Meltwater from Greenland substantially affects the flow of an ocean current known as the Atlantic meridional overturning circulation. Akin to a gigantic conveyor belt, the AMOC helps ferry warm water from the tropics to the Arctic. It distributes heat around the world gives it a major influence on global weather patterns—the AMOC’s warm-water flow is credited with the mild climate in places like Western Europe. As fresh water pours into the ocean from the melting Greenland ice sheet, it may cause this current to slow down.
We assume an extreme amount of ice melt by the end of the century, enough to raise global sea levels by about 3 feet. Research indicates that Antarctic glaciers destabilize under high levels of future warming—as ice shelves at the ocean’s edge melt and break apart, entire ice cliffs could collapse and unleash a massive outpouring of ice into the ocean.