The melting of a small area of ice on the shore of East Antarctica could lead to sea level rise for thousands of years, reports a new study. The study appears in Nature Climate Change by scientists from the Potsdam Institute for Climate Impact Research (PIK).
"East Antarctica's Wilkes Basin is like a bottle on a slant," said lead-author Matthias Mengel in a statement. "Once uncorked, it empties out."
A rim of ice currently holds back the largest region of marine ice on rocky ground in East Antarctica. Warming oceans could lead to loss of ice on the coast, while the air over Antarctica stays cold, the researchers say. If this rim is lost it could trigger sea-level rise of 300-400 centimeters (about 10-13 feet) the researchers report.
Sea level rise from Antarctica is projected to increase by 16 centimeters this century.
"If half of that ice loss occurred in the ice-cork region, then the discharge would begin. We have probably overestimated the stability of East Antarctica so far," said co-author Anders Levermann.
Computer simulations of the region show it would take 5,000-10,000 years for the basin to discharge completely. But once started the basin would empty, even if global warming was halted.
"This is the underlying issue here," said Matthias Mengel. "By emitting more and more greenhouse gases we might trigger responses now that we may not be able to stop in the future."
Rising sea level could put coastal cities at risk, including Tokyo, Mumbai or New York, the researchers said.