Carbon Dioxide Fertilization Effect

FeliX equation for magnitude of fertilization effect (γ) of atmospheric carbon dioxide concentration on agricultural yields. γmax = 0.1 (or 10%) represents the maximum effect of atmospheric carbon. Crat represents the ratio of present to preindustrial atmospheric carbon at each time step.

FeliX equation for magnitude of fertilization effect (γ) of atmospheric carbon dioxide concentration on agricultural yields. γmax = 0.1 (or 10%) represents the maximum effect of atmospheric carbon. Crat represents the ratio of present to preindustrial atmospheric carbon at each time step.

Rising atmospheric carbon dioxide concentrations have a moderate fertilizing effect on agricultural yields by increasing the availability of this essential input for photosynthesis and promoting water use efficiency [1].

In the equation at right, as the present/preindustrial ratio of atmospheric carbon rises monotonically from unity--doubling by 2100 in the BAU scenario--the magnitude of this effect also grows (up to 4% in BAU). With this (potentially) conservative estimate, the FeliX model reflects the loose consensus that carbon fertilization has or will have a net positive effect of magnitude less than 10%.

[1] Baldos, U.L.C., Hertel, T.W.: Global food security in 2050: the role of agricultural productivity and climate change. Aust. J. Agr. Resour. Ec. 58, 1–18 (2014)