A first-order analysis of the potential role of CO2 fertilization to affect the global carbon budget: A comparison of four terrestrial biosphere models - Kicklighter, D. W.; Bruno, M.; Donges, S.; Esser, G.; Heimann, Martin; Helfrich, J.; Ift, F.; Joos, F.; Kaduk, J.; Kohlmaier, G.; McGuire, A. D.; Melillo, J.; et al. (Tellus, Series B: Chemical and Physical Meteorology, 1999)