A new study has found that a previously recorded slowdown in Arctic sea ice decline has ended, with the largest year-to-year wintertime reduction ever observed. The research, led by the University of Southampton, shows that the apparent pause in melting during the early 2020s was a temporary blip rather than a sustained trend.
Last summer, scientists reported a surprising slowdown in Arctic sea ice loss between 2005 and 2024, with no statistically significant decline in extent despite rising global temperatures. They attributed this to natural variations in ocean currents that temporarily counteracted the effects of global warming, and warned that melting would resume at roughly double the long-term rate within five to ten years.
Using the latest satellite observations, the new study confirms that this slowdown has now ended. Dr Duo Chan, lead author from the University of Southampton's School of Ocean and Earth Science, said: 'What looked like a pause in the early 2020s now appears to have just been a temporary slowdown within a longer-term decline.'
Sea ice area in September, when it reaches its annual minimum, has halved since 1979. Between 2024 and 2025, Arctic sea ice declined by 5.8% – the largest year-to-year wintertime drop ever recorded. Dr Alessandro Silvano, co-author of the study, described the sharp drop as 'unusual but physically plausible under current Arctic warming.'
The researchers note that winter sea ice acts as an insulator between the relatively warm ocean and the much colder atmosphere. Its reduction allows more ocean heat and moisture to enter the atmosphere, potentially affecting pressure patterns, storm development and large-scale circulation, with knock-on effects on weather further south. Dr Chan added: 'Short-term recoveries can temporarily obscure the longer-term direction of Arctic sea ice change. The low winter sea ice extents in 2025 and 2026 clearly show that Arctic sea ice loss has not stopped – it is continuing in a warming climate.'
