An astonishing new report out of Antarctica indicates that glaciers are melting at an alarming rate, meaning that it could take decades, not thousands of years, to raise sea levels by more than 11 feet. Researchers examined the Thwaites and Pine Island glaciers in Antarctica, which span 150 miles in a remote area known as Pine Island Bay and appear to be collapsing at a much faster rate than thought.

The huge glaciers will definitely melt at some point, although researchers have been figuring out exactly when that will take place. Their collapse, since they sit on solid land and not in the ocean, would raise sea levels by up to 11.2 feet, which would flood coastal cities and leave millions homeless.

The Pine Island Glacier alone, the fastest melting glacier on the continent, would account for as much as 10 percent of the total sea level rise across the globe. As the climate continues to warm, ice will continue to melt into the ocean and further cause problems worldwide.

“New high-resolution maps of the complex landscape beneath a major West Antarctic glacier will be valuable for forecasting global sea level rise, researchers say,” reads the statement from the University of Edinburgh. “Radar surveys of the land beneath Pine Island Glacier, obtained by snowmobile, have revealed a surprisingly diverse, mountainous landscape under the ice. The findings are significant as Pine Island Glacier is the fastest melting glacier in Antarctica and currently accounts for up to 10 per cent of global sea level rise. Ice melting into the ocean in the region is expected to increase as the climate warms and the West Antarctic ice sheet continues to thin.”