Johan Rockström (born 31 December 1965) is a Swedish scientist, internationally recognised for his work on global sustainability issues. He is the joint director of the Potsdam Institute for Climate Impact Research (PIK) in Germany, together with economist Ottmar Edenhofer. Rockström is also chief scientist at Conservation International. He is Professor in Earth System Science at the University of Potsdam and Professor in Water Systems and Global Sustainability, Stockholm University.