AMOC shutdown

New climate research has reignited fears that the Atlantic Meridional Overturning Circulation (AMOC), a vast system of ocean currents that includes the Gulf Stream, could collapse within decades, potentially unleashing catastrophic weather worldwide.

Often likened to the fictional scenario in the 2004 film 'The Day After Tomorrow', the potential breakdown of this current is no longer considered a distant or unlikely event.

The AMOC plays a critical role in regulating global temperatures by transporting warm tropical waters northward and returning colder water southward at depth. Its weakening would disrupt this balance, leading to freezing winters in Europe, intensified tropical storms, and widespread droughts in regions dependent on stable rainfall patterns.

According to a study by Utrecht University, the AMOC could begin collapsing as early as the 2060s under current emissions trajectories.

European Climate Commissioner Wopke Hoekstra described the findings as a 'wake-up call', warning that the Gulf Stream 'could collapse in our lifetime.'

What Is the AMOC—and Why Does It Matter?

The AMOC is often referred to as the planet's "conveyor belt" of ocean heat. It carries warm water from the tropics up the eastern coast of North America and across to Europe, helping to keep northern Europe's climate relatively mild despite its high latitude.

If this system were to shut down, the consequences would be severe. A collapse would likely cause:

  • A dramatic drop in temperatures across Europe and parts of North America
  • Increased sea levels along the US East Coast
  • Disruption of monsoon systems in Africa and Asia
  • Intensified hurricanes and tropical storms in the Atlantic basin
  • Drier summers and reduced agricultural productivity in Europe

A report from MIT's Climate Portal notes that the AMOC has already slowed by up to 15% since the 1950s, though precise measurements remain debated. What is clear, however, is that warming oceans and melting ice are reducing the salinity and density of surface waters—key ingredients for the AMOC's continued flow.

Tipping Point Could Be Closer Than Expected

Previous climate models suggested that a complete shutdown of the AMOC was unlikely before 2100. However, new simulations extending into the 22nd and 23rd centuries show that under high-emissions scenarios, the current could collapse much earlier.

A study published by the Potsdam Institute for Climate Impact Research found that the tipping point for collapse is linked to the breakdown of deep ocean convection in the Labrador and Nordic Seas. As global temperatures rise, surface waters become warmer and less salty, making them lighter and less likely to sink to the bottom. This weakens the vertical mixing required to sustain the AMOC.

Lead researcher Sybren Drijfhout warned: 'The deep overturning in the northern Atlantic slows drastically by 2100 and completely shuts off thereafter in all high-emission scenarios, and even in some intermediate and low-emission scenarios.'

A Global Emergency in the Making?

The potential collapse of the AMOC has prompted calls for urgent action. A Daily Mail report described the situation as a 'global emergency', noting that the shutdown could devastate fishing industries, raise sea levels, and trigger extreme weather across both hemispheres.

A 2023 study by Ditlevsen and Ditlevsen estimates that, even under moderate emissions scenarios consistent with current government pledges, the probability of an AMOC collapse could be as high as 37%, with a possible tipping point occurring between 2025 and 2095.

These findings underscore the need to reassess climate risks and mitigation strategies, even under scenarios previously considered relatively safe.

European Commission Vice-President Teresa Ribera recently suggested that the AMOC should be 'added to the list of national security acronyms in Europe' due to its far-reaching impact.

Why A Collapse Would Matter For The UK

IPCC assessments indicate that an AMOC collapse would likely shift rainfall belts south, weaken the African and Asian monsoons, dry parts of Europe, and trigger abrupt regional changes.

A weaker AMOC is also linked to higher dynamic sea levels along the US East Coast, with studies attributing a sizable share of recent coastal flood days to AMOC-driven ocean heat changes.

The Caution: Not All Models See A Shutdown This Century

A 2025 Nature study led by the UK Met Office finds the AMOC weakens markedly under extreme greenhouse-gas and freshwater forcing across 34 models. Still, it does not fully collapse this century because Southern Ocean winds maintain a reduced overturning.

Experts stress that 'not collapsing' is not 'no problem': weakening alone can reshape European climate, sea level and storm patterns.

A Climate System on the Brink

While the idea of a sudden ice age may still belong to Hollywood, the science behind AMOC collapse is sobering. The current trajectory of global warming, driven by fossil fuel emissions and deforestation, is pushing Earth's climate systems toward irreversible tipping points.

Experts agree that deep and immediate cuts to greenhouse gas emissions are essential to reduce the risk. As Drijfhout and his colleagues concluded, 'The shutdown risk is more serious than many people realise.'

Whether or not the world heeds these warnings may determine whether the AMOC remains a stabilising force or becomes the trigger for a new era of climate chaos.

Risk is rising, timing is uncertain, and impacts from weakening are material even without a complete shutdown. Policymakers and forecasters will continue to monitor key indicators, including salinity near the southern Atlantic boundary and sustained observations from the RAPID array.

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