Prof. Dr. Rik Leemans chairs the Environmental Systems Analysis group of the Environmental Sciences Department of Wageningen University. He further co-chairs the Response Option Working group of the Millennium Ecosystem Assessment. He also participates in several (inter)national committees concerned with various aspects of global change. He currently leads multidisciplinary projects to develop integrated assessment models for global biodiversity and local/regional ecosystem vulnerability. He was further strongly involved in all assessments of the Intergovernmental Panel on Climate Change (IPCC) over the last decade.His early PhD-studies at Uppsala University (Sweden) emphasised the successional dynamics and structure of boreal forests. He then moved to a research position at the Biosphere Project of the International Institute of Applied System Analyses (IIASA, Austria). Here he developed several widely used environmental databases and a simulation model for the circumpolar boreal forest biome and used it to assess the impacts of climate change on these ecosystems. Over the last decade he was a senior scientist of the National Institute of Public Health and the Environment (RIVM) in Bilthoven and professor of integrated land-use modelling at Wageningen University. His skills and expertise have lead to the development of integrated modelling approaches for the biosphere within the IMAGE-2 model. This innovative model explicitly incorporates the anthropogenic influences on changing land cover patterns on greenhouse gas emission from the terrestrial biosphere. His current research aims to determine the responses and vulnerability of ecosystems, land-use systems and human sectors to environmental change, to develop the appropriate models and other tools to accomplish this, and to design interventions that capture positive and minimize negative impacts. The results of his research are used for (inter)national environmental assessments and development of policies.Dr. Leemans has published on a wide range of topics. These include forest dynamics, large-scale vegetation and crop distribution, global environmental databases, terrestrial C cycle and the importance of feedback processes, the incorporation of land-use change and other human dimensions into Earth system models, biodiversity, integrated assessment tools and, more recently, potential mitigation and adaptation options and strategies for environmental change.