NASA is currently operating 11 satellite missions that are monitoring the Greenland and Antarctic ice sheets. NASA says that those missions show that the ice sheets are melting six times faster than they were in the 1990s. The space agency also notes that if the melting trend continues, the regions are on track to match worst-case scenarios of the Intergovernmental Panel on Climate Change for sea-level rise by 2100.
The findings are published recently and come from a team of 89 polar scientists from 50 organizations marks the most comprehensive assessment to date of the changing sheets. Surveys used measurements taken from satellites including the NASA Ice, Cloud, and land Elevation Satellite and the NASA-German Aerospace Center Gravity Recovery in Climate Experiment satellite.
The team has calculated that the sheets together have lost 81 billion tons per year in the 1990s compared to 475 billion tons per year and 2010s. That represents a sixfold increase in ice loss. All total, the study shows that Greenland and Antarctica lost 6.4 trillion tons of ice since the 1990s. Meltwater from the ice melt has increased global sea levels by 0.7 inches and NASA says that together the melting polar ice sheets are responsible for 1/3 of all sea level rise.
Of the total sea level rise 60 percent of it came from the melting Greenland ice sheet and 40 percent from the melting Antarctica and sheet. A report issued in 2014 predicted that global sea levels could rise by 28 inches by 2100 and the new study shows that the ice melt is on track to hit that number.
Combined losses from both ice sheets peaked at 552 billion tons per year in 2010 averaging 475 billion tons per year for the remainder of the decade. The team does believe that 2019 will set a new record for ice sheet loss due to the Arctic heatwave, but they say more analysis is needed. As for what’s causing the ice loss, Antarctica’s outlet glaciers are being melted by the ocean, which causes them to speed up. The same phenomena accounts for half of Greenland’s ice loss while the rest is caused by rising air temperature melting the surface of its ice sheet.