Estimating environmentally relevant fixed nitrogen demand in the 21st century Winiwarter, Wilfried ; Erisman, Jan Willem ; Galloway, James N. ; Klimont, Zbigniew ; Sutton, Mark A. Abstract Publication: Climatic Change Pub Date: October 2013 DOI: 10.1007/s10584-013-0834-0 Bibcode: 2013ClCh..120..889W