Satellite data show that sea ice around Antarctica is well below levels recorded in any previous winter, a worrisome new benchmark for a region that once seemed to be resilient to global warming.
„It’s so far beyond anything we’ve ever seen that it’s almost alarming,“ said sea ice monitors at the National Snow and Ice Data Center.
Polar experts warn that an unstable Antarctica could have far-reaching consequences.
Antarctica’s massive ice surface regulates the Earth’s temperature because the white ice reflects the sun’s energy back into the atmosphere, while also cooling the water under and near the ice.
Without ice to cool the planet, experts say, Antarctica would go from being Earth’s refrigerator to a radiator.
There is currently less than 17 million square kilometers of ice floating on the surface of the Antarctic Ocean, 1.5 million square kilometers less than the September average and well below the record lows of previous winters.
The ice deficit is about five times the size of the British Isles.
Dr. Mayer is not optimistic about the extent of sea ice recovery.
Scientists are still trying to figure out all the factors that contributed to this year’s decline in sea ice, but studying trends in Antarctica has historically been a challenge.
In a year when global heat and ocean temperatures broke multiple records, some scientists insist that low sea ice is the scale to watch.
„We can see how fragile it is,“ said Dr. Robbie Mallette of the University of Manitoba, who is stationed on the Antarctic Peninsula.
He’s already risked isolation, extreme cold and strong winds, and this year’s thin sea ice makes his team’s job that much more difficult.“ Dr. Mallette said, „The sea ice has the potential to break off and then drift out to sea with us.
Sea ice, which forms during the continent’s winter months (March through October) and then mostly melts during the summer, is part of an interconnected system of icebergs, land ice, and giant ice shelves (floating extensions of land ice sticking out from the coast).
Sea ice protects the land-covering ice from ocean warming.
D., of the British Antarctic Survey, explains that the effects of shrinking sea ice may become apparent as the season transitions to summer – when there may be an unstoppable feedback loop of melting ice.
As more sea ice disappears, dark areas of the ocean are exposed that absorb sunlight rather than reflecting it, meaning heat gets into the water, which in turn melts more ice. Scientists call this the ice-reflection effect.
This could add more heat to the planet and undermine Antarctica’s consistent role as a global temperature regulator.
„Are we waking up the giant that is Antarctica?“ asks the professor at the University of Exeter. He said it was „an absolute disaster for the world“.
The professor, an earth scientist at the University of Leeds, said there were signs that what was already happening to the Antarctic ice sheet was among the worst-case scenarios predicted.
The reduction in Antarctica’s land ice has led to a 7.2 millimeters rise in sea level since the 1990s.
Even a small rise in sea level could lead to dangerous storm surges that could devastate coastal communities. If large amounts of land ice begin to melt, the impact on millions of people around the world will be catastrophic.
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