“We are approaching a turning point.” Scientists: The Gulf Stream will stop in 2025

In the 2004 film The Day After Tomorrow, humanity plunges into a nightmarish frozen collapse that sends the planet into a new ice age. And although the blockbuster has been classified as a science fiction film, the science behind this frightening scenario is correct. According to experts, in a few years the melting of glaciers could stop the Gulf Stream, a system of currents that brings heat to the northern hemisphere.

Without this additional heat source, average temperatures could drop several degrees in North America, parts of Asia and Europe, and people would see “serious and cascading impacts around the world.”

For the fact that the climate in the countries of the Old World is quite mild and pleasant, its inhabitants have to thank the system of currents in the Atlantic Ocean, primarily the Gulf Stream. It is its warm waters that wash the shores of this large peninsula in western Eurasia (and from the point of view of physical geography, this is what Europe is), so that in winter the weather there is quite bearable.

In recent years the climate has presented Europeans with many unpleasant surprises and there is an explanation for this. Scientists note that Atlantic currents are slowing down to critical levels. This means that Europe and part of North America may become covered in ice, as has happened before in history.

A recent study by specialists from Utrecht University (Netherlands) shows that collapse could happen as early as next year.

How does a conveyor work?

The current system in question is called the Atlantic Meridional Overturning Circulation (AMOC). It is driven by differences in temperature, salinity and density of water in different parts of the ocean.

The AMOC carries warm water from south to north, where it gives off heat to the atmosphere and, having cooled, sinks to depth, after which it flows back, from north to south. There it heats up again and the conveyor restarts.

Scientists have enough data that suggests that in the past (at least over the past 100 thousand years) the Atlantic current system has already stopped, which led to serious climate changes in just a few decades.

For example, in 2022, scientists from the University of Sao Paulo (Brazil) analyzed sediments on the ocean floor and found that twice (about 71 thousand years ago and 12 thousand years ago) icebergs broke off from the glaciers of Greenland and North America, bringing them into the Atlantic huge volume of fresh water. This is what disrupted the circulation of currents.

What was known before this?

Scientists have been saying for a long time that the conveyor belt has already begun to slow down. A study published in 2018 in the journal Nature showed that the Gulf Stream has been decreasing in speed over the past 150 years, and is now 15% weaker than it was in the mid-20th century.

In 2021, climate scientist Niklas Boers of the Potsdam Institute for Climate Impact Research published a study arguing that the AMOC system had suffered an “almost complete loss of stability.” She has become weaker than she has been in the last thousand years, and this trend is unlikely to stop.

“The findings indicate that the decline in Atlantic current circulation is likely to indicate a critical threshold at which the system may collapse,” Boers wrote at the time. “And it will happen sooner than we originally thought.” Stopping circulation will inevitably lead to serious consequences and catastrophic changes in weather throughout the world.”

What did the simulation show?

Now a new study on this topic has been published in the journal Science Advances. Its authors carried out modeling and suggested that a tipping point associated with the influx of fresh water into certain areas of the ocean (again, this is what slows down the conveyor) could occur as early as 2025.

As an example, they cite AMOC measurements at 34 degrees south latitude. Modeling shows that freshwater flow at this point reaches its minimum about 25 years before the collapse of the entire Atlantic system. But real climate data tells scientists that this minimum has long been reached! And we may already be at the end of the 25-year warning period.

So far, scientists are not completely sure of this, since they are unclear about the reason for the decrease in fresh water flow in the South Atlantic. However, it is a fact that it is declining.

“We are approaching a tipping point, but we cannot determine the exact distance to it,” says study author Rene van Westen from Utrecht University.

What does this mean?

If the Atlantic conveyor belt stops in the near future, the consequences will be dire, scientists say. This will inevitably affect the climate in Europe and North America – there will be a noticeable cooling there, even to the point of glaciation. According to the authors of the work, over the course of a century the average annual temperature in the countries of the Old World will drop by 10 degrees. But in some regions it will fall at a rate of 3 degrees per decade, which means it could fall by 30 degrees in a century.

In the Southern Hemisphere it should become warmer, although not by much. In general, the collapse of the AMOC can affect the distribution of precipitation around the world and result in weather disasters and crop failures in any corner of the planet.

In addition, this is fraught with a global humanitarian catastrophe – in many countries of the world there will be a shortage of food and drinking water.