What Happens During the Carbon Cycle? This Question Exploration helps students understand how carbon is the backbone of life on Earth. Carbon is stored in rocks, in the ocean, atmosphere, soil, plants, animals, and fossil fuels. How does carbon flow between each reservoir in an exchange called the carbon cycle? The Overall Idea for Ss is we are made of carbon, and our civilization—our economies, our homes, our means of transport—are built on carbon. We need carbon, but that need is also entwine