Why it's so important to figure out when a vital Atlantic Ocean current might collapse

As the planet heats up, Greenland's ice sheet is pouring more meltwater into the Atlantic. Scientists are tracking whether this could cause a collapse in a crucial ocean current. (Mario Tama/Getty Images)

Deep in the Atlantic Ocean, there's a massive current the size of 8,000 Mississippi Rivers. Its role in the Earth's climate is so powerful that it determines weather from the equator to Europe, crop production in Africa and sea level rise on the East Coast.

Scientists say there's a risk this vital current could shut down as the climate gets hotter, a collapse that could have dire consequences worldwide.