Climate cycles feedbacks

Feedbacks may be affected directly by atmospheric CO2, as in the case of possible CO2 fertilization of terrestrial production, or indirectly through the effects of atmospheric CO2 on climate. Furthermore, feedbacks between the carbon cycle and other anthropogenically altered biogeochemical cycles (e.g., nitrogen, phosphorus, and sulfur) may affect atmospheric CO2. If the creation or alteration of feedbacks have strong effects on the magnitudes of carbon cycle fluxes, then projections, made without consideration of these feedbacks and their potential for changing carbon cycle processes, will produce incorrect estimates of future concentrations of atmospheric CO2. 

The Coupling of Biogeochemical Cycles and Climate Forcings, Feedbacks, and Responses... 

K. G, Schnur, R., Strassmann, K., Weaver, A. J., Yoshikawa, C., and Zeng, N. (2006). Climate-carbon cycle feedback analysis Results from the (CMIP)-M-4 model intercomparison. J. Climate 19(14), 3337-3353. 

I. J. (2000) Acceleration of global warming due to carbon-cycle feedbacks in a coupled climate model. Nature 408, 184-187. 

Because both CO2 and CH4 are greenhouse gases and their partial pressures in the atmosphere are lower during glacial periods, they may play an important role in the feedback mechanism necessaiy to produce climate cycles. Although the processes controlling CO2 changes are still uncertain approximately 30 y after their discoveiy, it is fairly certain that the mechanism has to do with variations in the... 

Between the emission of greenhouse gases and change in the climate are a range of climate and biological cycles that can influence the end result. Such outcome-modifier effects are called feedbacks or indirect effects in the climate change literature. 

POST ET AL. Climatic Feedbacks in the Global Carbon Cycle... 

The complexities of land surface response and runoff generation have also presented a major obstacle to global climate modelers. Hydrologic response is linked to several important climate feedbacks (see Section 6.4.2), so imtil the hydro-logic cycle, and in particular its land surface component, can be accurately represented, there is little hope for accurate assessments of global change. 

Five components of the hydrosphere play major roles in climate feedbacks - atmospheric moisture, clouds, snow and ice, land surface, and oceans. Changes to the hydrologic cycle, among other things, as a result of altered climate conditions are then referred to as responses. Interactions with climate can best be explored by examirung potential response to a climate perturbation, in this case, predicted global warming. 

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