A high emissions future may see the world’s strongest ocean current, the Antarctic Circumpolar Current, slow down by 20% by 2050, according to an Australian-led study. The current plays a critical role in the climate system by influencing heat and carbon dioxide uptake in the ocean.
Researchers used Australia’s fastest supercomputer to analyze the impact of changing temperature, ice melting, and wind conditions on the Antarctic Circumpolar Current. Their results showed a clear link between meltwater from Antarctic ice shelves and the slowdown.
As Antarctic ice melts, cold fresh water is released into the ocean, causing changes in density variation that drive the current’s movement. The study found a “substantial reconfiguration of Southern Ocean dynamics” with far-reaching impacts on global climate patterns, oceanic heat distribution, and marine ecosystems.
The slowdown could lead to more climate variability, greater extremes in certain regions, and accelerated global warming due to reduced ocean capacity as a carbon sink. The consequences include a “vicious cycle” where more warm water reaches the Antarctic shelf, accelerating ice melting and further weakening the current.
Experts warn that concerted efforts to limit global warming can help mitigate this slowdown by reducing carbon emissions. The study’s findings also underscore the importance of monitoring ocean currents, which account for over 90% of extra heat trapped on Earth, affecting climate and weather patterns worldwide.
Source: https://www.theguardian.com/environment/2025/mar/03/antarctic-circumpolar-current-slow-down-ice-melting-climate