Between 1996 and 2014 he chaired the commission for climate, tourism and recreation the International Society of Biometeorology and he was vice-president of the International Society of Biometeorology between 2006 and 2009. Since 2016 he is the chairman or the German Society for the advancement of medical-meteorological research.

His core research interests are in human bioclimatology und urban climatology, climatology of tourism and climate change impact research. A further research focus is the development of models and tools for applied climatology and biometeorology (e.g. the RayMan model, SkyHelios model, Climate Mapping Tool and CTIS (Climate-Tourism-Information-System).