cross-posted from: https://hexbear.net/post/5204608

Just below Greenland is a menacing stretch of water known as the Cold Blob. As the planet heats up, the Cold Blob remains a spooky outlier — positioned right above the area where the Atlantic Ocean’s so-called conveyor belt is supposed to switch back and head south.

The Atlantic Meridional Overturning Current, or AMOC for short, comprises an enormous system of currents that carries water and nutrients across the world and plays a large part in stabilizing the global climate. For years, scientists have warned that the AMOC was slowing down, possibly nearing collapse. The Cold Blob is the most immediately visible proof of its decline, likely a result of Greenland’s melting glaciers, but research on the deep water current’s strength over recent years has varied wildly

The stakes could hardly be higher. Should the current break down, the most frightening predictions describe a world thrown into chaos: Drought could destroy India, South America, and Africa; the Eastern Seaboard of the United States would see dramatic sea level rise; and an arctic chill would spread across Europe.

Part of what makes AMOC’s behavior so hard to forecast is that consistent monitoring of the current didn’t begin until 2004, so the historical data is limited. When researchers run models to examine AMOC’s behavior in the past, they sometimes get baffling results. “The new models aren’t working for AMOC,” said David Thornalley, a paleoclimatologist at University College London, who wasn’t involved with the latest research. “Some people would say we don’t 100 percent know what AMOC did through the 20th century.”

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