Mt Everest stands 8,848m tall – and thanks to shifting tectonic plates that add a few millimetres a year, the world’s highest peak is getting even taller. But Everest’s height isn’t the only aspect of the mountain that’s growing. Since New Zealander Sir Edmund Hillary and Nepali Tenzing Norgay first summited the roof of the world in 1953, nearly 6,000 people have attempted the climb to the summit. Only 3,000 have succeeded. Meanwhile, visitors coming to see the region's myriad trails, small villages and to Everest Base Camp number in the hundreds of thousands. 

Tourism has become the lifeblood of this mountain economy, but at the same time, tourists are threatening the stability of the entire region. While foreigners bring a boost to the local community – trekkers spend about 10,000 to 20,000 Nepali rupees a day on food, lodging, guides and porters – they also bring loads of gear, human waste and toxic trash, all of which clog the trail in peak season and turn the picturesque region into the site of one of the world's most challenging environmental problems.

I travelled to Everest’s Base Camp – the starting point of any summit attempt – in late December 2013, on the camp’s 60th anniversary. After a short flight from Kathmandu to the mountain hamlet of Lukla, it took me 12 days to reach Base Camp, trekking 160km and climbing 10,000 feet, hiking through dense forest, over a dozen suspension bridges, above the tree line and, finally, into a frozen landscape of ancient rock and glacial ice. The higher I went, the less oxygen was in the air, with only 50% oxygen at Base Camp’s altitude of 5,364m.

On my journey, I quickly realised I was in a region in flux. Some communities are ecologically friendly: they use solar power and green methods of waste removal, undertaking the daunting challenge of hauling non-biodegradable items off the mountain via pack animals as opposed to burning or burying trash.

Many others, however, are too concerned with day-to-day subsistence to care about their carbon footprint. After all, when every breath and step is a cold challenge, the sheer difficulty of survival trumps everything – which is why, further up, there are still some 200 bodies on the way to the mountain’s summit that have not been hauled down, or even identified.

That day-to-day difficulty of survival, and the lack of real infrastructure, explains in part why so much tourism waste remains on the mountain. Only a small fraction has been removed, leaving eight to 10 tonnes, including in the "death zone", the part of the mountain closest to the summit – like discarded oxygen cylinders, ropes, tents, batteries and plastic. Helicopters cannot fly to the area because the thin air disables their blades, making hauling this graveyard down nearly impossible.

Climbing teams are responsible for hauling down their own trash. The process is expensive and lengthy, and includes bringing all non-disposables, like batteries and empty oxygen cylinders, back to Kathmandu and on to their home countries. Sherpas store toilet and kitchen waste in metal drums and haul it 50km down to the town of Namche Bazaar, where it is used for compost. To pay for the processing and facilities, climbers pay a tax of 1,000 Nepali rupees per kilogram. Yet this regulated process of climbing teams removing their own waste for a tax only applies to a small portion of total Everest travellers: trekkers who stay in hotels as opposed to camps. Those who live on the mountain don't haul their trash down, choosing instead to burn or bury it once tourists are gone.  

The trash build-up has led to some creative solutions. In 2011, Sherpa organisation Everest Summiteers Association and the Nepalese government collected 1.5 tonnes of trash, hauling it by yak to Lukla and flying it to Kathmandu, where items like ice axes were turned into local artwork for a temporary exhibition. Meanwhile, lobbying group-cum-NGO Nepal Mountaineering Association and another mountaineering agency, Asian Trekking, collect a few tonnes of trash from the mountain every year.

More collection trips are being organised – but they are not enough. On my trip, I noticed how many bottles, candy wrappers, cigarette butts and other signs of man pockmarked the land. Occasionally, deep piles of trash were piled high in mountain switchbacks. As well as unsightly, trash build-up has caused routes to become more dangerous: Sherpas avoid certain sections that are too covered with trash, leading to some paths becoming more used – which in turn causes melting snow and ice, exposing deep crevasses and risking an increase in the death toll. Of the two to three dozen yearly Everest summit attempts, only about 60 to 70% are successful, with three to four deaths a season, reports the Nepal Mountaineering Association.

Tourism is creating other problems for the local environment, too, including increased population density, over-dependence on wood as a fuel and construction source and the overgrazing and cutting of mountain slopes to feed livestock. Tourism accounts for an estimated 10% increase in wood consumption, according to the Nepalese government, which leads to an estimated 240 million cubic metres of mountain topsoil lost on Everest every year, further triggering forest depletion.

Beyond trash collection, groups such as the Nepal Mountaineering Association and the Trekking Agencies' Association of Nepal, an advocacy group issuing trekking permits, are lobbying the government to increase the use of renewable energies and develop permanent campsites with basic utilities. They also want to introduce a basic code of conduct in the Himalayas, banning firewood for fuel and the use of plastics. But it's unclear who would enforce those rules, and whether offenders would even be fined. In response to growing pressure, the government recently announced that officials now will check to ensure that climbers are bringing 8kg of waste down the mountain with them. How these regulations would be enforced, however, was not specified.

In Nepal, a country known for legislative deadlock, corruption allegations and weak infrastructure, effective change will be slow. Half a decade after a bloody civil war between Maoist insurgents and the ruling monarchy – and only months removed from a November 2013 presidential election precipitated by protests – Nepal's government is more concerned with the rising problems of hunger and geo-politics. “The majority of Nepal is fighting for basic needs. Until basic needs are fulfilled, people do not care about deforestation or pollution,” said Keshav Pandey, senior vice president of the Trekking Agencies’ Association of Nepal. “A porter doesn't care to throw plastic [onto the trail]. He just thinks about the money of the day."

Thanks to the money tourism brings, the region also has little reason to make changes that could curb visitor numbers. Everest climbing permits cost 235,929 Nepali rupees – an amount that excludes the cost of gear, air transport, porters, camp and staff fees, food or travel insurance. For comparison, climbing fees for Nepal's other mountains range from about 18,000 to 38,000 Nepali rupees. The 6% of climbers who take on Everest account for 65% to 70% of the monies collected in total revenue.

"The first thing [the government] are concerned with is money,” said Nima Nuru Sherpa, the vice president of the Nepal Mountaineering Association. “Locals are stakeholders. Money should go back to stakeholders." Instead, he said, only about 30% of the total money tourists spend returns to locals in terms of profit. The rest goes into government coffers, he said.

Repeated attempts to speak with government officials went unanswered. Emails and phone calls were not returned, and while in country, I was unable to secure a meeting with officials.

There may be one silver lining to Everest’s tourism problem, though: as word of the environmental issue spreads, hikers may begin to head to other Himalayan peaks, therefore reducing the traffic on Everest. After all, Nepal's Himalaya range is home to eight of the world's highest peaks. Supporters point out, however, that broad environmental policies will be needed to ensure those peaks are protected from tourism’s consequences too.

The attention caused by Everest's trash problem is a step in the right direction, said 31-year-old Suman Thapa, who started working as a porter at 17, but the mountain has a long way to go. One of the biggest hurdles, he said, is overcoming foreigners' blind excitement to just climb – and getting them to think about their impact on the mountain.

"People are not fully aware of the conservation of the mountain. They are educated but they don't understand even when we do our best to convince them," he said. "We have to think about the next generation."

Correction: This story has been updated to clarify how much trash remains on the mountain.