Roughly 160 people are dead and hundreds more—including dozens of international tourists—are missing after flash floods hit a region on the mountainous border of Nepal and Tibet. Devastating footage shows a wall of water washing away buildings and vehicles.

Initial analysis suggests that the flooding was likely triggered by a landslide caused when a piece of glacier fell hundreds of feet. As the region warms, its ice is becoming increasingly unstable, raising the risk of catastrophic flooding.

The glaciers over there are definitely in retreat,” says Joseph Shea, an associate professor of geography at the University of Northern British Columbia. “There’s a lot of glacier mass up there, but we’re seeing thinning, we’re seeing retreating.”

Nepal's glaciers lost nearly a quarter of their area between 1970 and 2010. More than 160 smaller glaciers in the country have vanished entirely.

A recent study finds that 40 percent of the world’s glacial ice could disappear if the world does not keep warming under 1.5 degrees Celsius. The impacts can cause cascading effects, triggering landslides and leaving large, dammed lakes at higher elevations. If a landslide suddenly hits these dams, it can lead to catastrophic flooding.