New study presents direct observational evidence of a weakening of part of the Atlantic overturning current system. Researchers warn of possible impacts on European winters, rainfall, storms and sea level rise
The great Atlantic Ocean current system, which plays a central role in regulating the Earth's climate, has been weakening for nearly 20 years, according to a new study by researchers at the Rosenstiel School of Ocean, Atmospheric and Earth Sciences at the University of Miami. The study was published April 8, 2026, in the journal Science Advances (science.org).
The study is about the Atlantic Meridional Overturning Circulation, or AMOC. It is a huge circulation system that moves relatively warm water northward in the Atlantic Ocean, and returns colder, deeper water southward. In simple terms, it is one of the important mechanisms that helps distribute heat between different regions of the Earth. Therefore, a change in its strength does not only affect the ocean. It can also affect temperatures, rainfall, storms, and sea level.
The researchers emphasize that the findings do not indicate an immediate collapse of the system. However, they provide some of the strongest direct evidence yet that a central part of the system has been consistently weakening. According to the study, the weakening was measured along the western boundary of the Atlantic Ocean, between the subtropics and midlatitudes, roughly between 16.5 and 42.5 degrees north.
To examine the state of the system, the researchers analyzed long-term measurements from four marine monitoring systems. The instruments were anchored to the seabed and measured pressure, temperature, density, and currents over time. The researchers used the same analysis method at all measurement stations, primarily examining the deep flow below about 1,000 meters.
The trend appeared in several latitudes
The importance of the study stems from the fact that the trend appeared across several latitudes and not just at one measurement point. This means, according to the researchers, that this is not necessarily a local fluctuation or a temporary event. The resulting picture is of a broader change in part of the Atlantic system.
Dr. Shane Allifoot, one of the senior authors of the paper, said that a weaker AMOC could shift weather patterns. He said this could be manifested in more extreme storms, changes in rainfall amounts, or colder winters in some areas. He added that the weakening of the system could also affect sea level rise along coasts, and therefore also on communities and infrastructure.
The AMOC is considered one of the most important climate components in the Atlantic region. It particularly affects the North Atlantic, but its potential implications are broader. Among other things, a change in its strength could affect winters in Europe, hurricane activity, precipitation patterns, and climatic conditions in other parts of the world.
The study fits into a broader scientific debate about the future of the Atlantic circulation system in the era of the Climate Crisis. In recent years, studies have been published that have warned of a growing risk of significant weakening and even future collapse of the AMOC. However, there is still uncertainty about the pace, intensity and precise threshold of the changes. The contribution of the new study is that it relies on long-term direct measurements, and not just on models or indirect indications.
Early warning system
The researchers suggest that measurements along the western boundary of the Atlantic Ocean could serve as a kind of early warning system. If this region does reflect a broader change in the system, continued monitoring of it could help better predict future climate changes.
According to Elipot, such information is important not only for scientists. Governments, businesses and communities use climate predictions to prepare for future environmental changes. The more accurately we understand the AMOC, the better we can assess risks such as rising sea levels, changing rainfall patterns or the worsening of extreme weather events.
The study is called “Meridionally consistent decline in the observed western boundary contribution to the Atlantic Meridional Overturning Circulation”. It was published in Science Advances, and was funded by the US National Science Foundation and the UK Natural Environment Research Council.
Short questions and answers
What is the AMOC system?
This is a large system of currents in the Atlantic Ocean, which moves warm water northward and cold, deep water southward.
Does the study determine that the system is about to collapse??
No. The study indicates a consistent weakening in part of the system, but does not state that it is an immediate collapse.
Why weakening is important?
Because it could affect winters in Europe, rainfall patterns, storms, and rising sea levels along coasts.
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