Atmospheric Carbon Dioxide Levels Over Phanerozoic Time
- 21 September 1990
- journal article
- research article
- Published by American Association for the Advancement of Science (AAAS) in Science
- Vol. 249 (4975), 1382-1386
- https://doi.org/10.1126/science.249.4975.1382
Abstract
A new model has been constructed for calculating the level of atmospheric CO2 during the past 570 million years. A series of successive steady states for CO2 is used in order to calculate CO2 level from a feedback function for the weathering of silicate minerals. Processes considered are: sedimentary burial of organic matter and carbonates; continental weathering of silicates, carbonates, and organic matter; and volcanic and metamorphic degassing of CO2. Sediment burial rates are calculated with the use of an isotope mass-balance model and carbon isotopic data on ancient seawater. Weathering rates are calculated from estimates of past changes in continental land area, mean elevation, and river runoff combined with estimates of the effects of the evolution of vascular land plants. Past degassing rates are estimated from changes in the rate of generation of sea floor and the shift of carbonate deposition from platforms to the deep sea. The model results indicate that CO2 levels were high during the Mesozoic and early Paleozoic and low during the Permo-Carboniferous and late Cenozoic. These results correspond to independently deduced Phanerozoic paleoclimates and support the notion that the atmospheric CO2 greenhouse mechanism is a major control on climate over very long time scales.This publication has 22 references indexed in Scilit:
- An Aptian Plant with Attached Leaves and Flowers: Implications for Angiosperm OriginScience, 1990
- Phanerozoic cycling of sedimentary carbonateAmerican Journal of Science, 1989
- A new approach to isotopic modeling of the variation of atmospheric oxygen through the PhanerozoicAmerican Journal of Science, 1989
- Sensitivity of climate and atmospheric CO2 to deep-ocean and shallow-ocean carbonate burialNature, 1989
- Rise of angiosperms as a factor in long-term climatic coolingGeology, 1989
- Ridge volume dependence on seafloor generation rate and inversion using long term sealevel changeAmerican Journal of Science, 1987
- Coupling of the sedimentary sulfur and carbon cycles; an improved modelAmerican Journal of Science, 1984
- The carbonate-silicate geochemical cycle and its effect on atmospheric carbon dioxide over the past 100 million yearsAmerican Journal of Science, 1983
- Potential significance of land—sea distribution and surface albedo variations as a climatic forcing factor; 180 m.y. to the presentPalaeogeography, Palaeoclimatology, Palaeoecology, 1980
- Chemical Weathering in Central Iceland: An Analog of Pre-Silurian WeatheringScience, 1969