‘Acting like a giant conveyor belt’
A shift in balance in the frozen reaches of Antarctica could disrupt the balance of all the world’s oceans, affecting weather patterns and even global food security.
What’s going on?
Researchers from the University of Queensland have conducted high-resolution ocean-ice simulations of the Cape Darnley region to identify factors that influence the formation of dense water on the continental shelf, which in turn affects ocean salinity and density.
They published a study that found the main factors are accelerated ice melt and decreased sea ice formation. A halt in sea ice formation can result in up to a 36% reduction in dense water on the continental shelf.
“This dense water sinks to the ocean floor where it flows north, acting like a giant conveyor belt driving currents around the planet that influence climate on a global scale,” explained lead researcher Dr David Gwyther, according to the University of Queensland News.
When ice shelves melt faster and sea ice becomes less stable, shelf water is less dense and the deep ocean system weakens – changes that affect global ocean systems and weather patterns.
Why is this concerning?
Although the study is theoretical and based only on simulated scenarios, the real changes occurring in Antarctica are already affecting the planet.
The northward flow of Antarctic bottom waters fell by about 12% between 2000 and 2020, according to the National Oceanic and Atmospheric Administration.
Meanwhile, Arctic sea ice is losing about 13% of its mass every decade, the World Wide Fund for Nature reported. Loss of Arctic ice can lead to higher tides and a higher risk of disease.
Together, melting polar ice at both ends adds fresh water to the oceans and makes it harder for heavy water to sink.
The slower movement of dense water can change ocean circulation, which can influence global currents and weather patterns, even in regions far from the poles. This could indirectly contribute to rising temperatures, which now acts like a steroid during extreme weather events.
Deep ocean changes from melting polar ice can also affect marine biodiversity: Antarctica, New Zealand noted that slow seafloor movement limits the movement of oxygen and nutrients.
Changes in salinity can destabilize ecosystems. Ultimately, these fluctuations disrupt the food chains that support coastal livelihoods and feed the world.
What are we doing to resolve this problem?
Scientists continue to closely monitor polar ice and ocean systems to provide early warnings and develop solutions that can slow these harmful effects.
Individuals can explore critical environmental issues and take local action to reduce human activities that generate air pollution, which accelerates the melting of polar ice and slows the formation of sea ice.
Understanding how remote polar regions affect the lives of people around the world is an important step towards protecting our oceans.
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