Evaluation of biospheric components in Earth system models using modern and palaeo-observations: the state-of-the-art - Foley, AM; Dalmonech, D; Friend, AD; Aires, F; Archibald, AT; Bartlein, P; Bopp, L; Chappellaz, J; Cox, P; Edwards, NR; Feulner, G; Friedlingstein, P; et al. (BIOGEOSCIENCES, 2013)