Earth's largest ocean current is slowing - and it could be disastrous

"Five times stronger than the Gulf Stream and 100 times larger than the Amazon River, the Antarctic Circumpolar Current (ACC) is by far the world's largest ocean current. But this key system is grinding to a halt, a new study has warned. Analysing core samples, scientists from the University of Bonn have found that the ACC has undergone a major slowdown. In fact, the ocean current is now running three times slower than it was 130,000 years ago. Worryingly, if it continues, this dramatic slowdown could have disastrous consequences."

"'If this current "engine" breaks down, there could be severe consequences, including more climate variability, with greater extremes in certain regions, and accelerated global warming due to a reduction in the ocean's capacity to act as a carbon sink,' warned Dr Bishakhdatta Gayen, associate professor at the University of Melbourne, who was not involved in the study. The ACC circles the Antarctic continent from East to West, connecting the Atlantic, Pacific and Indian Oceans."

"To get to the bottom of it, the University of Bonn scientists looked at sediment samples collected by a research vessel in the Scotia Sea north of Antarctica. This allowed them to work out how the ACC has changed in speed and position over the last 160,000 years. 'The velocity in the second-to-last warm period, roughly 130,000 years ago, was more than three times greater than in the last millennia comprising the current warm period,' said expedition lead Dr Michael Weber."

The Antarctic Circumpolar Current (ACC), the planet's largest ocean current, has experienced a major slowdown based on sediment core analyses. Sediment samples from the Scotia Sea reveal changes in ACC speed and position over the last 160,000 years, with velocities during a warm period roughly 130,000 years ago more than three times greater than in recent millennia. The ACC is driven by westerly winds and circulates heat, dissolved carbon, and nutrients between oceans. A continued slowdown could reduce oceanic carbon uptake, increase climate variability, and produce greater regional climate extremes.

Read at Mail Online