Is all of earths carbon dioxide supply constantly being used by organisms?

Answer 1

No, all of Earth's carbon dioxide supply is not constantly being used by organisms. While organisms, particularly plants, play a crucial role in the carbon cycle by absorbing carbon dioxide through photosynthesis, there are various other processes that contribute to carbon dioxide levels in the atmosphere. These include volcanic activity and human activities such as burning fossil fuels. Therefore, there is always a certain amount of carbon dioxide present in the atmosphere that is not being actively used by organisms at any given time.