Final answer:
Carbon dioxide is released back into the atmosphere through cellular respiration, decomposition, burning of fossil fuels and organic material, volcanic eruptions, and warming of ocean waters. Human activities have significantly contributed to this release, affecting the carbon cycle and the environment.
Step-by-step explanation:
The process that releases carbon dioxide back into the air include several biological and geological activities. One of the key processes is cellular respiration, where living organisms utilize oxygen and glucose to produce energy, carbon dioxide, and water. Another process is the decomposition of dead organisms and organic materials, which also releases carbon dioxide.
Additionally, human activities, such as the burning of fossil fuels and the production of cement, contribute significantly to the release of carbon dioxide. Natural processes, such as volcanic eruptions and the warming of ocean water leading to the release of dissolved carbon dioxide, also play a role.
The carbon cycle is a complex system, where carbon dioxide is also removed from the atmosphere through photosynthesis, cooling of ocean water, and long-term geological storage.