Since September 2022, Stefan leads the Hydrology, Water and Cryosphere program of the World Meteorological Organisation (WMO), the UN Specialized Agency for Weather, Climate and Water. He is very exciting to contribute to the Organisation’s program and, among other things, strengthen the early warning systems for floods and droughts as well as water resources assessment and management worldwide. During 2019-2022, he has focused his interest to water and food system transformations to provide healthy and nutritious food for all while considering the vital role of water and ecosystems. Previously, he served as the director of water, food and ecosystems at IWMI (2019-2022, Sri Lanka), Coordinator of UNESCO’s World Water Assessment Programme (WWAP, 2015-2019, Italy), and the Deputy Director and acting Director of UNESCO-IHE (now IHE-Delft, Netherlands, 2005-2015). He has been a professor at IHE-Delft (2005 onwards) and Delft University of Technology (2009-2020), The Netherlands. He did his PhD (1999) and habilitation (2003) at the University of Freiburg, Germany.