Definitions for "Carbon cycle"
Carbon is an essential element of life; it is necessary to form organic molecules, which are what makes up living tissue and sugars. Through photosynthesis, plants fix CO2 from the air into organic compounds, thereby incorporating it into their tissue. When an animal eats the plant, it is able to use that carbon inside its own body (animals cannot use atmospheric carbon). When the first animal is eaten by another, the carbon can then be used by the second, and so on. When plants and animals breathe, die, and decay, carbon is released back into the atmosphere in the form of CO2. This together is called the carbon cycle.
All carbon sinks and exchanges of carbon from one sink to another by various chemical, physical, geological, and biological processes. See Carbon sink and Carbon budget.
After use and recycling, wood-based products such as paper decompose, releasing carbon into the atmosphere as carbon dioxide. New forests established in place of those cut down remove carbon dioxide from the atmosphere
a thermonuclear reaction in the interior of stars
Cyclic movement of carbon in different chemical forms from the environment to organisms and then back to the environment.
The continual exchange of organic matter from one form to another, including living and dead tissue, gases, and minerals.
Keywords:  circulation, nature, forms
Circulation of carbon in various forms through nature.