Achim Steiner of Germany is the head of the United Nations Environmental Program,UNEP. With his 500 employees,he is considered one of the world's most important environmentalists.From UNEP headquarters in Nairobi,Kenya,his job is to coordinate campaigns against drought,deforestation and climate protection. At the moment,the 48-year-old is under quite a bit of stress. He is getting ready for the upcoming Climate Conference in Copenhagen,where almost 200 countries are expected to hammer out a new program for protecting the earth's environment. A portrait from Nairobi.