Slowing Ocean Circulation

Studies published in Nature report evidence that the strength of the Atlantic Meridional Overturning Circulation has weakened by about 15 percent since the 1950s. It's at the lowest point in the past 1600 years.

Climate scientists have been concerned since the 1980s that rising global temperatures could throw a wrench in the conveyor belt–like system, with possibly stark climatic consequences. Sea levels could ratchet upward along the U.S. east coast, key fisheries could be devastated by spiking water temperatures and weather patterns over Europe could be altered.

Such concerns had been quelled over the last decade as climate models suggested this branch of the ocean’s circulatory system was not likely to see a rapid slowdown, which would slow any consequences. But [the] new studies ... suggest the recent weakening spotted by ocean sensors is not just a short-term blip, as some had thought. Rather, it is part of a longer-term decline that has put the circulation at its weakest state in centuries. The results imply climate models are missing key pieces of the puzzle, and that ill effects could be on their way.

Update (April 28):  Thom Hartmann explains how the slowing AMOC could impact Europe.