The cycle repeats when the carbon stored in the atmosphere as carbon dioxide gas is taken in

Process of photosynthesis takes place.

Explanation:

When carbon dioxide comes inside the leaves from their stomata then water and carbon dioxide combine and form a six-carbon compound having six oxygen and twelve hydrogen compound as well. This process is called photosynthesis. The glucose formed in this process is used by plant and animal too. So this process is necessary for life on this earth.

the cell cycle is the final answer! : )

there are so many examples for that in different areas, like biology experiment carried out in our lab recently.

here's one link: