Carbon cycle diagram depicting the movement of carbon between the atmosphere, living organisms, and the environment.

1. Plants use CO₂ in the process of photosynthesis to make glucose and release O₂.
2. Animals obtain the process of cellular respiration and make more CO₂.
3. The decomposition of organic matter by decomposers releases CO₂ back into the atmosphere.
4. Some large deposits of carbon are stored as coal, oil, and natural gas (fossil fuels).
5. Carbon is also stored in oceans as dissolved CO₂ and in marine organisms' shells as calcium carbonate.
6. Humans burn fossil fuels for energy, releasing large amounts of CO₂ into the atmosphere.
7. Deforestation reduces the number of trees that absorb CO₂, increasing atmospheric CO₂ levels.
8. The main source of CO₂ is human activities such as burning fossil fuels and deforestation.
9. Too much CO₂ in the atmosphere can lead to global warming and climate change.
10. The chemical equation for photosynthesis: 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂
11. The chemical equation for cellular respiration: C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + energy