Researchers who “weighed” the Antarctic ice sheet found it lost more than 92 billion tons of ice every year between 2003 and 2014 and the rate is speeding up.
And man-made climate change is blamed.
Antarctica’s massive ice sheet lost twice the amount of ice in its western portion compared with what it accumulated in the east, meaning the southern continent’s ice cap is melting ever faster. West Antarctica is the smaller of the continent’s two main regions and abuts the Antarctic Peninsula that points towards South America.
Overall, Antarctic ice-loss rates increased by six billion tons per year during the 11-year period researchers examined, showing ice caps were becoming increasingly unstable.
However, the melting rate from West Antarctica grew by 18 billion tonnes every year and doubled between 2008 and 2014 to an average 241 billion tonnes per year.
The ice sheet on East Antarctica, the continent’s much larger and overall more stable region, thickened during that same time, but only accumulated half the amount of ice lost from the west.
The Princeton University study, published in the Earth and Planetary Science Letters journal, used gravitational satellite data to record the mass of ice, rather than its volume, which scientists more typically measure.
Associate professor of geosciences Frederik Simons said: “We have a solution that is very solid, very detailed and unambiguous.
“With the rapidly accelerating rates at which the ice is melting, and in the light of all the other, well-publicised lines of evidence, most scientists would be hard pressed to find mechanisms that do not include human-made climate change.”
The study found massive and accelerating ice melt occurred along West Antarctica’s Amundsen Sea, particularly Pine Island and the Thwaites Glacier, where heavy losses had already been recorded.
An iceberg more than 2,000 square miles in size broke off from the Thwaites Glacier in 2002.
Dr Christopher Harig explained that ocean currents, rather than air temperatures, melt ice in Antarctica, and melted land ice rather than icebergs contributes to higher sea levels.
As the ocean warms, floating ice shelves melt and can no longer hold back the land ice
He added: “The fact that West Antarctic ice-melt is still accelerating is a big deal because it’s increasing its contribution to sea-level rise. It really has potential to be a runaway problem.
“It has come to the point that if we continue losing mass in those areas, the loss can generate a self-reinforcing feedback whereby we will be losing more and more ice, ultimately raising sea levels by tens of feet.”
The study monitored gravity changes to find the mass of melting ice in specific Antarctic regions.