Mount Everest: Expeditions accelerate melting of Khumbu Glacier

Mount Everest is considered a dream destination for many mountaineers worldwide. But the rush to the highest mountain on earth has consequences: every year, thousands of people crowd into the base camp on the Khumbu Glacier during the climbing season. A new study now suggests that the expeditions themselves accelerate the melting of the ice.

The heat from burned fuel and even human urine is enough to melt around 2,500 tons of ice and snow every year, reports the British newspaper “The Independent,” citing the trade journal “Regional Environmental Change.”

An international team examined the glacier on the Nepalese side of Mount Everest, where thousands of climbers, guides and aid workers camp during the spring season. During this time, the base camp has developed into a veritable tourist village, with espresso cafes, big-screen TVs, fast internet, hot showers and heated tent floors.

According to the researchers, during the 50-day climbing season in 2023, a total of 824 canisters of liquid gas, 18,935 liters of kerosene and 5,130 liters of gasoline were used for cooking, heating and power supply for the approximately 1,600 tents in the camp. Together with the heat from human urine, the scientists calculated that the energy yield was 849,174 megajoules.

This amount of energy would be enough to melt an estimated 2,492 tons of ice and snow. Taking into account the error tolerance, the possible range is between 1964 and 3020 tons. That corresponds to the amount of water in an Olympic swimming pool.

According to the researchers, human urine turned out to be a surprisingly important source of heat. Mountaineers and mountain guides drink lots of water at high altitudes to prevent dehydration. According to estimates, this produces around 6,000 liters of urine every day. While solid waste is carried away from the mountain, much of the urine ends up directly on the glacier.

According to scientists' calculations, the heat from this urine alone could melt around 154 tons of ice within one season.

Satellite data also indicate increased warming in the area around the base camp. The analysis of Landsat images from 1991 to 2023 showed that surface temperatures in the camp rose by an average of 0.28 degrees Celsius per year. This means that the area warmed up about twice as fast as the surrounding Khumbu glacier.

The researchers point out that their calculations do not take into account the heat of helicopter flights, the body heat of mountaineers and the yaks used for transport. The actual human influence could therefore be even greater.

Climate change remains the main cause of glacier retreat on Mount Everest. Nevertheless, scientists consider the annual concentration of thousands of people on the already melting glacier to be problematic in the long term. “In the long term, consideration should be given to moving the base camp from the glacier to a stable site in a nearby area,” they write.