While 2023 made headlines for smashing global temperature records, last year also saw some truly remarkable events in the Antarctic.
After crashing to a record-low summer extent in February, sea ice around the southern continent regrew extremely slowly.
By July, when sea ice should be approaching its maximum winter coverage, there was an area of ice “missing” that was bigger than Algeria – the world’s 10th largest country.
When the annual maximum extent arrived – early – it was the smallest on record by a “wide margin”.
This made 2023 the second record-breaking year in a row, continuing the recent erratic swings in sea ice cover that had otherwise been preceded by several decades of steady, gradual increase.
In our new paper, published in the Royal Meteorological Society’s journal Weather, my coauthor and I explore what happened to sea ice in 2023, what caused the dramatic events and what the implications are for the future.
The importance of Antarctic sea ice
Antarctic sea ice is a critical puzzle piece in the regional and global climate picture.
The frozen continent as a whole acts as the Earth’s principal refrigerator, reflecting the sun’s energy from its bright, white mirror-like surface, helping keep temperatures cool.
Sea ice formation around its coastline acts as an engine for ocean currents and influences weather patterns that can have far-reaching effects.
Floating ice also acts as a buffer that can protect the exposed edges of the ice sheet from the destructive action of waves, meaning that it can curb Antarctica’s contribution to sea level rise. By influencing the availability of water from the open ocean, it also affects how much snow can fall to replenish the ice sheet’s losses.
And sea ice is vitally important for marine life, as demonstrated by the “catastrophic breeding failure” of Emperor penguin chicks following the (then) record-low sea ice coverage in 2022.
Long-term trends
Thanks to satellite data, scientists have a detailed picture of how Arctic and Antarctic sea ice have behaved since the late 1970s. And for Antarctica, this picture has been something of a puzzle.
Between 1979 and 2015, average Antarctic sea ice extent – the area of ocean with at least 15% sea ice cover – increased slightly, but fairly steadily. This is in stark contrast to the Arctic, where sea ice at the minimum summer extent plummeted by nearly 12% per decade.
Then, after a record high year in 2014, Antarctic sea ice extent dropped to a record low in 2017. Several years of low sea ice came after that, with the summer minimum record smashed in 2022, when it fell below 2m square kilometres for the first time.
How extreme was 2023?
Antarctic sea ice waxes and wanes throughout the year, reaching a minimum in February at the end of the southern-hemisphere summer and a maximum in September after a long, cold winter.
This seasonal expansion causes the area covered by sea ice to grow six-fold within a single year – as the chart below shows. It depicts Antarctic sea ice extent for each day of 2023 (blue line), along with how it compares to the historical range (blue shading) and the record low for the time of year (dotted line).

Antarctic daily sea ice extent from the US National Snow and Ice Data Center. The bold lines show daily 2023 values, the shaded area indicates the two standard deviation range in historical values between 1979 and 2010. The dotted line shows the record low. Chart by Carbon Brief.
As the chart shows, 2023 was an exceptional year in the satellite record, remaining well below average for the entire year.
The year started with a record-breaking minimum extent of 1.79m km2 in February 2023, which was 10% lower than the already record-breaking 2022.
Although the autumn freeze-up started off as usual, from April the seasonal expansion of sea ice was very slow. By July, the total sea ice extent was 13.5m km2 – 15% lower than average for the month.
The area of “missing” sea ice for the month of July, relative to the 1981–2010 average, was nearly two-and-a-half million square kilometres – an area larger than Algeria.
The period of extreme departure from average persisted from mid-May until mid-November, with conditions recovering a little, meaning that by the end of the year, they were no longer record-breaking.
Overall, the largest deviations from average conditions in 2023 were recorded in winter (June to August). To see this in context, the chart below shows winter sea ice extent from 1979 to 2023 and highlights how dramatically low winter sea ice was last year.

In addition, the table below shows the average winter sea ice extent and the anomaly – that is, the departure from the 1981-2010 average. It is clear that at 2.34m km2, the anomaly in the winter of 2023 was larger than in any other year. The next largest was 0.93m km2 in 2022.
| Year | JJA mean extent (million km2) | JJA anomaly (million km2) |
|---|---|---|
| 2023 | 13.34 | -2.34 |
| 2022 | 14.75 | -0.93 |
| 2002 | 14.95 | -0.73 |
| 2017 | 14.97 | -0.71 |
| 1986 | 15.00 | -0.69 |
Table showing the top five years with largest negative winter sea ice extent anomalies with respect to 1981–2010, ranked from lowest sea ice extent to highest. All extents and anomalies are shown in millions of square kilometres. Source: Gilbert & Homes (2024)
Drivers of low sea ice conditions
There is no single cause of record-low sea ice conditions, but it is likely that a combination of oceanic and atmospheric factors conspired to produce 2023’s record sea ice conditions.
Recent studies have pointed to the important role of ocean processes and heat stored below the surface, which have kept sea ice extent low since 2016. Warm sea surface temperatures in the Southern Ocean during the first half of 2023 probably also partly explain both the record minimum extent in February and the slow freeze-up afterwards.
But Antarctic sea ice is also closely controlled by atmospheric circulation. One such circulation pattern is the Amundsen Sea Low, which is a low-pressure weather system that consistently forms off the coast of West Antarctica. Exactly where it is and how low the atmospheric pressure gets can control winds and temperature in the region, impacting the movement, breakup, formation and destruction of sea ice.
The pattern in sea ice in 2023 was closely tied to the behaviour of the Amundsen Sea Low, which was unusually deep and far to the east in winter when the sea ice anomalies were at their peak.
This situation tends to blow warm air towards the coast and push sea ice back, limiting sea ice growth during the freeze-up season.
Other large-scale weather patterns – such as the Southern Annular Mode and El Niño-Southern Oscillation have historically contributed to the ups-and-downs observed in Antarctic sea ice, but they do not seem to have had a major influence in 2023.
These weather patterns can interact to either amplify or suppress sea ice changes by affecting the ways that sea ice moves, melts and freezes.
Links with climate change
Deciphering the role of climate change in Antarctic sea ice trends is much more complicated than in the Arctic because conditions are impacted by so many competing factors.
However, the sheer magnitude of 2023’s sea ice lows suggests that something unusual is happening.
Sea ice conditions during 2023 were far outside the bounds of normality, but it is difficult to say exactly how far. That is because the satellite record is relatively short (45 years) and the system is highly variable. In addition, climate change is already impacting the Southern Ocean in complex ways, making an estimation of what is “normal” impossible.
Climate models project a decline in Antarctic sea ice in response to greenhouse gas emissions and rising temperatures. However, until 2015 this prediction was largely at odds with what scientists were seeing – in part due to the complexity and uncertainty of the processes involved, and the impractically high detail required to accurately represent sea ice in models.
However, despite their limitations, it seems inescapable that models will ultimately be correct about Antarctic sea ice decline. Human emissions are raising temperatures in the Southern Ocean, and studies show a link between ocean warming and low Antarctic sea-ice extents.
Several papers – including one discussed in a previous Carbon Brief guest post – have argued that recent record-low sea ice years may be a taste of what is to come.
With 2024 likely to be another year of high global average temperatures and weather extremes, it may emerge as another year of low Antarctic sea ice. Although current sea ice extent is no longer the lowest on record, conditions are still well below the 1981-2010 average, and this situation may well persist into the 2024 melt season.
So, while it is too early to say conclusively that the recent sea-ice lows are the beginning of a regime shift in Antarctic sea ice, it seems inevitable that it will eventually decline in response to human-caused climate change.
For now, all scientists can say for certain is that the events of 2023 were entirely remarkable and unlike anything seen in the satellite record.
The post Guest post: Why 2023 was an exceptional year for Antarctic sea ice appeared first on Carbon Brief.
Guest post: Why 2023 was an exceptional year for Antarctic sea ice
Climate Change
Will new UK PM’s green measures at home cause climate finance pain overseas?
Britain’s new prime minister announced in his first week that he will cut the cost of public transport and electricity, making lower-emission technologies like bus travel, electric vehicles and heat pumps more affordable for voters. But some of the funding for those policies will come from the budget for international climate finance, the government has said, raising concerns about fairness.
Former Manchester Mayor Andy Burnham took over from Keir Starmer as Labour Party leader and prime minister on Monday, appointing climate advocates Ed Miliband as foreign and development minister and Miatta Fahnbulleh as climate and energy minister.
On Tuesday, Burnham said his government would cut the value added tax (VAT) households and some small businesses pay on their electricity bills from 5% to zero from October 1, saving households £45 ($60) a year.
On Wednesday, he said the maximum fare bus companies in England can charge for a single journey will be reduced from £3 ($4) to £2 ($2.67) from January 1, 2027. The government said the subsidies to achieve this would be mostly funded by switching money set aside for overseas climate finance projects from grants to loans. It did not give further information in its announcement, while the UK’s transport minister told Sky News the plan is still being worked out.
The floated changes to the climate finance budget were immediately criticised by groups working on climate justice for developing countries, including Bond, the UK network for NGOs, which described the decision as “disappointing”.
“Robbing Peter to pay Paul is not the answer and pitches marginalised communities in the UK against marginalised communities in lower-income and climate-vulnerable countries,” BOND CEO Romilly Greenhill said in a statement. “Climate finance must not worsen the debt burden of countries that are already suffering the worst – and most costly – impacts of a climate crisis they did not cause.”
Hunt for money
Burnham promoted both policies as measures to combat the rising cost of living and “give people breathing space”, with climate campaigners and industry groups noting they are also likely to reduce the UK’s climate-heating emissions by encouraging bus travel and the use of electric vehicles and heating.
But thorny questions remain over how the policies will be paid for. The government said Tuesday’s VAT cut for electricity would be funded by scrapping the previous government’s digital ID programme, but Darren Jones, a former minister involved with that policy, said it had been “unfunded” – a statement that dominated media coverage.
A day later, the government said the new bus fare cap would cost £454 million ($606m). Transport minister Heidi Alexander told Sky News that £54 million would be taken from an under-spend in the budget of the Department for Energy Security and Net Zero (DESNZ) and £400 million would come from changing unspecified international climate finance from grants to loans. The details “still need to be worked through”, she said, adding that the government “had wanted to make an announcement today”.
Mohamed Adow, director of Nairobi-based think-tank Power Shift Africa, said “climate finance was never meant to be a pot of money that governments raid when they need to pay for domestic spending”.
DESNZ had not responded to a request for comment at the time of publication. “We’re not wanting to fleece anyone here, and we actually want to maximise the development potential of this money that is available,” minister Alexander said in her TV interview.

Aside from the controversy over their funding, the policies themselves were widely welcomed by climate campaigners. Jess Ralston, energy lead at the Energy and Climate Intelligence Unit (ECIU), said the tax cut on electricity bills “could help households to switch to electric heat pumps, protecting UK homes from becoming ever more exposed to the whims of Putin and Trump when turning on their gas boiler”.
The last few months have seen global momentum build behind electrification, spurred by the US-Iran war disrupting oil and gas supplies and driving up prices. The Turkish and Australian COP31 presidencies have announced a global target to boost electrification, backed by the European Union, Canada, Philippines, UK and others.
Campaigners call for lower power prices
While reaction to the VAT cut was supportive, some questioned whether £45 a year of savings per household is enough and called for more measures to cut electricity bills.
Friends of the Earth’s energy lead Imogen Dow said those on the lowest incomes should be given cheaper electricity through a “social tariff” and the Institute for Public Policy Research (IPPR) think-tank – which is close to the Labour Party – said levies on energy bills should be shifted to general taxation.
Matthew Paterson, a politics professor at Manchester University, told Climate Home News that the most effective way to reduce electricity bills is to take on the UK’s private electricity companies, while consumer-oriented measures like the VAT cut are “tinkering around the edges”.
Jarrod Birch, head of policy and public affairs for the EV charging industry association Charge UK, said that while the policy would make home-charging cheaper, people who charge their vehicles at public points will still have to pay 20% VAT. The UK’s tax authority is fighting a court ruling that ordered it to reduce the tax motorists pay on public chargers to the current household rate of 5%.
Further measures will be the responsibility of Secretary of State for Energy Security and Net Zero Miatta Fahnbulleh, who is relatively new to politics after a career at left-wing, pro-climate think tanks the IPPR and the New Economics Foundation.

Michael Jacobs, political economy professor at Sheffield University and former adviser to UK Labour prime minister Gordon Brown, said Fahnbulleh would be a “climate advocate” who would continue the “progressive climate agenda” of her predecessor Ed Miliband.
“She’s a very creative policy wonk so I expect there to be lots of policy innovation under her,” he said, “I think she will be looking at new ways to encourage take-up of heat pumps and domestic batteries.”
Aid budget in Miliband’s hands
Despite reports he could be made finance minister, Miliband has been appointed Secretary of State for Foreign and Commonwealth Affairs. Miliband has attended many climate COP meetings over several decades, most recently representing the UK at COP29 and COP30, and has been targeted by the right-wing media for his support for climate action and opposition to new oil and gas drilling in the UK’s part of the North Sea.
In his new role, Miliband will be responsible for the UK’s overseas aid budget including its international climate finance, which the Starmer government had slashed to fund increases in defence spending.
UK cuts support for climate action abroad to fund military instead
Jacobs said he expected Miliband to prioritise climate and development in the UK’s foreign policy and to push Burnham and new finance minister John Healey to reverse Starmer’s aid cuts.
But there are fears Healey could try to cut the aid budget further to fund the military. Healey was a surprise pick for Chancellor of the Exchequer and grabbed headlines when he resigned as Starmer’s defence minister in June over what he saw as insufficient defence spending.
The post Will new UK PM’s green measures at home cause climate finance pain overseas? appeared first on Climate Home News.
Will new UK PM’s green measures at home cause climate finance pain overseas?
Climate Change
Greenpeace launches legal challenge against Australia’s biggest meat company
AMSTERDAM, Netherlands, 22 July 2026 – Greenpeace Netherlands has launched legal proceedings against a multi-billion-dollar global expansion plan by the biggest meat producer in Australia, JBS, in an escalation of climate litigation against the livestock industry.
Greenpeace petitioned a Dutch court to compel the meat giant to disclose information in order to challenge its business policies in court, including a US$6 billion global expansion, for which almost half is earmarked for Nigeria.
Elizabeth Atieno, Food Campaigner at Greenpeace Africa, said: “JBS’ meat empire expanded hand-in-glove with Amazon destruction, colossal emissions, human rights and corruption scandals, all with barely a semblance of transparency. This is the business model it wants to export to sub-Saharan Africa. JBS promises food security, but its expansion in Nigeria risks causing irreversible environmental damage and the displacement of smallholder farmers to line the pockets of wealthy global elites.
“Nigerians know well from the legacy of companies like Shell the destructive impact wrought by unchecked corporate power. As Greenpeace Africa has argued before the African Court of Human Rights, states with jurisdiction over multinationals must hold those corporate actors accountable – wherever they operate in the world. We welcome this bold legal action: the Netherlands and other European states must not be safe havens for corporations like JBS seeking to evade their responsibilities.”
In light of JBS’ longstanding failure to publish accurate and reliable information on its climate, nature and human rights impacts or its expansion plans, Greenpeace Netherlands views accessing this data as a necessary precursor to formal litigation in order to support its case. The case has the potential to be the first climate litigation of this scale against the livestock industry. This could set a major precedent for future legal challenges against the industrial agriculture sector, a major source of global emissions, particularly of methane, a potent greenhouse gas, responsible for 0.5°C of warming since the Industrial Revolution.[1]
JBS, via its subsidiary JBS Foods Australia, is the largest meat and food processing company in Australia. With a weekly processing capacity of over 50,000 cattle, it accounts for almost a quarter of all beef processing in the country, as well as a significant presence in the lamb, pork and farmed fish markets. [2] In 2022, ABC’s Four Corners accused the company of ‘repeatedly failing to protect its workers from horrific injuries.’ [3]
Marieke Vellekoop, Executive Director at Greenpeace Netherlands, said “In a month where JBS has thrown its flagship environmental commitments onto the scrap heap, JBS’ disdain for basic transparency only adds to the impression that this meat giant has something to hide and is desperate to prevent its expansion plans from going public. We were hoping we wouldn’t have to trouble a judge with this matter, but JBS has left us no choice but to seek our right to information through the Dutch courts.
“JBS appears to believe that despite moving to the Netherlands, our rules do not apply to it. This legal action aims to prove it wrong – and lay the ground for a first major climate and nature lawsuit against the dangerous expansion of the global meat industry.“
At the centre of the dispute is JBS’ planned US$ 2.5 billion investment in industrial livestock production in Nigeria.[2] Civil society groups in Nigeria have raised urgent warnings that the aggressive expansion will threaten local food security, drive regional instability, and accelerate ecological degradation. There is no available evidence that JBS has conducted any impact assessments or community consultations in Nigeria, and local efforts to gather more information via Freedom of Information requests have reportedly been ignored.[3]
The escalation to the courts follows the refusal of JBS, the world’s largest meat company, to comply with a formal disclosure demand delivered by Greenpeace Netherlands in April. The environmental group is utilising new Dutch legislation, which grants parties with a legitimate interest the right to demand access to specific corporate data necessary to build litigation against Dutch companies.[4]
Greenpeace Netherlands’ lawyers allege that JBS’ historic business practices and future expansion plans are inconsistent with the company’s climate and biodiversity obligations and represent a breach of its Dutch duty of care, which requires companies to act in line with international human rights law.[5]
If the court rules in favor of Greenpeace Netherlands, it is entitled to seek the required information in the form of documents and from senior JBS figures under oath, raising the prospect of the Batista brothers being forced to testify in Dutch court. JBS reincorporated as a Dutch entity (JBS N.V.) last year to facilitate a dual listing on the New York Stock Exchange.
In April, JBS was forced to temporarily suspend its first annual general meeting since moving its headquarters to Amsterdam after it was disrupted by dozens of Greenpeace Netherlands activists.
Last week, JBS scrapped two flagship commitments to reach Net Zero emissions by 2040 and eradicate deforestation from its supply chain. It also removed any explicit reference to Indigenous lands from all of its current policies. Greenpeace Netherlands is concerned this indicates JBS is seeking to expand unconstrained by the climate, nature and human rights impacts of its business.
–ENDS–
Notes:
[1] The livestock sector is estimated to be responsible for 31% of global methane emissions (more than oil and gas operations). In comparison to CO2, methane is shorter lived (around 12 years) but has a much stronger ability to trap heat in the atmosphere over its lifetime: it has approximately 80 times more climate impact than CO2 when measured over 20 years. This means that changes in methane emissions have a more rapid effect on the climate than changes in CO2. See Greenpeace Netherlands letter to JBS dated 30 April 2026.
[2] JBS Foods Australia, Our Business
[3] ABC, Australia’s biggest meat company JBS is repeatedly failing to protect its workers from horrific injuries, 25 April 2022
[4] JBS announcement
[5] Experts raise concerns over the risks of industrial animal farming (The Sun Nigeria)
[6] Simplification and modernisation of Dutch evidence law (Fieldfisher)
[7] Greenpeace Netherlands petition to Dutch court available here. Media briefing with further details on JBS expansion plans, including in Nigeria, available here.
Greenpeace launches legal challenge against Australia’s biggest meat company
Climate Change
“Next year is too late for regulations”: Beetaloo Energy’s 2GW gas-powered AI data centre a “disaster proposal” destined to cause climate chaos
SYDNEY, Wednesday 22 July 2026 — Beetaloo Energy has secured land from the NT Government for a massive $40 billion “hyperscale” AI data centre near Darwin, which would be powered by 2 gigawatts (GW) of gas power fracked directly from the Beetaloo basin, prompting calls from Greenpeace for urgent federal legislation.
The proposal marks a dangerous escalation in the AI data centre industry’s expansion, which threatens to entrench fossil fuel infrastructure for decades and put immense pressure on the region’s fragile water resources — while continuing to be unregulated.
Joe Rafalowicz, Head of Climate and Energy at Greenpeace Australia Pacific, said: “This disaster proposal for a 2GW gas-powered AI data centre in the NT is a shocking example of the unchecked expansion of hyperscale data centres in Australia. It is also, critically, more evidence for the urgent need for a moratorium on all new data centres until strong, binding regulations are put in place to protect our communities and climate.
“This proposal mirrors the frenzied, unchecked expansion currently wreaking havoc on communities in the US. We are seeing cowboy data centre operators treat Australia like a playground, steam-rolling ahead with projects that would lock down precious water resources and spike emissions, despite the overwhelming community opposition.
“Every day, more councils, communities and environmental groups are joining Greenpeace’s call for a moratorium on data centres, yet as of today there is still no system of safeguards or rules in place to regulate these companies.
“While Beetaloo Energy and the NT Government prepare to bulldoze ahead with this climate and water disaster, the Prime Minister is asleep at the wheel, promising to legislate a vague set of standards next year.
“Next year is too late, and anything less than mandating data centres cover their own energy demand, and then some, with new renewable energy is not enough.”
-ENDS-
Media contact
Lucy Keller on 0491 135 308 or lucy.keller@greenpeace.org
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