Mountain Climbers Should Know Better

Ken Noguchi is a mountaineer who is slowly cleaning up Mount Everest. [Way To Go, Ken!] During his five trips up the mountain, he has recovered an estimated 9,000 pounds (4100 kg) of rubbish. He recently completed another trip, where he brought a further 500 pounds (227 kg) down. Some estimates place the amount of rubbish on Everest at 50 tonnes.
At this rate, it will take a while.

You'd think that mountain climbers, nature folk by definition, would have better sense than to leave all that trash in their wake.
What happened to ... Take only pictures, Leave only tracks ??

source: The Guardian