More than 4,000 climbers have attempted to summit the world's tallest mountain, Everest. Some make it. Many others do not. But win or lose, when they go home, they leave behind more than just their footprints.
The chief of Nepal's mountaineering association recently announced that the levels of human waste left by climbers have reached a critical level, and the pollution is threatening to spread disease.
But Mount Everest is not the first to face that problem. Ask North America's tallest peak, Mount McKinley — also known as Denali — in Alaska.
As recently as 2000, rangers at Denali feared the mountain would have to close to the public due to an overwhelming amount of waste.
"Fifty years ago, it was huge," veteran mountaineer Roger Robinson tells Here & Now's Jeremy Hobson.
"I got involved, 40 years ago on a clean up climb, and started to experience the drama of Denali being a very dirty mountain both with garbage and human waste and everything you could imagine," Robinson said. "Back in those years, you could just pretty much poke an ice ax in the snow and come up with garbage."
It was easy to teach people to keep the garbage under control Robinson remembered, but human waste proved a challenge.
"People were often sick at the camps from acquiring bad snow to melt for water, it was a concern all the time," he said. "And that was one of our biggest issues, was having to go out and direct climbers to get snow away from the camps to melt for water."
In response, the national park designed the Clean Mountain Can, known as a CMC to climbers. These cylindrical containers measure 11 inches tall with an 8 inch diameter opening, and weigh 2.4 pounds. They are also specifically engineered to carry human waste at high elevations.
The CMC's, Robinson says, are lined with biodegradable bags, which people will then dispose of through "crevassing."
"These are large cracks in the glacier, 300 to 400 feet deep, and it takes fifty to several hundred or thousand years before it resurfaces," Robinson said.
But will a solution like this work on Everest?
"It should," Robinson said. "It really comes down to their government seeing this is a possibility."
- Roger Robinson, 35-year veteran mountaineering ranger for Denali National Park.
This segment aired on March 17, 2015.