A new study suggests that a vital system of Atlantic Ocean currents, known as the Atlantic Meridional Overturning Circulation (AMOC), could face a potentially catastrophic collapse as early as the late 2030s. This could drastically alter global weather patterns and climate.
The AMOC, often described as a conveyor belt, transports warm surface water from the Southern Hemisphere and tropics to the North Atlantic. Here, the water cools, becomes saltier, and sinks, flowing back southward. This process helps regulate temperatures and nutrient distribution, preventing extreme heat in the Southern Hemisphere and severe cold in the Northern Hemisphere.
Recent studies have highlighted that the AMOC is at risk due to human-induced climate change, which has warmed ocean temperatures and altered salinity levels. The new research, although peer-reviewed but not yet published in a journal, employs advanced modeling to project that the AMOC could collapse between 2037 and 2064, with a likelihood of occurring by 2050.
“This is really worrying,” said René van Westen, a marine and atmospheric researcher at the University of Utrecht and co-author of the study. “All the negative side effects of anthropogenic climate change, like more heat waves, more droughts, more flooding, will continue. If you also have an AMOC collapse, the climate will become even more distorted.”
The impacts of an AMOC collapse would be profound. Over decades, Arctic ice would advance southward, potentially reaching the southern coast of England within a century. Europe and North America would experience a significant drop in average temperatures, and the Amazon rainforest would face a dramatic shift in its seasonal patterns.
Stefan Rahmstorf, a physical oceanographer at Potsdam University who was not involved in the study, emphasized the gravity of the situation: “An AMOC collapse is a really big danger that we should do everything we can to avoid.”
The Utrecht scientists used cutting-edge models and identified the South Atlantic Ocean as a critical area for monitoring AMOC changes. Their research focused on temperature and salinity to refine predictions of the system’s potential tipping point.
Rahmstorf noted the progress in AMOC research, stating, “Until a few years ago, we were discussing whether it would happen at all. Now it looks a lot more likely that this will happen within this century.” He added that the risk of passing the tipping point within this century is now estimated to be over 50%.
However, Rahmstorf pointed out a significant gap in current models: they do not account for the impact of melting Greenland ice. This influx of fresh water into the North Atlantic disrupts the salinity-driven mechanisms of the AMOC. “You’re already getting a huge influx of fresh water into the northern Atlantic, which is going to completely disrupt the system,” he said.
This omission means that predictions about the timing and severity of an AMOC collapse may be underestimated. As research continues, the urgency to address and mitigate climate change’s impact on this critical ocean current system grows ever more pressing.
