Climbers' urine, fuel use melt 2,500 tons of Everest ice a year, study finds

Human activity on Mount Everest melts roughly 2,500 tons of glacier ice and snow each year, according to new research.

An international research team that included Kim Lal Gautam, a senior surveyor at Nepal's Department of Land Management, analyzed the Khumbu Glacier — where Base Camp sits on the Nepalese side of Everest — and published their findings in the journal Regional Environmental Change.

During the spring climbing season, thousands of climbers, guides and support staff converge on Everest Base Camp. The camp now operates cafes, high-speed internet, large-screen televisions, hot showers and tents with heated floors.

Researchers found that running the camp's 1,600 tents over roughly 50 days in the spring of 2023 consumed 824 canisters of liquefied petroleum gas, 18,935 liters of kerosene and 5,130 liters of gasoline. Adding up heat generated by fuel burned for cooking, heating and power production, as well as heat released by the human body, the team estimated a total thermal energy output of 849,174 megajoules.

That is enough energy to melt 2,492 tons of ice and snow — or between 1,964 and 3,020 tons when accounting for margins of error. Melting 2,500 tons of ice and snow would produce enough water to fill one Olympic-size swimming pool.

Urine emerged as a particularly significant heat source. At high altitude, climbers and support staff drink large amounts of water to prevent dehydration, collectively producing more than 6,000 liters of urine per day. Solid waste is collected in storage tanks and carried down the mountain, but much of the urine is discharged directly onto the glacier. The researchers estimated that heat from urine alone could melt about 154 tons of ice over a single season.

Satellite data confirmed a pronounced warming trend around Base Camp. Analyzing Landsat imagery from 1991 to 2023, the team found that surface temperatures at Base Camp rose at an average rate of 0.28 degrees Celsius per year — roughly twice as fast as on the adjacent Khumbu Glacier surface.

The researchers said the actual impact of human activity is likely even greater, as the calculations excluded heat generated by helicopter flights, climbers' body warmth and the yaks used to carry supplies.