The model of long-term evolution of the carbon cycle

The weathering processes and their role in the formation of the atmospheric carbon and, as a consequence, on the climate are considered. The model operates in the framework of “active planetary cover”, i.e. considering the interactive role of the biosphere, looking at its development as a non-linear evolutionary system of so-called “virtual biospheres”. of all, the mechanism of chemical equilibrium in closed system is described, applied to weathering in order to provide a better understanding of reactions in the solution of CaCO3 and CO2. The second stage is to describe the chemical transformations of carbon within the system. However here we deal with an open system, and therefore we were compelled to develop some partial case of the theory of chemical equilibrium in open systems, where the values of total amounts of calcium and carbon are slowly changed, described by the equations of slow dynamics of weathering by rain-fall. This relatively slow process of chemical weathering, which is accompanied by an uptake of carbon from the atmosphere and its transportation to the intercontinental and epicontinental seas, is significantly amplified by terrestrial ecosystems, i.e. in the ecosystem covered by vascular plants, that has evolutionary replaced the shallow-water-body system. In accordance with Zavarzinʹs estimation, the concentration of CO2 in the soil air is 60–80 times larger than in the atmosphere, caused by root respiration and the activity of micro-organisms. All this leads to a significant acceleration of weathering in soil. It seems that such a concentration gradient cannot be maintained and it will be eroded by diffusion. It is true if we consider bare soil. But in real ecosystems the litter covers soils, so that molecular diffusion becomes prevalent. In other words, the litter can be considered as a semi-permeable membrane for CO2.