The biogeochemical cycle of the carbon dioxide and the oxygen can be used as an example to describe the interactive components, and the impact of humans on the cycle.
All the organisms in a terrestrial ecosystem use oxygen gas and give off carbon dioxide gas as a byproduct of the process of respiration. The plants use this carbon dioxide to make food under the sunlight by the process of photosynthesis and give off oxygen as a byproduct. Thus, a delicate balance is maintained between the amount of the gases in the atmosphere.
Humans have negatively affected this delicate balance by setting up industries that give off carbon dioxide and other gases in excess amounts. This has increased the amount of carbon dioxide in the atmosphere causing a warming up of the Earth.
The balance can be maintained if the growth of the industries is kept in check and regulated. The emissions will decrease and slowly restore the balance of the two gases.