Climbers and custodians of Everest say rapid climate change could soon make for an ice-free ascent of the world's highest mountain.
Their warning comes amid a new international effort to gauge the effects of climate change in the Himalayas - and shield local people from potential hazards.
A US-funded mission, led by the Mountain Institute, opened a meeting in Kathmandu at the weekend aimed at finding practical solutions to the threat of catastrophic high-altitude flooding from lakes forming at the foot of melting glaciers.
Anecdotal evidence suggests the climbing experience is now far different from that Sir Edmund Hillary and Tenzing Norgay faced in 1953. However, scientists acknowledge they have yet to form a complete picture of the changes under way in the Himalayas.
The task of offering a definitive scientific account of the extent of melting is daunting - and not just because the area is so vast and inaccessible.
Scientists are still working to recover from a PR disaster early last year when it emerged that a United Nations report on climate change had claimed - wrongly - that the Himalayan glaciers would disappear by 2035.
But growing anecdotal evidence from climbers and local people suggests climate change is making a strong impact even well above the 8000m line, with signs of melting ice on the southern approach to Everest.
"When I climbed Mt Everest last year I climbed the majority of ice without crampons because there was so much bare rock," said John All, an expert on Nepal glaciers from the University of Western Kentucky.
"In the past that would have been suicide because there was so much ice."
He said the terrain he crossed was very different from the landscapes described by earlier generations of climbers. Historical photographs of the Everest region show a longer and deeper covering of ice.
All added: "I wonder when Mt Everest will finally become a rock climb rather than an ice climb."
Everest Base Camp has undergone similar changes, said Tshering Tenzing Sherpa, who has overseen rubbish collection at the site for the past few years.
The summer monsoon months brought several deep new crevasses in the black ice beneath the rocks, Tenzing said. "Everything is changing with the glaciers."