Climate Change Threat on Mt. Everest; Rising Risks Say Scientists

Scientists have warned that climate change is causing the Himalayas to warm faster than the global average, making summiting Mt. Everest, the world's tallest mountain, increasingly dangerous and risky. Worst, it may soon be not climbable at all.

The iconic Everest, the "roof of the world," sits in the Himalayas near the border with China, 100 miles east of Kathmandu, Nepal's capital.

Warmer temperatures, scientists said, could result in snow or ice avalanches, unsteady terrains, unpredictable glaciers, and erratic storms. The pictures are alarming: Heavier snow storms could lead to more snow accumulating, raising avalanche risks; shifting wind patterns could affect snow and ice behavior; and melting water trickling down could cause glacier to move more quickly.

The Himalayas are warming at the rate up to three times high, as global temperature has gone up to 0.75 degrees (1.4 degrees F) in the last century, according to the International Panel on Climate Change. Scientists said the Himalayas were melting from the top, a sign of rising temperatures even at high elevations. Less snow could lead to rock slides, posing danger to climbers. Snow and ice are the glue that holds the route up on Everest. When the glue melts, things may start to fall apart.

Between 1990 and 2010, more than 1,000 Himalayan glacial lakes expanded rapidly, increasing surface area by 17 percent, thus endangering climbers and residents. The Kathmandu-based International Center for Integrated Mountain Development said a glacial lake downstream from Everest is now 13 times larger than it was 40 years ago, a sign of warming temperature and melting ice.

"The mountain has been deteriorating rapidly in the past three years due to global warming. We need to learn more about what is going on up there," Tom Rippel, an expedition leader, said.

Popular Nepali climber Apa Sherpa, who conquered Everest a record 21 times, the last in 2011, warned about rising risks from climate change, recalling that when he first climbed it in 1990, the trails were covered by thick layers of packed ice and snow. "Now, the trail is full of bare and exposed rock, causing more rock falls," he said, making it dangerous and slippery for climbers to walk on bare rock with their spiky metal crampons.

In April 2014, an ice avalanche slammed down into a group of Sherpa guides and killed 16 in the deadliest single disaster on Everest. The link between the accident and the changing climate was not established, but scientists suggested more dangers in high-altitude regions in the future.

High-altitude mountain climbing has been inherently risky, yet many adventurers take the risks. In attempting to reach Everest, scores died from snow or ice avalanches or rock falls, or from hypothermia or altitude sickness.

More than 4,000 climbers were able to scale the 8,850-meter (29,035-foot) summit, first conquered in 1953 by New Zealand climber Edmund Hillary and Sherpa Tenzing Norgay. The number of climbers as well as guided expeditions to help beginners increased in recent years. The high number of unskilled climbers has alarmed the Indian Mountaineering Foundation, an association of seasoned climbers, saying that "for many attempting Everest, it is not for love of the mountains, but for the prestige."