Europe is warmed by heat from ocean currents, which move water from the warm tropics to the colder North Atlantic. Once the warm, salty water from the tropics reach the polar region, they cool enough to sink to the depths and flow back towards the Southern Ocean.
This enormous system of currents is known as the Atlantic Meridional Overturning Circulation (AMOC). Climate scientists are increasingly worried about the AMOC, which appears to be slowing down.
