Global warming takes its toll on the world's highest mountain as Everest shrinks by 4ft

It got bigger only recently, but now it may be shrinking. What on earth is happening to Mount Everest?

It got bigger only recently, but now it may be shrinking. What on earth is happening to Mount Everest?

News reports from China yesterday said there was official concern that the top of the world's tallest mountain is getting lower ­ and melting glaciers caused by global warming may be to blame.

A scientific team is to be sent to the mountain ­ known in Chinese as Mount Qomolangma, or Goddess Mother of the World ­ to remeasure its height, according to the state-run newspaper China Daily .

But Everest was last measured in 1999, and found to be higher than previously thought. A team of scientists supported by National Geographic Magazine and Boston's Museum of Science was able for the first time to operate Global Positioning System (GPS) satellite equipment from the summit, and thus take the most precise and authoritative measurements ever. They came up with a revised elevation of 29,035ft, seven feet higher than the previously accepted figure. That had been set in 1954 by the Survey of India after picking the mean of 12 altitudes determined from 12 different survey stations around the mountain.

Now, however, the Chinese think the summit may have got lower and, according to China Daily , the State Bureau of Surveying and Mapping, working with the Chinese national women's mountaineering expedition, will use radar and GPS equipment to remeasure the peak.

The newspaper said a recent survey found the summit of Everest had dropped by more than four feet, because ofmelting glaciers resulting from global warming.

Nepalese Sherpas who often climb the peak have reported seeing widespread evidence of snowlines receding. And in 2002, a team of climbers sponsored by the United Nations Environment Programme found signs that the landscape of Mount Everest had changed significantly since Sir Edmund Hillary and Tenzing Norgay first conquered the peak in 1953.

The team found that the glacier that once came close to Hillary and Norgay's first camp had retreated three miles, and a series of ponds near Island Peak ­ so-called because it was then an island in a sea of ice ­ had merged into a long lake.

Roger Payne, the sports and development director at the International Mountaineering and Climbing Federation (UIAA), and one of the expedition's leaders, said it was clear that global warming was emerging as one of the biggest threats to mountain areas. "The evidence of climate change was all around us, from huge scars gouged in the landscapes by sudden, glacial floods to the lakes swollen by melting glaciers," he said.

He added that the observations of local people who lived on the lower slopes of the mountain were even more telling. The president of the Nepal Mountain Association told the expedition that he had seen significant changes over the past 20 years in the ice fields, and that these changes appeared to be accelerating.

The expedition found that climatic changes had caused problems for residents of the area. A massive flood caused by water melted from the glaciers had wiped out old wooden bridges, which had to be replaced with higher, stronger metal ones to reduce the possibility of damage from future floods.

Everest sits on the borders of Tibet (occupied by China) and Nepal. Its name in English comes from Sir George Everest, the Surveyor-General of India, who was the first to produce detailed maps of the subcontintent including the Himalayas, and first calculated the great peak's height in 1852.

Since Hillary and Norgay first made it to the top, more than 1,300 people have climbed Everest, from either the Nepalese or the Tibetan side. At least 175 climbers have died in the attempt.