Lennart Bengtsson is a meteorologist currently interested in global climate modelling, global water vapour distribution and measurement of atmospheric water using GPS.He was Head of Research at the European Centre for Medium-Range Weather Forecasting from 1975 to 1981 and then Director until 1990; then director of the Max Planck Institute for Meteorology in Hamburg. He is now a Senior Research Fellow at the Environmental Systems Science Centre in the University of Reading.In 2005 he was awarded the Rene Descartes Prize for Collaborative Research together with Prof. Ola M. Johannessen and Dr. Leonid Bobylev from the Nansen Environmental and Remote Sensing Centre in Norway and Russia for the Climate and Environmental Change in the Arctic project. In 2006 he was awarded the 51st IMO prize of the World Meteorological Organization for pioneering research in numerical weather prediction.