Iceland has officially declared the potential collapse of the Atlantic Meridional Overturning Circulation (AMOC) as an existential threat, marking one of the strongest warnings yet over a key Earth-system tipping element. The highlights enormous influence AMOC has on Europe’s climate by bringing warm tropical waters into the North Atlantic and moderating winters across the region.
Iceland climate minister, Johann Pall Johannsson, told that the weakening of AMOC is now considered “a direct threat to our national resilience and security”. It is the first time the country has formally placed a climate-related system before the National Security Council as a potential existential risk.
Other North European governments, including climate and meteorological agencies, are now reassessing AMOC-related risks in their adaptation strategies.
AMOC is widely recognised as one of the critical tipping elements of the planet’s climate system. Scientists warn that beyond a threshold, its weakening could become irreversible, potentially leading to a complete collapse.
Accelerated melting of Greenland’s ice sheets is already pushing the system toward instability. According to recent scientific assessments, AMOC could collapse anytime between the near-term and late-21st century, with many uncertainties still unresolved.
A complete shutdown could bring a modern ice-age-like scenario to northern Europe, with extreme cold, intense snowfall and prolonged winters. The last time AMOC collapsed was before the last ice age just before agriculture and early civilisation began.
Iceland begins preparing for a new climate reality
Iceland ministries are now preparing for the possibility of losing warm tropical currents that shape its climate. According to sources, the government is assessing research needs, drafting a disaster-preparedness policy and reviewing risks related to food security, energy generation, distribution systems and sea-based transportation.
scientific warnings grow stronger
Continuous monitoring of AMOC began only in 2004 through a combination of underwater moorings, submarine cable current readings and satellite observations. A 2023 study published in Nature Communications found clear signs of AMOC slowing between 2004 and 2012, but emphasised the need for longer records to determine long-term trends.
An analysis of sea-surface temperatures in the North Atlantic subpolar gyre considered a fingerprint of AMOC stability found early warning signals emerging as far back as 1970. According to researchers, the most likely timeline for a transition ranges between 2037 and 2109.
A separate 2025 report from the Potsdam Institute for Climate Impact Research warns that the deep overturning circulation could slow drastically by 2100 and shut down entirely afterwards, even under some moderate-emission scenarios. Such a collapse, the report notes, would bring severe winter extremes to north-western Europe, major summer drying and major shifts in tropical rainfall belts.
A February 2025 study in Nature suggests AMOC may be more resilient than some analyses predict, though it still confirms ongoing weakening with significant regional impacts. The authors stress the need for better understanding of Southern Ocean and Indo-Pacific circulation patterns to refine AMOC projections.
Despite scientific debates over timing, European governments are treating the threat with growing urgency. Iceland has taken the lead by formally placing AMOC into its national security framework. Norway’s environment ministry has said it is “seeking to deepen our understanding of the issue through new research” before deciding whether to classify AMOC as a security risk.