Final answer:
The carbon cycle is a key biogeochemical cycle incorporating both rapid exchange of carbon among living organisms and a long-term geological cycle. It is crucial for recycling carbon necessary for life, but human activities have disrupted its balance by increasing atmospheric CO2 levels and contributing to climate change.
Step-by-step explanation:
The carbon cycle is a biogeochemical cycle that involves the movement of carbon through the biotic (living) and abiotic (non-living) components of Earth's ecosystems. A fundamental aspect of this cycle is the rapid carbon exchange among living organisms, which includes processes such as photosynthesis and cellular respiration. Plants absorb carbon dioxide (CO2) from the atmosphere during photosynthesis to form carbohydrates, which in turn are used by animals and other organisms for energy. Cellular respiration by both plants and animals returns CO2 to the atmosphere. In addition to these biological processes, carbon is also returned to the atmosphere through the decomposition of organic matter, and the combustion of organic matter and fossil fuels.
The carbon cycle also includes a long-term component involving the geological storage and release of carbon. This slow process includes the formation of sedimentary rocks, the subduction of tectonic plates, and volcanic activity, which can release carbon back into the atmosphere over geological timescales. The carbon cycle ensures that carbon is recycled and available for new life, maintaining the balance of carbon compounds necessary for life on Earth. However, human activities, particularly the burning of fossil fuels since the Industrial Revolution, have significantly increased the amount of CO2 in the atmosphere, contributing to climate change.