Antarctic sea ice has recorded its third-smallest winter peak extent since satellite records began 47 years ago, new data reveals.
Provisional data from the US National Snow and Ice Data Center (NSIDC) shows that Antarctic sea ice reached a winter maximum of 17.81m square kilometres (km2) on 17 September.
This is 900,000km2 below the 1981-2010 average maximum extent – the historical baseline against which more recent sea ice extent is typically compared.
According to one expert, the “lengthening trend of lower Antarctic sea ice poses real concerns regarding stability and melting of the ice sheet”.
Meanwhile, at the Earth’s other pole, Arctic sea ice reached its annual minimum on 10 September, ranking as the joint-10th lowest in the satellite record.
At 1.6m km2, the 2025 minimum shares the spot with 2008 and 2010. The NSIDC notes that all 19 of the lowest sea ice extents in the record have occurred in the past 19 years.
Antarctic peak
For decades, scientists have been using satellite data to track the annual cycle of sea ice growth and melt at the world’s poles. This is a key way to monitor the “health” of sea ice in both the Arctic and Antarctic.
The map below shows Antarctic sea ice on the day of its maximum extent for the year on 17 September 2025, where the yellow line shows the 1981-2010 average.
The NSIDC says that sea ice extent was “markedly below average” in the Indian Ocean and the Bellingshausen Sea, but “slightly above average” over the Ross Sea.

In an NSIDC press release announcing the Antarctic maximum, Dr Ted Scambos, a senior research scientist at the Cooperative Institute for Research In Environmental Sciences, said:
“The lengthening trend of lower Antarctic sea ice poses real concerns regarding stability and melting of the ice sheet. However, it may also be leading to greater snowfall over the continent, which would slow the progression of sea level rise.”
Antarctic sea ice growth
In its typical annual cycle, Antarctic sea ice grows during winter towards its annual maximum extent in September or October. It then melts throughout the spring and summer towards its March minimum.
Earlier this year, Antarctic sea ice recorded its second-smallest summer minimum on record.
At 1.98m m2, this was the fourth consecutive year that Antarctic sea ice had fallen below 2m km2, the NSIDC noted.
In its monthly sea ice updates, the NSIDC reported that sea ice then grew at a “near-average pace”. During this period, sea ice “expanded rapidly” in the last areas to lose ice, including the Ross Sea and eastern Weddell Sea, it said.

The NSIDC explained that sea ice rebounded quickly in the Ross Sea area because ice extent had retreated “slowly” there the month before – meaning that the upper ocean layer did not have time to accumulate heat which would slow the winter freeze.
In April, “the situation in the Antarctic remained fickle”, the NSIDC said. At the beginning of the month, sea ice extent neared “record-low” daily extents, but as the month progressed ice cover expanded “fairly quickly”, it said.
May had “below average growth” in Antarctic sea ice and saw the fifth lowest record for Antarctic sea extent.
As June began, the the Bellingshausen Sea and eastern Queen Maud Lord regions were “far behind” in ice re-growth, it said, adding that the Bellingshausen Sea was almost entirely ice-free as temperatures were 6-8C above average.
In June, Antarctic sea ice was 1.28m km2 below the 1981-2010 baseline, with “particularly low” sea ice extent in the Bellingshausen Sea and the Indian Ocean sector, according to the NSIDC. This was the third-lowest sea ice extent ever recorded for the month of June, it said.
Throughout July, Antarctic sea ice extent grew at a “slower-than-average” rate, according to the NSIDC. By the end of the month, Antarctic sea ice extent was 1.3m km2 below the baseline, it noted.

Arctic melt season
In the Arctic, sea ice cover typically reaches its high point in March, before dropping to its September minimum at the end of the northern-hemisphere summer.
The 2025 Arctic sea ice winter peak was the smallest since satellite records began. The peak, recorded on 22 March, was 1.31m km2 below the average maximum for the 1981-2010 historical baseline.
In March, Arctic sea ice extent averaged 14.14m km2 – the lowest in the satellite record, according to the NSIDC. It noted that, at the time, average air temperature was above the historical baseline across much of the Arctic region.

Arctic sea ice extent then “changed very little” throughout April, remaining “nearly constant” until the final days of the month, the NSIDC reported.
It added that the final days of April saw Arctic sea ice extent drop due to ice retreat along the coast of the Barents Sea.
According to data, the main reason why the April total extent remained largely flat was due to an increase of sea ice in the northeastern Barents Seas that “offset” losses elsewhere.
Below-average air temperatures over the northern Norwegian and Barents Seas was the most “notable feature” of April 2025, the NSIDC said.
May was marked by a decline in Arctic sea ice extent at a faster-than-average pace, the NSIDC noted, resulting in the seventh-lowest May extent on record.
It added that ice loss in May was “primarily” in the Barents Sea, Bering Sea and the Sea of Okhotsk.
In June, Arctic sea ice extent averaged 10.48m km2 – the second-lowest average on record for the month, the NSIDC said. It noted that sea ice hit record-low levels over 20 June and 26 June and tracked at “near-record” low levels through the month. The Barents and Kara Seas were both “nearly ice-free” by the end June.
Hudson Bay ice extent was also “considerably below average” throughout June and northern parts of Baffin Bay were nearly ice-free, it said.
By the end of July, daily sea ice extent in the Arctic had fallen to 7.66m km2 – the third lowest in the satellite record, the NSIDC reported. It noted that, for most of the month, Arctic sea ice extent tracked close to levels recorded for 2012 – the year in which Arctic sea ice extent reached its lowest-ever September minimum.

Throughout August, the NSIDC reported that sea ice “rapidly melted and compacted” north of Alaska in the Beaufort Sea, with sea ice extent averaging at 5.41m km2 – the seventh lowest on record.
Dr Zack Labe – a climate scientist at Climate Central – tells Carbon Brief that northern Siberia saw August air temperatures more than 5C above the 1981-2010 average, resulting in “a striking amount of open water along the Atlantic side of the Arctic that would normally be ice-covered”.
At an annual minimum of 1.6m km2, this year’s Arctic minimum is “pretty unremarkable”, Labe tells Carbon Brief, and “adds to the evidence of a clear slowdown in the rate of summer Arctic sea ice loss”.
However, Labe stresses that this is “not surprising” – referencing a recent study which “clearly shows how internal variability can temporarily drive periods of slower melt in a warming climate, as well as periods of rapid melt, such as in the early 2000s”. (For more on this research, read Carbon Brief’s guest post).
He adds:
“It is only a matter of time before summertime melt accelerates again. This is not a good news story, especially since in many other months we still see a clear downward trend…
“While the past decade of summers may give the appearance of a slowdown, regional extremes such as in the Kara Sea this year underscore that the Arctic is already radically different from past decades. The driver is clear – human-caused climate change.”
Satellite switch
For decades, NSIDC has tracked sea ice using data from weather satellites run by the US Navy. However, earlier this year, Mongabay reported that NSIDC scientists “noticed holes in the data they were receiving”.
The article explains:
“When scientists inquired with the Department of Defense (DoD), they were told not all data were being downloaded and access to the data had been deprioritised. Soon after, the DoD said it would stop sharing…data altogether, citing military cybersecurity risks in the old systems.”
NSIDC scientist Walt Meier told Science that while the US satellites “are up there and functioning…we’re not getting all the data anymore, at least regularly”.
The DoD then set a cut-off date to “cease distribution data from the Defense Meteorological Satellite Programme” on 31 July.
In June, the NSIDC announced that it would “explore switching to a different sensor” aboard a Japanese satellite that was launched in 2012.
The only other option available to NSIDC was a “series of Chinese weather satellites, which the country is already using to produce its own record of sea ice”, Science noted. It added that a new US DoD weather satellite, launched last year, is “also capable of collecting similar data, but its data have not yet been made public”.
The switch was completed by the July cut-off date and NSIDC reprocessed all data for 2025 to use the new data source to ensure “consistency through the year”.
The post Antarctic sea ice winter peak in 2025 is third smallest on record appeared first on Carbon Brief.
Antarctic sea ice winter peak in 2025 is third smallest on record
Climate Change
Marine Parks Explained
Australia’s network of marine parks is the largest in the world, covering more than half (52%) of Australia’s Commonwealth waters. You could be forgiven for assuming that a marine park is much like a national park on land: a highly protected place where people can enjoy nature while conservation efforts help habitats recover and wildlife thrive. You wouldn’t expect someone to bulldoze a national park, so why should they be allowed to bottom trawl in a marine park?
The reality is that not all marine parks are equally protected. Australia’s Marine Parks Network is divided into different zoning categories, with each zone determining which activities are permitted and the level of protection provided.
More than half of the Commonwealth Marine Parks Network allows industrial activities like oil and gas mining, and industrial fishing.
Our survival, and the survival of our planet, depends on the ocean. The ocean produces more oxygen than all of our forests combined, sustains communities and regulates the earth’s temperature. It’s home to wondrous wildlife and important ecosystems like coral reefs and kelp forests.
We love our big blue backyard
Australia’s ocean is teeming with life that is found nowhere else on earth. Schools of colourful fish, vibrant coral reefs, endemic shark nurseries, pods of dolphins, families of whales, playful seal pups and threatened Jurassic-era turtles call Australian waters home.
Since time began, from the turquoise waves to the deep blue, the ocean has connected our shorelines and communities, fed us, guided us and grounded us. We are intrinsically connected to our big blue backyard – more than 85% of us live within 50km of the shoreline. For tens of thousands of years, people have lived in harmony with the ocean and the wildlife within it, caring for and being sustained by its rich waters. Australia’s waters are some of the most unique and abundant places on Earth but our Marine Parks Network is falling short to properly protect them.
Australia’s marine parks aren’t living up to their name

The Australian Commonwealth Marine Parks Network covers commonwealth waters 5.5km from the coast. The network is divided into 7 regional management areas, overall the network contains 60 marine parks. Zoning types determine what activities are allowed in each area. Over half of the network allows industrial activities, risking our most precious and threatened ocean wildlife.
Within many of our marine parks, destructive industries are allowed to fish, trawl, dig and mine using barbaric and cruel methods. Here are some of the zones explained:
- Bottom Trawling: Special Purpose (trawl) zones allow bottom trawling. This covers 10 marine parks totalling almost 13 million hectares. Bottom trawlers bulldoze the seafloor with weighted nets, deforesting our underwater forests; a cruel, indiscriminate and inefficient way to fish.
- Other Industrial Fishing: Includes “Habitat Protection Zones, ““Multi Use Zones” and “Special Purpose Zones.” Fishing methods vary from park to park but many marine parks in these zones allow industrial fishing like longlining. Longlining involves setting lines that can be 100km long, bristling with deadly hooks designed to catch a specific fish species. But longlining is not a selective method of fishing – significant numbers of sharks, rays, turtles, dolphins and seabirds can be harmed or killed as bycatch in the process.
- Oil and Gas Mining: Many “Special Purpose” and “Multi Use” zones allow seismic blasting and oil and gas mining. 30 marine parks or 65 million hectares of Australia’s highest conservation value areas for ocean wildlife are open for mining and exploration of oil and gas.
- Ocean Sanctuaries: National Park and Sanctuary zones are fully and highly protected marine parks designed to conserve wildlife and their habitat, where fishing, mining, and other industrial activities are not allowed.
Industrial fishing is one of the biggest threats to the ocean

In May, Greenpeace Australia Pacific sailed our campaigning vessel Oceania through some of Australia’s most beautiful and threatened marine parks. Our crew visited Jervis and Hunter marine parks to document their beauty, showcase what’s at risk and aim to expose the industrial fishing activities in these protected waters. Both of these marine parks allow bottom trawling and longlining methods of industrial fishing.
Industrial fishing is ripping the ocean apart across the planet. Longlining, also known as longline fishing, is an industrial fishing method that involves the use of a fishing line with thousands of baited hooks. These fishing lines can stretch over 100 kilometers in length and are set to capture a fish species, often tuna or billfish species. But it is not a selective method of fishing and often results in significant bycatch. This includes a range of non-target species like sharks, rays, sea turtles, marine mammals, and seabirds which are often injured or killed as bycatch.
Bottom trawling involves dragging heavy weighted nets along the ocean floor. This fishing method is popular with commercial fishing companies, because it makes it easy to catch large quantities of fish in one go. But it also damages the seafloor, releasing carbon and can kill or injure non-target ocean life like coral, fur seals, dolphins and seabirds. You may have watched the reality of bottom trawling (and the benefits of ocean sanctuaries) in Ocean with David Attenborough, if not, add it to your watch list!
Fully protected ocean sanctuaries that ban industrial fishing and mining can protect ocean wildlife and underwater wonderlands for generations to come. Vast, robust sanctuaries create blue havens where ocean wildlife are safe from nets and hooks, and can truly rest, recover, thrive and replenish out into the surrounding waters. Ocean sanctuaries ensure a healthy ocean full of life.
A once-in-a-decade chance to fix what’s falling short
We have a unique opportunity to turn the tide.
The Australian Government is asking for your feedback on how our Commonwealth Marine Parks Network is managed. This is our once-in-a-decade chance to protect ocean wildlife, ban industrial fishing and create more ocean sanctuaries.
As part of the review the Government is asking for submissions from the public to hear from you on what improvements are needed to better protect our vast network of marine parks. Writing a submission is a powerful way to influence government decisions and create real change.
This is the moment to ban industrial activities like bottom trawling and oil and gas mining. But only if they hear from YOU. Add your name!
Greenpeace is calling on the Australian government to:
1. Ban industrial activities from Australia’s Marine Parks Network: Ban industrial activities, such as industrial fishing, seismic blasting and oil and gas mining, from Australia’s marine parks.
2. Create more ocean sanctuaries: Increase fully protected sanctuaries in Australia’s marine parks based on science principles.
3. Connect Australia’s Marine Parks Network to the High Seas: mCreate seascape connectivity by linking Australian marine parks to new high seas ocean sanctuaries.
References
Substantiation that more than half of the Marine Parks Network permits industrial activity comes from a peer-reviewed systematic literature review (Phillips et al. 2025, PLOS One, https://doi.org/10.1371/journal.pone.0307324). The study found that within the Commonwealth Marine Parks Network specifically, “all zones are considered partially protected areas, meaning areas where extractive activities are permitted, except ‘Pink zones’ (Preservation Zones; IUCN Ia) and ‘Green Zones’ (IUCN II).” In other words, every Commonwealth marine park zone type other than the network’s strict no-take sanctuary and national park zones (IUCN Ia and II) permits some form of extractive industrial activity. Since no-take zones are the minority zone type across the network by area, this supports the conclusion that the majority of the network’s area is zoned to permit industrial activity.
DCCEEW Australian Marine Parks spatial dataset (https://fed.dcceew.gov.au/datasets/erin::australian-marine-parks/explore), filtered by zone type. This confirms that 38.43% of the network’s area is zoned as Sanctuary or National Park zones (IUCN Ia and II). These are the no-take categories excluded from the peer-reviewed study’s definition of partially protected/industrial-permitting zones. The remaining 61.57% of the network falls within the zone categories the study classifies as permitting industrial activity (per The MPA Guide definition of “industrial” applied in Phillips et al. 2025), directly corroborating the peer-reviewed finding with current Commonwealth-specific spatial data.
For further information on activities permitted within the Marine Parks Network Zoning, you can refer to the Management Plans zoning and rules for each Marine Parks Network area, for example: Temperate East, Coral Sea, North.
Climate Change
Report: Trawling the Bottom Line
A new report from Greenpeace Australia Pacific advocates for the closure of bottom trawling in Australia’s Commonwealth Marine Parks Network. Bottom trawling continues to be a pervasive threat to ocean life in Australia, with 10 marine parks totalling almost 13 million hectares, allowing bottom trawling.
Australia’s network of marine parks, which is the biggest in the world, covers more than half (52%) of Australia’s Commonwealth domestic waters, but not all parks are created equal. Australia’s Marine Parks Network is divided into different zoning categories, with each zone determining which activities are permitted and the level of protection provided. More than half of the Marine Parks Network allow industrial activities like industrial fishing and oil and gas mining. This includes zoning types that allow destructive fishing by longliners and bottom trawlers, who pillage underwater wonderlands, rip up coral and indiscriminately and violently catch any animal in their path, including turtles, seals and dolphins, all within areas labelled a marine park.
The Federal government has commenced a review into the majority of Australia’s Commonwealth Marine Parks Network management plans. This presents an opportunity to ban industrial activities from our marine parks and create more ocean sanctuaries.

Climate Change
Sewing and Painting the Future

© Harriet Spark / Grumpy Turtle Film / Greenpeace
The banner drop is a distinctive part of the Greenpeace repertoire.
The moment of the unfolding is intrinsically dramatic. It is the reveal; when the moral and scientific truth of a situation is unveiled to the world. The wrong is being labelled—not through a written submission, or a social media post, or a statement in a meeting—but in words emblazoned in real physical space, chosen and occupied with precision, for all to see. There is jeopardy and transgression. And there are consequences—for the activists and for Greenpeace, as well as for the target of the communication. One of the reasons the banner remains such an effective tool in our toolbox is because of its undeniable clarity in cutting through, driving change and accountability in a way that few other tactics can. It is naming the wrong: in giant, clear letters.
We’ve hung these massive messages at environmental crime scenes, corporate headquarters, and iconic landmarks; on government buildings, ships and planes—in locations all around the world, for years.
My own memories unfurl even as I write this, but because the campaign to stop Woodside at Scott Reef is so pressing, what immediately springs to mind are two of our banners in that campaign: one on a crane outside their Perth HQ, and another on some of their corroding industrial junk at sea. What about you? Is there a particular banner that you picture when you think of Greenpeace?
The banners can attract global attention, but they have quiet beginnings. Each one is made by hand, often by volunteers. It is the invisible labour behind each spectacular public moment. One of the key pieces of equipment in our workshop at Rainbow Warrior House is the sewing machine. Sometimes our workshop is full of people and noise; at others it is quiet, the only sound being the gentle, purposeful, whir and buzz of a banner being sewn. It is usually our warehouse manager, Kieran Holmes, on the tools, head over the machine, carefully pouring over the raw canvas or tarp as the banner takes shape. Kieran’s one of those people who seems to be able to turn his hand to almost anything, but you wouldn’t know it because he’s old-school modest. In addition to being incredibly skilled, Kieran’s an all-round beaut human to have in the heart of our headquarters; never too busy to take the time to show a newcomer, or curious visitor, around his domain.
Once the banner is sewn up, the lettering needs to be outlined. This is done on a magnetic wall—a fit-for-purpose feature at Rainbow Warrior House, where the banner is held up with magnets, and the edges of the letters neatly traced from a projection.
Next comes the painting. It usually starts late in the afternoon, sometimes going into evenings and weekends, with volunteers, staff, mates crowded around, brushes in hand. It is a calming meditative feeling of shared purpose, giving each letter its visual heft, the colour building power and presence with each stroke.
Then you stand back, stretch, and look at the message, now ready.
S A V E S C O T T R E E F
Throughout history, every great push for social change has required some form of invisible labour; preparation in the form of quiet things seldom seen, but vital. It is the enabling work of love instantiated in action. And of course, so much of the time it has been women who have done this labour, so that the men could get the chance to make the speeches and stand on the podiums. The inaugural Greenpeace voyage to stop nuclear testing in 1971 had a male-only crew, but wouldn’t have happened without the ideas and work of women behind the scenes.
It is what we do together, after all, that changes the world. Sometimes that work happens on a stage, a ship on the wild seas, or up the side of a building. But mostly, it is the hidden diligence of those who care and contribute to all the enabling work that makes a change once thought impossible, inevitable. It is Kieran at his sewing machine. It was Dorothy Stowe doing the administrative work of the ‘Don’t Make A Wave Committee’ that became Greenpeace.
When we think of social change, it is the sturm and drang that we remember. The drop of the banner, the chant of the crowd, the raising of the new flag. But look behind the curtain, and there’ll be a crew of people who are taking responsibility for the administration, the sewing and the painting, making the food, checking the bus timetables, getting stuff done. And behind them are even more handsinvisibly donating time and trust; the financial, material and expert resources that make it all possible. There’s love, camaraderie and know-how at every stage.
We are social and cooperative creatures by nature. And we human beings have been stitching for millenia, sewing the possibilities of our common future. Political and corporate bullies and algorithmically manipulative platforms would have us forget this, and abandon who we are. But we should be in no doubt that the brighter prospects for ourselves and life on earth continue to be stitched and painted; collaboratively and with love, by the diligent hands of millions of people who care, each day, in every community and city across the world.
With Love,
David
Q & A
I always get great questions when interviewing prospective new team members. One that came up again recently was: “Is Greenpeace actually one organisation?”
Around the world, people know Greenpeace by our one global name, united by a shared mission: securing an Earth capable of nurturing life in all its magnificent diversity, with a particular focus on climate and biodiversity. Behind the scenes, though, we’re organised as a network of 25 legally autonomous national and regional offices, including Greenpeace Australia Pacific, working alongside Greenpeace International.
That structure gives us the best of both worlds: we work together leveraging the power of a global network on the issues that matter most, while each office remains legally independent and deeply connected to the communities, cultures and political realities where we’re embedded. Local knowledge informs global action, and global collaboration strengthens and supports local campaigns.
It’s a model that has enabled Greenpeace to take on some of the world’s biggest challenges for over five decades–while withstanding challenges and attacks from governments and corporations. Global enough to tackle global problems, local enough to understand our communities and the natural places we love.
If you’re curious to learn more, you can read about the Greenpeace Global Network structure here.
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