The Interaction of Climate Change and the Carbon Dioxide Cycle.

The flow of carbon dioxide through the atmosphere is a complex system because it consists of several cycles; e.g., through the biosphere which produces and consumes it, and through the Earth's water surfaces which absorb and emit it. These processes are dependent on temperature but their reactions to temperature have different signs. Temperature rise promotes both the consumption and the production of carbon dioxide by the biosphere but liberates carbon dioxide from water surfaces. This paper offers a comprehensive review of the behaviour of these processes. It considers these flows and assesses observations of the movement of carbon dioxide to and from the atmosphere. The disturbance of the natural cycle by current anthropogenic emissions is used as an instrument to throw light on what is actually happening to cause alteration to atmospheric carbon dioxide concentration. Also, these considerations are used in attempts to model the processes with mathematical equations derived from physics and biology. It is concluded that it is not possible to decide on a preferred mathematical model because the disturbing signal is still too low in comparison to the observed natural variation in the system. Hence, the use of existing models of the system would have high uncertainty if extrapolated to higher concentrations of atmospheric carbon dioxide. Lastly it is suggested that the consideration only of human emissions, neglecting the possibility of other natural sources contributing to the accumulation of carbon dioxide in the atmosphere, may lead to erroneous calculations of the involved flow rates. [ABSTRACT FROM AUTHOR]