Recent research indicates the AMOC is slowing significantly, with the climate emergency as the critical factor. What are the key political issues behind what may be one of the most challenging consequences of human-created climate change?
An Introduction to AMOC
Europe’s mild climate owes much to the AMOC, a vast system of ocean currents that transports warm tropical waters northward. This includes the Gulf Stream, which provides ice-free seas year-round for the British Isles, north-western Europe, and even the waters of northern Russia near the Kola peninsula. Places at similar latitudes, such as much of Canada, experience far harsher winters because they lack such a warming current.
The AMOC has played an important role throughout human history. For example, during World War II, convoys supplying Russia in its fight against the Nazis were able to reach Russia around northern Norway, despite German attacks. This helped build capacities to resist Nazi Germany, successfully. Russia, post-AMOC collapse, would have far more sea ice in the North-West – conditions that would make such supply routes impossible.
Although a shutdown of the AMOC would have global consequences, this article focusses on the implications for Europe. Briefly, a weakening of the subpolar gyre and its associated currents would reduce the transport of warm water from the tropics to the northern Atlantic. Some scientific studies suggest that the subpolar gyre could collapse if global warming reaches around 1.8°C above the pre-industrial levels, potentially within the coming decade. Further warming, approaching 3°C, could bring a collapse of this part of the AMOC. Several governments already regard this as a major security risk.
AMOC slowdowns and collapses have occurred before. Paleoclimate data has revealed disruptions over the past two million years, including as recently as 11-12,000 years ago. Each of these occurrences was marked by “abrupt climate shifts”.
A system in decline
Scientific observations of cooling waters south of Greenland date back more than a century. Research strongly suggests this has been driven by human-induced climate change, but this also demonstrates a weakening AMOC. Studies indicate that the AMOC has slowed over recent decades, and accelerated ice melting in Greenland is likely contributing to this trend. If the AMOC were to collapse, winter temperatures across Iceland, Britain, and Scandinavia could drop dramatically, even in an otherwise warmer world, with potentially severe impacts for the UK.
The Intergovernmental Panel on Climate Change (IPCC) warns that an AMOC failure would also lead to a drier Europe, intensifying droughts. Winters in the UK could become alarmingly colder, whilst summers grow even hotter, unless global warming is put into reverse. How human societies might adapt to the global effects of an AMOC collapse – on growing seasons, droughts, and different levels of sea level rise as examples – remains uncertain.
We should note that the AMOC is part of a globally-connected system. Evidence that Antarctic bottom-water circulation slowed by about 12% between 2000 and 2020 suggests that multiple components of the ocean’s circulation are changing simultaneously. These shifts make one thing clear: global climate changes are weakening the AMOC, and rapid global action is urgently needed.
An academic debate?
As with the issue of future sea-level rise, there is scientific debate about how quickly the AMOC might collapse. Views vary, and they continue to evolve as new data emerges. Some studies suggest that limiting global warming to 2°C above pre-industrial levels is achievable by 2100. However, temperatures could rise further in the following century. Recent COP discussions indicate that current emission reduction plans still risk temperature increases of around 2.6-2.8°C by 2100. This maintains the potential risk of an AMOC tipping point.
Uncertainty continues as to the temperature at which the AMOC might collapse. Some have suggested it to be as low as 1.4°C or as high as 4°C above pre-industrial levels. Notably, global temperatures are close to 1.4°C at present, highlighting the urgency of these risks.
When might the AMOC collapse occur?
Some studies suggest that the expansion of cold waters in the North Atlantic could permit a weakened AMOC to continue. Other research, however, places a possible AMOC collapse between 2037 and 2064, with an average estimate of around 2050. Climate projections also suggest that the AMOC could weaken by around 30% by 2060.
However, regardless of such scenarios, differences in evidence interpretation should not delay stronger action to prevent such a catastrophic tipping point. An AMOC collapse at any future date would have profound consequences, such as shorter growing seasons or harsher winters. These are outcomes that Europe is not prepared to face.
As climate scientist James Hansen has noted:
“…paleoclimate data, global modelling, and ongoing ocean and ice sheet observations raise concern that rapid shutdown of the ocean’s overturning circulation could occur within decades, which can affect ocean/ice sheet interactions and the rate of sea level rise.”
AMOC and the media: a critical gap
Media attention to the threat of AMOC has been slowly improving in UK. For example, when the Nordic Council of Ministers received a letter from climate scientists in October 2024 warning of the AMOC changes, the issue was covered by news organisations, such as the Daily Mail and The Times. However, some journalists are quick to side with scientists who argue that a potential AMOC collapse is unlikely before 2100. This influences how the issue is presented in public debate.
Jonathan Fuller has engaged with the BBC’s lack of AMOC coverage. In a letter to the organisation on 11th November 2025,: he wrote:
“…AMOC collapse. The ocean current that brings warm water from the Gulf Stream to the UK is at grave risk of collapse, with significant weakening expected over the next 3 decades…
The Institute and Faculty of Actuaries seeks to assess risk and has warned of the grave risk 4 billion people could be killed when global heating is 3°C above pre-industrial levels. The Institute warns the 3°C threshold could be reached by 2050.”
Whilst some people associate the AMOC collapse with the exaggerated scenario depicted in the film The Day After Tomorrow, it can also be interpreted as a highly accelerated version of an AMOC break down, one that centres primarily on the United States, but includes some portrayals of impacts on the UK.
Effects on the UK of a full AMOC collapse
A full collapse of the AMOC would have profound consequences for the UK. Winters could become longer, colder, and more snow-burdened, potentially reaching extreme temperatures. For example, around minus 20°C in London Summers, in contrast, could be hotter than the present.
This would cause a huge drop in UK food production, with some experts suggesting that many arable crops would no longer be viable. There would also be huge impacts upon existing transport, energy, water, and other forms of infrastructure, and increased migration may occur as people seek to relocate.
Political actions to avoid an AMOC collapse
The most urgent response to this exceptional risk of AMOC collapse should be action to radically reduce fossil fuel use. Key actions could include:
Clear, ambitious climate targets
- Implement sector-by-sector carbon-negative policies, rather than relying on the ambiguous “Net Zero”, ensuring industries cannot continue emitting through loopholes.
- Set shorter, specific timescales for full implementation, such as aiming for an absolute deadline of 2040, with specific targets between 2030 and 2040.
Redirecting resources away from fossil fuels
- End all forms of fossil fuel industry subsidies, concessions, tax advantages, and related tax loopholes wherever the UK has influence.
- Reassess relying on carbon capture and storage, considering past long-term leakages of stored C02 back into the environment.
- Reconsider new nuclear power stations on costs and safety grounds, favouring cheaper and lower-risk alternatives.
Strengthening infrastructure and adaptability
- Insulate or adapt all homes to withstand both extreme hot summers and cold winters.
- Upgrade transport systems, schools, and hospitals to maintain functionality under severe weather conditions, such as implementing more remote working.
Rapid emissions reductions in high-impact sectors
- Immediate, rapid cuts in the largest sources of UK emissions.
- Phase out the most polluting transport such as banning of private jets, halting airport expansions, and developing just transitions for some airport sites away from aviation uses.
- Implement measures such as electronic road pricing, beginning in areas with higher traffic movements, to help fund active travel, electric buses, and railway electrification.
Integrating adaptation and global climate considerations
- Ensure all actions to reduce the risk of the AMOC collapse also strengthen overall efforts towards the climate emergency which is currently not being stopped on a global scale.
- Reassess UK aid cuts and ensure that international support aligns with global climate priorities.
- Encourage academics and governments to challenge and update emergency planning, considering the full implications of an AMOC collapse, to prepare countering measures. The policy areas this will involve are extensive.
Looking forward
The threat of a declining AMOC, and that of its eventual collapse, illustrate that the idea of adaptation to climate change is seriously compromised by very large changes in conditions.The UK’s infrastructure has not been constructed with longer, bitterly cold winters in mind, especially not for such cold winters occurring every year. UK growing seasons would be shorter and in practice mean increased food imports. Unlike peoples around the planet used very cold winters, residents of the UK may not readily adjust to such large changes.
Migration of people either out of the UK or to its southernmost fringes would present huge challenges. The failure to make year-on-year cuts in greenhouse gas emissions and global temperatures would turn the existing climate emergency into catastrophic conditions for those countries afflicted by AMOC collapse. Deep, rapid cuts in emissions, especially by states with the greatest emissions, are needed; the foot-dragging tendencies of the present are ery ill-advised
Author’s note: Thanks to Hazel Dawe and Jon Fuller for their helpful comments.
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