During a sizeable chunk of the 20th century, the Soviet Union and the United States, along with their allies, were in a constant state of tension with a potential third world war conflict. That never happened, and the Cold War remained a period of bitter rivalry, espionage, and counter-espionage.
Some of the declassified data is now being employed in a completely different manner. Instead of monitoring possible soviet activities, images taken by CIA spy satellites are being used to understand how much Himalayan glaciers have changed over the last several decades.
Early last year, researchers reported data as far back as 1975 on the dramatic ice loss of 650 Himalayan glaciers. Now, a different team has pushed some of the observations back to the 1960s, highlighting how the glaciers have thinned by more than 80 meters (260 feet), with some reaching more than 91 meters (300 feet).
The finding was announced at the American Geophysical Union conference last month, where the work was presented by Dr Tobias Bolch, from the School of Geography and Sustainable Development at the University of St. Andrews in Scotland.
The team used declassified Corona and Hexagon spy satellites as well as modern-era satellites, such as Pleiades, GeoEye, TerraSAR-X, and ASTER. The loss over the last 60 years has been swift, and has been accelerating since the 1980s.
Researchers have predicted that Mount Everest, the tallest mountain on Earth, could be devoid of ice as soon as 2100. The causes for the dramatic ice loss are multiple, including increased levels of soot in the atmosphere darkening the glaciers and changes in precipitation patterns. However, the climate crisis is the main driver of the thawing.
From 2000 to 2016, the region has experienced a 1°C (1.8°F) increase in temperature. Combined with the trends highlighted by the researchers, there is little good news for the region and beyond. Meltwater from the Himalayan glaciers is crucial for the well-being of approximately 800 million people who rely on it for drinking, farming, and energy production.