Carbon cycle trends

Rotty, R. M., and G. Marland. 1986. Fossil fuel combustion Recent amounts, patterns, and trends of C02. In The Changing Carbon Cycle, a Global Analysis. Ed. J. R. Trabalka and D. E. Reichle, New York Springer-Verlag, pp. 474-90. 

Climate changes from the time ofthe disappearance of dinosaurs to our days have also been based up on deep-sea stable isotope data oxygen isotope data provide an insight into the temperature variations, while carbon isotope data are informative on the kind of global carbon cycle perturbation (Zachos 2001). These data suggest that the present conditions of temperature are similar to the late Middle Age. However, the trend toward higher temperatures is now more difficult to contrast because of the drastic deforestation and emission of gases. 

Natural Abundance Stable Carbon Isotopes (I3C). There are trends in 13C of plant, litter, and organic constituents in soil that can be used to investigate carbon cycling, but to date the trends have proven too subtle, the variation too high, or the mechanisms too poorly understood to exploit these patterns definitively. The 813C of plant litter and particulate SOM is typically close to that of the plant source,... 

Sabine, C. L., Heimann, M., Artaxo, E, Bakker, D. C. E., Chen, C.T. A.,Field, C. B., and Gruber, N. (2004). Current status and past trends of the global carbon cycle. In The Global Carbon Cycle Integrating Humans, Climate, and the Natural World, Field, C. B., and Raupach, M. R., eds., Island Press, Washington, D.C. 

Zhu, Y. G. Miller, R. M. (2003). Carbon cycling by arbuscular mycorrhizal fungi in soil-plant systems. Trends in Plant Science, 8, 407-9. 

Productivity and C-isotope records—Attributing trends in bulk S Corg only to the trade-off between dominance of respiration-influenced local carbon reservoirs versus dominance of production-influenced global carbon reservoirs is clearly a gross oversimphfication, as a number of other factors may influence C-isotope fractionation in the biogenic and aqueous reservoirs of the carbon cycle. However, this hypothesis finds support in the observations of Cretaceous and Devonian basins summarized herein. In each of these case studies, relative depletion of S Corg values are observed in association with units interpreted to represent examples of the anoxia-nutrient feedback mechanism, and recycling of... 

The likelihood of a Little Ice Age carbon-cycle perturbation poses a particular concern for the assumption of pre-anthropogenic steady state in models of the modem carbon cycle. Part of the increase in concentrations of CO2 and CH4 during recent centuries may be due to trends associated with the natural chmate anomaly. This association may seriously affect estimates of eighteenth- and early nineteenth-century human impacts on the... 

Carbon-cycle responses to Holocene climate change have been hypothesized to explain the atmospheric CO2 and CH4 trends observed in the ice-core record of this period. The early Holocene expansion of terrestrial vegetation and soils in areas that were previously glaciated has been suggested as the cause of the early Holocene decrease in CO2 (Indermuhle et al., 1999). Likewise, the increase in atmospheric CO2 between 8 ka and I ka has been attributed to a release of biospheric carbon caused by a global trend during... 

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