The carbon cycle describes the movement of carbon, in its many forms, between the biosphere, atmosphere, oceans, and geosphere. It is one of the most important cycles of the earth and allows for carbon to be recycled and reused throughout the biosphere and all of its organisms. Without the proper functioning of the carbon cycle, every aspect of life could be changed dramatically. Scientists believe that the combustion of fossil fuels and deforestation can cause imbalances in the carbon cycle.