Glacial-Holocene Changes in Atmospheric CO2 and the Deep-Sea Record
- James E. Hansen and
- Taro Takahashi
Published Online: 19 MAR 2013
Copyright 1984 by the American Geophysical Union.
Climate Processes and Climate Sensitivity
How to Cite
Berger, W. H. and Keir, R. S. (1984) Glacial-Holocene Changes in Atmospheric CO2 and the Deep-Sea Record, in Climate Processes and Climate Sensitivity (eds J. E. Hansen and T. Takahashi), American Geophysical Union, Washington, D. C.. doi: 10.1029/GM029p0337
- Published Online: 19 MAR 2013
- Published Print: 1 JAN 1984
Print ISBN: 9780875904047
Online ISBN: 9781118666036
- Ocean-atmosphere interaction—Congresses
An increase in atmospheric pCO2 during deglaciation, of about 100 ppm, has been ascribed to a change in the chemistry of the ocean (Broecker, 1982, Progr. Ocn. 11, 151). It appears that Broecker's phosphate-extraction model has to be modified by decoupling a fertility decrease of the ocean from organic carbon buildup on the shelves, because of constraints from the amplitude and timing of the foraminiferal δ13C signal. Denitrification and carbon/carbonate rain ratios are possible mechanisms. Buildup of shelf carbonates, during deglacial transgression, may deliver a considerable amount of CO2, to the atmosphere, through decreasing the alkalinity of upper ocean waters. This mechanism relies heavily on a decrease in oceanic mixing rate, to retard equilibration with the deep sea. The Holocene increase in the dissolution of deep sea carbonates may yield constraints on shelf carbonate buildup (basin-shelf transfer). Very few cores from the deep-sea floor have been studied in sufficient detail to produce tests for these various hypotheses.