Antarctic sea ice falls to lowest level ever recorded
Alex Berry
April 19, 2022
Researchers have been left baffled as, unlike the Arctic, Antarctica has generally seen an increase in sea ice. This marks the second big dip in just five years.
Unlike the Arctic, Antarctica comprises of a solid landmass as well as sea iceImage: Stanislav Rishnyak/Zoonar/picture alliance
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This year, the extent of sea ice in the Antarctic fell to its lowest recorded level, according to a report published in the Advances in Atmospheric Science journal on Tuesday.
Chinese researchers from the Sun Yat-sen University in Guangzhou and the Laboratory of Southern Marine Science in Zhuhai said the area covered by ice on February 22 was the lowest it had been since 1979, when records began.
The scientists are not sure about the cause for the decline — the second big drop in just five years.
Though global warming is causing the amount of ice in the northern Arctic to rapidly decline, the surface area covered by ice in the southern Antarctic has increased by about 1% per decade since the 1970s.
Antarctica: Mighty Thwaites Glacier threatens to melt
Global warming is threatening ice shelves linked to the Thwaites Glacier. If they fracture and break, much of the glacier could melt into the sea, causing a dramatic sea level rise.
Image: NASA/Zumapress/picture alliance
Thawing giant
Thwaites Glacier is one of the largest of its kind in Antarctica. Covering an area of 192,000 square kilometers, it is roughly the size of the UK. One third of the glacier consists of large floating ice platforms, or ice shelves. Increasingly, however, these platforms have been fracturing.
Image: NASA/Zumapress/picture alliance
Ice shelf could shatter like a windshield
Researchers warn that the mighty glacier could be undergoing dramatic change. It is possible that, within the next three to five years, a 45-kilometer-long ice shelf segment could shatter and break like a car window, researchers from the International Thwaites Glacier Collaboration project say.
Image: NASA/AFP
Serious rise in sea level looms
The ice shelf currently prevents the gargantuan glacier from slipping into the sea. If it were to shatter, huge amounts of glacial ice could end up melting into the water. Much of the glacier would break up into floating icebergs, say scientists.
Image: M. DeFreitas /blickwinkel/imago images
No isolated event
It would not be the first incident of this kind. In July 2017, the vast A68 iceberg detached from the Larsen C ice shelf in West Antarctica. While icebergs break off constantly, the timing of the event — during the cold Antarctic winter months — baffled scientists. Many suspect global warming could be a factor.
Over the past 20 years, seven ice shelves along the Antarctic Peninsula have shattered, or drastically receded. This means more ice has melted into the sea, which has caused sea levels to rise.
Image: Michael S. Nolan/imago images
Warm water accelerates thaw
Climate change, or the warming of the sea more specifically, is to blame for the Thwaites Glacier melting. Warm water flowing beneath the ice shelves have caused large sections to thaw, forming glacier caves. This melting process has accelerated tremendously over the past 30 years. Scientists are closely monitoring the development.
Image: Michael S. Nolan/imago images
Breakup could trigger major sea level rise
Together, the melting Thwaites Glacier and Pine Island Glacier already account for a 10% rise in global sea levels. If the Thwaites Glacier were to break up entirely, releasing all its ice into the water, sea levels worldwide would rise by about 65 centimeters (25 inches).
Image: John Sonntag/Zumapress/picture alliance
'Doomsday Glacier'
The breakup of the Thwaites Glacier would trigger a dangerous chain reaction. Should it melt, other nearby glaciers (like the Pine Island Glacier, pictured) could follow. Vast swaths of the West Antarctica ice could break off, causing sea levels to rise by up to 3,3 meters. That’s why the Thwaites Glacier has been nicknamed the Doomsday Glacier.
Image: ESA/dpa/picture-alliance
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Scientists search for answers
The observation matched another by the EU's Copernicus program that was released last month.
February's dip took place during the summer in the Southern Hemisphere, and it marked the first time that the area covered by the ice has fallen below 2 million square kilometers (about 772,200 square miles).
It also marked a decrease of about 30% in comparison with the average area between 1981 and 2010.
The researchers have been investigating possible causes, including ocean currents and weather phenomena, but could give no conclusive answer in their report.
The 1,200-square-kilometer Conger ice shelf in East Antarctica collapsed in February, after a period of extreme heat when temperatures reached levels 40 degrees Celsius (104 F) higher than normal.
Such ice shelves take thousands of years to build up and can release enormous amounts of snow and ice that had been held in behind them.
The most recent Intergovernmental Panel on Climate Change (IPCC) report from the UN warned that melting ice sheets from Antarctica, among other places, are set to increase sea levels, forcing millions to flee their homes.
Melting ice at the polar caps leads to rising sea levelsImage: NASA/AP/picture alliance
Correction: A previous version of this article incorrectly said temperatures in February reached 40 degrees Celsius. The temperatures were rather 40 degrees higher than normal.
