Global warming has made the ice on the Khumbu Icefall, one of the most dangerous parts of climbing Mount Everest, less stable.
Conquering Mount Everest is inherently a dangerous activity. Before climbers following the South Col route can reach Camp 1, they face one of the deadliest sections of the route: the Khumbu Icefall, a 2.6km long sheet of slow-moving ice just above Base Camp.
An icefall, similar to a waterfall, is where a glacier cascades down a cliff. The ice above breaks into large blocks, called seracs, while the ice below cracks, creating deep fissures. Everything in Khumbu is giant, so seracs can be 30m tall ice towers and crevasses can be 30m wide canyons in the ice.
This icefall is so dangerous that there is a group of experts in charge of plotting a route through it called Icefall Doctors. This year, they delayed the Everest climbing season by 12 days due to unsafe conditions, Business Insider said on May 5. The Khumbu Icefall will only become more dangerous as global temperatures rise, according to Paul Mayewski, a climatologist and Mount Everest researcher from the University of Maine.
Essentially, the Khumbu Icefall is a slow-moving glacier that gradually cascades down a cliff. The movement of the icefall is what makes it unstable, creating deep crevasses and deadly avalanches. Between 1953 and 2019, 45 people died at Khumbu Icefall. The three main causes of death are avalanches on icefalls (49%), ice collapses (33%) and falls into crevasses (13%), according to Alan Arnette, mountaineering instructor and Everest conqueror.
Deep crevasses and avalanches make the Khumbu Icefall one of the most dangerous sections of climbing Mount Everest. Image: Olaf Rieck/Wikimedia Commons
At the beginning of each climbing season, the Icefall Doctors are the first to traverse this dangerous icefall. They found the safest route, placing ropes and ladders along the way to help people move over cliffs and crevices.
This year, Doctor Icefall continuously encountered dangers that slowed down the progress of his mission. Low snowfall in winter and high temperatures caused the ice towers and bridges to become unstable, forcing them to reassess the route multiple times. “Going up there one time of day and going down the next day, things can look very different,” Mayewski said.
Rapid melting causes glaciers, such as the Khumbu Glacier, to shrink and erode. This brings more lakes and streams, but also increases the risk of avalanches, falling ice and making crevasses more dangerous.
“It’s likely that the situation will get worse as the climate warms because the ice becomes more mobile. The warmer it gets, the more water flows. That flowing water will obviously destabilize the ice,” Mayewski said.
Mayewski’s research shows that conditions are changing across Mount Everest, not just at Khumbu Icefall. One-third of the ice on South Col, Everest’s highest glacier, has disappeared in the past two to three decades. “Even just walking around the Base Camp area, there are a lot of melting spots,” he said.
However, Mayewski doesn’t think the increased risks from climate change will make climbing Mount Everest impossible someday. “Can people still climb mountains? Yes, I think they still will. So is this more dangerous? Yes – it is already very dangerous,” he said.