Simple Model for the Antropogenically Forced CO2 Cycle Tested on Measured Quantities

The carbon dioxide information analysis center ( CDIAC ) provides a remarkable 163 years of data on atmospheric CO2 concentrations, man-made CO2 emissions, and from 1959 onwards CO2 net-fluxes into oceans and biosphere. Currently, half of the anthropogenic CO2 emissions remain in the atmosphere. Predominantly the ocean and the biosphere absorb the second half in about equal parts. We describe the anthropogenically forced CO2 dynamics by a linear model of only two parameters which represent physics and biological laws. Our model reproduces the CDIAC measurements perfectly, and allows thus predictions for the future. It does not deal with the equilibrium exchanges of CO2 between atmosphere, oceans and biosphere, but treats merely the net-fluxes resulting from the perturbation of the equilibrium by the anthropogenic emissions. Details as yielded by tracer measurements or ocean chemistry are not required. We applied the model for a tentative projection of the future CO2 cycle based on prospective anthropogenic emission scenarios from the literature. As a result, the increase of atmospheric CO2 will gradually come to an end and the ocean as well as the biosphere will be the primary sinks of future CO2 emissions of mankind.