Why last two years are worrying for future of Arctic

Arctic winter sea ice is back in rapid decline after a slowdown in melting at the start of the decade, scientists have found.

According to new analysis led by the University of Southampton, between 2024 and 2025, the amount of Arctic sea ice measured during the peak winter period – from February to March – plummeted by a whopping 5.8%.

It was the largest year-to-year wintertime drop in the satellite record, which began in 1978.

Duo Chan, lead author of the paper from the university's School of Ocean and Earth Science, said: "This sharp drop changes the way we interpret recent Arctic winter sea ice change.

"What looked like a pause in the early 2020s now appears to have been a temporary slowdown within a longer-term decline associated with global warming."

Why does it matter?

Winter sea ice loss in the Arctic is a consequence of human-driven global warming.

The sea ice acts as a barrier between the relatively warm Arctic Ocean and the much colder winter atmosphere, which makes it an important bellwether of climate change.

Its breakdown allows more ocean heat and moisture to enter the atmosphere, which can influence pressure patterns, storm development and large-scale atmospheric circulation – impacting the weather further south.

Professor Simon Josey, co-author of the study at the National Oceanography Centre, said the research suggests it's unlikely there will be a quick "rebound" to early 2020s conditions.

Earlier this year, the planet came close to breaching a landmark global warming target to keep global temperatures to less than 1.5C above pre-industrial levels.

The UK is among the countries to have experienced the extreme impact of climate change, with a recent report confirming last year was its warmest on record. This summer has also seen multiple heatwaves.

It comes amid a pushback in some democracies, including the UK, to net zero policies designed to combat climate change, while Donald Trump promotes the benefits of continuing to drill for oil and gas.

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Mr Chan said "short-term recoveries" in Arctic sea ice in the early 2020s had obscured the "longer-term direction".

"The low winter sea ice extents in 2025 and 2026 clearly show that Arctic sea ice loss has not stopped," he said. "It is continuing in a warming climate."

The study was funded by a UK Research and Innovation's Future Leaders Fellowship and the Natural Environment Research Council.

(c) Sky News 2026: Why last two years are worrying for future of Arctic