European Commission – DG Joint Research Centre, Institute for Environment and Sustainability, Ispra, Italy

European Commission – DG Joint Research Centre, Institute for Environment and Sustainability, Ispra, Italy

European Commission – DG Joint Research Centre, Institute for Environment and Sustainability, Ispra, Italy

now at: Institute of Energy Economics and the Rational Use of Energy, Department of Technology Assessment and Environment, Stuttgart, Germany

University of Bonn, Institute for Food and Resource Economics, Bonn, Germany

European Commission – DG Joint Research Centre, Institute for Environment and Sustainability, Ispra, Italy

University of Bonn, Institute for Food and Resource Economics, Bonn, Germany

Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH 03824, USA