A new scientific survey has found that the glaciers of the Arctic are the world’s biggest contributors to rising seas, even though the Antarctic contains far more ice.
However, the biggest problem is that both ice regions appear to be accelerating their losses—suggesting that we could be in for an even faster rate of sea-level rise in future decades. Seas are rising by about three millimeters each year, according to NASA. That’s mainly driven by the Arctic contribution, the Antarctic and a third major factor—that ocean water naturally expands as it warms.
“For Arctic ice loss, the rate has become faster since 1986,” said Jason Box, first author of the new study. “So it clearly shows an acceleration of the sea-level contribution. The Antarctic will probably take over at some point in the future, but during the past 47 years of this study, it’s clear that the Arctic is the largest contribution of land ice to sea-level rise.” The total Arctic loss at present is 447 billion tons of ice per year—which is about 14,000 tons of water per second. That’s for the period between 2005 and 2015. Between 1986 and 2005, the loss is around 5,000 tons per second—therefore, the rate has almost tripled.
Assuming these numbers are correct, the polar regions are losing about 666 billion tons of ice to the ocean each year—reaching a little bit less than two millimeters of sea-level rise every year. “With respect to the present rate of ice mass loss, it is Greenland that has the most significant rate of increased mass loss in the present day,” Larsen said, a glacier expert at the University of Alaska. “If you take the 7.7 billion people on Earth and divide the present-day numbers, from 2005 to 2015, each person on Earth would have 160 liters per day, every day, every year,” Box said.
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