Garbage on Mount Everest is not new but this year's haul from an estimated 700 climbers, guides and porters has been a shock to the local Sherpas.
After every party it's time to clean up and Mount Everest is no different. The record number of climbers crowding the world's highest mountain this season has left a government clean up crew grappling with how to clear away everything from abandoned tents to human waste that threatens drinking water.
Budget expedition companies charge as little as $US30,000 ($A43,172) per climber, cutting costs including waste removal. Everest has so much garbage - depleted oxygen cylinders, food packaging, rope - that climbers use the rubbish as a kind of signpost. But this year's haul from an estimated 700 climbers, guides and porters on the mountain has been a shock to the ethnic Sherpas who worked on the government's clean up drive this spring.
Moreover, the tents are littering South Col, or Camp 4, which, at 8,000 metres is the highest campsite on Everest, just below the summit. The high winds at that elevation have scattered the tents and rubbish everywhere.
"The altitude, oxygen levels, dangerously icy and slippery slopes, and bad weather of South Col make it very difficult to bring such big things as tents down," said Dawa Steven Sherpa, who led an independent clean up last month and has been a leading figure in the campaign to clean Mount Everest for the past 12 years.
Exhausted climbers struggling to breathe and battling nausea leave heavy tents behind rather than attempt to carry them down. Sherpa said the logos on the ice-embedded tents that identify the expedition companies were deliberately ripped out so the culprits could evade detection.
"It took us an hour to dig out just one tent out of the frozen ice and bring it down," said Sherpa. His expeditions have alone brought down some 20,000 kilograms of garbage since 2008.
Sherpa estimated 30 tents had been left on South Col, and as much as 5,000 kilograms of garbage. Bringing it down is a herculean task when any misstep at such altitudes could be fatal.
It is impossible to know exactly how much litter is spread across Everest because it only becomes visible when the snow melts. At Camp 2, two levels higher than Base Camp, the campaigners believe that around 8,000 kilograms of human excrement were left during this year's climbing season alone.
Some climbers do not use makeshift toilets, instead digging a hole in the snow, letting the waste fall into small crevasses. However, rising temperatures have thinned the glacier, leaving fewer and smaller crevasses. The overflowing waste then spills downhill toward Base Camp and even communities below the mountain.
People living at the Base Camp use melted snow for drinking water that climbers' toilets threaten to contaminate.