Final answer:
Carbon is added to the atmosphere through burning fossil fuels, cellular respiration, decomposition, geological activities like volcanic eruptions, and released by oceans as temperature rises. It is removed through photosynthesis, oceanic cooling and diffusion, sedimentation, and formation of sedimentary rocks. The numbers in carbon cycle models likely represent the rates of carbon transfer between these processes.
Step-by-step explanation:
Processes Adding Carbon to the Atmosphere:
Places where carbon is being added to the atmosphere include the burning of organic material like fossil fuels, which releases carbon dioxide, a process exacerbated by the reduction of photosynthetic trees due to deforestation. Living organisms also contribute to atmospheric carbon through the process of cellular respiration, emitting carbon dioxide as a byproduct. Additionally, the decay and decomposition of dead organisms release stored carbon into the atmosphere. Geological processes such as the eruption of volcanoes and weathering also release carbon dioxide, though these occur over longer timescales.
Processes Removing Carbon from the Atmosphere:
Carbon is pulled out of the atmosphere primarily through the process of photosynthesis, where plants use carbon dioxide to make organic compounds. The oceans also play a crucial role; when ocean water cools, it dissolves more carbon dioxide from the air, and some carbon may gradually settle to the ocean floor, eventually forming sedimentary rocks or fossil fuels. Additionally, the formation of calcium carbonate from ions in seawater contributes to long-term carbon storage in the form of marine organism shells, which become part of ocean sediments.
Hypothesis on Carbon Cycle Numbers:
The numbers in the arrows likely represent the amount of carbon being transported in each process, indicating the rate at which carbon enters or leaves a particular store in the carbon cycle. For instance, larger numbers may indicate a higher rate of carbon emission from burning fossil fuels or a greater rate of carbon absorption by photosynthetic plants.