Ken Noguchi is a mountain climber. He's climbed Mount Everest. It wasn't the Japanese climber's first visit to the top of the world's highest mountain. He's climbed it five times, and he's going to do it again. He doesn't do it for fun. He goes there to collect something - rubbish!

Ken's team of climbers from Japan and Nepal have collected over 500 kilograms of rubbish and brought it down the mountain. They have collected tins, tents, sleeping bags, food, medicine, empty oxygen bottles. Where has all this rubbish come from?

The first people to climb Mount Everest were Sir Edmund Hillary from New Zealand and Tenzing Norgay from Nepal (the home of Mount Everest). They reached the top in May 1953. Since then, modern equipment has made it a lot easier, and thousands of people have climbed the mountain. Unfortunately, they have left tonnes of rubbish there, and it doesn't decompose in the cold air. Now there is so much rubbish that people have called the mountain "the highest rubbish dump in the world".

Ken Noguchi wants to make people aware of the problem. He has taken some of the rubbish to Japan and Korea and put it on display. "We must keep the world's highest mountain clen," he said. Things are better now. All climbers must bring their own rubbish back or pay a big fine. However, Ken thinks there is probably about 50 tonnes of old rubbish still there.