Iceland flags AMOC collapse risk as national security threat amid growing scientific alarm
Following a formal designation by the Icelandic government in November 2025, researchers argue that the ocean current system vital to northern Europe's climate is approaching a critical threshold that could trigger severe global disruption.
Scientists are increasingly concerned that the Atlantic Meridional Overturning Circulation (AMOC), a critical system responsible for warming northern Europe and regulating global climate patterns, is nearing a potential tipping point. While earlier assessments suggested a collapse was unlikely before 2100, recent studies indicate the current may have already begun to slow and could weaken by 50 per cent by the end of the century.
In November 2025, the Icelandic government made the unusual move of designating the risk of an AMOC shutdown as a national security threat. This decision reflects a growing consensus among experts, including physical oceanographer Stefan Rahmstorf and Neil Fraser, that the consequences of a shutdown would be catastrophic, including severe cooling in Europe, disrupted monsoons, and intensified storms.
The mechanism driving this concern lies in the physics of the ocean itself. The AMOC is powered by cold, salty water sinking near Greenland, a process that pulls warm surface waters northwards. However, climate change is reducing water density by warming the ocean and adding fresh water from melting Greenland ice, which inhibits the sinking mechanism and slows the circulation.
Recent research has constrained climate models using real-world Atlantic temperature and salinity data, suggesting a potential 50 per cent weakening of the AMOC by 2100. This finding contrasts with the 30 per cent reduction predicted in the 2021 IPCC report, leading some scientists to argue that previous models may have been overcautious. Statistical analysis of sea surface temperatures over more than a century further predicts the AMOC could hit its tipping point between 2037 and 2109 if global emissions continue to grow.
Long-term climate model runs extending to 2300 suggest a 70 per cent chance of collapse under high-emissions scenarios, with the event most likely occurring in the early 2200s. Despite these projections, researchers caution that the science remains far from certain, with data collection on the AMOC limited to a consistent dataset from moored buoys dating back only to 2004.
The potential impacts of a shutdown would be drastic, with Europe potentially drying out and the temperature difference between northern and southern Europe increasing by approximately four degrees Celsius. Historical precedent exists, as an AMOC shutdown 12,000 years ago plunged Europe into ice-age-like conditions, underscoring the severity of the risk experts now face.
