KATHMANDU – Human waste, empty oxygen cylinders, kitchen leftovers and discarded ladders.

Sherpas working on Mount Everest carry all that and more – 20kg per person – navigating a four-hour hike that traverses crumbling glacial ice and treacherous crevasses to bring rubbish back to base camp.

During the most recent climbing season, they had new assistance from two giant SZ DJI Technology Co drones, which can complete the same journey in six minutes, sharing the task of clearing an expanding volume of refuse piling up on the world’s highest peak.

Drones have been deployed to haul garbage from Everest’s Camp 1, which sits at 6,065m above sea level down to base camp, about 700m below.

After a DJI FlyCart 30 delivers supplies like ropes and ladders up the peak, Sherpas hook on a debris-filled garbage bag for the drone’s return journey as it buzzes down the mountain, sounding like an oversized mosquito.

Between mid-April and mid-May, the drones operated by Nepal-based firm Airlift Technology handled more than 280kg of refuse, according to the Sagarmatha Pollution Control Committee, a local non-profit that manages trash collection on Everest.

The drones are part of a growing effort to clean the slopes of the mountain, which has become so trash-strewn, it’s been referred to as the “world’s highest garbage dump.”

Enlisting robots can help not only speed up the process but also reduce the danger for the Sherpas carrying decades-worth of garbage down the treacherous peak.

“We’re very happy,” said Mr Lhakpa Nuru Sherpa, a 33-year-old Sherpa at local expeditions firm Asian Trekking who has reached the summit of Everest 15 times.

He estimates that about 70 per cent of the garbage usually carted off the mountain by his team was transported by drone in 2025. 

“When you’re coming down from Camp 1 and it’s warm, you can smell the garbage,” and that has caused respiratory problems for some Sherpas, he said. “We want more drones carrying heavier weights.”

The 8,849m Everest has seen an influx of rubbish since the 1990s, when visiting grew in popularity following multiple successful summit attempts.

During climbing season, which typically lasts from late April until the end of May, tens of thousands of people trek to base camp, though only hundreds attempt to reach the top of the peak each year.

Everest’s garbage problem is worst at higher altitude campsites, which are also more challenging to clean, given the logistical hurdles of reaching them.

Since 2019, the Nepalese army and Sherpas have worked together to remove more than 100 tons of waste from the mountain and several surrounding peaks.

In the last decade, the government has also implemented rules requiring climbers who venture above base camp to carry back at least 8kg of rubbish each or risk forfeiting a US$4,000 (S$5,090) deposit that those visiting the mountain must pay.

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Climate change is only adding to the urgency to clean Everest. 

Snow and ice are melting, exposing decades-old garbage that can contaminate waterways fed by the run-off and that flow down to villages below. 

To combat the risks of human waste spreading diseases such as cholera, local officials in 2024 put in place regulations compelling climbers to keep it in doggy bags to be brought back to base camp.

At the same time, rising temperatures are making trash collection more dangerous.

Ice is weakening, crevasses are widening and meltwater within the Khumbu Glacier – situated between base camp and Camp 1 – is causing ice blocks to collapse more quickly.

At lower altitudes, the Khumbu Icefall at the head of the glacier “is by far the most dangerous part of the mountain, and towards the end of the season, it starts to melt,” said Mr Tenzing David Sherpa, a director at Asian Trekking, which employs about 30 Sherpas.

“It is much safer for drones to bring down the waste.”

The Chinese drones, which cost US$70,000 each, can fly in temperatures of minus 20 deg C and brave wind speeds of more than 40kmh.

Asian Trekking said it would pay for Airlift’s equipment and trash delivery services if the drone company decides to officially offer them commercially.

Even so, there are limitations.

Drones aren’t able to reach higher campsites, where the air is too thin to fly.

Weather at high altitude can also be erratic, and during a flight in April, a drone automatically deployed a parachute when wind speeds hit more than 60kmh.

The machine was then dragged and damaged by further gusts.

The accident highlighted the need for specialised insurance before expanding the project, according to Mr Tshering Sherpa, SPCC’s chief executive officer.

Such policies are not currently readily available and “if we don’t have any insurance, it is a very high-risk project,” he said.

Airlift, which is working with Nepalese authorities, is planning to try more drone models on Everest and the country’s other 8,000m peaks, said co-founder Milan Pandey. 

At least five drone manufacturers from the US and Europe have already reached out to Airlift offering their equipment for testing, Mr Pandey said.

At these altitudes, “we’re the only company in the world doing this operation.” BLOOMBERG

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