Comparing data obtained by Cold War-era spy satellites with images from modern stereo satellites, scientists have shown that Himalayan glaciers have lost more than a quarter of their ice mass since 1975, with melting occurring twice as fast after the turn of the century as average temperatures rose.
In the 1970s, at the height of the Cold War, the U.S. had deployed spy satellites that orbited the globe and took thousands of photographs, using a telescopic camera system, for reconnaissance purposes.
More than four decades later, scientists are using those same images to show the devastating impact of a warming earth on the Himalayan glaciers.
Findings of the study
Annual mass losses suggest that of the total ice mass present in 1975, about 87% remained in 2000 and 72% remained in 2016, a doubling of the average rate of loss during 2000–2016 relative to the 1975–2000 interval.