Since Sir Edmund Hillary and his Sherpa Guide, Tenzing Norgay, first conquered Mount Everest in

According to the Nepalese Ministry of Culture, Tourism and Civil Aviation, more than 3,500 have successfully climbed the 8,848-meter(29,029-foot) mountain, the  world's highest. More than a tenth of that number scaled the summit last year alone.

But with the mountaineers' lofty dreams come a price: a trial of trash that now threatens the  peak's environment.