kwaio community leader and conservationist, Chief Esau Kekeubata, are shining examples. They show individual bravery and diligence, but they’re also humble and listening.

On the subject of leadership, they share similar sentiments with Australia’s Dharawal and Yuin custodian and community leader Paul Knight.

It’s about bringing other people along with you. It’s not some strong-arm thing, like you often see at our federal level, in our politics. It’s about listening, developing a consensus. It takes time, a lot of effort, and you’ll probably never get full consensus, but we’ll get most of the way there, convincing people.

I’ve seen Chief Esau work. He says very little in the most important meetings, but when someone says something he thinks is on the right track, he’ll say, “Oh, that’s really interesting. Can you can you tell us a bit more”. He directs the conversation.

So in a species like ours, that’s what true leadership consists of. Intelligence, persistence, bravery bordering on heroism sometimes, because climate change is the enemy of everyone.

What’s holding us back?

There’s a very strong relationship in Australia between political power and fossil fuels. The links are interwoven, with people moving from the fossil fuel industry to politics and back.

And we still allow people to become extremely rich at the expense of all of us. I think that’s what’s holding us back.

I expect those who are very wealthy, who have made their money in fossil fuels, imagine they’ll be able to retire to some gated community and live their life in luxury.

But we all depend on a strong global economy and trade, which is under threat as the climate breaks down.

The idea that you can somehow isolate yourself from the environment and the rest of society is one of the great failings of human imagination that has brought us so close to catastrophe.

Rise up

I do see individual people rising to the occasion. And the story is usually somewhat similar: people realise they could lose something very precious. We heard it time and time again in the making of this documentary.

For community campaigner Jo Dodds the trigger was the Black Summer bushfires, the near-loss of her house and the loss of her neighbours’ houses. For former US Vice President Al Gore it was having his son in critical care for 30 days, having to put aside his politics and think about what his life was really about. Those sort of moments do bring out great climate leaders. Even Kean talked about bringing his newborn son home from hospital, shrouded in bushfire smoke.

The level of public awareness is far greater now than when I came to this issue in the early 2000s.

The most important thing I can do now is inspire and enable others to be climate leaders. Because we need a diversity of voices out there. We need women. We need younger people. We need people from the Pacific Islands, and First Nations people.

This documentary is about trying to inspire and encourage emerging leaders to give us the diversity of voices we need to make a difference. It’s never too late – we can always prevent something worse from happening.

Climate Changers launches nationally with a livestreamed Q&A on September 17 and will screen in cinemas and at community events.

Tim Flannery, Honorary fellow, The University of Melbourne

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

We just blew past 1.5 degrees. Game over on climate? Not yet

July 2023 was the hottest month ever recorded. And now we know something even more alarming. This week, the European Space Agency announced the July heat pushed the global average temperatures 1.5℃ above the pre-industrial average.

The ominous headlines seemed to suggest we’d blown past the 2015 Paris Agreement goal of holding warming to 1.5℃ – and around a decade earlier than expected.

Is that it? Game over, we lost?

Well, like all things to do with climate change, it’s not quite that simple. The threshold was breached for a month before average temperatures dropped back. And July 2023 isn’t actually the first time this has happened either – the dubious honour goes to February 2016, where we broke the threshold for a few days.

Remind me – why is 1.5℃ so important?

In 2015, the world looked like it was finally getting somewhere with action to combat climate change. After decades of arduous debate, 195 nations adopted the Paris Agreement, a formal but non-binding agreement with a clear goal: limit global warming to 1.5℃ above pre-industrial levels to avoid the worst effects of climate change.

But there’s nothing magic about this number. Every increase worsens the impacts. So why is 1.5℃ so important?

Essentially, it was thrashed out by experts as a threshold representing heightened danger. The Paris Agreement states avoiding dangerous climate change means keeping global temperatures “well below 2℃” of warming, and so the 1.5℃ threshold was born.

What’s a dangerous level of climate change? Basically, levels of warming where the damage becomes so widespread or severe as to threaten economies, ecosystems, agriculture, and risk irreversible tipping points such as the collapse of ice sheets or ocean circulations. More importantly, this level of warming risks pushing us beyond the limits of being able to adapt.

Put simply, the 1.5℃ threshold is the best estimate of the point where we are likely to find ourselves well up the proverbial creek, without a paddle.

Is it too late to act on climate change?

So, should we all just give up?

Not yet.

The global authority on climate change, the Intergovernmental Panel on Climate Change, defines 1.5℃ as a departure from global average temperatures above the 1850 to 1900 (pre-industrial) average.

It’s true that this threshold was exceeded for the month of July 2023. But the climate is more than a single month.

Global average temperatures go up and down every year on top of the global warming trend, because climates naturally vary year-to-year.

The most recent few years have been much warmer than average, but cooler than they could have been because of consecutive La Niña events.

This year, there’s been a significant acceleration in warming, largely due to the brewing El Niño event in the Pacific. El Niño years tend to be hotter.

To iron out year-to-year differences, we typically average data over several decades. As a result, a 2021 IPCC report defines the 1.5℃ threshold as the first 20-year period when we reach 1.5℃ of global warming (based on surface air temperatures).

Recent research shows the best estimate to pass this threshold is in the early 2030s. That means, by IPCC definitions, the average global temperature between the early 2020s and early 2040s is estimated to be 1.5C.

Dangerously close to the red line

All of this means we haven’t yet failed to meet our Paris targets. But the July record shows us we are dangerously close to the line.

As the world keeps heating up, we’ll see more and more months like this July, and move closer and closer to the threshold of 1.5℃, beyond which global warming will become more and more dangerous.

Is it still possible to stay below 1.5℃? Maybe. We would need extremely aggressive cuts to emissions to have a chance. Failing that, we will likely exceed the Paris target within the next decade or so.

Let’s say that happens. Would that mean we just give up on climate action?

Hardly. 1.5℃ is bad. 1.6℃ would be worse. 2℃ would be worse still. 3℃ would be unthinkable. Every extra increment matters.

The closer we stay to the line – even if we cross it – the better.

And there’s now good evidence that even if we overshoot 1.5℃, we could still reverse it by ending emissions and soaking up excess greenhouse gas emissions. It’s like turning around an enormous container ship – it takes time to overcome the inertia. But the sooner we turn around, the better.

Ailie Gallant, Senior Lecturer, School of Earth, Atmosphere and Environment, Monash University and Kimberley Reid, Postdoctoral Research Fellow in Atmospheric Sciences, Monash University

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

Our planet is burning in unexpected ways - here’s how we can protect people and nature

People have been using fire for millennia. It is a vital part of many ecosystems and cultures. Yet human activities in the current era, sometimes called the “Anthropocene”, are reshaping patterns of fire across the planet.

In our new research, published in the Annual Review of Environment and Resources, we used satellite data to create global maps of where and how fires are burning. We calculated about 3.98 million square kilometres of Earth’s land surface burns each year. We also examined research spanning archaeology, climatology, ecology, Indigenous knowledge and paleoecology, to better understand the causes and consequences of fires.

Our international team found strong evidence fires are burning in unexpected places, at unusual times and in rarely observed ways. These changes in fire patterns are threatening human lives and modifying ecosystems.

But the future does not have to be bleak. There are many opportunities to apply knowledge and practice of fire to benefit people and nature.

Here’s how fire patterns are changing

Exploring multiple approaches and scales enables a deeper understanding of where, when and how fires burn.

Satellite data provide evidence of changes in fire patterns at a global scale. Annual fire season length increased by 14 days from 1979 to 2020 and night fires, which indicate fires that cannot be quickly controlled, increased in intensity by 7.2% from 2003 to 2020.

Other changes are apparent only when we look at data from particular regions. An increase in fire size and the frequency of large fires has recently been observed in forests and woodlands of the western United States. Meanwhile fire-dependent grasslands and savannahs across Africa and Brazil have experienced reductions in fire frequency.

It’s also important to consider the timescale and type of fire when interpreting changes. In Australia, satellite records show the frequency of very large forest fires has increased over the past four decades. At longer time scales, charcoal and pollen records indicate the frequency of low-intensity fires decreased in parts of southeastern Australia following British colonisation in 1788.

Changes in fire affect air, land and water

Many animals and plants have evolved strategies that enable them to thrive under particular fire patterns. This means changes to fire characteristics can harm populations and ecosystems.

Large and intense fires are reducing the available forest habitat preferred by the greater glider. But a lack of fire can be problematic too. Threatened species of native rodents can benefit from food resources and habitats that flourish shortly after fire.

There is evidence that emissions from recent fires are already modifying the atmosphere. The historically exceptional 2019–20 Australian wildfires produced record-breaking levels of aerosols over the Southern Hemisphere, as well as substantial carbon emissions.

The wildfire smoke-related health costs of the 2019–20 wildfires in Australia included an estimated 429 smoke-related premature deaths as well as 3,230 hospital admissions for cardiovascular and respiratory disorders.

Changes in fire patterns are modifying water cycles, too. In the western United States, fires are reaching higher elevations and having strong impacts on snow and water availability.

New studies are revealing how the air, land and water that support life on Earth are connected by fires. Smoke plumes from the 2019–20 Australian wildfires transported nutrients to the Southern Ocean, resulting in widespread phytoplankton blooms.

Humans are responsible for the changes

Human drivers such as climate change, land use, fire use and suppression, and transportation and extinction of species are causing shifts in fire patterns.

Increasing global temperatures and more frequent heatwaves and droughts increase the likelihood of fire by promoting hot, dry and windy conditions. A pattern of extreme fire weather outside of natural climate variation is already emerging in North America, southern Europe and the Amazon basin.

Humans modify fire regimes by changing land use for agricultural, forestry and urban purposes. Until recent decades, large fires in tropical forests were uncommon. But deforestation fires used to clear primary forest for agriculture often promotes more frequent and intense uncontrolled fires.

Humans have transported plants and animals across the globe, resulting in novel mixes of species that modify fuels and fire regimes. In many parts of the world, invasive grasses have increased flammability and fire activity.

Social and economic changes propel these drivers. Colonisation by Europeans and the displacement of Indigenous peoples and their skilful use of fire has been linked with fire changes in Australia, North America and South America.

Using knowledge and practice of fire to achieve sustainability goals

The pace and scale of these changes represent challenges to humanity, but knowledge and practice of fire can help to achieve sustainability goals.

This includes:

• good health and wellbeing, by supporting community-owned solutions and fire practices that increase social cohesion and health
• sustainable cities and communities, by designing green firebreaks and mixed-use areas with low fuels, strategically located in the landscape
• life on land, by tailoring use of fire to promote and restore species and ecosystems
• climate action, by applying low-intensity fire to promote the stability of soil organic matter and increase carbon storage
• reduced inequalities, by allocating resources before, during, and after wildfires to at-risk communities and residents.

As the world changes, society as a whole needs to keep learning about the interplay between people and fire.

A deep understanding of fire is essential for achieving a sustainable future – in other words, a better Anthropocene.

Luke Kelly, Associate Professor in Quantitative Ecology, The University of Melbourne; David Bowman, Professor of Pyrogeography and Fire Science, University of Tasmania; Ella Plumanns Pouton, PhD candidate, The University of Melbourne; Grant Williamson, Research Fellow in Environmental Science, University of Tasmania, and Michael-Shawn Fletcher, Professor in Biogeography, The University of Melbourne

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

We are poised to pass 1.5℃ of global warming – world leaders offer 4 ways to manage this dangerous time

For three decades, the goal of international climate negotiations has been to avoid “dangerous” warming above 1.5℃. With warming to date standing at around 1.2℃, we haven’t quite reached the zone we labelled dangerous and pledged to avoid.

But recent scientific assessments suggest we’re on the brink of passing that milestone. Within this decade, global annual temperatures will likely exceed 1.5°C above the pre-industrial average for at least one year. This threshold was already briefly passed for the month of July 2023 during the Northern summer.

The question is, how do we manage this period of “overshoot” and bring temperatures back down? The goal will be to restore a more habitable climate, as fast as possible.

Today an independent group of global leaders released a major report. The Climate Overshoot Commission offers guidance at this crucial time. So far the report’s call for an immediate moratorium on “solar radiation management” (deflecting the sun’s rays to reduce warming) has attracted the most attention. But the details of other recommendations deserve closer inspection.

How can we respond to climate overshoot?

Historically, climate policies have focused on mitigation (reducing greenhouse gas emissions). More recently, adaptation has gained prominence.

But the climate overshoot report identifies at least four different kinds of responses to warming above 1.5℃:

1. cut emissions to mitigate warming

2. adapt to the changing climate

3. remove carbon that is already in the atmosphere or ocean

4. explore intervening to limit warming by intentionally reflecting a fraction of sunlight into space.

The commission’s task was to examine how all possible responses might best be combined. Their report was written by 12 global leaders – including former presidents of Niger, Kiribati and Mexico – who worked alongside a youth panel and a team of scientific advisers.

The four-step plan to reining in warming

Not surprisingly, the commission argues our central task is mitigation. Transitioning away from fossil fuels remains the first priority.

But reaching net zero emissions is just the first step. The commission argues developed countries like Australia should go further and aim for net-negative emissions.

Why net-negative? In the short term, drawing down carbon can create space for the least industrialised countries to fight poverty while transitioning to clean energy. In the longer term, the whole global economy must achieve net-negative emissions if the planet is to return to our current “safe” climatic zone.

The second step is adaptation. Only a few decades ago former United States Vice President Al Gore branded adapting to climate change a “lazy cop-out”. Today we have no choice but to adapt to changing conditions.

However, adaptation is expensive – whether it is developing new crop varieties or rebuilding coastal infrastructure. Since the poorest communities who are most vulnerable to climate harms have the least capacity to adapt, the commission recommends international assistance for locally controlled, context-specific strategies.

As a third step, the commission agrees with scientific assessments that carbon dioxide “will need to be removed from the air on a significant scale and stored securely” if we are to avoid permanent overshoot beyond 1.5℃ warming. But how to achieve large-scale permanent, carbon removal?

Some environmental activists support natural solutions such as planting trees but oppose industrial methods that seek to store carbon in inorganic form such as carbon capture and storage underground. The commission agrees the organic/inorganic distinction is important. However, it points out while forests bring many benefits, carbon stored in ecosystems is often re-released – for example, in forest fires.

The commission worries many carbon removal approaches are phoney, impermanent or have adverse social and environmental impacts. However, instead of ruling out technologies on ideological grounds, it recommends research and regulation to ensure only socially beneficial and high-integrity forms of carbon removal are scaled up.

The fourth step – “solar radiation management” – refers to techniques that aim to reduce climate harms caused by reflecting some of the Sun’s energy into space. No-one likes the idea of solar radiation management. But no-one likes getting vaccinated either – our gut reactions don’t provide a fool-proof guide to whether an intervention is a worth considering.

Should we trust our guts on this one? While climate models suggest solar radiation management could reduce climate harms, we don’t yet properly understand associated risks.

The commission approaches this topic with caution. On the one hand, it recommends an immediate “moratorium on the deployment of solar radiation modification and large-scale outdoor experiments” and rejects the idea that deployment is now inevitable. On the other hand, it recommends increased support for research, international dialogue on governance, and periodic global scientific reviews.

Time to examine intervention in the climate system?

The idea we can avoid dangerous warming completely seems increasingly quaint. Like baggy jeans, the boy band NSYNC and the iPod shuffle, it reminds us of a more innocent era. Yet, Australia’s climate debate often seems stuck in this era.

The widespread hope we “still have time” means we are not yet discussing the merits of more interventionist responses to the climate crisis. However, there’s increasing reason to be sceptical incremental measures will be sufficient. We may soon be forced to move beyond the non-interventionist, conservation paradigm.

Whether or not its recommendations are taken up, the Climate Overshoot Commission’s work shows how the international community has failed to avert dangerous climate change. Reckoning with the consequences of this failure will dominate public policy for decades to come. This new report takes us a step forward.

Jonathan Symons, Senior Lecturer, Macquarie School of Social Sciences, Macquarie University

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

Devastatingly low Antarctic sea ice may be the ‘new abnormal’, study warns

For most of us, Antarctic sea ice is an abstraction – something far away we may have seen on a documentary. But the radiant white sheets of ice floating on the seas around the snowy continent are a crucial component of Earth’s climate processes.

Sea ice insulates the ocean, reflects heat, drives currents, supports ecosystems and protects ice shelves. It also has an annual seasonal cycle – some of the ice melts, then freezes again.

Every year, the cycle of freeze and melt around Antarctica has been extremely reliable. Until recently.

In a new study published today in Communications Earth & Environment, we have found a preliminary indication that Antarctic sea ice may have entered a new state of diminished coverage.

A sudden, dramatic loss

For many years, while the Arctic lost sea ice, the Antarctic did not. Then, in the spring of 2016, Antarctic sea-ice coverage dropped dramatically. Over two years, the Antarctic lost as much sea ice as the Arctic had lost in three decades. Since then, Antarctic sea ice has been below average almost constantly.

This past Southern Hemisphere summer, Antarctic sea ice was the lowest it has ever been, with dire consequences. In late 2022 we saw the heartbreaking loss of 10,000 emperor penguin chicks, when the sea ice they lived on melted before they had grown their waterproof feathers.

On February 19 2023, Antarctic sea ice set a new record minimum of 1.77 million square kilometres, 36% below the 1979–2022 average for the summer minimum.

Since then, things have gone from bad to worse. The winter around Antarctica is cold and dark. Ever since we’ve had satellites to measure it, the surface of the ocean has reliably frozen into sea ice at about the same pace every winter, even following low sea ice summers. Except for this year.

This winter we have seen the largest negative anomaly – deviation from the norm – since reliable satellite measurements began in the late 1970s. What’s more, this record negative anomaly happened at a time of year when there has historically been very little variation from one year to the next.

Something has fundamentally changed Antarctic sea ice this year.

Two main drivers of sea ice

In our study, we used a statistical algorithm to identify three different periods in the sea-ice record. The first was a neutral sea-ice period from November 1978 to August 2007, the second a high sea-ice period from September 2007 to August 2016, and the third a low sea-ice period from September 2016 until now.

Our analysis of the relationship between sea ice and the underlying ocean suggests this current low sea-ice period may represent a new state or “regime” for Antarctic sea ice. What does that mean?

Sea ice forms a thin layer between the ocean and the atmosphere. Therefore, it is affected by both.

On timescales of days and weeks, the atmosphere is what controls sea ice – it forms when the air above is cold, and is blown around by the wind.

However, the ocean is crucial in determining how the sea ice responds to the atmosphere. The waters beneath are what influences sea ice variation and change in the long term.

Lately, sea ice seems to be responding to atmospheric drivers differently than it did in the past, suggesting an influence from the slowly varying ocean may be important.

Research published in 2019 suggested ocean warming may have played a role in the low sea ice extent observed in the 2016/17 summer.

Building on this hypothesis, our study examined the long-term variations in sea ice and ocean temperature, finding that ocean warming has pushed Antarctic sea ice into a new low-extent state.

A clear warming trend

Using data from ocean temperature measurements 100-200m below the surface, we found a clear warming trend over the period for which we have reliable observations.

Importantly, strong subsurface ocean warming began in 2015, in the same regions that lost substantial sea ice in 2016. This is a key indication the ocean was important in driving the low sea ice in 2016. Since then, the warm subsurface ocean seems to be maintaining the low sea-ice coverage.

Prior to 2016 there was no relationship between the amount of sea ice at the summertime minimum and the amount at the following wintertime maximum. Since 2016 there is a strong relationship. This change suggests something has fundamentally altered the relationship between the ocean and the sea ice.

Together, this evidence suggests the overall way of how Antarctic ice behaves in the atmosphere-ocean-sea ice system has changed.

Our results suggest that even though the record-breaking low sea ice we’ve seen this year is shocking, it is likely to be the new abnormal.

We may now be seeing the inevitable decline in Antarctic sea ice, long projected by climate models. The Antarctic region is changing rapidly. To understand these rapid shifts, we urgently need to support fieldwork in sea ice, and develop computer models that will help us to understand the changes we are already seeing, and to predict what the future will look like.

Reduced sea ice will have serious implications for Southern Ocean ecosystems and global consequences for the climate system. Dramatic changes in a seasonal cycle as reliable and critical as Antarctic sea ice underscores the urgency to reduce fossil fuel emissions.

Edward Doddridge, Research Associate in Physical Oceanography, University of Tasmania and Ariaan Purich, Lecturer in Climate Variability and Change, Monash University

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

Faster disaster: climate change fuels ‘flash droughts’, intense downpours and storms

The run of extreme weather events around the world seems to be never-ending. After the northern summer of extreme heat and disastrous fires, we’ve seen more exceptional autumn weather over Europe with record-breaking heat in the UK.

Meanwhile, record-breaking rain and intense flash floods struck Greece before the same storm devastated Libya, with thousands dead.

Almost 20% of Africa is estimated to be in drought, and drought conditions are returning to parts of Australia. To top it off, we’ve seen several hurricanes intensify unusually quickly in the Atlantic.

We know climate change underpins some of the more extreme weather we’re seeing. But is it also pushing these extreme events to happen faster?

The answer? Generally, yes. Here’s how.

Flash droughts

We usually think of droughts as slowly evolving extreme events which take months to form.

But that’s no longer a given. We’ve seen some recent droughts develop unexpectedly quickly, giving rise to the phrase “flash drought”.

How does this happen? It’s when a lack of rainfall in a region combines with high temperatures and sunny conditions with low humidity. When these conditions are in place, it increases how much moisture the atmosphere is trying to pull from the land through evaporation. The end result: faster drying-out of the ground.

Flash droughts tend to be short, so they don’t tend to cause the major water shortages or dry river beds we’ve seen during long droughts in parts of Australia and South Africa, for example. But they can cause real problems for farmers. Farmers in parts of eastern Australia are already grappling with the sudden return of drought after three years of rainy La Niña conditions.

As we continue to warm the planet, we’ll see more flash droughts and more intense ones. That’s because dry conditions will more often coincide with higher temperatures as relative humidity falls across many land regions.

Flash floods and extreme rainfall

Climate change can cause increased rainfall variability. Some parts of the world will get a lot wetter, on average, while others will get drier, increasing the variation in rainfall between different regions. For Australia, most locations are generally expected to have intensified downpours of rain, as well as intensified droughts. So we might be saying more often “it doesn’t rain, it pours!”.

We’re seeing exceptionally extreme rainfall in many recent events. The recent floods that submerged villages in Greece came from a sudden downpour of over 500 millimetres in a single day. Hong Kong was hit last week by the heaviest rains in 140 years, flooding subway stations and turning streets into rivers.

But why does it happen so quickly?

Sudden extreme rains fall when we have very moist air coupled with a weather system that forces air to rise.

We’ve long known human-caused climate change is increasing how much moisture the air can hold generally, rising by about 7% per degree of global warming. That means storms now have the potential to hold and dump more water.

Notably, the impact of climate change on rain-bearing weather systems can vary by region, which makes the picture more complicated. That means, for instance, climate change may lead to more extreme rain in some places, while other places may only see an intensification in really short extreme rain events and not for longer timescales.

We can safely say, though, that in most parts of the world, we’re seeing more intense storms and sudden extreme rainfall. Sudden dumps of rain drive flash floods.

More moisture in the air helps fuel more intense convection, where warm air masses rise and form clouds. In turn, this can trigger efficient, quick and intense dumps of rain from thunderstorms.

These short-duration rain events can be much larger than you’d expect from the 7% increase in moisture per degree of warming.

Flash cyclones? Hurricanes are intensifying faster

Last month, Hurricane Idalia caused major flooding in Florida. As we write, Hurricane Lee is approaching the US.

Both tropical storms had something odd about them – unusually rapid intensification. That is, they got much stronger in a short period of time.

Usually, this process might increase wind speeds by about 50 kilometres per hour over a 24-hour period for a hurricane – also known as tropical cyclones and typhoons. But Lee’s wind speeds increased by 129km/h over that period. US meteorological expert Marshall Shepherd has dubbed the phenomenon “hyperintensification”, which could put major population centres at risk.

Rapidly intensifying tropical cyclones are strong and can be very hazardous, but they aren’t very common. To trigger them, you need a combination of very high sea surface temperatures, moist air and wind speeds that don’t change much with height.

While still uncommon, rapid intensification is potentially getting more frequent as we heat the planet. This is because oceans have taken up so much of the heat and there’s more moisture in the air. There’s much more still to learn here.

Australia’s El Niño summer in a warming world

Spring and summer in Australia are likely to be warmer and drier than usual. This is due to the El Niño climate cycle predicted for the Pacific Ocean. If, as predicted, we also get a positive Indian Ocean Dipole event, this can heighten the hotter, drier weather brought by El Niño. After three wet La Niña years, this is likely to be a marked shift.

If it arrives as expected, El Niño would lower the risk of tropical cyclones for northern Australia and reduce chances of heavy rain across most of the continent.

But for farmers, it may help trigger flash droughts. Prevailing warm and dry conditions may rapidly dry the land and reduce crop yields and slow livestock growth.

Drier surfaces coupled with grass growth from the wet years could worsen fire risk. Grass can dry out much faster than shrubs or trees, and grass fires can start and spread very rapidly.

Climate change loads the dice for extreme weather. And as we’re now seeing, these extremes aren’t just more intense – they can happen remarkably fast.

Andrew King, Senior Lecturer in Climate Science, The University of Melbourne and Andrew Dowdy, Principal Research Scientist, The University of Melbourne

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

How rising water vapour in the atmosphere is amplifying warming and making extreme weather worse

This year’s string of record-breaking disasters – from deadly wildfires and catastrophic floods to record-high ocean temperatures and record-low sea ice in Antarctica – seems like an acceleration of human-induced climate change.

And it is. But not only because greenhouse gas emissions continue to rise. What we are also observing is the long-predicted water vapour feedback within the climate system.

Since the late 1800s, global average surface temperatures have increased by about 1.1℃, driven by human activities, most notably the burning of fossil fuels which adds greenhouse gases (carbon dioxide and methane) to the atmosphere.

As the atmosphere warms, it can hold more moisture in the form of water vapour, which is also a greenhouse gas. This in turn amplifies the warming caused by our emissions of other greenhouse gases.

Some people mistakenly believe water vapour is a driver of Earth’s current warming. But as I explain below, water vapour is part of Earth’s hydrological cycle and plays an important role in the natural greenhouse effect. Its rise is a consequence of the atmospheric warming caused by our emissions arising especially from burning fossil fuels.

Water vapour: the other greenhouse gas

For every degree Celsius in warming, the water-holding capacity of the atmosphere increases by about 7%. Record-high sea temperatures ensure there is more moisture (in the form of water vapour) in the atmosphere, by an estimated 5-15% compared to before the 1970s, when global temperature rise began in earnest.

Water vapour is a powerful greenhouse gas. Since the 1970s, its rise likely increased global heating by an amount comparable to that from rising carbon dioxide. We are now seeing the consequences.

In many ways, water vapour is the most important greenhouse gas as it makes Earth habitable. But human-induced climate change is primarily caused by increases in the long-lived greenhouse gases carbon dioxide, nitrous oxide, methane and chlorofluorocarbons (CFCs).

As a general rule, any molecule with three or more atoms is a greenhouse gas, owing to the way the atoms can vibrate and rotate within the molecule. A greenhouse gas absorbs and re-emits thermal (infrared) radiation and has a blanketing effect.

Clouds have a blanketing effect similar to that of greenhouse gases but they are also bright reflectors of solar radiation and act to cool the surface by day. In the current climate, for average all-sky conditions, water vapour is estimated to account for 50% of the total greenhouse effect, carbon dioxide 19%, ozone 4% and other gases 3%. Clouds make up about a quarter of the greenhouse effect.

Why is water vapour different?

The main greenhouse gases – carbon dioxide, methane, nitrous oxide and ozone – don’t condense and precipitate. Water vapour does, which means its lifetime in the atmosphere is much shorter, by orders of magnitude, compared to other greenhouse gases.

On average, water vapour only lasts nine days, while carbon dioxide stays in the atmosphere for centuries or even millennia, methane lasts for a decade or two and nitrous oxide a century. These gases serve as the backbone of atmospheric heating, and the resulting rise in temperature is what enables the observed increase in water vapour levels.

The rise in carbon dioxide doesn’t depend on weather. It comes primarily from the burning of fossil fuels. Atmospheric carbon dioxide has increased from pre-industrial levels of 280ppmv to 420ppmv (an increase of 50%) and about half of that increase has happened since 1985.

This accounts for about 75% of the anthropogenic heating from long-lived greenhouse gases. The rest of human-induced atmospheric warming mainly comes from methane and nitrous oxide, with offsets from pollution aerosols.

The extra heating from water vapour has been on a par with that from increased carbon dioxide since the 1970s.

Water vapour and the water cycle

Water vapour is the gaseous form of water and it exists naturally in the atmosphere. It is invisible to the naked eye, unlike clouds, which are composed of tiny water droplets or ice crystals large enough to scatter light and become visible.

The most common measure of water vapour in the atmosphere is relative humidity.

During heatwaves and warm conditions, this is what affects human comfort. When we sweat, the evaporation of moisture from our skin has a cooling effect. But if the environment is too humid, then this no longer works and the body becomes sticky and uncomfortable.

This process is important for our planet, too, because about 70% of Earth’s surface is water, predominantly ocean. Extra heat generally goes into evaporating water. Plants also release water vapour through a process called transpiration (releasing it through tiny stomata in leaves as part of photosynthesis). The combined process is called evapotranspiration.

The moisture rises into the atmosphere as water vapour. Storms gather and concentrate the water vapour so that it can precipitate. As water vapour has an exponential dependence on temperature, it is highest in warm regions, such as the tropics and near the ground. Levels drop off at cold higher latitudes and altitudes.

The expansion and cooling of air as it rises creates clouds, rain and snow. This vigorous hydrological cycle means water vapour molecules only last a few days in the atmosphere.

Water is the air conditioner of the planet. It not only keeps the surface cooler (albeit at the expense of making it moister) but rain also washes a lot of pollution out of the atmosphere to everyone’s benefit.

Precipitation is vitally important. It nourishes vegetation and supports various ecosystems as long as the rate is moderate. But as the climate warms, higher moisture levels increase the potential for heavier rainfall and the risk of flooding.

Moreover, the latent energy that went into evaporation is returned to the atmosphere, adding to heating and causing air to rise, invigorating storms and making weather extremes greater and less manageable.

These changes mean that where it is not raining, drought and wildfire risk increase, but where it is raining, it pours.

Kevin Trenberth, Distinguished Scholar, NCAR; Affiliate Faculty, University of Auckland

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

Seaweed is taking over coral reefs. But there’s a gardening solution – sea-weeding

In the early 1990s, marine researchers in the Caribbean found something alarming. On reef after reef, corals were dying off – and seaweed was growing in their place.

Since then, this pattern has been observed on reefs around the world: as corals die, seaweed takes over.

Once seaweed gets a foothold, it’s hard for coral to compete. These large, fleshy algae can quickly come to dominate. As the oceans heat up and reefs degrade, the trend is expected to accelerate. Former coral reefs will become dominated by seaweed instead, with cascading damage to reef ecosystems.

This shift hasn’t happened widely on the Great Barrier Reef – yet. But there are worrying signs of seaweed takeover on some reefs, including those fringing Yunbenun (Magnetic Island).

We wondered – what if you could help corals by weeding out intruding seaweed? In our new research, we found sea-weeding actually worked, giving coral time to recover.

Of course, this is a stopgap measure. It’s designed to buy time while we tackle the main threats to the world’s largest reef system – notably, climate change.

How can seaweed take over?

Corals don’t like hot water, sediment or an overload of nutrients. So when there’s a mass bleaching or coral death event after a marine heatwave or cyclone, there’s empty space on the reef.

Seaweeds are similar to weeds in a garden. They can colonise quickly, grow fast and tall, soaking up sunlight and competing directly with surviving corals for light and space.

Once these tough algae establish, corals struggle to come back. Then there are feedback loops which can further prevent coral return – coral larvae are put off by chemicals emitted by seaweed. Seaweed growth takes the space where coral larvae could have settled. And the health of adult corals can be hit by algae just living nearby. It’s safe to say coral and algae are not best friends.

You might wonder why nature doesn’t even the balance. At Yunbenun, the main genus of seaweed is Sargassum, most famous for their massive blooms in the Sargasso Sea. The problem is, not many fish like the taste. When Sargassum is fully grown, it’s especially unpalatable to herbivorous fish.

Many fish will actively avoid areas with long, dense growth of seaweed for fear of predators hiding among the foliage.

Weeding the sea

So if grazing fish won’t eat the problem, and urchins aren’t very abundant, it’s up to us. We set about testing sea-weeding, where you dive down and cut back stands of macroalgae. Would the corals bounce back?

The process is just like weeding a garden, but underwater. You dive down, yank fronds of seaweed off the seafloor and dispose them back on shore. It’s labour intensive, but simple. We were aided in weeding by citizen scientists through Earthwatch Institute.

It took three years, and the removal of three tonnes of seaweed, but it worked. In the areas we’d weeded (300m², or about 1% of the seafloor at our study site) twice or three times a year, the coral had made a spectacular recovery. Corals now covered between 1.5 to six times the area they had before.

After the coral returned, seaweed has been growing back less and less. Seaweed originally covered 80% of the seafloor, but now covers less than 40%. That suggests it might need only a few years of effort to suppress the seaweed and push the coral ecosystem toward recovery.

Importantly, the diversity of coral species increased too – and that means weeding isn’t favouring any single coral species.

We disposed of the seaweed in a local school’s organic compost heap. While not part of this project, there is promising new research showing macroalgae like Sargassum could be a carbon sink. Seaweed has many uses, ranging from bio-plastics, fertiliser or biofuels. If the economics stack up, removing mature macroalgae could provide a win-win for reef and climate health – even if it’s only small scale.

Where would this approach be most useful?

On the Great Barrier Reef, the reefs most prone to seaweed takeover are those near to shore. These are, as you’d expect, also the most accessible and the ones most often visited by tourists.

If you were going to use this technique more widely, it would make sense, therefore, to focus on nearshore reefs. They’re economically important for industries like tourism and fishing.

At present, there’s a lot of research being done on high-tech interventions such as breeding corals to tolerate hotter water, or brightening clouds. What we hope to show is the equal value of testing low-tech, low-cost methods which can achieve scale by harnessing citizen science volunteers and community programs. This has the added advantage of building public support and giving concerned citizens a clear way to help. It could be useful not only in Australia, but on island nations in the Pacific with limited resources.

By our estimates, the cost – around A$104,000 per hectare – is a fraction of other reef restoration techniques, which have a median cost of about $616,000 per hectare, ranging all the way up to $6.2 million per hectare.

This isn’t a silver bullet. We have no reef restoration or management approaches able to keep our reefs alive if we don’t tackle the big issues – hotter, more acidic seas brought about by climate change, as well as nutrient runoff and other threats.

So what role could sea-weeding have? Even if we manage to significantly cut emissions globally in the coming decades, there’s so much CO₂ already in the atmosphere that reefs will keep deteriorating.

That means there could well be a role for this approach. This low-tech but rapidly effective technique could help keep corals alive while we work for decisive action on climate change.

Hillary Smith, Senior Research Officer, James Cook University and David Bourne, Professor of Marine Biology, James Cook University

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

Our unsung farm dams provide vital habitat to threatened species of frogs

Frogs are in trouble. While many of the world’s animal species are now at risk from habitat loss, climate change and other human pressures, frogs are particularly at risk.

That’s because they rely on fresh water – and rivers, creeks and lakes are especially vulnerable to threats and habitat loss. Freshwater creatures are going extinct faster than land or sea-based lifeforms. Frogs are at even higher risk because their life stages require pristine terrestrial and aquatic habitats – and because the lethal amphibian chytrid fungus is after them.

Frogs could use some good news. Here it is: the farm dam. These ubiquitous human-made ponds are scattered across Australia’s rural regions. Our new research has found they have become home to over two-fifths of Australia’s 240-plus surviving frog species. Better still, as we compiled more than 100,000 audio recordings made by citizen scientists, we could hear the unmistakable calls of species threatened with extinction, such as the green and golden bell frog.

Which dams are important for frogs?

Australia has almost 1.8 million farm dams, storing 20 times the volume of Sydney Harbour. Tens of thousands more are excavated each year.

But which of these small, widely distributed ponds offer the best habitat for frogs? And which of our native frogs are able to use them?

To find out, we drew heavily on the power of citizen science. Thousands of people used the Australian Museum’s FrogID app or Melbourne Water’s Frog Census app to record calling frogs and upload the audio.

We compiled more than 100,000 recordings near 8,800 farm dam sites. When experts listened to these recordings, they identified 107 different species.

What we were most excited by was discovering species at very real risk of extinction, croaking happily in unnamed dams. These included growling grass frogs (Litoria raniformis), green and golden bell frogs (Litoria aurea), Sloane’s froglet (Crinia sloanei) and northern heath frogs (Litoria littlejohni).

This tells us that farm dams can provide breeding habitat for frogs that are vulnerable to extinction – not just for common species.

In the recordings, we heard the growling grass frog over 3,200 times near 315 farm dams dotted around southeast Australia. That’s an important find, given it’s one of six priority frog species in the government’s threatened species action plan.

Frogs love mid-sized old dams

When we crunched the numbers, we found distinct trends in frog abundance. The dams richest in frog species were those older than 20 years, with a medium surface area around 0.1 hectares (dams get a lot bigger than this), and located in areas with high rainfall and intermediate temperatures.

That makes sense. The older the dam, the more natural it becomes. Aquatic plants have time to grow, while shrubs and plants around the dam provide shelter and calling sites for frogs.

Medium size dams provide frogs with the ideal balance between protection from drying out and reduced danger from fish and reptile predators.

We also detected more frog species in dams close to rivers, lakes or conservation sites. Leapfrogging between nearby wetlands is likely to be an important way frogs colonise farm dams.

Farms and frogs can happily coexist

Is there a clash between what farmers want from their dams and what frogs need? Not necessarily.

It’s certainly true that the banks of dams can, if not looked after, be trampled by livestock into mud. But when farmers fence off parts of the dam banks to protect plants, it benefits livestock health, increases water quality, cuts greenhouse gas emissions, and safeguards breeding habitats for crustaceans, birds and amphibians, which, in Australia, means frogs.

Researchers from Sustainable Farms have released guides on how to make farm dams even better oases for native wildlife by managing and revegetating farm dams to boost water quality and biodiversity.

As the federal government advances its plans for a nature repair market, it’s possible we could see a surge of interest in farm dams.

In this scenario, making farm dams more wildlife-friendly could net farmers and landholders biodiversity credits. Given the wealth of frog species in dams, this could present a cost-effective strategy.

Does this mean we should encourage more farm dams? Not necessarily. Farm dams can compete for water with natural freshwater systems and reduce habitat for species relying on ephemeral ponds or streams to breed. Any future financial incentives to re-wild farm dams must not reward the mass creation of farm dams.

As we grapple with the ongoing biodiversity crisis, it makes sense to make the most of what we have. Farm dams are everywhere. Let’s make them a haven for our frogs.

Martino Malerba, ARC DECRA Fellow, Deakin University; Don Driscoll, Professor in Terrestrial Ecology, Deakin University; Jodi Rowley, Curator, Amphibian & Reptile Conservation Biology, Australian Museum, UNSW Sydney; Nick Wright, Research scientist, Department of Primary Industries & Regional Development, The University of Western Australia, and Peter Macreadie, Professor of Marine Science & Founder/Director of Blue Carbon Lab, Deakin University

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

We urgently need $100bn for renewable energy. But call it statecraft, not ‘industry policy’

This week, a diverse group of organisations called on the Australian federal government to establish a A$100 billion, ten-year policy package to turbocharge Australia’s green energy transition.

Proposed by groups including the Australian Council of Trade Unions, Australian Conservation Foundation, Climate Energy Finance, Rewiring Australia and the Smart Energy Council, the Australian Renewable Industry Package (ARIP) would dwarf the government’s existing commitments.

Its proponents claim that by 2035, the package would generate at least $300 billion annual clean export revenue and 700,000 much needed jobs, mainly in rural and regional Australia.

So will Australian policymakers from across the political spectrum heed this call and agree to spend big on Australia’s green energy industry capabilities?

If we want policymakers to unify and to act, we have to use language that widely resonates. This, we argue, must be the language of green energy statecraft, not industry policy.

A response to the US

The ARIP is explicitly framed as a response to the United States’ impactful Inflation Reduction Act (IRA). The act, passed in August 2022, is Washington’s response to its pressing geostrategic, economic, energy and environmental security challenges.

The IRA contains US$370 billion worth of incentives for clean tech and is estimated to spur US$2.9 trillion of cumulative investment opportunity by 2032.

This comprehensive suite of policy supports has put Australian efforts to shame. As a result, the IRA is now drawing much needed green energy investment away from Australia. Given the support on offer, it is no surprise US manufacturing spending has nearly doubled in the last 12 months, while Australia remains stuck in the investment slow lane.

Even more worrying for Australia is the fact the US is not the only rapid mover in the green energy space. A number of middle powers more similar to us in capacity – such as Canada and Japan – have also announced hugely ambitious green energy investment packages that leave Australia lagging.

There is no question Australia needs the ARIP, and needs it urgently.

Industry policy – Australia’s dirtiest word

In arguing for a new big renewables push, some proponents have couched it in the language of a “new industry policy”. But this language is problematic for two main reasons.

First, this language in Australia is highly politicised and divisive. Since the 1980s, “industry policy” has arguably become one of the most misused and abused terms in our nation’s political discourse.

To even utter the words “industry policy” is often enough to spark fierce ideological objection, or to cause people’s eyes to glaze over with disinterest, disillusionment or both. In this sense, the term has become the ultimate thought blocker and conversation stopper.

Unfortunately, such reactions make it almost impossible to have a sensible national debate about what effective industry policy actually looks like. For its many detractors “industry policy” means protectionism and picking winners, and should therefore be avoided at all costs.

This unsophisticated view ignores the fact that in countries that have historically practised highly effective and strategic industry policy – including our northeast Asian neighbours of Japan, South Korea and Taiwan – “protectionism” and “picking winners” was far from the norm.

Indeed, because of the goal orientation of East Asian policymakers, who wanted to catch up with developed countries extremely quickly, industry policy was a highly disciplined affair tied to stringent performance incentives.

In this context, East Asian governments did not pick winners. Rather, winning firms self-selected by opting into government support programs, and by then outperforming competitors to keep earning that support.

By contrast, in Australia “industry policy” has become a highly politicised and partisan affair. For this reason, calls for industry policy often fall on deaf ears, and do more to divide policymakers and business leaders than unite them.

Towards ‘statecraft’, not industry policy

But there is another, even more compelling reason for advocates of the renewables package to avoid the language of “industry policy”. The term doesn’t adequately capture the kinds of policies our competitors – both rivals and partners – are now enacting in the green energy space, or the kind of response we require.

Instead, Australia needs to embrace “green energy statecraft”.

Such statecraft involves bold government initiatives to build, grow and dominate the high-technology markets essential to the green transition, and to fend off or outflank rival powers, be they economic, geo-strategic or both.

Green energy statecraft is different from plain old energy policy, or even “industry policy”. Its focus is squarely on building new industries with the intention of ensuring success in hyper-competitive global markets and, simultaneously, bolstering national security.

We argue that in recent years, the most significant obstacle to Australia’s success in the green energy arena has been the prevailing policymaking mindset: viewing the green energy shift principally as an energy and climate policy challenge, rather than statecraft.

With national security motivations at play, governments that practice green energy statecraft create bold visions for new industries like green hydrogen, green steel and bioenergy. They set clear production, export and, most importantly, technology-upgrading targets. They also mobilise all available financial incentives and policy instruments to ensure these targets are met.

To become a green energy superpower, Australia needs to match our strategic vision with a new green energy statecraft.

Language matters. If we want policymakers to act, and if we want our calls to unite rather than divide, we need to choose our words very carefully.

Elizabeth Thurbon, Professor in International Relations / International Political Economy, UNSW Sydney; Alexander M. Hynd, PhD candidate, UNSW Sydney, and Hao Tan, Associate Professor, Newcastle Business School, University of Newcastle

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

Fire regimes around Australia shifted abruptly 20 years ago – and falling humidity is why

This century, Australia has suffered more frequent and more severe bushfires. The Black Summer fires of 2019–20 were the worst on record for the area burned and property loss.

How much climate change has contributed to these increases is a hot topic. Bushfire risk is dialled up by four switches: fuel amount and condition, fire weather and ignition sources. Untangling these various influences is difficult, so the role played by the warming climate is heavily debated.

Fire-weather measures fire risk on a daily basis, while a fire-climate regime measures fire risk over seasonal and longer time scales. Our research shows almost everywhere in Australia is now in a different fire climate than it was just 20 years ago, with falling relative humidity a key factor. Previous research has also identified these sudden jumps in fire danger.

What caused fire climates to shift? Conventional scientific wisdom assumes the climate’s response to increasing emissions is gradual and linear. When rapid change happens, it’s often thought to be due to climate variability. But that’s not what happened here.

Most Australian fire climate regimes have already shifted

Fire weather is calculated using the Forest Fire Danger Index, which takes into account vegetation dryness, windspeed, temperature and relative humidity.

Obtaining reliable long-term records using these measures is difficult, so we used high quality seasonal and annual climate inputs to estimate the annual fire climate for different regions of Australia from 1957–58 to 2021–22.

We tracked changes in this fire danger index over that 64-year period across all states and the Northern Territory. We also looked at distinct sub regions such as southwest Australia. What we found was startling. Rather than a linear increase, fire regimes tracked along a similar line – and then suddenly jumped. For most states and territories, that happened around the year 2000.

There is no evidence for a long-term trend. Instead, the data shows a shift from one stable fire climate regime to another.

We’re already seeing these changes play out. Whenever you see a news article about intense fires in areas not used to fire, that’s likely to be due to a shift in fire climate. Think of the fires devastating Tasmania’s alpine regions in 2016, killing off many old pencil and King Billy pines.

When did these jumps happen?

Here’s when each region shifted from one fire regime to the next:

You can see the shift in the number of days above “high fire danger”.

When we showed this research to Greg Mullins, former Commissioner of Fire & Rescue New South Wales, he said it was

utterly consistent with what firefighters are experiencing worldwide: more frequent, intense, and damaging bushfires that sometimes are impossible to control.

Is it really that bad? Yes.

For instance, what would have been the one in ten bad fire season under the earlier regime (occurring once in ten years) became, on average, a one in two fire season in the second regime.

That means the worst 10% of fire years were now happening every second year.

When we looked at even worse fire years – the worst year in 20 fire seasons – the shift was shocking. On average, we are now seeing these years twice every five years.

Why did fire climates shift so abruptly?

That’s the big question.

To find out, we analysed all the available input variables for regime shifts and tested their influence on the results. We found wind speed was not a factor. Changes in rainfall had little effect.

So what was it? We found the main driver was relative humidity in combination with higher daily temperatures during the fire season. Recently, we examined global humidity data and found large-scale downward shifts in humidity. In the Southern Hemisphere, that happened in 2002. In the Northern Hemisphere, it happened in 1999.

Humidity reductions in each region of Australia were closely followed by shifts to higher fire season maximum temperatures, amplified by soils drying out.

We also tested global average fire season length from 1979 to 2013 for regime shifts, finding a rapid expansion in 2002. That’s the same year Australia’s median fire danger jumped.

The consequences of these shifts are profound. The unprecedented fires in Canada and Europe, the devastating fires in Hawaii and the increasing frequency of wildfires around the world have their roots in lower relative humidity, which leads to higher daytime temperatures. That, in turn, creates these dangerous new fire regimes.

Why haven’t we heard about these sudden shifts in fire climate? One reason is much of our modelling is built on the assumption the steady accumulation of heat trapped by greenhouse gases leads to linear changes elsewhere.

But as this year’s climate chaos suggests, this assumption may be unfounded.

In our earlier research, we found zero of 32 climate models were able to reproduce the sudden shifts in relative humidity across the globe.

What does this mean for this year’s fire season?

Many parts of New South Wales, Queensland, the western Northern Territory and northwest Victoria have already dried out, though large forests will keep some moisture after the years of rain. Grass fires are already raging in the Northern Territory.

That suggests the greatest risks this summer will be in grassland, scrubland and suburbs on the fringe of cities. Widespread catastrophic forest fires are probably less likely. But the major fires will return if dry conditions persist.

In fact, in the current climate, land can dry out much faster than it used to, leading to flash droughts which swing from very wet to very dry in a short period of time.

Remember – this current fire regime may not be permanent. As the climate warms further, it’s entirely possible our fire regimes could warp into something even more dangerous. Ensuring our climate models are capable of predicting these changes is an urgent task.

Roger Jones, Professorial Research Fellow, Victoria University

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

Solar panel technology is set to be turbo-charged – but first, a few big roadblocks have to be cleared

Solar panel technology has made enormous progress in the last two decades. In fact, the most advanced silicon solar cells produced today are about as good as the technology will get.

So what’s next? Enter “tandem solar cells”, the new generation in solar technology. They can convert a much greater portion of sunlight into electricity than conventional solar cells.

The technology promises to fast-track the global transition away from polluting sources of energy generation such as coal and gas. But there’s a major catch.

As our new research shows, current tandem solar cells must be redesigned if they’re to be manufactured at the scale required to become the climate-saving technology the planet needs.

The solar story so far

A solar cell is a device that turns sunlight into electricity. One important measure when it comes to solar cells is their efficiency – the proportion of sunlight they can convert into electricity.

Almost all solar panels we see today are made from “photovoltaic” silicon cells. When light hits the silicon cell, electrons inside it produce an electric current.

The first silicon photovoltaic cell, demonstrated in 1954 in the United States, had an efficiency of about 5%. That means that for every unit of the Sun’s energy the cell received, 5% was turned into electricity.

But the technology has since developed. At the end of last year, Chinese solar manufacturer LONGi announced a new world-record efficiency for silicon solar cells of 26.81%.

Silicon solar cells will never be able to convert 100% of the Sun’s energy into electricity. That’s mostly because an individual material can absorb only a limited proportion of the solar spectrum.

To help increase efficiency – and so continue to reduce the cost of solar electricity – new technology is needed. That’s where tandem solar cells come in.

A promising new leap

Tandem solar cells use two different materials which absorb energy from the Sun together. In theory, it means the cell can absorb more of the solar spectrum – and so produce more electricity – than if just one material is used (such as silicon alone).

Using this approach, researchers overseas recently achieved a tandem solar cell efficiency of 33.7%. They did this by building a thin solar cell with a material called perovskite directly on top of a traditional silicon solar cell.

Traditional silicon solar panels still dominate manufacturing. But leading solar manufacturers have signalled plans to commercialise the tandem cell technology.

Such is the potential of tandem solar cells, they are poised to overtake the conventional technology in coming decades. But the expansion will be thwarted, unless the technology is redesigned with new, more abundant materials.

The problem of materials

Almost all tandem solar cells involve a design known as “silicon heterojunction”. Solar cells made in this way normally require more silver, and more of the chemical element indium, than other solar cell designs.

But silver and indium are scarce materials.

Silver is used in thousands of applications, including manufacturing, making it highly sought after. In fact, global demand for silver reportedly rose by 18% last year.

Likewise, indium is used to make touchscreens and other smart devices. But it’s extremely rare and only found in tiny traces.

This scarcity isn’t a problem for tandem solar technology yet, because it hasn’t yet been produced in large volumes. But our research shows this scarcity could limit the ability of manufacturers to ramp up production volumes in future.

This may represent a substantial roadblock in tackling climate change. By mid-century, the world must install 62 times more solar power capacity than is currently built, to enable the clean energy shift.

Clearly, a major redesign of tandem solar cells is urgently needed to enable this exponential acceleration of solar deployment.

Ramping up the transition

Some silicon solar cells don’t use indium and require only a small amount of silver. Research and development is urgently needed to make these cells compatible with tandem technology. Thankfully, this work has already begun – but more is needed.

A scarcity of materials is not the only barrier to overcome. Tandem solar cells must also be made more durable. Solar panels we see everywhere today are generally guaranteed to produce a decent amount of electricity for at least 25 years. Perovskite-on-silicon tandem cells don’t last as long.

Solar power has already shaken up electricity generation in Australia and around the world. But in the race to tackle climate change, this is only the beginning.

Tandem solar cell research is truly global, conducted within a range of countries, including Australia. The technology offers a promising way forward. But the materials used to make them must be urgently reconsidered.

Bruno Vicari Stefani, CERC Fellow, Solar Technologies, CSIRO and Matthew Wright, Postdoctoral Researcher in Photovoltaic Engineering, University of Oxford

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How we brought mistletoes back to the trees of Melbourne – while warding off hungry possums

Until recently, mistletoes were regarded as problematic pests across Australia. They were seen as having been introduced from elsewhere, exploiting helpless trees and driving their premature demise.

Around the world, arborists and plantation managers used to be trained to remove mistletoes as part of routine maintenance. They went to extraordinary lengths to rid trees of these dense parasitic clumps, using flamethrowers, high-powered rifles, even herbicide-spritzing drones.

But just as we now know that hollows are essential for wildlife, including many threatened species, awareness of the positive side of parasitic plants is growing. Mistletoes have been shown to boost biodiversity and increase resilience of wildlife populations to drought, habitat loss and predators.

However, unlike other plants that can be grown as seedlings and planted out, mistletoes rely on animals to plant their seeds on the branches of host trees. This means they aren’t included in revegetation efforts, and it was unclear whether it would even be possible.

We set out on a world-first trial to attempt to reintroduce mistletoe to the trees of Melbourne. As our recently published research shows, we succeeded. Some of the mistletoes are now even bearing fruit.

The only factor that stood in the way of success was the bane of many gardeners’ lives – hungry brushtail possums.

Productive parasites

Mistletoes provide many benefits for local biodiversity. Their flowers provide reliable nectar that encourages pollinators to linger longer. They then boost the populations of other plant species they visit.

The nutrients in mistletoe leaves boost soil health and dramatically increase insect numbers when they fall to the forest floor.

The ripples of these interactions spread right through woodland food webs. One study demonstrated the most significant impacts on ground-feeding insect-eating birds, whose numbers have declined across eastern Australia.

Many birds nest in mistletoes. Their dense evergreen foliage provides cover from predators.

All of Australia’s mistletoes are native species. Most hail from ancient lineages dating all the way back to Gondwanaland.

The knowledge we have gained about mistletoes has led to an about-face in natural resource management. Managers are rethinking mistletoe removal and embracing these native plants as ecological keystones.

In some areas where mistletoes no longer occur, restoration practitioners have suggested reintroducing them. It had been unclear if this was feasible.

Making Melbourne even more marvellous

Working closely with City of Melbourne staff, research scientists from the Gulbali Institute undertook a world-first trial of the reintroduction of a native mistletoe to street trees. Rather than eucalypts or other native trees, we decided to use plane trees, a European species that is a feature of city streets the world over. In Australia, very few things interact with plane trees — nothing eats them, which is one reason they’re popular street trees.

Rather than replace these established trees with more fitting local species and waiting a few decades for them to grow, we tried something a little different. We added a native mistletoe to their canopies to boost the resources available to urban wildlife.

We chose creeping mistletoe (Muellerina eucalyptoides), which is now scarce in Melbourne, but is just as happy growing on exotic deciduous trees as the evergreen eucalypts this species depends on as hosts in the bush.

Our research paper summarises the outcomes of the trial. Almost 900 seeds were carefully wiped on the branches of 28 plane trees. We were replicating the efforts of mistletoebirds, which usually spread these sticky seeds.

Five years after inoculation, we found mistletoes had established on five trees. Even better, two of these plants were full of fruit. There is now a ready-made seed source in the heart of Melbourne for further expansion of these beneficial native plants.

The problems with possums

Rather than establishment depending on the size of the branch, the age of the tree or which direction it faced, the only factor that emerged as a significant determinant of success was whether or not the tree was fitted with a possum collar. These acrylic or metal sheets wrapped around the trunk are too slippery for possums to climb. The city’s tree management team routinely uses these collars to grant a reprieve to trees whose canopies have been badly damaged by these marsupials.

Previous work has found possums love to eat mistletoe foliage. This is likely due to their high concentration of nutrients and lack of chemical defences that eucalypts have.

Our study is the first to provide direct evidence of the effect of common brushtail possums on mistletoe recruitment. Its findings reinforce reports from New Zealand, where introduced brushtail possums have devastated three mistletoe species and been implicated in the extinction of a fourth, the only mistletoe known to have gone extinct worldwide.

Beautiful butterflies are returning

Time will tell how the addition of these plants to the urban forest will affect Melbourne wildlife. Already, gorgeous imperial jezebel butterflies have been spotted emerging from creeping mistletoes in Princes Park.

Even better, our work has inspired three other urban mistletoe reintroductions elsewhere in Melbourne. In New South Wales, Birdlife Australia and Mindaribba Local Aboriginal Land Council are working together to restore mistletoe to woodlands on Wonnarua Country. The mistletoe will supply missing nectar resources for the critically endangered regent honeyeater.

Collectively, this work is helping to shift the public perception of these native plants – from pernicious parasites to ecological keystones.

David M Watson, Professor in Ecology, Charles Sturt University and Rodney van der Ree, National Technical Executive in Ecology at WSP Australia Pty Ltd. Adjunct Associate Professor, School of BioSciences, The University of Melbourne

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

China makes developers pay compensation for their ecological impacts – here’s how this unique scheme works

In 2017, the Chinese environmental NGO, Friends of Nature, sued the developer of a dam in Yunnan province in the country’s south west. The NGO alleged that the project’s environmental impact assessment had failed to fully capture how the dam would affect the surrounding rainforest, and particularly the endangered green peafowl that lives there. This weak assessment report was one reason why the project was granted consent and even highlighted as best practice by the local government.

In 2020 a court in Yunnan ordered a halt to construction of the dam, but the discussion around the case did not end. This was not an isolated issue related to one local government’s hasty approval of a project with a flawed environmental impact assessment. Instead, it revealed systemic challenges for China’s ecological compensation system in which developers often get to assess their own environmental impacts.

Nowhere in the world are these potential trade-offs between infrastructure and the environment more stark than in China, which features both a global biodiversity hotspot and huge and fast-developing economy. This all adds up. For instance, it is estimated that between 2010 and 2013 China poured more concrete than the US did in the entire 20th century.

Weak environmental impact assessments and the subsequent approval of harmful development projects are endemic to planning processes worldwide. However, the ecological compensation system in China is rather different to those elsewhere. In China, developers first assess the environmental impact of their new projects. They can then choose to redress these impacts by themselves or to pay upfront restoration fees to the government, who will use the money to do it for them. We recently published research exploring how this system works (and when it doesn’t) and what other parts of the world could learn from it.

Unreliable and often ineffective

We reviewed 31 projects across different regions in China, including the Yunnan dam. We found that only seven of the relevant environmental impact assessments used quantitative metrics to measure their impact on biodiversity. This is perfectly legal, as these metrics are not compulsory. But the lack of standard measurements means any compensation programmes can’t be reliable.

Nonetheless, developers are encouraged to design restoration and compensation schemes and include them in their environmental assessment reports submitted to the government. However, they are not required to restore habitats which are similar to the ones being lost. This means projects can replace valuable habitats with less valuable areas – planting roadside trees to make up for lost wetland forest, for example. Species and habitats could therefore be degraded or lost even though ecological compensation has been paid.

When developers don’t want to restore nature themselves, or their proposals are not significant enough to make up for the habitat loss they have caused, they are required to pay restoration fees to the government.

Under China’s environmental laws and regulations, local government collects these restoration fees from developers and spends them on creating new habitats or recovering degraded habitats elsewhere. For instance, forestry law requires restoration fees to be spent towards ensuring no net loss in the area covered by forest (albeit without consideration of forest type, so a native forest could be replaced with a non-native plantation).

It might be better if China’s public sector was fully in charge of ecological compensation, rather than letting developers design their own compensatory projects. But it’s very hard to find information that would let us know.

Out of 2,844 local governments across China, fewer than 1% have disclosed how much restoration money they have collected and spent and what they spent it on. We did manage to sample ten reports disclosed by local governments and found that they implement similar biodiversity-enhancement projects to developers.

Individual species can fall through the net

Due to the lack of proper metrics to capture biodiversity losses and inadequate information published, it is near-impossible to compare outcomes and to evaluate the effectiveness of ecological compensation projects. However, it is clear that there is a lack of regulatory safeguards for biodiversity on China’s development sites.

This is because the ecological compensation policy relates mostly to habitat area. It does not well account for a habitat’s quality, its functional role within a wider ecosystem, its conservation value, the amount of species that live there and many other such attributes. The focus on habitat means individual threatened species (such as the green peafowl) can fall through the net.

China’s central government should consider passing a law that would mean biodiversity impact measurements would have to use a unified indicator framework, and, if possible, make it compulsory for all development activities. Equally, China may also need to improve compensation governance for data tracking and conservation effectiveness monitoring. Establishing a public national offset register would help.

Other countries might learn from China. Paying upfront restoration fees could encourage developers elsewhere to avoid and minimise their environmental impacts at the early stages of their projects. Besides, the levying of fees from developers to be spent by local governments on projects to enhance both nature and people’s wellbeing in a strategic way could be a useful model for ecological compensation elsewhere.

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Shuo Gao, PhD Candidate, Interdisciplinary Centre for Conservation Science, University of Oxford; Eleanor Jane Milner-Gulland, Tasso Leventis Professor of Biodiversity, University of Oxford; Joseph William Bull, Associate Professor in Climate Change Biology, University of Oxford, and Sophus zu Ermgassen, Postdoctoral Researcher, University of Oxford

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

Fashion industry’s environmental impact is largely unknown – here’s why

How do the clothes you buy wear out the natural world? To take stock of the damage you have to account for the materials, water and energy that went into making a garment, and the greenhouse gas emissions, chemical pollutants and other byproducts associated with its disposal.

For example polyester, a kind of plastic widely used in T-shirts, is made from oil – a fossil fuel. If you throw it out it degrades slowly, and chemicals from its dyes and surface treatments leach into the soil.

The UK consistently buys more garments than any other European country, spending more than £45 billion (US$56 billion) annually. Fast fashion, an industry trend which involves getting cheap reproductions of catwalk designs out to a mass market as quickly as possible, encourages this buying frenzy.

Much of fast fashion is known to depend on sweatshop labour and polluting factories. But alongside the demand for ever faster fashion at low prices, there is a growing awareness among consumers that something has to change.

Some firms have caught on: many brands now report their environmental footprint and have disclosed their intention to shrink it.

But how trustworthy are these assessments? My research uncovers how the fashion industry collates, analyses and assesses environmental impact data. Unfortunately, as a result of inaccurate and unreliable methods, among other issues, the true cost of fast fashion remains largely unknown.

The hidden price tag

A multitude of metrics, certification schemes and labels mark the environmental consequences of making and selling clothing. Brands have been accused of greenwashing due to the poor quality of information used in some of them.

One common product-labelling tool within the industry was the Higg Materials Sustainability Index. Introduced in 2011, the Higg Index was a rating system used by several large brands and retailers to determine and report the global warming impact and water consumption of different products, among other environmental measures.

The approach adopted by the index was challenged by the Norwegian Consumer Authority for limiting its assessment to only certain phases of a product’s lifecycle, such as the sourcing of materials. It was criticised for overlooking pollutants such as microfibres, which are released from textiles during manufacture, wear and washing. As a result, the index was suspended pending a review in June 2022.

Since then, further issues have come to light. These include:

• unreliable data – measures often rely on brands self-reporting without their information being verified by an impartial third party
• vested interests – many tools and indices are funded, or part funded, by organisations that could benefit from more positive reporting
• tunnel vision – existing methods tend to focus on only one environmental impact, such as water use or carbon emissions, while the relationship between these factors is overlooked
• paywalls – many tools require brands to pay into them. This can effectively exclude smaller businesses and limit the tool’s coverage
• lack of standards – there is no official baseline to determine acceptable thresholds of environmental footprint of any one product.

Without reliable and accurate assessments of a product’s environmental impact, consumers are left in the dark. For example, a common misconception is that cotton, being a natural fibre, is better for the environment than synthetic materials such as acrylic and elastane.

But cotton requires vast quantities of water to grow, harvest and process. A standard cotton t-shirt, for example, requires 2,500 litres while a pair of jeans consumes 7,600 litres.

One fibre is not necessarily better than the other. Rather, every material and manufacturing process affects the natural world in one form or another. With such misconceptions rife, it’s difficult for consumers to make sound comparisons. That’s why accurate measures are desperately needed.

The true cost of fashion

The complexity of fashion’s global supply chain, which spans thousands of miles from fields to shop floors, makes accurate measurements exceptionally difficult. Capturing an accurate picture of the industry’s environmental footprint will rely on a certain level of transparency across the industry. It will also require multiple sectors – including production, manufacturing and retail – working collectively towards a common goal.

An acceptable definition for “sustainable”, informed by standards and baselines, could empower consumers to make more informed decisions about their purchases. With Gen-Z labelled the sustainable generation, it is time for fashion to reform.

An earlier version of this article stated that the Higg Materials Sustainability Index had been suspended. The index is actually paused pending a review.

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Alana James, Assistant Professor in Fashion, Northumbria University, Newcastle

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People who grow their own fruit and veg waste less food and eat more healthily, says research

The rising cost of living is making it harder for people, especially those on lower incomes (who often have poorer diets), to afford to eat healthily. Despite this, households in the UK continue to waste a shocking amount of food – including around 68kg of fruit and vegetables each year.

Food waste is not only damaging to your pocket, it’s also bad for the environment too. Globally, 1.3 billion tonnes of food are wasted every year, generating about 8% of the world’s greenhouse gas emissions. These emissions arise from unused food at all stages of the food supply chain, from production to decomposition.

However, our recent study revealed that those who grow their own food in gardens and allotments waste an average of just 3.4kg of fruits and vegetables – 95% less than the UK average. These households adopted various practices to minimise food waste, including preserving or giving away their excess produce.

There has been renewed interest in growing fresh produce in gardens, community gardens and allotments in the UK and elsewhere in recent years. But the available supply of allotments is not enough to meet increasing demand.

Allocating more land for household fruit and vegetable production could make a significant contribution to the availability of fresh produce for urban residents.

Research has shown that using a mere 10% of the available space in the English city of Sheffield for food cultivation could supply enough fruit and vegetables to meet the needs of 15% of the city’s population. And more people growing their own food could also reduce waste.

Food diaries

Our study involved 197 households in the UK that grow their own food. We asked them to maintain a food diary, where they recorded the amounts of fruits and vegetables they acquired each week. We received complete records from 85 separate households.

They specified whether each item was cultivated in their garden or allotment, bought from shops or markets, sourced from other growers, or foraged in the wild. The households also recorded the quantity of the produce they gave away to family and friends, and the amounts they had to throw out.

Our findings suggest that individuals who grow their own food may be more inclined to avoid food wastage than the average person in the UK. This is possibly because they place a higher value on produce they had grown themselves.

The results align with earlier research that was conducted in Germany and Italy. This study found that the amount of discarded food was greatest among people who shopped exclusively in large supermarkets. People who purchased items from various small stores tended to waste less food, while those that grew their own food wasted the least.

Our findings also suggest that the households we studied can produce roughly half of all the vegetables, and 20% of the fruit, they consume annually. These households consumed 70% more fruits and vegetables (slightly more than six portions per day) than the national average.

Eating plenty of fruits and vegetables as part of a balanced and nutritious diet is key to maintaining good health. This kind of diet can help prevent diseases such as type 2 diabetes, certain cancers and heart disease.

Yet, in the UK, less than one-third of adults and only about 8% of teenagers eat their “five-a-day”. This target, which is based on advice from the World Health Organization, recommends eating at least five 80g portions of fruit and veg every day.

Grow your own food security

Growing your own food can improve access to fresh fruits and vegetables, promote good health and reduce food waste. However, several obstacles hinder involvement in household food production. These obstacles include limited access to the land, skills and time needed to grow your own fruit and veg.

Approximately one in eight UK households lacks access to a garden. And, since the 1950s, the availability of allotments throughout the UK has declined by 60%. This decline has been particularly evident in more deprived areas of the country, where people could benefit most from better availability of nutritious foods.

We also found that those who grew their own food dedicated approximately four hours each week to working on their allotment or garden. Unfortunately, not everyone has the luxury of having the time to do so.

Nonetheless, raising awareness about the benefits of home food production, beyond just food security and reducing waste, to include its positive impacts on social cohesion, overall wellbeing and biodiversity could encourage more people to participate. Increasing demand for growing space may also encourage local authorities to allocate more land for this purpose.

Whether you grow your own food or not, everyone can adopt mindful practices when purchasing or growing food. Planning ahead and freezing or sharing excess food with others to prevent it from going to waste are good options.

But some food waste is inevitable. Composting it instead of sending it to landfill will substantially lower its impact on the planet.

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Boglarka Zilla Gulyas, Postdoctoral Research Associate in SCHARR, University of Sheffield and Jill Edmondson, Research Fellow in Environmental Change, University of Sheffield

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As climate change warms rivers, they are running out of breath – and so could the plants and animals they harbor

As climate change warms rivers, they are losing dissolved oxygen from their water. This process, which is called deoxygenation, was already known to be occurring in large bodies of water, like oceans and lakes. A study that colleagues and I just published in Nature Climate Change shows that it is happening in rivers as well.

We documented this change using a type of artificial intelligence called a deep learning model – specifically, a long short-term memory model – to predict water temperature and oxygen levels. The data that we fed the model included past records of water temperature and oxygen concentrations in rivers, along with past weather data and the features of adjoining land – for example, whether it held cities, farms or forests.

The original water temperatures and oxygen data, however, were measured sparsely and often in different periods and with different frequency. This made it challenging before our study to compare across rivers and in different periods.

Using all of this information from 580 rivers in the U.S. and 216 rivers in central Europe, our AI program reconstructed day-to-day temperatures and oxygen levels in those rivers from 1981 to 2019. We also used future climate projections to predict future water temperature and oxygen levels. This enabled us to consistently compare past and future river water temperatures and oxygen levels across hundreds of rivers, which would not have been possible without using AI.

On average, we found, rivers were warming by 0.29 degrees Fahrenheit (0.16 degrees Celsius) per decade in the U.S. and 0.49 F (0.27 C) per decade in central Europe. Deoxygenation rates reached as high as 1% to 1.5% loss per decade. These rates are faster than deoxygenation rates occurring in oceans, and slower than those in lakes and coastal regions.

Urban rivers are warming up most rapidly, while rivers in agricultural areas are losing oxygen most rapidly. This could be partly due to nutrient pollution, which combines with warmer waters to fuel large blooms of algae. When the algae die and decompose, this process depletes dissolved oxygen in the water.

Why it matters

Oxygen is crucial for plants, animals, fish and aquatic insects that live in rivers. These organisms breathe dissolved oxygen from river water. If oxygen levels drop too low, river species will suffocate.

While scientists know that oceans and lakes have been losing oxygen in a warming climate, we have mainly thought that rivers were safe from this problem. Rivers are shallow, and fast-moving water can absorb oxygen directly from the air more rapidly than standing water. Rivers also harbor plants that make oxygen.

The health of rivers affects everything in and around them, from aquatic life to humans who rely on the rivers for water, food, transportation and recreation. Warming rivers with low oxygen could suffer fish die-offs and degraded water quality. Fisheries, tourism and even property values along rivers could decline, affecting livelihoods and economies.

As the air warms in a changing climate, rivers will also become warmer. As a liquid’s temperature increases, its capacity to hold gases declines. This means that climate change will further reduce dissolved oxygen in river water.

At extreme levels, this process can create dead zones where fish and other species cannot survive. Dead zones already form in coastal areas, such as the Gulf of Mexico and Lake Erie. We found that some rivers, especially in warmer areas like Florida, may face more low-oxygen days in the future.

Low oxygen in rivers also can promote chemical and biological reactions that lead to the release of toxic metals from river sediments and increased emissions of greenhouse gases, such as nitrous oxide and methane.

What’s next

Most of our data on dissolved oxygen was collected during the day, when plants in rivers are actively making oxygen through photosynthesis, powered by sunlight. This means that our findings may underestimate the low-oxygen problem. At night, when plants aren’t producing oxygen, dissolved oxygen levels could be lower.

I see this research as a wake-up call for more study of how climate change is affecting river water quality worldwide. Better monitoring and more analysis can make the full scope of river deoxygenation clearer. Ultimately, I hope more research will lead to policy changes that promote responsible land use and water management and better stewardship of rivers, our planet’s veins.

The Research Brief is a short take about interesting academic work.

Li Li (李黎), Professor of Civil and Environmental Engineering, Penn State

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

Summer 2023 was the hottest on record – yes, it’s climate change, but don’t call it ‘the new normal’

Summer 2023 was the hottest on record by a huge margin. Hundreds of millions of people suffered as heat waves cooked Europe, Japan, Texas and the Southwestern U.S. Phoenix hit 110 degrees Fahrenheit (43 degrees Celsius) for a record 54 days, including a 31-day streak in July. Large parts of Canada were on fire. Lahaina, Hawaii, burned to the ground.

As an atmospheric scientist, I get asked at least once a week if the wild weather we’ve been having is “caused” by climate change. This question reflects a misunderstanding of the difference between weather and climate.

Consider this analogy from the world of sports: Suppose a baseball player is having a great season, and his batting average is twice what it was last year. If he hits a ball out of the park on Tuesday, we don’t ask whether he got that hit because his batting average has risen. His average has gone up because of the hits, not the other way around. Perhaps the Tuesday homer resulted from a fat pitch, or the wind breaking just right, or because he was well rested that day. But if his batting average has doubled since last season, we might reasonably ask if he’s on steroids.

Unprecedented heat and downpours and drought and wildfires aren’t “caused by climate change” – they are climate change.

The rise in frequency and intensity of extreme events is by definition a change in the climate, just as an increase in the frequency of base hits causes a better’s average to rise.

And as in the baseball analogy, we should ask tough questions about the underlying cause. While El Niño is a contributor to 2023’s extreme heat, that warm event has only just begun. The steroids fueling extreme weather are the heat-trapping gases from burning coal, oil and gas for energy around the world.

Nothing ‘normal’ about it

A lot of commentary uses the framing of a “new normal,” as if our climate has undergone a step change to a new state. This is deeply misleading and downplays the danger. The unspoken implication of “new normal” is that the change is past and we can adjust to it as we did to the “old normal.”

Unfortunately, warming won’t stop this year or next. The changes will get worse until we stop putting more carbon dioxide and other greenhouse gases into the atmosphere than the planet can remove.

The excess carbon dioxide humans have put into the atmosphere raises the temperature – permanently, as far as human history is concerned. Carbon dioxide lingers in the atmosphere for a long time, so long that the carbon dioxide from a gallon of gasoline I burn today will still be warming the climate in thousands of years.

That warming increases evaporation from the planet’s surface, putting more moisture into the atmosphere to fall as rain and snow. Locally intense rainfall has more water vapor to work with in a warmer world, so big storms drop more rain, causing dangerous floods and mudslides like the ones we saw in Vermont, California, India and other places around the world this year.

By the same token, anybody who’s ever watered the lawn or a garden knows that in hot weather, plants and soils need more water. A hotter world also has more droughts and drying that can lead to wildfires.

So, what can we do about it?

Not every kind of bad weather is associated with burning carbon. There’s scant evidence that hailstorms or tornadoes or blizzards are on the increase, for example. But if summer 2023 shows us anything, it’s that the extremes that are caused by fossil fuels are uncomfortable at best and often dangerous.

Without drastic emission cuts, the direct cost of flooding has been projected to rise to more than US$14 trillion per year by the end of the century and sea-level rise to produce billions of refugees. By one estimate, unmitigated climate change could reduce per capita income by nearly a quarter by the end of the century globally and even more in the Global South if future adaptation is similar to what it’s been in the past. The potential social and political consequences of economic collapse on such a scale are incalculable.

Fortunately, it’s quite clear how to stop making the problem worse: Re-engineer the world economy so that it no longer runs on carbon combustion. This is a big ask, for sure, but there are affordable alternatives.

Clean energy is already cheaper than old-fashioned combustion in most of the world. Solar and wind power are now about half the price of coal- and gas-fired power. New methods for transmitting and storing power and balancing supply and demand to eliminate the need for fossil fuel electricity generation are coming online around the world.

In 2022, taxpayers spent about $7 trillion subsidizing oil and gas purchases and paying for damage they caused. All that money can go to better uses. For example, the International Energy Agency has estimated the world would need to spend about $4 trillion a year by 2030 on clean energy to cut global emissions to net zero by midcentury, considered necessary to keep global warming in check.

Just as the summer of 2023 was among the hottest in thousands of years, 2024 will likely be hotter still. El Niño is strengthening, and this weather phenomenon has a history of heating up the planet. We will probably look back at recent years as among the coolest of the 21st century.

This article was updated Sept. 15, 2023, with NOAA and NASA also confirming summer 2023 the hottest on record.

Scott Denning, Professor of Atmospheric Science, Colorado State University

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What Arizona and other drought-ridden states can learn from Israel’s pioneering water strategy

Arizona is one of the fastest-growing states in the U.S., with an economy that offers many opportunities for workers and businesses. But it faces a daunting challenge: a water crisis that could seriously constrain its economic growth and vitality.

A recent report that projected a roughly 4% shortfall in groundwater supplies in the Phoenix area over the next 100 years prompted the state to curtail new approval of groundwater-dependent residential development in some of the region’s fast-growing suburbs. Moreover, negotiations continue over dwindling supplies from the Colorado River, which historically supplied more than a third of the state’s water.

As a partial solution, the Arizona Water Infrastructure Finance Authority is exploring a proposal to import desalinated water from Mexico. Conceptualized by IDE, an Israeli company with extensive experience in the desalination sector, this mega-engineering project calls for building a plant in Mexico and piping the water about 200 miles and uphill more than 2,000 feet to Arizona.

Ultimately, the project is slated to cost more than US$5 billion and provide fresh water at nearly 10 times the cost of water Arizona currently draws from the Colorado River, not including long-term energy and maintenance costs.

Is this a wise investment? It is hard to say, since details are still forthcoming. It is also unclear how the proposal fits with Arizona’s plans for investing in its water supplies – because, unlike some states, Arizona has no state water plan.

As researchers who focus on water law, policy and management, we recommend engineered projects like this one be considered as part of a broader water management portfolio that responds holistically to imbalances in supply and demand. And such decisions should address known and potential consequences and costs down the road. Israel’s approach to desalination offers insights that Arizona would do well to consider.

Lands and waters at risk

Around the world, water engineering projects have caused large-scale ecological damage that governments now are spending heavily to repair. Draining and straightening the Florida Everglades in the 1950s and ′60s, which seriously harmed water quality and wildlife, is one well-known example.

Israel’s Hula wetlands is another. In the 1950s, Israeli water managers viewed the wetlands north of the Sea of Galilee as a malaria-infested swamp that, if drained, would eradicate mosquitoes and open up the area for farming. The project was an unmitigated failure that led to dust storms, land degradation and the loss of many unique animals and plants.

Arizona is in crisis now due to a combination of water management gaps and climatic changes. Groundwater withdrawals, which in much of rural Arizona remain unregulated, include unchecked pumping by foreign agricultural interests that ship their crops overseas. Moreover, with the Colorado River now in its 23rd year of drought, Arizona is being forced to reduce its dependence on the river and seek new water sources.

The desalination plant that Arizona is considering would be built in Puerto Peñasco, a Mexican resort town on the northern edge of the Gulf of California, also known as the Sea of Cortez. Highly saline brine left over from the desalination process would be released into the gulf.

Because this inlet has an elongated, baylike geography, salt could concentrate in its upper region, harming endangered aquatic species such as the totoaba fish and the vaquita porpoise, the world’s most endangered marine mammal.

The pipeline that would carry desalinated water to Arizona would cross through Organ Pipe Cactus National Monument, a fragile desert ecosystem and UNESCO biosphere reserve that has already been damaged by construction of the U.S.-Mexico border wall. To run the facility, IDE proposes to build a power plant in Arizona and lay transmission lines across the same fragile desert.

No single solution

Israel has adapted to water scarcity and has learned from its disastrous venture in the Hula wetlands. Today the country has a water sector master plan that is regularly updated and draws on water recycling and reuse, as well as a significant desalination program.

Israel also has implemented extensive water conservation, efficiency and recycling programs, as well as a broad economic review of desalination. Together, these sources now meet most of the nation’s water needs, and Israel has become a leader in both water technology and policy innovation.

Water rights and laws in Arizona differ from those of Israel, and Arizona isn’t as close to seawater. Nonetheless, in our view Israel’s approach is relevant as Arizona works to close its water demand-supply gap.

Steps Arizona can take now

In our view, Arizona would do well to follow Israel’s lead. A logical first step would be making conservation programs, which are required in some parts of Arizona, mandatory statewide.

Irrigated agriculture uses more than 70% of Arizona’s water supply, and most of the state’s irrigated lands use flood irrigation – pumping or bringing water into fields and letting it flow over the ground. Greater use of drip irrigation, which delivers water to plant roots through plastic pipes, and other water-saving techniques and technologies would reduce agricultural water use.

Arizona households, which sometimes use as much as 70% of residential water for lawns and landscaping, also have a conservation role to play. And the mining sector’s groundwater use presently is largely exempt from state regulations and withdrawal restrictions.

A proactive and holistic water management approach should apply to all sectors of the economy, including industry. Arizona also should continue to expand programs for agricultural, municipal and industrial wastewater reuse.

Desalination need not be off the table. But, as in Israel, we see it as part of a multifaceted and integrated series of solutions. By exploring the economic, technical and environmental feasibility of alternative solutions, Arizona could develop a water portfolio that would be far more likely than massive investments in seawater desalination to achieve the sustainable and secure water future that the state seeks.

Gabriel Eckstein, Professor of Law, Texas A&M University; Clive Lipchin, Adjunct Professor of Environmental Studies, Tel Aviv University, and Sharon B. Megdal, Professor of Environmental Science and Director, Water Resources Research Center, University of Arizona

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