Satellite images from US espionage programmes for ecology and nature conservation

The images taken by US spy satellites since the late 1950s have long been classified. They became publicly accessible in the late 1990s and are used, among others, in climate research and archaeology. Researchers from the Conservation Biogeography Lab of the Institute of Geography at Humboldt-Universität led by Tobias Kümmerle also take interest in the black-and-white photographs. They provide a detailed look into the planet's recent past. "What is unique about the images from the spy satellites is that they depict a large part of the Earth's surface in high resolution, at a time from which little or no image material was previously available for most regions. This allows us to look back to a time when many environmental changes, such as the destruction of tropical forests, had simply not yet happened," says Kümmerle. The historical satellite images are so detailed that individual trees can be recognised with the naked eye.