Climate change has “almost complete[ly]” destabilized the Atlantic Meridional Overturning Circulation (AMOC), a critical aquatic “conveyor belt” that plays a major role in global temperature and weather systems, a new analysis published Thursday in Nature Climate Change reveals. Increasing ocean temperatures and, especially, the influx of freshwater from melting ice sheets and glaciers is slowing the AMOC, which includes the Gulf Stream. If circulation shuts off, North America and Europe could be plunged into extreme cold, U.S. East Coast sea levels could rise, and seasonal monsoons critical to much of the world’s water supply could be disrupted. The AMOC has stopped circulating before — at the end of the last ice age, setting off a Northern Hemisphere cold spell that transformed ecosystems and threw human societies into upheaval for 1,000 years. (Washington Post $, New York Times $, Reuters, The Guardian, USA Today)