Abstract :
The purpose of the paper is to follow up the contribution by Dyrssen and Turner to the Hemavan meeting in 1993
on CO2 chemistry. Machta’s treatment from 1971 of the role of oceans and biosphere in the carbon dioxide cycle is
reviewed. Using data on the emission of CO2 and the atmospheric content in addition to the value recently
presented by Takahashi et al. for the net sink for global oceans the following numbers have been calculated for the
period 1990 to 2000, annual emission of CO2, 6.185 PgC ŽPetagram 1015 g.. Annual atmospheric accumulation,
2.930 PgC. Annual sinks, 3.255 PgC. Net uptake for 1990 by the oceans, 1.151 PgC year. Solubility pump into the
mixed layer, 0.828 PgC year. Residual input Že.g. riverborne., 0.323 PgC year. Annual uptake by land phytomass,
2.104 PgC. In addition, perturbations involving irrigation and fertilization, limestone dissolution, iron and clathrate
addition are mentioned.
