The Gulf Stream could collapse in the next 100 years.The devastating effects in a new study

The melting of the ice slows down the Atlantic circulation, which has never been so weak in the last thousand years and according to scientists it could be at the point of no return

The Gulf Stream has already begun its journey towards the point of no return.The moment he will become so weak that even if the melting of ice due to climate change of anthropic origin were interrupted, there will no longer be any way to restore the flow of warm water which, starting from the Gulf of Mexico, currently brings warm water to all of Europe, guaranteeing the continent the mild winters it enjoys.These are the conclusions of a new study which highlights how the Atlantic circulation - the complex system of currents of which the Gulf is also part - risks collapsing.What would happen in this increasingly concrete scenario is only partially predictable, but the interruption of the Atlantic circulation would upset the climate of a large part of the planet.

The Gulf Stream has never been so weak in the last 1000 years

The study, published in the journal Science Advances It has an eloquent title: Physics-based early warning signal shows that AMOC is on tipping course (van Westen et al.) and some of the scientists who today constitute a point of reference for the analysis of the behavior of the Atlantic circulation worked on it.This is – he reports Climate control – the first work of its kind to bring together, through climate models, both the effects of climate change on the oceans and those on the atmosphere.And its results are in line with those of other important research published in recent years, which demonstrate that circulation has already slowed down by 15%, making it weaker than it has ever been in the last thousand years, and that its collapse could take place between 2025 and 2095.The time horizon traced by van Westen et al.is slightly wider:over the next 100 years.

Because the Gulf Stream is collapsing

The models show the future trajectory, but the signs are already there.As well as the main cause of the slowdown of the current:the melting of the ice – particularly that of Greenland – which dilutes the flow.To understand how, you need to understand how the current system works.The Atlantic circulation works like a giant ocean conveyor belt, moving heat, carbon and nutrients from the Tropics to the Arctic and back again.

In the specific example of the Gulf Stream, when the water crosses the warm Caribbean seas, it warms up and rises to the surface, continuing its journey towards northwestern Europe.There it releases the accumulated heat, increases its salinity becoming denser and heavier, and sinks and then returns southwards, touching the coast of Africa.However, the excess of fresh water coming from the melting of the ice makes the water less dense and salty, hindering the process of sinking towards the South.And it is precisely the signals on current salinity that worry scientists.

What would happen if the Gulf Stream collapsed

What would be the consequences of a collapse of the Atlantic circulation?If the interruption of the currents were to occur, in some regions such as the east coast of the USA, the level of the Atlantic Ocean would rise by one meter, inundating many coastal cities.The wet and dry seasons in the Amazon would reverse, potentially pushing the already weakened rainforest beyond its point of no return.Temperatures around the world would fluctuate much more erratically than they do now.

The Southern Hemisphere would become warmer, while Europe would cool dramatically and receive less precipitation.This latter effect might seem attractive compared to the current warming trend, but scientists point out that the changes would be 10 times faster than what we are experiencing now, making adaptation almost impossible.A scenario that Westen - the main author - defines as "devastating".

Collapse of the Atlantic circulation, the effects on Europe

The study focuses on the effects that would occur on Italy and Europe in the event of collapse.Italian cities are not examined, but it is possible to get a rough idea of ​​what could happen to our country, located in an intermediate range between Madrid and Vienna.If you look at the Spanish capital, you notice that summer temperatures would remain almost the same, with a decrease in the average temperature of between 1 and 2 degrees centigrade.

The winter differences are greater, with averages that could decrease by up to 4 degrees compared to current ones.The difference becomes more and more marked as we go north, above all due to the ice which, in the event of collapse, would extend towards the south much further than now, reflecting the sun's heat and preventing it from warming the earth's surface.Thus, in Vienna, February would become almost 10 degrees colder than now, while February in London, which now has temperature values ​​not too far from that of Milan, would cool down by as much as 15 degrees compared to now.

On the cover:OPEN / AMOC diagram, background graphics on currents in the Atlantic Ocean (generated with AI)