The Cryosphere, August 24
Since the 1980s, ice loss from the Greenland Ice Sheet has increased six-fold. The Ryder Glacier, one of the four major glaciers in North Greenland, extends into the water between two steep walls of rock before discharging ice and meltwater into the Arctic Ocean. From about 6,000-11,000 years ago, Arctic summer temperatures were about the same as the past decade, or around 1-3°C above the 20th century average. These warmer conditions forced the Ryder Glacier to retreat 120 kilometers inland. This extreme retreat occurred even though the sloped sea floor protected the base of this glacier from warm Atlantic waters. If climate warming continues at its current level, the Ryder Glacier may fully retreat again as glacial melt accelerates across northern Greenland. Rising temperatures may similarly threaten the stability of all glaciers located in Greenland’s northern fjords.