1 In the natural carbon cycle, there are two main processes which occur: photosynthesis and metabolism. During photosynthesis, plants use carbon dioxide and produce oxygen. During metabolism oxygen is used and carbon dioxide is a product.
2 Carbon Balance. Carbon balance is the difference between CO2 uptake by ecosystems (photosynthesis) and CO2 loss to the atmosphere by respiration.
3 Human activities, especially conventional farming activities and burning fossil carbon as fuel, have disturbed the carbon cycle's balance, leading to more carbon dioxide being released into the atmosphere than is being taken up by plants.
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