Mount Everest is about 12ft lower than previously thought, according to the results of a Chinese survey of the world's highest peak. It revealed the summit is now only 29,017.16ft above sea level - 12.14ft below a 1975 Chinese survey and 21.65ft lower than a 1999 American study. Using a combination of radar and global positioning system (GPS) equipment, Chinese mountaineers scaled the peak in May this year and measured the height against six control points near the mountain's base for reference. The revised measurement does not threaten Everest's revered position as the world's highest peak - the second highest, K2, is 28,251ft above sea level - but it may surprise some observers, while perhaps confirming suspicions that the mountain has been shrinking due to the effects of global warming. Speaking when the study was proposed earlier this year, Dr Hugh Sinclair, an expert on the processes of mountain formation and erosion at Edinburgh University's school of geosciences, said he was "extremely doubtful" that the mountain would have shrunk. He said: "The Himalayas are uplifting at a rate of about 1cm a year due to the collision of the Indian continental plate with the Asian plate. Basically, we have India pushing into Asia at a rate of about 25mm a year, and this causes the high Himalayas to rise up in response to that pressure at about 10mm a year, so the overall tendency should be for the mountain range to grow." At a news conference in Beijing yesterday, Chen Bangzhu, the director general of China's state bureau of surveying and mapping, was non-committal in accounting for the discrepancy, saying "we cannot arrive at the conclusion now that Everest has become shorter, because there have been problems ... of surveying technology with previous measurements".

