The Atlantic Current, a vast marine conveyor belt that transports warm tropical waters toward the North Atlantic, is weakening and may soon falter, bringing notable shifts to European temperatures. Researchers have warned about this trend for years. The latest study confirms a drop in the current’s power and suggests a potential abrupt halt in the not too distant future. Should this occur, Europe could face extended droughts and a tendency toward colder winters across the continent.
“When this occurs, the movement of warm tropical waters into the North Atlantic would pause, and those waters would cool, exerting a decisive influence on regional climate,” explains a meteorology expert from the Complutense University of Madrid, Juan Jesus Gonzalez Aleman.
The Nature journal study presents evidence of the behavior of this oceanic conveyor, known as the Atlantic Meridional Overturning Circulation AMOC, indicating it is near an imminent collapse.
Thermohaline circulation THC is a key global component of ocean dynamics. It plays a central role in shaping the world’s climate by contributing significantly to the planet’s net heat distribution.
Within this conveyor the AMOC helps regulate temperatures in the southern Atlantic. “Thanks to its action, Madrid can enjoy milder winters than New York at a similar latitude,” notes the atmospheric scientist.
Its mechanism involves a current of warm, salty water riding the upper Atlantic, while a colder, deeper flow sinks southward to feed the deeper parts of the circulation system.
Over the last decade the engine driving the Atlantic current has weakened, a trend many attribute to climate change. While the exact cause remains debated, melting Greenland ice is a leading theory, since the added freshwater can disrupt sinking water that fuels the current.
This shift, coupled with the increased stratification of surface waters due to rapid warming, has pushed the system closer to a potential tipping point.
The study does not give a precise timeline, but it does not rule out a disruption within decades and possibly before century’s end. “A abrupt change would have disastrous consequences for Europe and globally,” the researcher states, as a radical climate shift could unfold.
In fact this scenario is considered a climate system tipping point, meaning once reached, the regional climate may never revert to its former state.
Nine climate tipping points
The Intergovernmental Panel on Climate Change identifies nine critical tipping points that face severe risk of disruption. These include Arctic sea ice, the Greenland ice sheet, boreal forests, permafrost, the Atlantic current system, the Amazon rainforest, warm water coral systems, and both western and eastern Antarctic ice sheets. These points are interconnected; stress in one area can ripple across the system.
“This could be more threatening than gradual warming alone. Effects accumulate, yet the changes may be abrupt and unexpected,” the expert notes. Expected impacts span reduced rainfall in some regions, heavier snow cover in parts of Europe, agricultural challenges, and a greater likelihood of intense cyclones.
Gonzalez Alemán cautions that the observed effects may seem counterintuitive yet not improbable. He emphasizes that some regions might experience balance shifts where some climate interactions weaken while others intensify.
He adds that the future climate landscape will be far from simple. “We do not know all the possible outcomes, and there will likely be unpredictable events,” he says.
Reference work: Nature 2021 study on AMOC behavior and tipping points. You may also be interested in recent reports confirming the Atlantic conveyor belt is slowing down.