The melting of West Antarctica's ice sheets is worse than previously believed. An analysis of 21 years' worth of data reveals that every two years, the region loses volume of ice comparable to that of Mount Everest.

By analyzing data from four sets of observations from the Gravity Recovery and Climate Experiment satellites of the U.S. space agency, Operation IceBridge ICESat laser altimetry, radar altimetry from the Envisat satellite of the European Space Agency (ESA), and analyses made using radars and the Regional Atmospheric Climate Model of the University of Utrecht between 1992-2013, Tyler Sutterley, from the Department of Earth System Science at the University of California, and colleagues found that the rate of the melting of the glaciers in West Antarctica's Amundsen Sea Embayment has increased three times over the past ten years.

The researchers also discovered that the embayment loses about 83 gigatons or 91.5 billion U.S. tons of mass annually. Given that the weight of Mount Everest is approximately 161 gigatons, Antarctic's fastest melting region loses an amount of water weight comparable to Mount Everest every two years since 1992 and the rate of loss has increased to about 6.7 billion tons per year over the past two decades.

"Previous studies had suggested that this region is starting to change very dramatically since the 1990s, and we wanted to see how all the different techniques compared," Sutterley said. "The remarkable agreement among the techniques gave us confidence that we are getting this right."

Although West Antarctica is often viewed as the least stable region in Antarctica and dubbed by the Jet Propulsion Laboratory as a significant threat of rapid rise in sea level, experts did not realize that the Amundsen Sea Embayment loses ice this fast.  

The region has enough ice to increase global sea levels by four feet. If all the ice sheets melt in West Antarctic, the consequence would be a rise in global sea level by about 16 feet.  

The National Aeronautics and Space Administration (NASA) said that while the sea level is expected to rise by 2100, most of the projections did not take into account major loss of ice in Antarctica. The findings of the study suggest that the rise in sea level will likely lean toward the high-end estimate of the  U.N. Intergovernmental Panel on Climate Change (IPCC), which is about 3 feet.