According to the study, the Gulf Stream could collapse before the end of this century

The circulation of the Atlantic is facing a "devastating tipping point" due to global warming, according to the latest study results from Dutch researchers at Utrecht University. This will lead to a cessation of the Gulf Stream and thus to drastic cooling in Europe and a significant rise in sea levels at a rate that will probably make it impossible to adapt to the serious changes. These are the scientists' warnings.

For decades, researchers have been warning of the negative effects of global warming on ocean currents, in particular of a possible collapse of the so-called Atlantic Meridional Overturning Circulation (AMOC). What is new about the Dutch study by René M. van Westen, Michael Kliphuis and Henk A. Dijkstra from the Institute for Marine and Atmospheric Research in Utrecht is the development of an early warning signal to detect a possible collapse of this system.

What exactly is the study about?

Specifically, the Dutch study by René M. van Westen, Michael Kliphuis and Henk A. Dijkstra from the Institute for Marine and Atmospheric Research in Utrecht deals with the consequences of climate change for AMOC, as reported by CNN and the Guardian , citing the journal "Science Advances".

"One of the best-known climate tipping elements is the AMOC, which can collapse due to the input of freshwater into the North Atlantic. Although AMOC collapses have been triggered by strong freshwater forcing in complex global climate models, the processes of an AMOC tipping event have not yet been investigated," the study authors state in their article.

According to the authors, the study results provided a "clear answer" to the question of whether such an abrupt shift in the AMOC is possible. "This is bad news for the climate system and humanity, because until now it was thought that the AMOC tipping was only a theoretical concept and that the tipping would disappear as soon as the entire climate system with all its additional feedbacks was taken into account." The Dutch researchers expressed shock at the predicted speed of collapse once the point is reached, although they said it is not yet possible to predict how quickly this will happen.

You can read the original study here: Physics-based early warning signal shows that AMOC is on tipping course.

What is AMOC?

AMOC describes a complex system of currents in the Atlantic Ocean, of which the Gulf Stream is also a part. It is considered a key component in regulating the climatic conditions on the planet. It transports heat, carbon and nutrients from the tropics towards the Arctic Circle. There, the current cools down and sinks into the deep sea. There it flows south again. This circulation helps to distribute energy across the earth and to dampen the effects of man-made global warming.

Circulation has decreased by 15% since the 1950s. Due to the melting of the Greenland glaciers and the Arctic ice sheets, more fresh water is flowing into the sea and preventing the saltier, warmer water from the south from sinking.

Complex, expensive computer models

Using computer models and data from the past, the researchers developed an early warning indicator for the collapse of the AMOC. This took them six months of computing time on the Dutch national supercomputer Snellius. In addition to factors such as precipitation and evaporation, the calculations also included an increased supply of freshwater in the North Atlantic, which gradually reduced the circulation in the simulation.

On the way to the tipping point

The Utrecht researchers found that the AMOC circulation is already on the way to an abrupt shift that has not occurred for more than 10,000 years and would have catastrophic consequences for large parts of the world. The timing is still unclear, but with a statistical certainty of 95%, this shift will occur this century.

"But we can at least say that we are approaching the tipping point of climate change," lead author René van Westen, a marine researcher at Utrecht University, is quoted as saying. "What surprised us was the speed with which the reversal is occurring," he says, adding: "It will be devastating. Once the circulation in the Atlantic Ocean breaks down, the resulting climate impacts are almost irreversible on human timescales." The tipping point must be avoided in order to prevent devastating consequences for the climate, society and the environment.

Oceanographer Prof. Dr. Stefan Rahmstorf from the Potsdam Institute for Climate Research praised the work of his Dutch colleagues on Deutschlandfunk radio. They had carried out an "almost epic model simulation" on a thousand computer nodes. For the first time, this had been done with a "really good climate model".

"The risk of collapse must be prevented at all costs," says Rahmstorf. "If we have a definitive warning signal, it will be too late to do anything about it."

According to the Guardian, there is still no consensus among researchers on how quickly we are heading towards this tipping point: While a study from 2023, which was based on changes in sea surface temperatures, placed the tipping point between 2025 and 2095, the UK Met Office classifies large, rapid changes in AMOC in the 21st century as "very unlikely".

The consequences would be dramatic

The consequences would be dramatic and devastating. According to the study, temperatures in Europe would fall by up to 30 degrees within a decade, with significant temperature differences between winter and summer. "There are no realistic adaptation measures that can cope with such rapid temperature changes," write the authors of the study, according to the Guardian and CNN.

In the southern hemisphere, it could lead to further warming and a reversal of the rainy and dry seasons in the Amazon, which would pose a massive threat to the rainforest.

Furthermore, there would be a shift in tropical rainfall, leading to droughts and flooding in various regions. This would have a significant impact on global food production, as the area under cultivation for wheat and maize would be greatly reduced, which would jeopardize food security.

In addition, the collapse of the AMOC will lead to a rise in sea level of one meter and the associated flooding of many coastal towns.

Getting measures underway as a matter of urgency

Experts emphasize the urgency of taking climate protection measures to prevent this potential catastrophe. This requires the reduction of emissions and the increased use of renewable energies. Ultimately, it is about taking responsibility for the future and protecting the natural foundations of life. This is also emphasized by study director van Westen: "We need to take climate change more seriously. We, as a global society, must stop emissions."

All the major media reported on it. Will the knowledge of this impending tipping point change our behavior?

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