Everest Meltdown

Mountaineering is a sport for people who enjoy the challenge and freedom of climbing and who care about the environment. This commitment to protecting the mountain environment is why the United Nations Environment Programme (UNEP) and the International Mountaineering and Climbing Federation (UIAA) joined forces for World Environment Day 2002 and dispatched an expedition to the Himalayas to chronicle the environmental health of one of the world's most famous mountain ranges.

The aim for the expedition of 7 members was to record observations of environmental change and climb Island Peak, which is 6189 meters above sea level and a neighbor of Everest in the Khumbu Region of Nepal (Figure 1). The expedition gathered startling evidence of the impacts of climate change. The glacier from where Sir Edmund Hillary and Sherpa Tenzing Norgay set out to make the first ascent of Everest nearly 50 years ago has retreated by around 5 km up the mountain. Other evidence of climate change included huge scars gouged in the landscape by sudden glacial floods from the lakes swollen by melting glaciers.

However, perhaps the biggest indicator of climate change was the glacial lake at the foot of Island Peak (Figure 2). Thirty years ago there was a rubble-strewn glacier, but as the climate has become warmer the glacier has melted and been replaced by a lake over 100 m deep, 500 m wide and 2 km long. What is very worrying is that the wall of rubble that contains this lake could fail and cause a life-threatening flood to the villages downstream. This lake is just one of 20 glacial lakes in Nepal identified by experts as being in danger of bursting its banks.

On the trek to the mountain the expedition visited the Thyangboche monastery, home to 60 Buddhist monks. Here they met the Lama Rinpoche, who has lived there for over 30 years and witnessed two big floods from glacial lakes. The Lama said that in recent years the climate had grown noticeably warmer and floods were now more common. The expedition experienced very poor weather in what was described as the wettest spring season in Nepal for at least a decade.

The warmer and wetter weather, the shrinking glaciers, and the growing glacial lakes can only lead to the conclusion that global warming is emerging as the biggest threat to mountain environments. We may think of mountains as being permanent and unchanging, but they are as vulnerable to climate change as forests and oceans.

The expedition reached the summit of Island Peak on 27 May and made a film of the journey. But mountains are not just for sport, they are the world's vital water towers, and floods and landslides alternating with droughts cause chaos downstream. In the extreme environment of high mountains the evidence of climate change is clear to see. But the solution to global warming is not to be found in the mountains; so we must all think about how we can act to protect the mountains and the flow of clean water essential to our everyday lives.