This diagram of the fast carbon cycle shows the movement of carbon between land, atmosphere, soil and oceans in billions of tons of carbon per year. Yellow numbers are natural fluxes, red are human contributions in billions of tons of carbon per year. White numbers indicate stored carbon. The atmospheric net carbon increase is the result of
the imbalance between natural carbon fluxes and human contributions. The diagram shows that the natural fluxes include carbon exchange between plants and the atmosphere through photosynthesis and respiration, as well as carbon transfer between the atmosphere and oceans through physical processes such as diffusion and mixing.
Human contributions to the carbon cycle include the burning of fossil fuels, deforestation, and land-use changes, which release carbon dioxide into the atmosphere. These human activities increase the carbon content in the atmosphere, leading to a net carbon increase.
The white numbers indicate stored carbon, which represents carbon that is sequestered or stored in various reservoirs such as forests, soils, and the oceans. These reservoirs act as sinks, absorbing and storing carbon from the atmosphere.
Overall, the diagram illustrates how human activities have disrupted the balance of the fast carbon cycle by releasing more carbon into the atmosphere than natural processes can absorb. This imbalance has contributed to the increase in atmospheric carbon levels, which is a major driver of climate change.