By Eric Holthaus
Scientists are expressing alarm over “utterly terrifying” new findings from NASA and the European Space Agency that Antarctica has lost about 3 trillion tons of ice since 1992, and in the past five years—as the atmospheric and ocean temperatures have continued to climb amid ongoing reliance on fossil fuels—ice losses have tripled.
“These events and the sea-level rise they’ve triggered are an indicator of climate change and should be of concern for the governments we trust to protect our coastal cities and communities.”
— Andrew Shepherd, University of Leeds
This should be a wake-up call, said University of Leeds professor Andrew Shepherd, a lead author of the report. “These events and the sea-level rise they’ve triggered are an indicator of climate change and should be of concern for the governments we trust to protect our coastal cities and communities.”
Published in the journal Nature, “This is the most robust study of the ice mass balance of Antarctica to date,” said NASA’s Erik Ivins, who co-led the research team. The report offers insight into the future of the Antarctic Ice Sheet, which the authors note “is an important indicator of climate change and driver of sea-level rise.”
“The outlook for the future is looking different to what it was,” explained Shepherd. “There has been a sharp increase, with almost half the loss coming in the last five years alone.”
Up until 2012, “we could not detect any acceleration,” but after that, based on surveys by satellites, they saw a threefold increase in the rate of ice melt. “That’s a big jump, and it did catch us all by surprise,” Shepherd said. “A threefold increase now puts Antarctica in the frame as one of the largest contributors to sea-level rise. The last time we looked at the polar ice sheets, Greenland was the dominant contributor. That’s no longer the case.”
Today’s news on Antarctica — ice loss there has accelerated 300% over the past 25 years — is utterly terrifying.
— Eric Holthaus (@EricHolthaus) June 13, 2018
Even so, Dr. James Hansen, “the father of modern climate change awareness,” warned at the time, “The primary issue is whether global warming will reach a level such that ice sheets begin to disintegrate in a rapid, non-linear fashion on West Antarctica, Greenland or both.”
“Once well under way, such a collapse might be impossible to stop, because there are multiple positive feedbacks,” Hansen wrote for New Scientist in 2007. “In that event, a sea level rise of several meter at least would be expected.”
According to the report out this week—which was conducted by 84 researchers across 44 institutions—and others that have preceded it, the most serious melting is occuring in West Antarctica. “When we look into the ocean we find that it’s too warm and the ice sheet can’t withstand the temperatures that are surrounding it in the sea,” which is causing glaciers to melt more rapidly into the oceans, Shepherd explained.
East Antarctica, meanwhile, has experienced far less melting because the bulk of its ice is above sea level, he added. That is “an important distinction, because it means it’s insulated from changes in the ocean’s temperature.”
“I think we should be worried. That doesn’t mean we should be desperate,” University of California Irvine’s Isabella Velicogna, one of 88 co-authors,” told the Associated Press. “Things are happening. They are happening faster than we expected.”