(MENAFN - Gulf Times) Shrinking glaciers in Greenland have been a worsening problem for the entire planet. A latest study has just revealed that the situation has sadly crossed a point of no return. Nearly four decades of satellite data from Greenland shows that glaciers on the island have shrunk so much that even if global warming were to stop today, the ice sheet would continue shrinking.
The finding, published on August 13, in the journal Nature Communications Earth and Environment, means that Greenland's glaciers have passed a tipping point of sorts, where the snowfall that replenishes the ice sheet each year cannot keep up with the ice that is flowing into the ocean from glaciers. The alarming information is contained in a report released by The Ohio State University.
It may be noted that the ice that melts or breaks off from Greenland's ice sheets ends up in the Atlantic Ocean and, eventually, all of the world's oceans. Ice from Greenland is a leading contributor to sea level rise last year, enough ice melted or broke off from the Greenland ice sheet to cause the oceans to rise by 2.2mm in just two months. Explaining the new finding, Michalea King, lead author of the study and a researcher at The Ohio State University's Byrd Polar and Climate Research Center, said that the ice that is discharging into the ocean is far surpassing the snow that is accumulating on the surface of the ice sheet. The study depended on remote sensing observations on how ice discharge and accumulation have varied.
King and other researchers analysed monthly satellite data from more than 200 large glaciers draining into the ocean around Greenland. Their observations show how much ice breaks off into icebergs or melts from the glaciers into the ocean. They also show the amount of snowfall each year the way these glaciers get replenished. The researchers found that, throughout the 1980s and 90s, snow gained through accumulation and ice melted or calved from glaciers were mostly in balance, keeping the ice sheet intact. Through those decades the ice sheets generally lost about 450 gigatonnes (about 450bn tonnes) of ice each year from flowing outlet glaciers, which was replaced with snowfall.
The researchers measured the pulse of the ice sheet how much ice glaciers drain at the edges of the ice sheet which increases in the summer. They saw it was relatively steady until a big increase in ice discharging to the ocean during a short five- to six-year period. Their analysis found that the baseline of that pulse the amount of ice being lost each year started increasing steadily around 2000, so that the glaciers were losing about 500 gigatonnes each year. Snowfall did not increase at the same time, and over the last decade, the rate of ice loss from glaciers has stayed about the same meaning the ice sheet has been losing ice more rapidly than it's being replenished. Before 2000, the ice sheet would have about the same chance to gain or lose mass each year. In the current climate, the ice sheet will gain mass in only one out of every 100 years.
King said that large glaciers across Greenland have retreated about 3km on average since 1985, which is a lot of distance. The glaciers have shrunk back enough that many of them are sitting in deeper water, meaning more ice is in contact with water. Warm ocean water melts glacier ice, and also makes it difficult for the glaciers to grow back to their previous positions. Yes, there is no going back now. What about adaptation and mitigation remains to be seen.
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2020-08-17 04:00:51Z
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