The top of the world is melting at an alarming rate

Mountain glaciers worldwide are melting due to climate change. Monitoring ice loss in these glaciers is crucial to understand new risks posed to downstream communities and local biodiversity. As glaciers melt, downstream communities become increasingly vulnerable to disasters like floods. When glaciers eventually shrink, water unavailability presents another problem. Scientific studies have focused on tracking changes in glaciers at lower altitudes, often less than 5000 meters. However, there is a significant lack of studies monitoring glaciers at higher elevations. In 2019, a group of researchers undertook the first on-site study of Mount Everest’s South Col glacier—the mountain’s highest glacier at 8020 meters—to help fill this knowledge gap. The findings are alarming.

Researchers from National Geographic and Rolex’s Perpetual Planet Everest Expedition extracted ice cores from the South Col glacier coupled with written and photographic records to study glacier retreat. The study, recently published in Nature Climate and Atmospheric Science, found that the highest point on earth, Mount Everest, is experiencing melting at a much faster pace than anticipated. At a rate of 2 meters of ice lost per year, the researchers estimate the South Col glacier may disappear within a few decades. The ice loss began in the mid-1800s and has intensified since the 2000s, as a consequence of anthropogenic climate change. Sublimation, a process in which snow becomes vapor, has been primarily responsible for transitioning the permanent snow surface to thin ice since 1950. The researchers note that while warming has amplified the sublimation process, declining relative humidity and stronger winds are also contributing factors. 

Despite freezing temperatures, Mount Everest’s upper reaches appear highly sensitive to climate change. The study reveals that models employed to study glacier behavior at high altitudes underestimate the melting rate. Previous models did not consider that strong winds in the upper reaches may also influence glacier melt. Additionally, as Mount Everest warms, darker bedrock beneath the thin ice will become more exposed, absorbing more heat and accelerating warming by twenty times. Furthermore, climate change-induced disasters like icefalls and avalanches pose severe increased threats to climbers on the Everest climbing route, including residents and tourists.

The study shows that present knowledge of glacier retreat is inadequate, and the fate of the highest glacier in the world may sink faster than expected. New research casts doubt on prior models predicting glacier behavior at high altitudes. It is imperative to track glaciers across the Hindu Kush Himalayas, home to the world’s tallest peaks, to inform disaster management plans in the region and to protect the billion people who depend on water from the mountains. Worldwide, other high-altitude communities may face similar risks. Therefore, predicting glacial responses to climate change is more urgent than ever.