%0 Journal Article %T Contributions to accelerating atmospheric CO 2 growth from economic activity, carbon intensity, and efficiency of natural sinks %A Canadell, Josep G. %A Le Quéré, Corinne %A Raupach, Michael R. %A Field, Christopher B. %A Buitenhuis, Erik T. %A Ciais, Philippe %A Conway, Thomas J. %A Gillett, Nathan P. %A Houghton, R. A. %A Marland, Gregg %A , %J Proceedings of the National Academy of Sciences %@ 0027-8424 %D 2007-11-20 %I Proceedings of the National Academy of Sciences %~ DeepDyve