In Unit 2 of this course, I learned that the carbon cycle involves the movement of carbon through the atmosphere, biosphere, geosphere, and hydrosphere. Carbon dioxide is a key component of this cycle, with the atmosphere acting as a major carbon source. Biomass, which includes living organisms and debris, is also an important aspect of the carbon cycle as it helps to trap carbon from the atmosphere. Additionally, keystone species play a crucial role in cycling carbon as they have a disproportionate effect on their ecosystems. Marine snow, which consists of organic debris sinking from the surface ocean to the deep sea, serves as a significant carbon sink in the ocean.
