In the 1930s, Danish pilots wearing suits made of polar bear fur flew open-cockpit planes along the coastline of Greenland. From the air, they took roughly 200,000 photographs.

The images were intended to be used for mapping. But now, scientists are using them to see how global warming has affected Greenland’s peripheral glaciers, which dot the land around the central ice sheet.

Larocca: “And these glaciers are really important to study because they contribute significantly to sea level rise.”

Laura Larocca worked on the project while at Northwestern University and as a NOAA climate and global change postdoctoral fellow.

Using the Danish images, military photos, and satellite data, the researchers found that Greenland’s glaciers retreated throughout the 130-year study period. But their melting sped up over the past two decades.

Larocca: “Glaciers are now retreating at a rate roughly twice the rate observed over the 20th century.”

She says the study highlights the urgent need to limit global warming.

Larocca: “It’s just a stunning landscape, and it’s really sad to see the loss of these glaciers.”

Reporting credit: ChavoBart Digital Media