Scientists are sounding the alarm, warning that the Atlantic Meridional Overturning Circulation (AMOC) – the most critical system of ocean currents – may have passed a tipping point. A new study published on the Earth ArXiv platform uses complex climate models to assess the probability of this system's collapse. Under a conservative scenario of Greenland ice sheet melting, the likelihood of an inevitable collapse is estimated at ten percent, but under the worst-case emissions scenario by the year 2100, it rises to eighty percent. The AMOC plays a critical role in redistributing heat from the tropics to the Arctic, maintaining global climate stability and marine ecosystems, but rapid planetary warming and massive Arctic ice melt disrupt the fragile balance of salinity and temperature that drives this giant system.

If the AMOC does shut down, it will trigger global climate changes with catastrophic regional consequences that will inflict colossal damage on the global economy. Sea levels will rise sharply along the US East Coast and other densely populated coastal areas, requiring gigantic financial investments to protect infrastructure. Significant temperature shifts will also occur: for instance, average temperatures in Northern Europe could drop by five to fifteen degrees Celsius, dealing a severe blow to agriculture and the energy sector. The world will also face an increase in extreme weather events, including more destructive storms and a shift in the tropical rain belt, causing massive droughts in some regions and catastrophic floods in others, thereby destabilizing global food markets.

Although there is no scientific consensus on the exact timing of a potential AMOC collapse, the new study adds to a growing body of data indicating critical problems within this system. Previously published research predicted a slowdown of forty-three to fifty-eight percent by the end of the century, although other studies paint a less alarming picture and find no evidence of a sharp collapse. The authors of the new research emphasize that the probability of an already predetermined collapse exceeds ten percent regardless of future mitigation measures, meaning the window of opportunity to avoid the worst-case scenario may have been missed. Nevertheless, the fastest possible reduction in greenhouse gas emissions remains the only chance to prevent irreversible changes and protect the global economy from devastating climate shocks.