WASHINGTON: Glaciers on Greenland have shrunk so much that even if global warming were to stop today, the ice sheet would continue to melt, according to a study of nearly 40 years of satellite data from the island. The finding, published in the 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.
“We’ve been looking at these remote sensing observations to study how ice discharge and accumulation have varied,” said Michalea King, lead author of the study, and a researcher at the Ohio State University in the US. “And what we have found is that the ice that’s discharging into the ocean is far surpassing the snow that’s accumulating on the surface of the ice sheet,” King said. The researchers analysed monthly satellite data from over 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 in balance, keeping the ice sheet intact. Through those decades, the researchers found, the ice sheets generally lost about 450 gigatonnes of ice each year from flowing outlet glaciers, which was replaced with snowfall.