H. R. Brannon Jr., A. C. Daughtry, D. Perry, W. W. Whitaker, M. Williams
First published: October 1957
The dilution of atmospheric carbon dioxide by carbon dioxide from fossil fuels is estimated to be about 3½ pct, on the basis of radiocarbon assays of tree rings of known ages from several trees of different genera, after allowance has been made for effects attributable to ecological differences. The cumulative mass of fossil carbon dioxide released to the atmosphere is 3.3 x 10^17 gm, equivalent to about 14 pct of the carbon dioxide in the atmosphere. Based on these data, the fractional part of the atmospheric carbon dioxide which enters the ocean each year is estimated to be 0.062. Radiocarbon assays of several nineteenth-century marine shells and of their modern counterparts indicate a one to two per cent dilution of shallow oceanic carbonates by carbon dioxide from fossil fuels. Use of these data in a simplified mathematical model of atmosphere-ocean yields information on mixing times of the ocean.