Why an Atlantic circulation collapse could spell disaster

It’s hard to overstate how widespread and calamitous the impacts could be if the system of ocean currents known as the Atlantic Meridional Overturning Circulation were to collapse.

Among the many reasons why we ought to cut climate-warming greenhouse gas emissions as quickly and sharply as possible, the weakening of a system of ocean currents known as the Atlantic Meridional Overturning Circulation, or AMOC, ranks high indeed. Several key scientific papers over the last couple of years have put this long-percolating climate concern back on the front burner. It’s hard to overstate how widespread and calamitous the impacts could be if this conveyor belt were to collapse—and it’s a process that could begin in the next several decades, if the new work is on target.

The AMOC is a vast oceanic loop that carries warm water northward through the uppermost Atlantic toward Iceland and Greenland, where it cools and descends before returning southward. It ferries colossal amounts of heat from the tropics toward the polar region, helping balance Earth’s climate machine just as it’s done on and off for millions of years.