Affiliation: | a Olav Benestad, Alexander Kristiansen and Eivind Selvig are with the Centre for Development and the Environment, University of Oslo, PO Box 1116 Blindern, N-0317, Oslo, Norway b Lars Brinck is with the Department of Environment and Energy Systems, University of Lund, Gerdagt 13, S-223 62, Lund, Sweden c Lennart Emborg, Bjarne Juul-Kristensen and Niels I. Meyer are with the Physics Department, Technical University of Denmark, Building 309 C, DK-2800, Lyngby, Denmark d Kyösti Pulliainen is with the University of Joensuu, PO Box 111, SF 80 101, Joensuu 10, Finland e Anssi Vaittinen is with Statistics Finland, Helsinki, Finland |