Melting Antarctic ice sheets could slow ocean’s strongest current 20% by 2050

By Silan Turp and Beril Canakci

Melting Antarctic ice is weakening the world’s strongest ocean current, the Antarctic Circumpolar Current, according to research published in the journal Environmental Research Letters on Monday.

The researchers, from the University of Melbourne and NORCE Norway Research Center, warn that the current could slow by 20% by 2050 under a high carbon emissions scenario.

This could impact both global climate and marine ecosystems, they suggest.

"The ocean is extremely complex and finely balanced. 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,” co-author Bishakhdatta Gayen said in a press release.

Additionally, the weakened current may allow invasive species to reach Antarctica, potentially threatening its fragile food web.

The research suggests that the weakened current could lead to a “vicious cycle” where ice caps are exposed to warmer water that leads to more melting, which further weakens the current.

The study also indicates that even under lower emissions scenarios, melting ice will likely continue to disrupt the current, although at a slower pace.

“Concerted efforts to limit global warming – by reducing carbon emissions – will limit Antarctic ice melting, averting the projected slowdown,” co-author Taimoor Sohail said.