New studies show global warming has helped cause an irreversible collapse of the ice sheet in western Antarctica. Scientists from NASA and the University of Washington say human driven-climate change has sped up the glaciers’ retreat, threatening a global sea rise in the coming centuries from four to 13 feet. In a video released by NASA, scientist Eric Rignot of the University of California-Irvine said the melting has “passed the point of no return.”

Eric Rignot: “We’ve passed the point of no return, and at this point it’s just a matter of time before these glaciers completely disappear to sea. This system is evolving very fast and is progressing exactly as you would expect if it was about to collapse to sea. They’re retreating at rates of about a kilometer per year. If these glaciers were sustaining this rate of retreat, they would disappear completely in a couple of centuries.”

Rising sea levels pose the biggest threat to coastal areas and low-lying island nations, which are vulnerable to surging waters like those seen in Superstorm Sandy.