Climate change - ice loss in Antarctica has serious implications

Antarctic summer sea ice is at record lows. Here’s how it will harm the planet – and us

An icebreaker approaches Denman Glacier in March, when there was 70% less Antarctic sea ice than usual. Pete Harmsen AAD

Edward Doddridge, University of Tasmania

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

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

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

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

Sea ice around Antarctica waxes and wanes with the seasons, growing in the cold months and melting in warm ones. But this rhythmic cycle is changing.

What we did and what we found

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

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

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

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

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

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

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

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

1. Ocean warming is compounding

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

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

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

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

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

Comparing an average sea ice summer (a) to an extreme low sea ice summer (b) in which there is less sea ice for wildlife and more sunlight is absorbed by the ocean. The ice shelf is more exposed to ocean waves, calving more icebergs. The ocean is also less productive and tourist vessels can make a closer approach. Doddridge, E., W., et al. (2025) PNAS Nexus., CC BY-NC-ND

2. More icebergs are forming

Sea ice protects Antarctica’s coast from ocean waves.

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

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

Antarctic ice sheets without sea ice are more exposed to waves. Pete Harmsen AAD

3. Wildlife squeezed off the ice

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

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

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

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

4. Logistical challenges at the end of the world

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

Supply ships typically unload their cargo directly onto the sea ice, but that may have to change. Jared McGhie, Australian Antarctic Division

No longer safe

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

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

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

Antarctic sea ice extent anomalies (the difference between the long-term average and the measurement) for the entire satellite record since the late 1970s. Edward Doddridge, using data from the US NSIDC Sea Ice Index, version 3., CC BY

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

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

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

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

Sentinel Owl - readership data - June 2025

                                                                                                Shutterstock

 
Sentinel Owl access data as at 2 July 2025.

Grand total pageviews all time: 444,348 (2 July 2025)

Countries that accessed in June 2025 (numbers):

• Singapore: 30.9k 
• Brazil: 7.54k
• Vietnam: 4.61k
• US: 737
• Hong Kong: 649
• Argentina: 572
• Ecuador: 337
• Australia: 267
• Indonesia: 217
• United Kingdom: 137
• Mexico: 135
• Germany: 104

A multipolar world - spheres of influence

Trump’s worldview is causing a global shift of alliances – what does this mean for nations in the middle?

Dilnoza Ubaydullaeva, Australian National University

Since US President Donald Trump took office this year, one theme has come up time and again: his rule is a threat to the US-led international order.

As the US political scientist John Mearsheimer famously argued, the liberal international order was destined to fail from the start, as it contained the seeds of its own destruction.

This perspective has gained traction in recent years. And now, Trump’s actions have caused many to question whether a new world order is emerging.

Trump has expressed a desire for a new international order defined by multiple spheres of influence — one in which powers like the US, China and Russia each exert dominance over distinct regions.

This vision aligns with the idea of a “multipolar” world, where no single state holds overarching global dominance. Instead, influence is distributed among several great powers, each maintaining its own regional sphere.

This architecture contrasts sharply with earlier periods – the bipolar world of the Cold War, dominated by the US and the Soviet Union; and the unipolar period that followed, dominated by the US.

What does this mean for the world order moving forward?

Shifting US spheres of influence

We’ve seen this shift taking place in recent months. For example, Trump has backed away from his pledge to end the war between Russia and Ukraine and now appears to be leaving it to the main protagonists, and Europe, to find a solution.

Europe, which once largely spoke in a unified voice with the US, is also showing signs of policy-making which is more independent. Rather than framing its actions as protecting “Western democratic principles”, Europe is increasingly focused on defining its own security interests.

In the Middle East, the US will likely maintain its sphere of influence. It will continue its unequivocal support for Israel under Trump.

Amid shifting global alliances, the Trump administration will continue to support Israel, led by Prime Minister Benjamin Netanyahu. noamgalai/Shutterstock

The US will also involve itself in the region’s politics when its interests are at stake, as we witnessed in its recent strikes on Iranian nuclear facilities.

This, along with increasing economic ties between the US and Gulf states, suggests US allies in the region will remain the dominant voices shaping regional dynamics, particularly now with Iran weakened.

Yet it’s clear Trump is reshaping US dynamics in the region by signaling a desire for reduced military and political involvement, and criticising the nation building efforts of previous administrations.

The Trump administration now appears to want to maintain its sphere of influence primarily through strong economic ties.

Russia and China poles emerging elsewhere

Meanwhile, other poles are emerging in the Global South. Russia and China have deepened their cooperation, positioning themselves as defenders against what they frame as Western hegemonic bullying.

Trump’s trade policies and sanctions against many nations in the Global South have fuelled narratives (spread by China and Russia) that the US does not consistently adhere to the rules it imposes on others.

Trump’s decision to slash funding to USAID has also opened the door to China, in particular, to become the main development partner for nations in Africa and other parts of the world.

And on the security front, Russia has become more involved in many African and Middle Eastern countries, which have become less trustful and reliant on Western powers.

Russian President Vladimir Putin and Chinese leader Xi Xinping see opportunities to spread their influence in the Global South. plavi011/Shutterstock

In the Indo-Pacific, much attention has been given to the rise of China and its increasingly assertive posture. Many of Washington’s traditional allies are nervous about its continued engagement in the region and ability to counter China’s rise.

Chinese leader Xi Jinping has sought to take advantage of the current environment, embarking on a Vietnam, Malaysia and Cambodia push earlier this year. But many nations continue to be wary of China’s increasing influence, in particular the Philippines, which has clashed with China over the South China Sea.

Strategic hedging

Not all countries, however, are aligning themselves neatly with one pole or another.

For small states caught between great powers, navigating this multipolar environment is both a risk and an opportunity.

Ukraine is a case in point. As a sovereign state, Ukraine should have the freedom to decide its own alignments. Yet, it finds itself ensnared in great power politics, with devastating consequences.

Other small states are playing a different game — pivoting from one power to another based on their immediate interests.

Slovakia, for instance, is both a NATO and EU member, yet its leader, Robert Fico, attended Russia’s Victory Day Parade in May and told President Vladimir Putin he wanted to maintain “normal relations” with Russia.

Then there is Central Asia, which is the centre of a renewed “great game,” with Russia, China and Europe vying for influence and economic partnerships.

Yet if any Central Asian countries were to be invaded by Putin, would other powers intervene? It’s a difficult question to answer. Major powers are reluctant to engage in direct conflict unless their core interests or borders are directly threatened.

As a result, Central Asian states are hedging their bets, seeking to maintain relations with multiple poles, despite their conflicting agendas.

A future defined by regional power blocs?

While it is still early to draw definitive conclusions, the events of the past few months underscore a growing trend. Smaller countries are expressing solidarity with one power, but pragmatic cooperation with another, when it suits their national interests.

For this reason, regional power blocs seem to be of increasing interest to countries in the Global South.

For instance, the China-led Shanghai Cooperation Organisation has become a stronger and larger grouping of nations across Eurasia in recent years.

Trump’s focus on making “America Great Again,” has taken the load off the US carrying liberal order leadership. A multipolar world may not be the end of the liberal international order, but it may be a reshaped version of liberal governance.

How “liberal” it can be will likely depend on what each regional power, or pole, will make of it.

Dilnoza Ubaydullaeva, Lecturer in Government - National Security College, Australian National University

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

Heat is being trapped on Earth in greater levels than modelled

Earth is trapping much more heat than climate models forecast – and the rate has doubled in 20 years

NASA, CC BY-NC-ND

Steven Sherwood, UNSW Sydney; Benoit Meyssignac, Université de Toulouse, and Thorsten Mauritsen, Stockholm University

How do you measure climate change? One way is by recording temperatures in different places over a long period of time. While this works well, natural variation can make it harder to see longer-term trends.

But another approach can give us a very clear sense of what’s going on: track how much heat enters Earth’s atmosphere and how much heat leaves. This is Earth’s energy budget, and it’s now well and truly out of balance.

Our recent research found this imbalance has more than doubled over the last 20 years. Other researchers have come to the same conclusions. This imbalance is now substantially more than climate models have suggested.

In the mid-2000s, the energy imbalance was about 0.6 watts per square metre (W/m2) on average. In recent years, the average was about 1.3 W/m2. This means the rate at which energy is accumulating near the planet’s surface has doubled.

These findings suggest climate change might well accelerate in the coming years. Worse still, this worrying imbalance is emerging even as funding uncertainty in the United States threatens our ability to track the flows of heat.

Energy in, energy out

Earth’s energy budget functions a bit like your bank account, where money comes in and money goes out. If you reduce your spending, you’ll build up cash in your account. Here, energy is the currency.

Life on Earth depends on a balance between heat coming in from the Sun and heat leaving. This balance is tipping to one side.

Solar energy hits Earth and warms it. The atmosphere’s heat-trapping greenhouse gases keep some of this energy.

But the burning of coal, oil and gas has now added more than two trillion tonnes of carbon dioxide and other greenhouse gases to the atmosphere. These trap more and more heat, preventing it from leaving.

Some of this extra heat is warming the land or melting sea ice, glaciers and ice sheets. But this is a tiny fraction. Fully 90% has gone into the oceans due to their huge heat capacity.

Earth naturally sheds heat in several ways. One way is by reflecting incoming heat off of clouds, snow and ice and back out to space. Infrared radiation is also emitted back to space.

From the beginning of human civilisation up until just a century ago, the average surface temperature was about 14°C. The accumulating energy imbalance has now pushed average temperatures 1.3-1.5°C higher.

Ice and reflective clouds reflect heat back to space. As the Earth heats up, most trapped heat goes into the oceans but some melts ice and heats the land and air. Pictured: Icebergs from the Jacobshavn glacier in Greenland, the largest outside Antarctica. Ashley Cooper/Getty

Tracking faster than the models

Scientists keep track of the energy budget in two ways.

First, we can directly measure the heat coming from the Sun and going back out to space, using the sensitive radiometers on monitoring satellites. This dataset and its predecessors date back to the late 1980s.

Second, we can accurately track the build-up of heat in the oceans and atmosphere by taking temperature readings. Thousands of robotic floats have monitored temperatures in the world’s oceans since the 1990s.

Both methods show the energy imbalance has grown rapidly.

The doubling of the energy imbalance has come as a shock, because the sophisticated climate models we use largely didn’t predict such a large and rapid change.

Typically, the models forecast less than half of the change we’re seeing in the real world.

Why has it changed so fast?

We don’t yet have a full explanation. But new research suggests changes in clouds is a big factor.

Clouds have a cooling effect overall. But the area covered by highly reflective white clouds has shrunk, while the area of jumbled, less reflective clouds has grown.

It isn’t clear why the clouds are changing. One possible factor could be the consequences of successful efforts to reduce sulfur in shipping fuel from 2020, as burning the dirtier fuel may have had a brightening effect on clouds. However, the accelerating energy budget imbalance began before this change.

Natural fluctuations in the climate system such as the Pacific Decadal Oscillation might also be playing a role. Finally – and most worryingly – the cloud changes might be part of a trend caused by global warming itself, that is, a positive feedback on climate change.

Dense blankets of white clouds reflect the most heat. But the area covered by these clouds is shrinking. Adhivaswut/Shutterstock

What does this mean?

These findings suggest recent extremely hot years are not one-offs but may reflect a strengthening of warming over the coming decade or longer.

This will mean a higher chance of more intense climate impacts from searing heatwaves, droughts and extreme rains on land, and more intense and long lasting marine heatwaves.

This imbalance may lead to worse longer-term consequences. New research shows the only climate models coming close to simulating real world measurements are those with a higher “climate sensitivity”. That means these models predict more severe warming beyond the next few decades in scenarios where emissions are not rapidly reduced.

We don’t know yet whether other factors are at play, however. It’s still too early to definitively say we are on a high-sensitivity trajectory.

Our eyes in the sky

We’ve known the solution for a long time: stop the routine burning of fossil fuels and phase out human activities causing emissions such as deforestation.

Keeping accurate records over long periods of time is essential if we are to spot unexpected changes.

Satellites, in particular, are our advance warning system, telling us about heat storage changes roughly a decade before other methods.

But funding cuts and drastic priority shifts in the United States may threaten essential satellite climate monitoring.

Steven Sherwood, Professor of Atmospheric Sciences, Climate Change Research Centre, UNSW Sydney; Benoit Meyssignac, Associate Research Scientist in Climate Science, Université de Toulouse, and Thorsten Mauritsen, Professor of Climate Science, Stockholm University

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

Iran - background

Regime change wouldn’t likely bring democracy to Iran. A more threatening force could fill the vacuum

Andrew Thomas, Deakin University

The timing and targets of Israel’s attacks on Iran tell us that Prime Minister Benjamin Netanyahu’s short-term goal is to damage Iran’s nuclear facilities in order to severely diminish its weapons program.

But Netanyahu has made clear another goal: he said the war with Iran “could certainly” lead to regime change in the Islamic republic.

These comments came after an Israeli plan to assassinate the supreme leader of Iran, Ayatollah Ali Khamenei, was reportedly rebuffed by United States President Donald Trump.

It’s no secret Israel has wanted to see the current government of Iran fall for some time, as have many government officials in the US.

But what would things look like if the government did topple?

How is power wielded in today’s Iran?

Founded in 1979 after the Iranian Revolution, the Islamic Republic of Iran has democratic, theocratic and authoritarian elements to its governing structure.

The founding figure of the Islamic republic, Ayatollah Ruhollah Khomeini, envisioned a state run by Islamic clerics and jurists who ensured all policies adhered to Islamic law.

As Iran was a constitutional monarchy before the revolution, theocratic elements were effectively grafted on top of the existing republican ones, such as the parliament, executive and judiciary.

Iran has a unicameral legislature (one house of parliament), called the Majles, and a president (currently Masoud Pezeshkian). There are regular elections for both.

But while there are democratic elements within this system, in practice it is a “closed loop” that keeps the clerical elite in power and prevents challenges to the supreme leader. There is a clear hierarchy, with the supreme leader at the top.

Khamenei has been in power for more than 35 years, taking office following Khomeini’s death in 1989. The former president of Iran, he was chosen to become supreme leader by the Assembly of Experts, an 88-member body of Islamic jurists.

While members of the assembly are elected by the public, candidates must be vetted by the powerful 12-member Guardian Council (also known as the Constitutional Council). Half of this body is selected by the supreme leader, while the other half is approved by the Majles.

The council also has the power to vet all candidates for president and the parliament.

In last year’s elections, the Guardian Council disqualified many candidates from running for president, as well as the Majles and Assembly of Experts, including the moderate former president Hassan Rouhani.

As such, the supreme leader is increasingly facing a crisis of legitimacy with the public. Elections routinely have low turnout. Even with a reformist presidential candidate in last year’s field – the eventual winner, Masoud Pezeshkian – turnout was below 40% in the first round.

Freedom House gives Iran a global freedom score of just 11 out of 100.

The supreme leader also directly appoints the leaders in key governance structures, such as the judiciary, the armed forces and Islamic Revolutionary Guard Corps (IRGC).

The all-powerful IRGC

So, Iran is far from a democracy. But the idea that regime change would lead to a full democracy that is aligned with Israel and the US is very unlikely.

Iranian politics is extremely factional. Ideological factions, such as the reformists, moderates and conservatives, often disagree vehemently on key policy areas. They also jockey for influence with the supreme leader and the rest of the clerical elite. None of these factions is particularly friendly with the US, and especially not Israel.

There are also institutional factions. The most powerful group in the country is the clerical elite, led by the supreme leader. The next most powerful faction would be the IRGC.

Originally formed as a kind of personal guard for the supreme leader, the IRGC’s fighting strength now rivals that of the regular army.

The IRGC is extremely hardline politically. At times, the IRGC’s influence domestically has outstripped that of presidents, exerting significant pressure on their policies. The guard only vocally supports presidents in lockstep with Islamic revolutionary doctrine.

In addition to its control over military hardware and its political influence, the guard is also entwined with the Iranian economy.

The IRGC is heavily enriched by the status quo, with some describing it as a “kleptocratic” institution. IRGC officials are often awarded state contracts, and are allegedly involved in managing the “black economy” used to evade sanctions.

Given all of this, the IRGC would be the most likely political institution to take control of Iran if the clerical elite were removed from power.

In peacetime, the general consensus is the IRGC would not have the resources to orchestrate a coup if the supreme leader died. But in a time of war against a clear enemy, things could be different.

Possible scenarios post-Khamenei

So, what might happen if Israel were to assassinate the supreme leader?

One scenario would be a martial law state led by the IRGC, formed at least in the short term for the purposes of protecting the revolution.

In the unlikely event the entire clerical leadership is decimated, the IRGC could attempt to reform the Assembly of Experts and choose a new supreme leader itself, perhaps even supporting Khamenei’s son’s candidacy.

Needless to say, this outcome would not lead to a state more friendly to Israel or the US. In fact, it could potentially empower a faction that has long argued for a more militant response to both.

Another scenario is a popular uprising. Netanyahu certainly seems to think this is possible, saying in an interview in recent days:

The decision to act, to rise up this time, is the decision of the Iranian people.

Indeed, many Iranians have long been disillusioned with their government – even with more moderate and reformist elements within it. Mass protests have broken out several times in recent decades – most recently in 2022 – despite heavy retaliation from law enforcement.

We’ve seen enough revolutions to know this is possible – after all, modern Iran was formed out of one. But once again, new political leadership being more friendly to Israel and the West is not a foregone conclusion.

It is possible for Iranians to hold contempt in their hearts for both their leaders and the foreign powers that would upend their lives.

Andrew Thomas, Lecturer in Middle East Studies, Deakin University

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

Technology - Uranium for civilian and military purposes - what's the difference ?

What is uranium enrichment and how is it used for nuclear bombs? A scientist explains

Uranium ore. RHJPhtotos/Shutterstock

Kaitlin Cook, Australian National University

Late last week, Israel targeted three of Iran’s key nuclear facilities – Natanz, Isfahan and Fordow, killing several Iranian nuclear scientists. The facilities are heavily fortified and largely underground, and there are conflicting reports of how much damage has been done.

Natanz and Fordow are Iran’s uranium enrichment sites, and Isfahan provides the raw materials, so any damage to these sites would limit Iran’s ability to produce nuclear weapons.

But what exactly is uranium enrichment and why does it raise concerns?

To understand what it means to “enrich” uranium, you need to know a little about uranium isotopes and about splitting the atom in a nuclear fission reaction.

What is an isotope?

All matter is made of atoms, which in turn are made up of protons, neutrons and electrons. The number of protons is what gives atoms their chemical properties, setting apart the various chemical elements.

Atoms have equal numbers of protons and electrons. Uranium has 92 protons, for example, while carbon has six. However, the same element can have different numbers of neutrons, forming versions of the element called isotopes.

This hardly matters for chemical reactions, but their nuclear reactions can be wildly different.

The difference between uranium-238 and uranium-235

When we dig uranium out of the ground, 99.27% of it is uranium-238, which has 92 protons and 146 neutrons. Only 0.72% of it is uranium-235 with 92 protons and 143 neutrons (the remaining 0.01% are other isotopes).

For nuclear power reactors or weapons, we need to change the isotope proportions. That’s because of the two main uranium isotopes, only uranium-235 can support a fission chain reaction: one neutron causes an atom to fission, which produces energy and some more neutrons, causing more fission, and so on.

This chain reaction releases a tremendous amount of energy. In a nuclear weapon, the goal is to have this chain reaction occur in a fraction of a second, producing a nuclear explosion.

In a civilian nuclear power plant, the chain reaction is controlled. Nuclear power plants currently produce 9% of the world’s power. Another vital civilian use of nuclear reactions is for producing isotopes used in nuclear medicine for the diagnosis and treatment of various diseases.

What is uranium enrichment, then?

To “enrich” uranium means taking the naturally found element and increasing the proportion of uranium-235 while removing uranium-238.

There are a few ways to do this (including new inventions from Australia), but commercially, enrichment is currently done with a centrifuge. This is also the case in Iran’s facilities.

Centrifuges exploit the fact that uranium-238 is about 1% heavier than uranium-235. They take uranium (in gas form) and use rotors to spin it at 50,000 to 70,000 rotations per minute, with the outer walls of the centrifuges moving at 400 to 500 metres per second.

This works much like a salad spinner that throws water to the sides while the salad leaves stay in the centre. The heavier uranium-238 moves to the edges of the centrifuge, leaving the uranium-235 in the middle.

This is only so effective, so the spinning process is done over and over again, building up the percentage of the uranium-235.

Most civilian nuclear reactors use “low enriched uranium” that’s been enriched to between 3% and 5%. This means that 3–5% of the total uranium in the sample is now uranium-235. That’s enough to sustain a chain reaction and make electricity.

What level of enrichment do nuclear weapons need?

To get an explosive chain reaction, uranium-235 needs to be concentrated significantly more than the levels we use in nuclear reactors for making power or medicines.

Technically, a nuclear weapon can be made with as little as 20% uranium-235 (known as “highly enriched uranium”), but the more the uranium is enriched, the smaller and lighter the weapon can be. Countries with nuclear weapons tend to use about 90% enriched, “weapons-grade” uranium.

According to the International Atomic Energy Agency (IAEA), Iran has enriched large quantities of uranium to 60%. It’s actually easier to go from an enrichment of 60% to 90% than it is to get to that initial 60%. That’s because there’s less and less uranium-238 to get rid of.

This is why Iran is considered to be at extreme risk of producing nuclear weapons, and why centrifuge technology for enrichment is kept secret.

Ultimately, the exact same centrifuge technology that produces fuel for civilian reactors can be used to produce nuclear weapons.

Inspectors from the IAEA monitor nuclear facilities worldwide to ensure countries are abiding by the rules set out in the global nuclear non-proliferation treaty. While Iran maintains it’s only enriching uranium for “peaceful purposes”, late last week the IAEA board ruled Iran was in breach of its obligations under the treaty.

Kaitlin Cook, DECRA Fellow, Department of Nuclear Physics and Accelerator Applications, Australian National University

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

Sydney Film Festival 2025 - Film Review - It was just an accident

It was an accident film still

Iranian director and screenwriter, Jafar Panahi has brought an Iranian style road movie to the screen broaching a subject with an intense moral dilemma but one which many people in many conflict zones must confront. What does the a victim of torture do, if the opportunity to take revenge against their tormentor inadvertantly becomes possible ?

This moral dilemma is presented clearly in this film with the story commencing late one night when a worker recognises the owner of a broken down car as being the intelligence agent who had tortured him many years previously when he was arrested for a protest. The worker takes it upon himself to track down the agent and kidnap him with the intention of exacting revenge. Having completed the abduction, the worker finds self doubt creeps into his actions and he then seeks out other victims of the agent (including a soon-to-be-married bride) to verify he has abducted the correct man and then to resolve what to do. The reactions of the different victims who are now confronted with this situation forms the bulk of the film.

Panahi adds some comedic relief to the film in parts which lessens the intensity of the storyline, nevertheless the choice between forgiveness and retribution remains the central focus. As a film maker Panahi has also experienced the power of the Iranian state having his films banned and being imprisoned himself.

'It was just an accident' was awarded the Sydney Prize by the festival jury at the 2025 Sydney Film Festival. The film also won the Palme d'Or at the Cannes Film Festival in 2025.

Evaluation:

Production values: 9/10

Narrative and direction: 10/10

Cast: 8/10

Sydney Film Festival 2025 - Film Review - Orwell 2+2=5

Orwell 2+2=5 still slide

George Orwell's writings, particularly his diary and his acclaimed books, Animal Farm and 1984 are the focus of this film which seeks to apply the Orwellian observations to current international events. Documentary director and producer, Raoul Peck traverses Orwell's life from childhood to his experiences in Burma (as a colonial policeman), his participation in the Spanish Civil War and the progress of his writing. Current illustrations and examples which support Orwell's warnings (Trump, Musk, Putin and the war on Ukraine etc) are interspersed with quotations. 

The chief weakenss of this film is the seemingly random nature of drawing quotes from different Orwell sources then connecting with a variety of film clips from multiple sources including feature films with no direct Orwell connection. Constantly jumping from his diary to book quotes to film scripts often blurs the examples of the messages being conveyed.  The film has very high production values and has been carefully researched but it lacks a discipline in structural continuity to assist with easy viewing and comprehension.

Nonetheless the central message conveyed is that Orwell's warnings about totalitarianism and authoritarianism was very prescient and remains as relevant today as when he was first published.

Evaluation:

Production values: 10/10

Narrative and direction: 5/10

Cast: 7/10

Sydney Film Festival 2025 - Film Review - The Blue Trail

The Blue Trail - Rodrigo Santoro and Denise Weinberg

 

Screenwriter and Director, Gabriel Mascaro has provided a dystopian alternate fate for older citizens in this Amazon River 'road' movie set only a few years into the future. In this world, older citizens are relocated to a housing colony by the Government upon reaching old age (around 75). Failure to comply with the edict leads to be rounded up by civil authorities and detained before being given care backpacks and loaded onto buses. Wearing of adult diapers is mandatory before departing on the buses. 

Against this reality,  77 year old Tereza (Denise Weinberg) decides she will not be left to this fate and does a runner. She cannot buy any transport tickets for air or boat without the approval of an authorised family member who is designated her guardian (in this case her daughter) so she resorts to finding her own transport. She begins her journey through the Amazon's rivers and tributaries meeting a colourful cast of characters from a skipper (Rodrigo Santoro) of an Amazon smuggling boat (who introduces her to a psychedelic blue liguid from a snail and shows her how to run the boat) to a digital bible-selling woman running her own floating pulpit along the river.   

Mascaro's story is innovative with the stunning imagery of the Amazon as the backdrop. The anti-authoritarion theme is balanced with various playful surprises as Tereza makes good her escape.

Evaluation:

Production values: 10/10

Narrative and direction: 7/10

Cast: 8/10

Sydney Film Festival 2025 - Film Review - Vie Privee

Still from Vie Privee - Jodie Foster 

Described as a "gently comic murder mystery", Vie Privee is more absurdist than funny and somewhat muddled in the construction of the parts that form the storyline. With the well established and experienced principal actors (being Jodie Foster, Daniel Auteuil, Mathieu Almaric and Virginie Elfira) and a half decent story idea, it's surprising the film comes across as patently serious and misses most of the comedic elements, if there are any.  

In terms of the story, psychiatrist Lilian Steiner (Jodie Foster) is annoyed that her patient of the past nine years, Paula (Virginie Efira) has failed to appear for her sessions. She is horrified to learn her patient is dead and becomes convinced that Paula's husband (Mathieu Almaric) has murdered Paula. She seeks guidance from a hypnotist and engages her ex-husband (Daniel Auteil) to help investigate her theory.  

Jodie Foster is a very experienced French speaker although she has appeared in a very small number of French language films. Her intensity of presence however is not one that lends itself easily to comedy. Likewise the script does not provide much in the way of comedic relief and only Daniel Auteuil's character has softer dialogue. In general the characters appear more neurotic than amusing throughout the film.

Recommended viewing when perservance is possible.

Evaluation:

Production values: 9/10

Narrative and direction: 6/10

Cast: 8/10

Sydney Film Festival 2025 - Film Review - Mr Nobody Against Putin

Mr Nobody against Putin -  Pavel Talakin

Russian school teacher, Pavel "Pasha" Talakin enjoyed his job teaching at a primary school in the small Russian town of Karabash, famous only for its polluting copper smelter, the largest in Russia. Everything changed when Russia invaded Ukraine and the war began. The Russian state started to increasingly intervene into the curriculum and classrooms promoting nationalism and the war to the dismay of Talakin. Determined to ensure this situation was both documented and opposed, Talakin filmed the events as they occured eventually leading to police surveillance of his activities until he was forced to flee his country. 

His film documents the progressive requirements placed on teachers to recite propaganda against the West and Ukraine, the institution of military training for children and the shock appearance of uniformed Wagner mercenaries to provide weapons instruction to the school children. As the timeline of the film progresses, the sadness of former school graduates being killed in action in the war emerges. This is a heartfelt, sentimental and personal voyage documented by Talakin and serves again to reinforce the tragedy that authoritarian regimes can inflict on their communities.

Often filmed using a handheld camera, the documentary had post production assistance including historical footage added once Talakin reached the West.

Evaluation:

Production values: 9/10

Narrative and direction: 8/10

Cast: 9/10

Sydney Film Festival 2025 - Film Review - The Golden Spurtle

Still from The Golden Spurtle 

An Australian documentary team led by director and screenwriter, Constantine Conti travelled to the Scottish highlands community of Carrbridge to film the annual World Porridge Making Championship and what a charming film has emerged. This is a well-paced, nicely constructed documentary with a clear narrative and progressive action as contestants prepare and then engage in the contest to win the trophy of the Golden Spurtle. Context and background information are neatly woven into the interviews with a collection of colourful eccentric personalities from both the local organising committee and the participants. This documentary is uplifting, funny and a joy to watch.

Evaluation:

Production values: 10/10

Narrative and direction: 10/10

Cast: 10/10

Sydney Film Festival 2025

 
The Sydney Film Festival is currently running in Sydney from the 4th to the 15th June 2025. Now in its 72nd year, the festival has continued to develop and consolidate as a multi-venue event and at various times has between 13 and 18 venues screening films simultaneously. Traversing across various genres, the films are mainly recent and new releases with additional retrospective programs focussed on one particular film director (this year its American director, Elaine May) and specialist restoration films (this year, "Classics Restored").

The festival website: Sydney Film Festival

Climate change - some progress has been made but......

Earth is heading for 2.7°C warming this century. We may avoid the worst climate scenarios – but the outlook is still dire

Aliraza Khatri's Photography/Getty

Sven Teske, University of Technology Sydney

Is climate action a lost cause? The United States is withdrawing from the Paris Agreement for the second time, while heat records over land and sea have toppled and extreme weather events have multiplied.

In late 2015, nations agreed through the Paris Agreement to try to hold warming well under 2°C and ideally to 1.5°C. Almost ten years later, cutting emissions to the point of meeting the 1.5°C goal looks very difficult.

But humanity has shifted track enough to avert the worst climate future. Renewables, energy efficiency and other measures have shifted the dial. The worst case scenario of expanded coal use, soaring emissions and a much hotter world is vanishingly unlikely.

Instead, Earth is tracking towards around 2.7°C average warming by 2100. That level of warming would represent “unprecedented peril” for life on this planet. But it shows progress is being made.

How did we get here?

Global greenhouse gas emissions have risen since industrialisation began around 1850. Carbon dioxide (CO₂) is far and away the most common greenhouse gas we emit, while methane and nitrous oxide also play a role. These gases trap the sun’s heat in the atmosphere, preventing it from radiating back out to space.

In 2023, 41% of the world’s energy-related CO₂ emissions came from coal, mainly for electricity generation. Some 32% came from burning oil in road vehicles, and 21% from natural gas used for heating buildings and industrial processes.

The world is certainly feeling the effects. The World Meteorological Organization confirmed 2024 was the hottest year on record, temporarily hitting 1.5°C over the pre-industrial era. In turn, the world suffered lethal heatwaves, devastating floods and intense cyclones.

Extreme weather hit hard in 2024. Pictured: Flooded houses after Cyclone Debby hit Florida. Bilanol/Shutterstock

How are we tracking?

In 2014, the world’s peak body for assessing climate science – the Intergovernmental Panel on Climate Change – began using four scenarios called Representative Concentration Pathways (RCPs). These four big picture climate scenarios are based on what actions humanity does or doesn’t take. They comprise:

• rapid climate action, low emissions (RCP 2.6)
• two scenarios of some action and medium emissions (RCP 4.5 and 6.0)
• no action, high emissions (RCP 8.5).

The numbers refer to how many more watts of heat strike each square metre of the planet.

Of these four, only the RCP 2.6 scenario is compatible with the Paris Agreement’s goal of holding climate change well under 2˚C.

But Earth is tracking towards somewhere between RCP 2.6 and 4.5, which would translate to about 2.7°C of warming by 2100.

IPCC experts also developed five pathways of possible social, economic and political futures to complement the four scenarios.

Of these pathways, we are tracking closest to a middle of the road scenario where development remains uneven, the intensity of resource and energy use declines, and population growth levels off.

While effective, these scenarios are now more than a decade old and need to be updated. In response, my colleagues and I produced the One Earth Climate Model to outline rapid pathways to decarbonise. We set an ambitious carbon budget of 450 gigatonnes of CO₂ before reaching net zero – a pathway even more ambitious than the RCP 2.6.

The US, European Union and China together represent about 28% of the global population, but are responsible for 56% of historic emissions (926 gigatonnes) . The pathways compatible with 1.5°C give them a remaining carbon budget of 243 Gt CO₂. China would require the largest carbon budget to reach decarbonisation.

For this to happen, by 2050, the world would have to be 100% powered by clean sources and phase out fossil fuel use. This would limit global warming to around 1.5°C, with a certainty of just over 50%. We would also have to end deforestation within the same timeframe.

Emissions peak – are we there yet?

Emissions of carbon dioxide and other greenhouse gases have still not plateaued, despite sharply increasing renewable electricity generation, battery storage and lower-cost electric vehicles.

But there has been real progress. The EU says its emissions fell by 8.3% in 2023 compared to 2022. Europe’s net emissions are now 37% below 1990 levels, while the region’s GDP grew 68% over the same period. The EU remains on track to reach its goal of reducing emissions by at least 55% by 2030.

Australia’s emissions fell by 0.6% last year. The country is now 28.2% below June 2005 levels, which is the baseline set for its Paris Agreement goal of a 43% reduction by 2030.

In the US, emissions are still below pre-pandemic levels and remain about 20% below 2005 levels. Since peaking in 2004, US emissions have trended downward.

The world’s largest emitter, China, is finally cutting its emissions. Huge growth in renewables has now led to the first emissions drop on record, despite surging demand for power. This is good news. For years, China’s domestic emissions remained high despite its leading role in solar, wind, EVs and battery technology.

China produces almost one-third (31%) of the world’s energy-related carbon emissions – not least because it is the workshop of the world. Every cut China makes will have a major global effect.

According to the IPCC, limiting warming to around 1.5°C requires global emissions to peak before 2025 at the latest. It now looks like the peak may occur this year.

Despite daily negative news, the decarbonisation train has left the station. In 2024, renewables accounted for more than 90% of growth in electricity production globally. Electric vehicles became cost competitive, while heat pumps are developing fast and solar is on a winning streak.

So, is it too late to save the climate? No. The technologies we need are finally cheap enough. The sooner we stop climate change from worsening, the more disasters, famine and death we avert. We might not manage 1.5°C or even 2°C, but every tenth of a degree counts. The faster we make the shift, the better our climate future.

Sven Teske, Research Director, Institute for Sustainable Futures, University of Technology Sydney

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

Russia - the need for better expertise

Australia’s knowledge of Russia is dwindling. We need to start training our future experts now

Shutterstock

Jon Richardson, Australian National University

Russia’s possible interest in basing long-range aircraft at an Indonesian airbase not far from Australian shores shook up a relatively staid election campaign last month.

The news, which Jakarta immediately dismissed, caught many by surprise in Australia. It shouldn’t have. While Indonesia’s non-aligned stance makes granting such a request highly unlikely, Russia’s defence and political ties with Southeast Asia have actually been deepening over the last decade, at least.

All of this has gone largely unnoticed in Australia. And this highlights a significant problem: Australia has something of a knowledge deficit when it comes to Russia. This is in part due to the fact our expertise on the country has been hollowed out since the Cold War ended.

Russia’s power plays are expanding globally

The Soviet Union loomed large in Australia’s consciousness during the Cold War, if not high on its list of priorities.

Today, Russia remains a major, albeit slightly diminished, power. It is a nuclear weapons state (it has more than 5,500 nuclear warheads, the most of any nation) and a permanent member of the United Nations Security Council. It is also active in other forums of importance to Australia, such as the G20 and APEC, as well as in issues like arms control and climate change.

Most worryingly, under President Vladimir Putin, Russia will no doubt continue to be a disruptor on the international stage.

Russia’s political and security elite perceive the country to be a great power with interests and a right to influence in every part of the world. Just to drive that message home, a giant sign quoting Putin last year read: “Russia’s borders do not end anywhere”.

Even before its full-scale invasion of Ukraine in 2022, Moscow perpetuated an ideology that it is at war with the West. This idea is a key source of legitimacy for Putin’s regime. Russia’s hostile actions against Western democracies continue to proliferate. These include disinformation campaigns, cyber attacks, election interference and, in some regions, sabotage and assassinations.

This isn’t focused entirely on Europe and the US, either. Russia has an active – and expanding – military presence in the Asia-Pacific. Russia’s Pacific Fleet, based in Vladivostok, now has more than 20 nuclear and conventional submarines and frequently engages in training exercises with the Chinese navy.

More “normal” relations with Russia will not return soon. A lasting peace in Ukraine seems unlikely if any interim ceasefire deal leaves large swathes of the country under a brutal Russian occupation regime. Putin is unlikely to let go of his ambitions to subjugate Ukraine and limit its independence.

While sanctions have made it harder for Moscow to conduct the war, the Russian economy also does not appear in danger of imminent collapse.

Meanwhile, Southeast Asia has proven susceptible to Russia’s anti-Western narratives, particularly when it comes to the claim that the Russian invasion was provoked by Western policies and threats. Most regional governments have been loathe to criticise the invasion and the leaders of Indonesia and Malaysia have made state visits to Moscow despite it.

Russia has had similar success in pushing disinformation through orchestrated social media campaigns across the Global South, including in parts of Africa where Australian companies have made significant investments in the mining sector.

Reviving Russia literacy

All these trends point to the need to enhance Australia’s modest level of Russia literacy, both in language skills and broader country expertise.

This was the key message of a recent conference on “Russian activities and Australian interests in the Indo-Pacific”, hosted by the ANU’s Centre for European Studies. It was attended by a wide range of government officials, academics, analysts and foreign diplomats.

Australia once had strong Russian-language departments at several universities. It also boasted numerous Russian and Soviet scholars of global repute, such as Harry Rigby, Sheila Fitzpatrick, Graeme Gill, Stephen Wheatcroft, Geoffrey Jukes and Stephen Fortescue.

Today, the number of university departments teaching Russian language, history or politics has dwindled, with only the University of Melbourne offering a major in Russian language and literature. That university has also added a much-welcomed fellowship in Ukrainian studies.

And Australia has few lecturers or researchers in international relations, history or social sciences with Russia expertise, including language skills.

We can – and should – return our university Russian offerings to the levels we had 30 years ago. This can be done without cutting back on the existing expansive focus on other countries and regions. There is also scope for greater focus on Russia and the former Soviet countries in government.

It will hard for Russia to shake off the pattern of failed government reform efforts defaulting to strong, centralised rule with imperial ambitions and an anti-Western posture.

But moves towards reform could eventually bear fruit (again) when Putin leaves the stage. If this were to happen, Russia would remain a major power with a rich cultural legacy and many common interests with Australia in areas such as natural resources. There is also a significant Russian diaspora in Australia.

For Australia, it is a mistake to think of Russia as somewhere far away. Both in simple geography – all state capitals except Perth are closer to Vladivostok than to New Delhi – and in terms of the interplay of global interests.

Or, as British commentator Keir Giles puts it: “You may not be interested in Russia, but Russia is interested in you.”

Jon Richardson, Visiting Fellow, Centre for European Studies, Australian National University

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