Telegraph | April 19, 2007
By Richard Spencer in Hong Kong

China claimed yesterday to have caused a snowfall for the first time as part of its increasingly ambitious attempts to control the weather.

Officials in the meteorological bureau in Tibet said they had used "rain-seeding" techniques to trigger a snowfall over the city of Nagqu last week.

"This proves it's possible for humans to change the weather on the world's highest plateau," said Yu Zhongshui. The bureau said it had produced just under half an inch of snow at a height of 15,000ft.

Mr Yu said the experiment was conducted in the hope it would lead to alleviating drought on the northern Tibetan plateau, whose grasslands are turning brown as global warming melts and drains its permafrost.

The government also hopes that the project will benefit the great river systems of China. The Yellow, Yangtse, Salween, Mekong and Brahmaputra rivers all rise in Tibet, and the effects of damming and over-extraction for agriculture are beginning to threaten water supplies to major cities.

China is the world's largest practitioner of rain-seeding, a controversial procedure that involves releasing silver iodide as a catalyst into clouds either by aircraft or by firing cannon shells into them. It employs 37,000 people on the programme, which it uses to trigger rainfall principally to maximise water supply in the drought-prone north of the country, although in Beijing it is often said to be part of attempts to ensure a blue sky for major events.

Authorities have already promised to use rain-seeding before the Olympics to clear the often gloomy August skies for the opening ceremony.