Meltwater – Issue 01, June 2026

This is the first of a monthly letter I’m going to keep – a short read on what’s happening in the Arctic and across the cryosphere, and why it’s worth paying attention to. I spent years measuring this before I made pots. This is my way of staying close to it, and passing on what I find. Every item links to its source, so you can read further or check it for yourself.

The glacier I studied just set a record – for retreating

Kronebreen is a glacier that ends in the sea at the head of Kongsfjorden, in north-west Svalbard. It’s where I spent my PhD, measuring how meltwater moves beneath the ice and changes the way the fjord circulates. This year it set a record I never wanted to see attached to it: its front retreated 715 metres in a single year, to 20 September 2025 – the largest one-year retreat measured there.

The Norwegian Polar Institute has tracked these glaciers since the 1960s, going out each spring and autumn to read the stakes drilled into the ice. The longer picture is stark. Kronebreen and its neighbour Kongsbreen have each pulled back more than five kilometres since the 1990s, and two of those kilometres have gone in just the last five years. Tidewater glaciers like these melt from warm air above and warm seawater at the front, which is why they retreat faster than glaciers that end on land.

2025 was not even the worst recent year. That was 2024. Norwegian researchers reported in PNAS that roughly 1% of all the ice on Svalbard melted in that one summer – about a tenth of the entire world’s glacier contribution to sea-level rise that year. As much ice was lost from Svalbard as from Greenland, even though the Greenland ice sheet is around fifty times larger.

Why it matters: this isn’t only ice disappearing from a map. The meltwater I used to measure feeds the fjord with fresh water and sediment, shifts its currents, and changes where nutrients and life turn up. When a glacier retreats this fast, the whole working system of a place changes with it. I measured the water under this ice for years. Seeing a number like 715 metres put on it now is strange – but I’d rather know than not.

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Also this month

Arctic winter sea ice tied its record low – again

Arctic sea ice reaches its yearly peak at the end of winter. This year it topped out on 15 March at 14.29 million km² – statistically tied with 2025 for the lowest maximum in the 48-year satellite record, and about 1.3 million km² below the 1981-2010 average. That missing area is roughly twice the size of Texas. NASA’s ICESat-2 also found the ice noticeably thinner, especially in the Barents Sea.

Why it matters: less ice survives each summer, so less old, thick multi-year ice builds up. A thinner, younger ice pack melts out more easily the following year.

Source: NASA / NSIDC

Greenland’s extreme melt has multiplied sixfold

A study in Nature Communications found that meltwater produced during Greenland’s most extreme melt episodes has risen from about 12.7 gigatonnes per decade (the 1950-2023 baseline) to 82.4 gigatonnes per decade since 1990 – roughly a sixfold jump. The trigger is persistent high-pressure ridges parked over the ice, helped along by warmer Atlantic water reaching the glaciers that end in the sea. Greenland has lost ice every single year since the late 1990s.

Why it matters: Greenland is the single largest source of land ice raising global sea level. How fast it melts in the coming decades is, in large part, everyone’s coastline.

Source: Nature Communications, via ScienceDaily

The permafrost carbon line in the sand

Frozen Arctic ground holds an enormous amount of old carbon – somewhere between 1,330 and 1,580 billion tonnes, close to twice what’s in the atmosphere now. New research points to a tipping point at around 2-4°C of local warming, beyond which thawing soil releases ancient carbon faster than plants can lock new carbon away. Crucially, that’s genuinely new carbon entering the air, not modern carbon being recycled – the kind many climate models still struggle to account for.

Why it matters: this is the feedback that turns Arctic warming into a global problem. Past a certain point the ground itself starts adding to the total, whatever we do.

Source: Nature Communications; Tibetan Plateau study, via Phys.org

Svalbard’s polar bears are, surprisingly, doing alright

Not every line points the same way. Researchers took more than 1,000 body measurements of nearly 800 Svalbard polar bears between 1995 and 2019. Despite Svalbard losing sea ice more than twice as fast as other bear habitats, the bears’ fat reserves actually improved over that period. They’ve been flexible – feeding on reindeer, eggs, walrus carcasses and seals, with some now spending up to 90% of their time on land.

Why it matters: it’s a real complication to the usual story, and worth holding honestly. But flexibility has limits, and the ice is still going. Resilience now isn’t a guarantee for later.

Source: Scientific Reports, via CNN

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Sources

1. Ny-Ålesund Research Station – Record Glacier Retreat in Ny-Ålesund: Monitoring Insights from 2025. nyalesundresearch.no
2. Schuler et al. (2025), Svalbard’s 2024 record summer: An early view of Arctic glacier meltdown?, PNAS. doi.org/10.1073/pnas.2503806122
3. NASA / NSIDC – Arctic Winter Sea Ice Ties Record Low (Mar 2026). science.nasa.gov
4. NSIDC – Arctic sea ice record low maximum strikes again. nsidc.org
5. Bonsoms et al. (2026), Greenland extreme melt, Nature Communications, via ScienceDaily. sciencedaily.com
6. Permafrost carbon tipping point – Nature Communications & Tibetan Plateau study, via Phys.org. phys.org
7. Svalbard polar bear body condition (1995-2019), Scientific Reports, via CNN. cnn.com

Meltwater is a monthly letter from Cryosphere Ceramics, hand-thrown stoneware made in Dunoon by a former Arctic scientist.