Global warming is changing the range of water currents that flow deep under the surface of the Atlantic Ocean. That’s according to new research from Yale examining the effects of melting sea ice in the Arctic Ocean.
There’s a vast undersea current that carries warm water and cold water all around the Atlantic Ocean. Matthew Thomas with Yale said climate change causes ice to melt in the Arctic, and then the water from that melting ice interferes with the current and causes hot water from the south to flow north instead.
“The water flows to the high northern latitude, where it becomes very dense, and then the water can sink into the deep ocean. So if you warm the surface of the water and you freshen it, it acts to sort of hinder the ability of the water to sink into the deep ocean.”
As the surface becomes fresher and warmer, the currents need to flow further north into the Arctic in order to sink. Thomas says global warming could start a vicious cycle – a feedback loop of warming water and melting ice.
“Once some ice has been melted, it’s now no longer reflecting the sunlight back to space, which means that what was previously ice-covered now absorbs solar radiation, which means it becomes warmer, therefore it can melt more ice.”
It’s not a pretty picture. But Thomas says it’s important to know these mechanisms so we can prepare for all the threats of climate change.