The letters following each Review Question refer to the corresponding Learning Objective from the Chapter Opener. Describe the reservoirs that play a role in the carbon cycle and how carbon transfers among reservoirs. (C)

The carbon cycle involves four main reservoirs: atmosphere, oceans, living organisms, and Earth's crust. Carbon is transferred among these reservoirs through processes such as photosynthesis, respiration, decomposition, and human activities. Photosynthesis transfers carbon from the atmosphere into living organisms, while respiration returns carbon from living organisms back to the atmosphere. Decomposition breaks down dead organic matter, returning some of its carbon to the atmosphere and incorporating some into the Earth's crust. Oceans store carbon in various forms, including carbonate rocks and marine sediments. Human activities like burning fossil fuels, deforestation, and cement production increase atmospheric carbon dioxide levels and contribute to global climate change.