Kathmandu, June 9 -- The face was sunburned and weathered by years in the high Himalayas. Thin and pale from weeks spent above 6,000 metres, the man in a black cap quietly stepped onto a stage in Kathmandu last week. He was introduced as Ngima Wangchu Sherpa-Nepal's first mountain ranger.

For most people, the title may sound unusual. But on Mount Everest, where decades of commercial climbing has left behind tonnes of garbage and human waste, the role could become one of the most important jobs on the mountain.

During this spring climbing season, Ngima Wangchu, 53, spent weeks stationed at Camp II, nearly 6,400 metres above sea level, overseeing waste management, educating climbers and providing emergency support in one of the harshest e...