dramatized the effects of the AMOC collapsing. Things won’t play out so swiftly or stunningly—but it will be bad.The bad climate news keeps coming: A new study adds to the evidence that the Atlantic Ocean’s critical system of currentsin response to melting ice sheets in Greenland . These currents shuttle water—and along with the water, heat—between the poles, influencing climate around the world.
Ocean circulation is driven by density differences, which depend on the salinity and the temperature of the water. Cold, salty water is heavier than warm, fresh water. When flowing water reaches Greenland, it becomes very cold and salty, causing it to sink and flow south, where the water warms and rises closer to the surface again. Van Westen compares the process to a conveyor belt going around and around.Changing the salinity of the water messes up the way the water flows.
A huge effort has been in place for decades to monitor changes in the AMOC. It’s extremely expensive to maintain, says Talley, but worth it to understand what’s happening in the ocean.