The Earths atmosphere contains 0.035% carbon dioxide. The earth contain so little,but it is relied on for this planet to function and survive. The environment relies on carbon to to pull proteins, sugars, and fats out of plants. Carbon is also relied on to be a reactant in the production of oxygen. Through the tropic system carbon also plays a big role. Herbivores eat plant and in turn the herbivores are eaten by carnivores.
Carbon is used in the process of many things. But you may be wondering how it gets back to the environment? Animals play a huge part in this, in the sense that animals absorb oxygen but exhale carbon dioxide. Dead organisms also have a part in getting CO2 back into the environment due to that during fossilization some carbon returns to the physical environment.
Resource for this post: http://www.starsandseas.com/SAS%20Ecology/SAS%20chemcycles/cycle_carbon.htm
