Research published in Environmental Research Letters reveals that the Antarctic Circumpolar Current (ACC), the world’s strongest ocean current, is slowing down due to melting ice sheets. The ACC plays a crucial role in regulating global climate indicators, including sea level rise, ocean warming, and marine ecosystems.
According to researchers from the University of Melbourne and NORCE Norway Research Center, the ACC will slow by around 20% by 2050 in a high carbon emissions scenario. This change is expected to alter the properties of the ocean, such as density and circulation patterns, which could have severe consequences for global climate variability and marine ecosystems.
The researchers used Australia’s fastest supercomputer and climate simulator, GADI, to analyze the impact of changing temperature, saltiness, and wind conditions on the ACC. Associate Professor Bishakhdatta Gayen said that if the current ‘engine’ breaks down, it could lead to more extreme climate events and accelerated global warming.
The ACC acts as a barrier to invasive species from other continents reaching Antarctica, but its weakening could allow such species to invade the fragile continent, potentially disrupting the food web and affecting the diet of Antarctic penguins. The current is also critical for the exchange of heat, carbon dioxide, chemicals, and biology across ocean basins.
The study’s findings contrast with previous research that suggested the ACC may be accelerating due to climate change. However, the new model resolves small-scale processes controlling current strength, showing a mechanism through which the ACC will slow down in the future.
Source: https://phys.org/news/2025-02-antarctic-ice-sheets-earth-strongest.html