Declassified Cold War–era spy satellite film shows that the melting of hundreds of Himalayan glaciers has sped up in recent decades.
An analysis of 650 of the largest glaciers in the mountain range revealed that the total ice mass in 2000 was 87 percent of the 1975 mass. By 2016, the total ice mass had shrunk to only 72 percent of the 1975 total. The data show that the glaciers are receding twice as fast now as they were at the end of the 20th century, report Joshua Maurer, a glaciologist at Columbia University, and colleagues June 19 in Science Advances.