Climate change is making Mount Everest more dangerous to climb, a Nepalese Sherpa said in Kathmandu Tuesday after breaking his own record by making a 20th ascent of the world's highest peak.
Apa Sherpa, who dedicated his latest climb to the impact of global warming on the Himalayas, said he was disturbed by the visible changes on the mountain caused by rising temperatures.
"The snow along the slopes had melted, exposing the bare rocks underneath, which made it very difficult for us to walk up the slope as there was no snow to dig our crampons into," he told AFP on Tuesday.
"This has made the trail very dangerous for all climbers."
Apa, 50, has been nicknamed the "super Sherpa" for the apparent ease with which he climbs Everest, but he was visibly exhausted as he spoke to journalists in the Nepalese capital three days after reaching the summit.
He led an expedition aimed at raising awareness of the impact of climate change in the Himalayas and clearing up the tonnes of rubbish left on the mountain by previous expeditions.
The team brought down 4.8 tonnes of rubbish from the mountain, some of which will be displayed at a festival to be held next month in the Everest region to highlight the problems of global warming.
Around 250 people scaled Mount Everest from the south side this year, Nepal's mountaineering department said Tuesday, as heavy snow brought the brief climbing season to an early close.
They said the weather on Everest had deteriorated since snow began falling on Sunday, ending a climbing season that has set a record for the youngest person ever to reach the top as well as the highest number of summits.
"We have come to the end of the Everest season," mountaineering department official Tilak Pandey told AFP by telephone from Everest Base Camp on the south side of the mountain, which straddles Nepal and China.
"The spring season can often go on until the end of May, but the weather has got worse since Sunday. As far as we know, there are no more teams left to climb this season."
Mountaineering blogs reported a rush for the summit over the weekend as expedition leaders tried to ensure as many climbers as possible made it to the top before the weather closed in.
An estimated 200 people reached the summit on Saturday, the busiest day, when 13-year-old American Jordan Romero became the youngest person ever to climb Everest, tackling the mountain from the quieter north side.
Around 2,900 people have scaled Mount Everest since Edmund Hillary and Tenzing Norgay became the first people to conquer the 8,848-metre (29,028-foot) eak in 1953.
Most climbers make their attempt in late April and May, when a small window between spring and the summer monsoon offers the best conditions for the ascent, although it is also possible to do so in early autumn.
Pandey said 2010 had been a successful season on Everest, with no serious casualties, although two people had to be airlifted off the mountain on Tuesday, one with altitude sickness and another with a minor injury.
"The summit rate this year was very encouraging. Most of those who applied for a permit, or around 250 climbers, were able to make it to the top," he said.
Explore further: No plan B on Rio sailing as Brazil chases pollution target