Yes, the biosphere is necessary for the carbon cycle. The biosphere, which includes all living organisms on Earth, plays a crucial role in both carbon uptake and release. Through the process of photosynthesis, plants and algae absorb carbon dioxide from the atmosphere and convert it into organic matter, releasing oxygen as a byproduct. Carbon is then transferred from these photosynthetic organisms to other organisms through the food chain. Without the biosphere, these processes would not occur, leading to a disruption of the carbon cycle and imbalance in atmospheric carbon dioxide levels.