To understand how warming could impact Antarctica, experts are looking to the past, to a time more than 100,000 years ago when the Antarctic was around 3 degrees C warmer than it is now. A new study finds that the West Antarctic ice sheet did not completely collapse during this period, as prior modeling had suggested, offering some hope for the future.
Scientists found a detailed record of the past in a 2,100-foot ice core extracted from the western edge of Antarctica. An analysis of the core revealed that during the last warm era the West Antarctic ice sheet shrunk to roughly half its current size. But the adjoining Ronne Ice Shelf, which extends out into the ocean, remained intact.
“This information from the last time Antarctica was warmer than present day is crucial for predicting how and when the West Antarctic ice sheet will change under future warming,” said study coauthor Louise Sime, of the British Antarctic Survey.
The findings, published in Nature, suggest the ice sheet may not see a total collapse as the climate warms. Still, during the last warm period enough ice melted globally to raise sea levels by several feet.
“Although our findings are partly positive news,” wrote lead author Eric Wolff, of the University of Cambridge, “they also show that ice was still lost from the [West Antarctic ice sheet], confirming its vulnerability to warming in the future.”
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