Kamal Ghorui
Scientists are again examining the strength of the Atlantic Meridional Overturning Circulation, the vast ocean system that moves warm water northwards through the Atlantic. The current, often linked in public discussion to the Gulf Stream, helps shape weather patterns across Europe, North America and parts of the tropics. New modelling suggests the circulation is now weaker than at any point in the past 1,600 years. Researchers say global warming and rising sea levels are contributing to the decline. Earlier climate projections considered a full collapse before 2100 unlikely. More recent simulations, extending further into the future, indicate the tipping point may be closer than previously assumed, though uncertainty remains.
Gulf Stream system faces up to 70 per cent collapse risk under rising emissions
According to the Arctic Portal, earlier studies suggested that a breakdown of the system this century was improbable. The new research uses more complex simulations and runs them over longer periods. In these projections, a tipping point could be reached within decades if greenhouse gas emissions continue to rise.The collapse itself, if triggered, might unfold over 50 to 100 years rather than happening suddenly. Still, scientists describe the probability as higher than past estimates. The study places the risk at 70 per cent under rising emissions. If emissions stabilise at current levels, the probability falls to 37 per cent. Even under reductions aligned with the Paris Agreement, researchers calculate a 25 per cent risk. Those figures have drawn attention because they suggest the system is more sensitive than once thought.
The gulf stream forms part of a wider climate system
The Gulf Stream carries warm water from the Gulf of Mexico along the eastern coast of the United States before turning towards Europe. It is one element of the broader Atlantic overturning circulation.As warm surface water travels north, it cools and becomes denser. It sinks into the deep ocean and flows back southward. This vertical movement acts as part of a global ocean conveyor, redistributing heat and nutrients.Western Europe is milder than other regions at similar latitudes partly because of this heat transport. Florida winters are also shaped by the same system. The circulation does not act alone, but it plays a steady role.
A collapse would reshape regional climates and sea levels
Researchers warn that a weakening or collapse could shift the tropical rainfall belt, affecting food production for millions. Some areas may see heavier rainfall, others prolonged drought. Sea levels along parts of the North Atlantic coast could rise by an additional half metre beyond existing projections. Winters in western Europe could turn colder, even as global temperatures continue to climb overall.Weather systems elsewhere may also destabilise. The changes would not be uniform. They rarely are.For now, scientists describe the findings as a warning rather than a forecast. The circulation continues to flow, though more slowly than before.
