Nature Communications, 25 July 2023
New findings reveal that if global fossil emissions are not reduced, the Atlantic Meridional Overturning Circulation (AMOC) could collapse as soon as 2025 — in two years — with a range up to 2095, and central estimate of 2050. The AMOC is a large system of Atlantic ocean currents that carries warm water from the tropics northwards into the North Atlantic, where it plays a vital role in regulating Europe’s temperature and weather. This study used sea surface temperature records dating back to 1870 as a way of assessing the change in strength of AMOC currents over time. The data show that increased amounts of freshwater feeding into the North Atlantic from increased rainfall, river run-off and Greenland melt is decreasing the density of these waters. This creates a dangerous feedback loop which can cause the AMOC to slow down or even collapse. Current measurements in the 2000’s already document a slowdown; a collapse of the AMOC would have disastrous consequences around the world, severely disrupting rainfall patterns upon which billions of people depend for food in India, South America and West Africa. It would also increase storms and drop temperatures in Europe, and increase sea level rise along the eastern coast of North America.