Ocean Current Shutdown Could Be Catastrophic – GWC Mag

If AMOC stops circulating, the impact could be catastrophic.

It’s a real possibility but opinions differ on the time horizon.

The Atlantic Meridional Overturning Circulation or AMOC, is part of a water “global conveyor belt.” It contributes to everything from sea level rise on the East Coast to European temperatures.

AMOC moves water and heat between the Southern Ocean and the North Atlantic Ocean. The currents are driven by differences in water density that are determined by changes in temperature and salt concentration.

As warm waters on the ocean’s surface move north, evaporation increases the level of salt while decreasing the temperature. As a result, the water becomes denser, sinking deeper into the ocean. The water then slowly spreads southwards before rising in the Southern Ocean. The process is called “upwelling” which completes the current’s trip around the world.

Studies have shown that AMOC is weakening. This is increasing the amount of lighter freshwater in the North Atlantic which is contributing to accelerating ice melts in Greenland. The same studies believe that human-caused climate change is causing it to weaken further.

It is believed that if AMOC were to cease flowing altogether, it would be irreversible. Thus, it represents a potential tipping point. Let’s hope such an outcome is a distant possibility, and that we have sufficient time to prevent it from happening.