Changes in the Global Carbon Cycle: Evidence from the Measurements of O_2/N_2 in the Atmosphere and CO_2 Partial Pressure at the Ocean-Atmosphere Boundary

摘要

The global carbon budget includes inorganic and organic constituents. The rates of fossil fuel combustion and inorganic carbon accumulation in the atmosphere and the ocean are known. The organic constituents include changes in the abundance of organic matter in ocean and land areas. Proceeding from changes in CO_2 content and O_2/N_2 concentration ratio in the atmosphere and the known stoichiometric proportions of oxygen binding at organic matter decomposition, changes in the masses of organic substances were quantified in terrestrial and marine environments. The resulting values of organic constituents of the carbon budget are consistent with independent estimates based on the data on anthropogenic land cultivation and the concentration ratio ~(14)C/~(12)C in the dissolved organic carbon of the ocean. We took into account an increase with time in the rate of concentration changes of dissolved inorganic carbon in the ocean inferred from ~(13)C/~(12)C measurements. Profiles were constructed for changes in CO_2 partial pressure and #delta#~(13)C through the atmosphere-ocean boundary, which corresponding to the obtained values of the total carbon uptake by the ocean in inorganic and organic forms.