General director
In 1998 Töpfer was appointed Under Secretary General of the United Nations, General director of the United Nations office in Nairobi and Executive Director of the United Nations Environment Programme. Among the milestones of his eight-year tenure are a number of important environmental agreements, including the Cartagena Protocol on Biosafety and the Stockholm Convention on Persistent Organic Pollutants. Töpfer was also closely involved in behind-the-scenes negotiations in support of the Kyoto Protocol on climate change. In June 2006 he was succeeded in this office by Achim Steiner. As director of UNEP, he has had a key role in gauging and attempting to remedy the environmental costs of the 2004 Asian tsunami.