The graph illustrates the carbon manufacturing progress in nature. The whole carbon production programme is sustainable which is called the “carbon cycle”.
According to the graph, carbon dioxide and sunlight are absorbed by trees, where photosynthesis releases organic carbon and decays organisms into nature. The released organic carbon combines with the dead organisms and waste products produced by animals. Part of composites stay under the earth and become fossils and fossil fuels after manufacturing for thousands of years. While other composites are absorbed by the roots of plants, used in industries and back to nature respectively. However, the industries not only emission carbon dioxide but also some chemical gas.
What’s more, animal and plant respiration both release carbon dioxide into nature. This carbon becomes a source of new carbon manufacturing. Therefore, plants and animals became producers in the new carbon cycle.