Europe and the east coast of North America benefit from a massive system of circulating seawater called the Atlantic Meridional Overturning Current.
Sunlight might be most intense at Earth’s equator, but ocean circulation pushes that tropical heat toward the poles. When the currents transporting that heat change, it can have major impacts.
And now new evidence suggests that climate change is already weakening this massive ocean circulatory system. In a pair of papers published Wednesday in Nature, two sets of independent researchers used very different techniques to reach the same startling conclusion.
Both studies found that melting ice from Greenland has spilled huge quantities of freshwater into the North Atlantic, diluting the dense salinity of North Atlantic currents and weakening the AMOC by 15 percent. However, the results disagree on when the changes started.