Meltwater from Greenland, like this iceberg off the eastern coast, once disrupted the Atlantic Ocean’s “conveyor belt.” By Paul VoosenThe Atlantic Ocean’s “conveyor belt,” a powerful current that drags warm water north before submerging it in the North Atlantic, has been humankind’s constant companion.
For 8000 years, it has held steady, nourishing Western Europe with tropical warmth. But a new study of the current’s strength over the past half-million years suggests global warming may not shut down the current any time soon, as some scientists fear.
Instead, it could trigger a replay of ancient events, when multiple bouts of warming caused rapid, centurylong swings in the current’s strength, sowing climate chaos that may have alternately