Global carbon cycle level

If oxygen is produced by the reduction of carbon dioxide, then atmospheric C02 levels must have declined over the life of the Earth, and there is evidence that this has indeed occurred.The climatic implications of changes in atmospheric C02 levels and how the global carbon cycle operates are addressed in Chapter 6, after the various elements of the carbon cycle have been introduced in the intervening chapters. For the moment, we continue with a more detailed look at the evolution of life in terms of the organisms that are most important by way of their contributions to the organic matter that is eventually buried in sedimentary rocks. 

Freeman, K.H., and J.M. Hayes. 1992. Fractionation of carbon isotopes by phytoplankton and estimates of ancient CO2 levels. Global Biogeochemical Cycles 6 185-198. 

Freeman KH, Hayes JM (1992) Fractionation of carbon isotopes by phytoplankton and estimates of ancient CO2 levels. Global Biogeochem Cycles 6 185-198 Freeman KH, Hayes JM, Trendel JM, Albrecht P (1990) Evidence from carbon isotope measurements for diverse origins of sedimentary hydrocarbons. Nature 343 254-256 Freyer HD (1979) On the C-record in tree rings, I, C variations in northern hemisphere trees during the last 150 years, TeUus 31 124-137... 

To analyze the dynamics of C02 in the biosphere, it is important to take into account the maximum possible number of its reservoirs and fluxes as well as their spatial distribution. It is in this that numerous global models of the carbon cycle differ. The present level of these studies does not allow us to answer the principal question as to how extensive is information in the database about the supplies and fluxes of carbon. Therefore, many authors analyzing the dynamic characteristics... 

Studies of the modem global biogeochemical cycle of carbon form one basis for understanding the geologic history of atmospheric CO2. In turn, these investigations of the history of carbon dioxide in the atmosphere provide knowledge that can be used to interpret the future of atmospheric CO2 levels and... 

Happen J. D. and Chanton J. P. (1993) Carbon remineralization in a North Florida swamp forest effects of water level on the pathways and rates of soil organic matter decomposition. Global Biogeochem. Cycles 7, 475 -490. 

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