Most of the carbon dioxide found in the air is the same amount, which is transmitted in living organisms. The atmospheric composition of carbon dioxide is about 0.03moles in terms of percentage. Nevertheless, atmospheric carbon dioxide is not the main natural reservoir of this gas. The main reservoir is, however, located on the surface of the earth, which most living organisms cannot access.
The global carbon cycle entails four main quantifiable reactions. For natural systems to run well, these four reactions must strike a particular state of balance. To begin with, soils contribute petagrams of carbon dioxide into the atmosphere. The burning of fossil fuels accounts for about 6.3 petagrams of the gas released into the atmosphere. In addition, the total amount of destroyed vegetation releases approximately 1.6 petagrams of carbon dioxide to the atmospheric pool, which has a total of 560 petagrams of the reserved carbon dioxide gas. Moreover, carbon dioxide is also emitted by aquatic animals from water bodies like rivers, streams, oceans, and seas, and this is about 90 petagrams in any given period of time.
On the other hand, primary production through the process of photosynthesis by plants consumes about 580 petagrams of carbon dioxide from the atmosphere while some quantity is removed from the atmosphere through changing land use. The decay process, either on land or in water, also eliminates about 1390 pg of the gas from the atmosphere. The process repeats itself and leads to an elaborate global carbon cycle.
The atmospheric carbon cycle does not balance at all due to the prevalence of human activities like the burning of fossil fuels which has greatly destabilized the volume of the gas in the cycle. Moreover, the “green revolution” has led to increased plant growth and hence more of the gas in the atmosphere. Therefore, achieving the atmospheric balance may not be easy at all. The “missing carbon” from the cycle has been absorbed by the terrestrial ecosystems, which include both soils and vegetation, and therefore, cannot be accounted for in the overall carbon budget.