By Zohar Ben Simon, Science and Technology Editor
The world’s strongest ocean current is at risk of being weakened, a new study warns, as global warming melts the Greenland and Antarctic ice sheets.
The Antarctic Circumpolar Current (ACC) is the Earth’s strongest ocean current. It plays a crucial role in regulating climate change and maintaining various ecosystems. By acting as a conveyor belt, it transports heat and carbon dioxide from surrounding oceans.
This “conveyor belt” moves water, heat and nutrients around the world, providing a stable environment and food web for various species. The melting of ice sheets could cause this current to weaken, which would destabilize the priorly balanced oceans. Sea levels would rise due to the melting ice, and global climate patterns and marine ecosystems would be disrupted.
According to the study, if fossil fuel emissions continue to grow over the next 25 years, the ACC current could slow down by a significant 20 percent, severely impacting oceans globally. To conduct the study, scientists at the University of Melbourne utilized a climate simulator to project the effect of global warming on the already fragile ice sheets and our oceans, which in turn would majorly affect global climate patterns. The ACC is a gateway for carbon, heat and nutrients to circle the globe. Four times stronger than the Gulf Stream, it plays a major role in moving water around the Earth, including the Atlantic, Pacific and Indian Oceans.
As ice sheets melt, they provide a large influx of fresh water, which changes the salinity of the ocean drastically. This makes it more difficult for cold water to flow between the surface of the water and its depths, ultimately causing the strong ocean current to weaken.
Due to the oceans’ lessened capacity to act as a carbon sink, certain areas would be impacted with extreme weather changes such as droughts or flooding. This would subsequently cause global warming and climate variability to increase. This ultimately creates a vicious cycle, the melting ice sheets caused by global warming further the process of global warming itself.
Bishakhdatta Gayen, a professor at the University of Melbourne, explains another adverse impact of a weakened ACC. The ocean is a complicated “engine,” he said, and any imbalance can have serious consequences. The ACC works as a blockade to keep invasive species from other continents, such as bull kelp and mollusks, from reaching Antarctica, which could significantly affect the food web and severely affect the diet of animals such as the Antarctic penguin. Penguins rely on a specific, stable diet, and a massive alteration such as this one could cause significant damage to these animals and their habitats.
Melting ice sheets could have devastating impacts on our environment; biodiversity and our oceans are one of the biggest contributors to a balanced life and climate on Earth, and their stability is crucial. Combined efforts to limit global warming, such as reducing carbon emissions, will help prevent or at least mitigate the Antarctic ice melting, and ultimately control the decline of the ACC.