Final answer:
Decomposition returns carbon from detritus back to the atmosphere through the process of respiration.
Step-by-step explanation:
Decomposition plays a crucial role in the carbon cycle by returning carbon from detritus back to the atmosphere. When organisms die, decomposers such as bacteria and fungi break down their bodies and organic compounds through the process of decomposition. During decomposition, carbon that was stored in detritus is released back into the atmosphere as carbon dioxide through the process of respiration. This carbon dioxide can then be used by producers during photosynthesis to create organic carbon compounds, thus completing the carbon cycle.