Study warns that climbers' urine on Everest melts tons of ice

Every year, hundreds of tourists flock to the Himalayas to face the ultimate climbing challenge: Mount Everest, the highest mountain on planet Earth (8,848 meters). But a new study warns that these climbers are unknowingly destroying the Everest glacier in a very peculiar way: with their urine.

With an altitude of 5,350 meters, the Khumbu Glacier is the highest glacier in the world and is also home to Everest Base Camp. In a new study, scientists from Nepal's Department of Surveying set out to understand the impact that climbers, trekkers and support staff have on the glacier.

The team focused on the spring 2023 season, during which more than 2,000 people stayed at base camp. According to their calculations, the visitors' urine alone could have melted more than 150 tons of ice on the glacier.

"Human urine is released directly onto ice at high altitudes, where the ice temperature is constantly kept below 0°C," the researchers explain. "Urine, with a temperature of around 37°C (human body temperature), causes ice to melt," they add.

Since 2003, climbers and visitors to Everest Base Camp have used blue barrels to collect excrement. However, their urine is poured directly onto the ice.

In their new study, published in Regional Environmental Change, the researchers, led by Khim Lal Gautum, set out to analyze the effects of this phenomenon. "Camp Everest Base (CBE), a critical starting area for mountaineers attempting to reach the summit of Everest, has seen a significant increase in human activity in recent decades," the authors say.

"The increasing number of climbers, hikers and support staff, especially in the camping area, has intensified the environmental impact on the Khumbu Glacier," they continue.

According to the researchers' calculations, the average daily urine production at the base camp is approximately 3,181 liters per person. With around 2,127 people staying at base camp an average of 50 days during the spring, the total urine discharge amounts to approximately 338,299 liters.

In theory, this means that urine released at base camp could provide enough heat to melt 154 tons of ice, the authors say.