Marine Carbonate Formations, their Role in Mediating Long-Term Ocean-Atmosphere Carbon Dioxide Fluxes. A Review.

The Gaia hypothesis suggests that homeostatic mechanisms exist which tend to prevent gross change in surface planetary conditions. The evidence of the geological record is somewhat equivocal on thhis point, since it shows both evidence for stability and evidence for conditions whhich differ significantly from those experienced today. The purpose of this paper is to consider the mechanisms involving CO2 which may be significant on various geological timescales, and to consider how these might relate to the geological evidence of past surface conditions. There is evidence that large fluctuations in atmospheric carbon dioxide have occured in the past. In order to predict even the broad outline of this adjustment, it is necessary to consider the behaviour of CO2 in the atmosphere, the oceans, the sediments and in the deep lithosphere. The ultimate adjustment of the system to anthropogenic inputs of fossil fuel carbon will take many tens of thousands of years, and the time constants of this process cannot be predicted with accuracy at the present state of knowledge. However, it is possible to draw inferences from what is known, and the conclusions have relevance to discussion of the question of disposal of carbon dioxide within the natural system.

WILSON T.R.S.; 

1996-09-03

JRC13603