A vital system of Atlantic Ocean currents is weakening and closer to collapse than thought, new studies find
The critical system of ocean currents that loops around the Atlantic Ocean is weakening and may be much closer to collapse than previously thought, according to two new studies – an event that would have catastrophic impacts on the planet’s weather and climate.
The Atlantic meridional overturning circulation, known as the AMOC, functions like a vast conveyor belt, transporting heat, salt and fresh water across the ocean and influencing climate, weather and sea levels across the planet.
A growing body of research suggests it is weakening as human-caused global warming disrupts its delicate balance of heat and salinity, with one study even predicting it could collapse as soon as the next decade. But the AMOC is complex and has only been continuously monitored since 2004. Climate models generally agree that it is on track to weaken this century, but there is great uncertainty about the extent of its decline.
The stakes are incredibly high; a collapse of the AMOC, which last occurred around 12,000 years ago, would cause chaos. It would plunge Europe into a deep winter freeze, accelerate sea level rise along the U.S. east coast and lead to prolonged droughts in part of Africa.
The two new studies – one focused on AMOC’s future, the other on its present – provide new and alarming evidence of its decline.
The findings are “important and concerning,” said Stefan Rahmstorf, an oceanographer at the University of Potsdam who has studied AMOC for decades and was not involved in either report.
People load containers of water onto an animal in a drought-hit region of Kenya in August 2025. The collapse of the AMOC would have catastrophic consequences, including prolonged droughts across much of Africa. -Gerald Anderson/Anadolu/Getty Images
In the most recent study, published Thursday in the journal Science Advances, scientists combined climate models with real-world data, including ocean temperature and salinity, to chart the future of the AMOC over the coming decades.
They found that most climate models underestimate its decline. The AMOC is on track to slow by more than 50% by the end of the century, a “substantial weakening” 60% stronger than that estimated by the average of all climate models, according to the study.
The results show that “pessimistic” climate models, those that show a strong weakening of the AMOC, “are unfortunately the most realistic,” Rahmstorf said. This reinforces fears that it could pass a tipping point as early as the middle of this century, he added, at which point the shutdown “basically cannot be stopped.”
Alarmingly, the weakening of the AMOC could be even more pronounced than the study reveals, because Greenland’s meltwater is not included in climate models, Rahmstorf said.
Thursday’s study follows research published last week by scientists at the University of Miami, who looked at what’s happening to AMOC now.
They analyzed actual data from four moorings along the western edge of the North Atlantic Ocean, which have measured water temperature, salinity and ocean current speeds since 2004. They found that the AMOC had weakened at four different latitudes over the past two decades.
Disko Bay, Greenland, March 15, 2026. Melting ice disrupts the salinity balance that drives the AMOC. -Florent Vergnes/AFP/Getty Images
The fact that weakening was observed at all four sites is significant, said Shane Elipot, a physical oceanographer at the University of Miami and author of the report. Although the results focus only on the western edge of the Atlantic Ocean, that region is “the canary in the coal mine” for what happens to the AMOC, he said.
Real-world data helps validate predictions made by climate models, Elipot added. “What is worrying is that the same models predict that AMOC is likely heading towards a tipping point where it will eventually stop,” he said.
The study provides “strong observational evidence that the current AMOC is indeed in decline,” said René van Westen, a marine and atmospheric researcher at Utrecht University in the Netherlands, who was not involved in the research.
The results of both studies are very worrying, he said. They show that AMOC weakening is already underway and is underestimated by current projections.
“This also means that the risk of AMOC tipping becomes greater,” he added, “as each additional weakening of the AMOC pushes the system towards the tipping point.”
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