By Umair Irfan
The Stange ice shelf in the Ronne Entrance, Southern Bellingshausen Sea along the Antarctic Peninsula.
Nearly 2.4 billion people, or 40 percent of the world’s population, live within 60 miles of the ocean. And so it’s clearly not good that higher average temperatures are causing water in the ocean to expand. Hotter weather is also melting ice on land, increasing the volume of water in the ocean.
Scientists are now paying particularly close attention to warming in Antarctica, home to 90 percent of our planet’s ice. If it were all to melt, it would raise sea levels by 190 feet. Oceans have already risen more than 8 inches since 1880, and between 1992 and 2017, Antarctica lost 2.71 trillion metric tons of ice. This is roughly the volume of three Olympic-size swimming pools every second. Half of these losses came in the last five years, a sign of an accelerating melt rate....
...Average global temperatures are closely related to the amount of heat-trapping gases like carbon dioxide people pump into the sky, and climate researchers use this mechanism to anticipate future warming. However, predicting sea level rise as the climate changes is much more difficult because there are so many local and global factors at play. “There’s always been quite a lot of uncertainty in sea level rise because it’s hard to figure out how ice sheets behave,” said Tamsin Edwards, a lecturer in physical geography at King’s College London in the United Kingdom.
Edwards, the lead author of one of the Nature papers published Wednesday, decided to examine a particular kind of ice loss in Antarctica known as marine ice-cliff instability to try to get more clarity. Ice cliffs are the craggy sides of the ice sheet that can tower more than 300 feet high.
An alarming 2016 paper theorized that when these cliffs extrude over coastal waters, warming air and warming water could cause them to catastrophically collapse under their own weight. The fractured ice would then thaw and contribute to sea level rise, which would then melt more ice....
