Scientists warn global warming could create 100-mile whirlpools

Scientists have discovered when the “juggernaut” current that keeps Antarctica cool first began and warned any changes to it may contribute to global warming.

The Antarctic Circumpolar Current (ACC) moves 130-180 million cubic metres of water around the Southern Ocean every second, more than 100 times the flow of all the Earth’s rivers combined.

It keeps Antarctica cold and isolated from warmer oceans and seas, and affects water welling up from the deep Southern Ocean, one of the largest repositories of carbon dioxide on the planet.

Dr Uisdean Nicholson and Professor Dorrik Stow, from HeriotWatt University in Edinburgh, combined seismic surveys off the Falkland Islands and data from sediment cores extending several hundred metres below the seabed to calculate when the ACC began, dating it to 34 million years ago.

The researchers warn warmer air temperatures could strengthen the current and create 100-mile wide whirlpools that will shift carbon dioxide from the depths to the atmosphere, contributing to global warming. Dr Nicholson, a sedimentary geologist at HeriotWatt, said: “Understanding the oceanographic events of that era and how they changed will help us predict future changes and feedbacks between oceans and the atmosphere in a warming world.”

The new research, published in the journal Scientific Reports, also outlines how a stronger ACC could disrupt the carbon cycle.

Professor Stow, a sedimentologist and oceanographer, said: “Warmer air temperatures caused by higher atmospheric carbon dioxide will shift and strengthen the southwesterly winds that drive the ACC.

“This will change the dynamics of deep ocean currents and could resultin upwelling of carbondioxide from the deep ocean - which will, in itself, cause more global warming.

“It could also create more intense eddies – giant, 100-mile wide whirlpools that extend deep into the ocean – which could weaken the thermal isolation and increase the rapid melting of Antarctica.”