Atlantic meridional overturning circulation

When people think about the risks of climate change, the idea of abrupt changes is pretty scary. Movies like “The Day After Tomorrow” feed that fear, with visions of unimaginable storms and populations fleeing to escape rapidly changing temperatures. While Hollywood clearly takes liberties with the speed and magnitude of disasters, several recent studies have raised real-world alarms that a crucial ocean current that circulates heat to northern countries might shut down this century, with potentially disastrous consequences. That scenario has happened in the past, most recently more than 16,000 years ago. However, it relies on Greenland shedding a lot of ice into the ocean. Our new research, published in the journal Science, suggests that while Greenland is indeed losing huge and worrisome volumes of ice right now, that might not continue for long enough to shut down the current on its own. A closer look at evidence from the past shows why. Blood and water The Atl...