Scientists have expressed growing concern over a major Atlantic current that could collapse and send northern Europe into the next Ice Age.
Like much of Europe, Iceland witnessed its hottest year in 2025 – as heat-trapping gases continue to warm the planet.
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According to the Icelandic Met Office, the national average temperature last year was 5.2°C. This is a 1.1°C increase from the average for the years 1991-2020 and the highest since records began.
Temperatures were “well above average” for almost every month of the year, particularly during spring. In fact, in mid-May, a 10-day heatwave baked the country, with temperatures reaching a scorching high of 26.6°C at Egilsstaðir Airport.
Annual rainfall was below average for the past 10 years across most of the country, but it still exceeded the 1991-2020 average in many locations. For every 1℃ rise in air temperature, the atmosphere can hold around seven per cent more moisture, which can lead to more intense and heavy rainfall.
Despite increasing temperatures, scientists worry that global warming could eventually have the opposite impact in northern Europe.
The threat of an AMOC slowdown
Fears of rapid cooling all come down to the Atlantic Meridional Overturning Circulation (AMOC), a system of ocean currents that circulate water within the Atlantic Ocean – bringing warm water north and cold water south.
As warming temperatures accelerate the thaw of Arctic ice and trigger meltwater from Greenland's ice sheet to pour into the ocean, the current’s flow could be disrupted.
If this were to happen, scientists warn a “modern-day ice age” could be triggered across northern Europe, plummeting countries like Iceland into new cold extremes. The AMOC has collapsed previously, before the last Ice Age that ended around 12,000 years ago.
It’s why in September 2025, Iceland’s National Security Council officially designated the potential collapse of the AMOC as a security risk.
Will Iceland turn into ‘one giant glacier’?
A new report, published on the Nordic Council’s website on 5 February, warns that the AMOC’s collapse could trigger “extreme impacts” in Nordic countries that differ from, and in part oppose, those expected from global climate change.
Climate models show that Iceland’s winter extremes could reach a bone-chilling -45°C. It could cause sea ice to surround the country for the first time since the Viking era.
Speaking to the Washington Post, Hildigunnur Thorsteinsson, director general of the Icelandic Meteorological Office, says: “At that point, Iceland would be one giant glacier.”
Of course, it’s one scenario amongst many, but scientists warn it can no longer be dismissed as a doom-mongering fantasy.
“The AMOC is a key part of the climate system for the Nordic region. While the future of the AMOC is uncertain, the potential for a rapid weakening or collapse is a risk we need to take seriously,” says Aleksi Nummelin, Research Professor at the Finnish Meteorological Institute.
How can Iceland be pulled out of a deep freeze?
The report calls for “vigorous mitigation” to achieve decarbonisation and net negative emission targets – warning that the longer global temperatures overshoot 1.5°C above pre-industrial levels, the greater the risk of triggering an AMOC tipping point.
Researchers are also urging more long-term funding to be secured and to build an AMOC early warning system that “couples Earth observations with model simulations”.
“This early warning system should be embedded in policy-making processes to create rapid knowledge-to-action abilities,” the report reads. “The new EU Ocean Act provides possibilities for coordinating this effort.”
The study was conducted following a letter from climate scientists in 2024 that suggested the risk of an AMOC collapse might have been previously overlooked.