A sharp weakening of ocean currents, or even a shutdown, could be upon us by century’s end. The Atlantic Meridional Overturning Circulation (the ocean’s “great conveyor belt”), has weakened and shut down before in the past 13,000 years. As a result, mean temperatures in parts of Europe may have rapidly dropped to about 15 degrees Celsius below today’s averages, ushering in arctic-like conditions. Parts of northern Africa and northern South America became much drier. Rainfall may even have declined as far away as what is now China. Some of these changes may have occurred in a matter of decades, maybe less. No one knows if this will happen, but it’s one more increasingly common worrisome example of scientists coming up with something unexpected.
www.theguardian.com/environment/2023/jul/25/gulf-stream-could-collapse-as-early-as-2025-study-suggests