Not if, but when

In recent years, scientists have tracked and measured the flow of the Atlantic Meridional Overturning Circulation (AMOC), which Americans often call the Gulf Stream, although this flow is only part of this huge ocean current. It has long been believed that the AMOC - which transports heat from the tropics to Greenland, Iceland and northern Europe, making them much warmer than they would otherwise be - will continue to flow with no discernible end date.

But two recent studies suggest that sometime around mid-century, the current could not just slow down but stop altogether, dropping temperatures in northern Europe dramatically. An earlier study from 2023 suggested that the collapse could occur sometime between 2025 and 2095, a wide interval but really a blink of an eye in geologic time. The most recent study published this year used a more sophisticated model and narrowed the window from 2037 to 2064. Both studies put the most likely collapse date at mid-century (either 2050 or 2057). (Kurt Cobb, originally published by Resource Insights, more at resilience.org)