Warmer climates are shrinking Tibetan glaciers at their summits, researchers have discovered.
A study has shown that the glaciers may be losing ice at altitudes of up to 6000 metres.
Examining trapped chemical compounds in the ice, the research team discovered they were able to detect the signature of nuclear tests that occurred between 1952 and 1963, but not those of more recent events such as the Chernobyl nuclear disaster which happened in 1986.
This suggests that ice layers formed on the glacier from the 1950s onwards have melted away.
The Tibetan ice acts as a water reservoir for vast regions in China and South Asia and to the hundreds of millions of people that live there.