Agence France-Presse: Apa Sherpa has stood on top of the world more times than anyone in history, and now he is heading back up Mount Everest, not for the fame or glory, but in the name of environmental protection. Apa, 49, has become increasingly concerned about the damage inflicted on the world’s highest mountain by both climate change and the waste left by careless climbers. This spring season he hopes to conquer Everest for the 19th time, and he will use the trip to focus attention on how …