Southern Ocean current faces slowdown threat

HOBART (Reuters) – The impact of global warming on the vast Southern Ocean around Antarctica is starting to pose a threat to ocean currents that distribute heat around the world, Australian scientists say, citing new deep-water data.

Melting ice-sheets and glaciers in Antarctica are releasing fresh water, interfering with the formation of dense “bottom water,” which sinks 4-5 kilometers to the ocean floor and helps drive the world’s ocean circulation system.


A slowdown in the system known as “overturning circulation” would affect the way the ocean, which absorbs 85 percent of atmospheric heat, carries heat around the globe.

“If the water gets fresh enough … then it won’t matter how much ice we form, we won’t be able to make this water cold and salty enough to sink,” said Steve Rintoul, a senior scientist at the Australian government-funded CSIRO Marine Science.

Reuters