Cenozoic Fluctuations in Biotic Parts of the Global Carbon Cycle

  1. E.T. Sundquist and
  2. W.S. Broecker
  1. Jerry S. Olson

Published Online: 18 MAR 2013

DOI: 10.1029/GM032p0377

The Carbon Cycle and Atmospheric CO2: Natural Variations Archean to Present

The Carbon Cycle and Atmospheric CO2: Natural Variations Archean to Present

How to Cite

Olson, J. S. (1985) Cenozoic Fluctuations in Biotic Parts of the Global Carbon Cycle, in The Carbon Cycle and Atmospheric CO2: Natural Variations Archean to Present (eds E.T. Sundquist and W.S. Broecker), American Geophysical Union, Washington, D. C.. doi: 10.1029/GM032p0377

Author Information

  1. Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831

Publication History

  1. Published Online: 18 MAR 2013
  2. Published Print: 1 JAN 1985

ISBN Information

Print ISBN: 9780875900605

Online ISBN: 9781118664322

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Keywords:

  • Carbon cycle (Biogeochemistry)—Congresses;
  • Atmospheric carbon dioxide—Congresses;
  • Geological time—Congresses;
  • Paleothermometry—Congresses;
  • Geology, Stratigraphic—Congresses

Summary

The mass of organic carbon in land plants presumably decreased over much of Tertiary time. Global average cooling, mountain building, rain shadows, and other drying displaced forests and led to the expansion of shrublands, grasslands and deserts. Quaternary cold repeatedly stimulated the expansion of tundra and cold deserts. Lowering of sea level partly compensated with new areas for coastal and wetland vegetation. Interglacial an postglacial ice retreats opened new lands for boreal, mostly conifer forests (taiga), and for renewed storage of peat in mires. Early Holocene broad-leaved forests expanded again (along with temperate and humid tropical/subtropical climates) and constitute most of the world's plant carbon mass. Slightly less than 800 109 metric tons C is a plausible estimate in all live land plants in mid-Holocene time. Variations from this estimate by a factor of about 2 seem likely within the late Cenozoic Era: higher in early Miocene and lower in glacial times; 460–660×109 metric tons C from A.D. 1980 to ∼1780 A.D.