A sudden halt of Atlantic Ocean currents, which could result in a severe drop in temperature in Europe, is becoming increasingly possible and closer in time according to a recent computer simulation. The model suggests a “cliff-like” tipping point may occur in the future.

A new research in Science Advances suggests that the long-feared consequence of Greenland’s ice sheet melting due to global warming may not be as far off as previously thought. However, the study, which utilized advanced simulations and considered various factors, indicates that this scenario may still take several decades to occur, rather than centuries. It also highlights the decline in the overall strength of ocean circulation, a crucial measure in understanding this process.

A potential failure of the Atlantic Meridional Overturning Circulation, known as AMOC, would have significant impacts on global weather patterns and ocean dynamics. This could result in a decrease of 5 to 15 degrees Celsius in temperatures in northwestern Europe over a period of decades, as well as an expansion of Arctic ice further south and increased heat in the Southern Hemisphere. The study also suggests that such a collapse could alter global rainfall patterns and disrupt the Amazon. Other experts warn that it could lead to catastrophic consequences, including food and water shortages worldwide.

The lead author of the study, Rene van Westen from Utrecht University in the Netherlands, stated that we are getting closer to the point of collapse, but the exact distance is uncertain. He also mentioned that we are approaching a tipping point.

The timing of when this exaggerated global weather disaster, depicted in the film The Day After Tomorrow, may occur is uncertain and cannot be determined at this time, according to van Westen. He believes it could potentially happen in the next 100 years, which could still be within his lifetime as he recently celebrated his 30th birthday.

According to van Westen, the extent of climate change is influenced by the rate of change caused by human activities.

Research indicates that the AMOC is slowing down, but the concern lies in its potential for a total collapse or shutdown. The Intergovernmental Panel on Climate Change, comprised of numerous scientists who provide regular, reliable updates on global warming, has stated with moderate confidence that a collapse is not likely to occur before 2100 and has largely dismissed catastrophic scenarios. However, van Westen, along with several other scientists and a recent study, suggest that this belief may be inaccurate.

Stefan Rahmstorf, leader of the Earth Systems Analysis division at the Potsdam Institute for Climate Research in Germany, did not contribute to the study, however he praised it as “a significant step forward in understanding AMOC stability.”

According to an email from Rahmstorf, the recent study contributes greatly to the growing worry about a potential collapse of the AMOC in the near future. Disregarding this information could have serious consequences.

According to Tim Lenton, a climate scientist at the University of Exeter who did not participate in the study, the results make him increasingly worried about the possibility of a collapse.

Lenton stated that a potential collapse of AMOC could have far-reaching consequences on global climate, which would be extremely sudden and extreme, making it nearly impossible to adjust to in certain areas.

Oceanographer Wei Cheng, who was not involved in the study, stated that while there is evidence of past collapse of the AMOC, the timing and manner of future changes remains uncertain.

NASA states that the AMOC is a component of a complex system of ocean currents that circulate varying levels of salt and warm water throughout the world at various depths. This pattern helps to control Earth’s temperature, absorb carbon dioxide, and power the water cycle.

According to van Westen, when the AMOC ceases, there is a decrease in global heat exchange which greatly affects Europe.

For centuries, the oceans of Earth have depended on a circulation system that functions like a conveyor belt. While it is still operational, its pace is decreasing.

The motor of the conveyor belt is located near Greenland’s coast. Due to increased ice melting caused by climate change, more fresh water is entering the North Atlantic, causing a slowdown in the system. Currently, colder and fresher water moves south past both Americas and then east past Africa. Meanwhile, warmer and saltier water from the Pacific and Indian oceans flows past the southern tip of Africa, turns around Florida, and continues up the east coast of the United States towards Greenland.

The researchers from the Netherlands recreated 2,200 years of the AMOC’s flow, taking into account the effects of human-caused climate change. They discovered that after 1,750 years, there was a sudden collapse of the AMOC. However, they are currently unable to apply this simulated timeline to predict the actual future of the Earth. A crucial aspect in monitoring these changes is a complex measurement of flow near the tip of Africa. A more negative measurement indicates a slower AMOC.

According to van Westen, this numerical measurement is becoming increasingly negative due to the effects of climate change. He also mentioned that once it reaches a specific threshold, it abruptly drops off rather than gradually decreasing.

Joel Hirschi, division leader at the National Oceanography Centre in the United Kingdom, emphasized the importance of monitoring the potential collapse of AMOC. However, he also noted that there is a greater global priority to consider.

“I am more worried about the quickly rising temperatures and extreme temperature events that we have been seeing in recent years, rather than the possibility of the AMOC shutting down,” stated Hirschi. “The warming is not just a theoretical problem, it is already occurring and affecting society at this moment.”

Source: voanews.com