Scientists say human activity at Mount Everest Base Camp may be contributing to the melting of the Khumbu Glacier, with urine alone potentially responsible for more than 150 tonnes of ice loss during a single climbing season.
Research published in the journal Regional Environmental Change examined the impact of Everest Base Camp, which is located on the Khumbu Glacier on the Nepalese side of the mountain.
At high altitude, climbers and guides need to drink large amounts of water to avoid dehydration. Researchers estimate that people at the camp collectively produce more than 6,000 litres of urine every day. While solid human waste is generally collected and removed from the area, much of the urine is discharged directly onto the glacier.
By calculating the amount of heat transferred from the liquid to the surrounding ice, researchers estimated that urine could have contributed enough thermal energy to melt around 154 tonnes of ice during the climbing season.
However, urine represents only a small part of the overall heat generated by human activity at the camp.
During the 2023 spring climbing season, around 1,600 tents were in use over approximately 50 days. Operating the temporary settlement required an estimated 824 canisters of liquefied petroleum gas, 18,935 litres of kerosene and 5,130 litres of petrol.
When the heat generated from fuel use and urine was combined, researchers estimated that human activity at Everest Base Camp produced enough energy to potentially melt around 2,492 tonnes of ice and snow during the season.
The estimate may still be conservative because the study did not include several additional sources of heat, such as climbers’ body heat, helicopters or yaks used to transport equipment and supplies.
Researchers emphasized that climate change remains the main driver of long-term glacier loss on Mount Everest. The study does not suggest that climbers are primarily responsible for the glacier’s retreat, but instead highlights how concentrated human activity can add further heat to an already vulnerable environment.