Climate change

Study: World's Strongest Ocean Current Will Slow 20% by 2050

Published MAR 4 2025

Story

Above: Elephant Island, Antarctica. Image credit: Unsplash

The Facts

According to research published in Environmental Research Letters, the Antarctic Circumpolar Current (ACC) — four times stronger than the Gulf Stream — could slow down by 20% by 2050 due to the influx of freshwater from melting Antarctic ice sheets.
guardian
Essopenarchive
PHYS
The ACC functions as a critical component of Earth's climate system by connecting the Atlantic, Pacific, and Indian oceans, preventing warmer waters from reaching Antarctica and acting as a barrier against invasive species.
Findanexpert
Iopscience
Using Australia's fastest supercomputer and climate simulator, researchers discovered that melting ice sheets release cold, fresh water into the ocean, altering density variations and disrupting the ACC's natural flow patterns.
The Debrief
BBC News
The study warns that the weakening ACC could initiate a "vicious cycle" in which more warm water reaches the Antarctic shelf, accelerating ice melting and further weakening the current while disrupting marine ecosystems and food webs.
Aa
Iopscience
Study co-author Bishakhdatta Gayen said that "the ocean is extremely complex and finely balanced," however, if "this current 'engine' breaks down, there could be severe consequences, including more climate variability, with greater extremes in certain regions."
Dailygalaxy
Aa
The ocean currently stores more than 90% of Earth's excess heat, while the ACC distributes this heat and affects global weather patterns. Since 2022, the Antarctic Sea ice extent has dropped below 2M square kilometers every summer for the first time in recorded history.
guardian
Earthobservatory

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The Spin

Narrative A

The slowing of the ACC is an unprecedented threat to global climate stability. It could lead to more extreme weather events, accelerated global warming, and disruption of marine ecosystems. The weakening current may also allow invasive species to reach Antarctica and threaten its delicate food web.

Astrobiology

Narrative B

Previous research suggested the ACC would actually accelerate due to ocean warming. Further observational studies are needed in this poorly observed region to definitively determine the current's response to climate change, as there is a possibility that limiting carbon emissions could prevent the projected slowdown.