Stop me if you’ve heard this one before but the ice is screwed. New findings released on Thursday reveal that a quarter of the ice sheets in West Antarctica, the most vulnerable part of the continent, have destabilised. Ice loss has sped up fivefold across the region’s most imperilled glaciers in just 25 years.
Scientists used 800 million satellite measurements taken since 1992 to reach their conclusions. The results, published in Geophysical Research Letters, underscore just how rapid the changes taking place are and the perils coastal communities could face if ice continues its runaway melt.
The ways that we know the West Antarctic is melting down are manifold. There’s measurements on the ground, flyovers by NASA scientists, and occasional visits by boat. But to get the big picture, satellites provide a crucial view from space. Researchers used data from a suite of European Space Agency satellites that have been monitoring Antarctica since 1992. Those satellite have lasers that measure how high the ice that covers Antarctica and extends out to sea is, and the 25 years of records in the analysis allowed the researchers to see how ice height has changed over time. The researchers identified areas where rapid thinning and ice loss occurred as unstable.
The good news is that the East Antarctic, the highest and coldest part of Antarctica (and which contains most of the continent’s ice), is largely stable. Still, what’s happening in the west isn’t insignificant.
The findings show that 24 per cent of the ice sheet is now unstable, with some parts having thinned 400 feet over the past 25 years alone. That’s what ice researcher at the University of Leeds and lead author Andy Shepherd called “extraordinary amounts” in a press release. Extraordinary is not a superlative you want to hear in the case of the West Antarctic, though. The imbalance has caused ice from the imperilled Pine Island and Thwaites glaciers, which hold back massive stores of ice on land, to spill into the ocean five times faster in 2017 compared to 1992, contributing to an uptick in sea levels.
If those glaciers break up and the ice behind them falls into the sea, it could raise sea levels more than 10 feet and completely reshape coastlines. The new study is an important check-in on how close to the edge we might be.