Without changing the Gizmo, list the carbon reservoirs from largest to smallest.
The Correct Answer and Explanation is:
To rank the carbon reservoirs from largest to smallest based on the carbon cycle, the order is typically as follows:
- Sedimentary Rocks (Largest)
- Oceans
- Soil
- Atmosphere
- Living Organisms (Smallest)
Explanation:
- Sedimentary Rocks:
Sedimentary rocks, primarily limestone, hold the largest amount of carbon on Earth, estimated to store approximately 80% of Earth’s carbon. This carbon is stored in the form of calcium carbonate (CaCO₃) and other compounds that have accumulated over millions of years, buried in Earth’s crust. - Oceans:
The oceans store about 38,000 gigatons of carbon, making them the second largest carbon reservoir. Carbon is present in oceans as dissolved CO₂, in the form of bicarbonates, and through marine life like plankton and fish. Oceans act as a major carbon sink, absorbing more CO₂ from the atmosphere than any other reservoir. - Soil:
Soils hold around 2,500 gigatons of carbon. This carbon is primarily in the form of organic matter, such as decomposed plant material. Soil also acts as a key carbon sink, storing large amounts of carbon, especially in wetland soils or forests with high organic content. - Atmosphere:
The atmosphere contains about 750 gigatons of carbon, mainly in the form of CO₂ and methane. The carbon in the atmosphere plays a significant role in regulating Earth’s climate and is constantly cycling through photosynthesis, respiration, and other processes. - Living Organisms:
Living organisms—plants, animals, and microbes—store carbon in their biomass, but this amount is quite small compared to other reservoirs, estimated at only around 3,000 gigatons. Carbon is present in living organisms primarily as proteins, carbohydrates, and fats.
Understanding the distribution of carbon across these reservoirs is key to grasping the dynamics of the global carbon cycle and its influence on climate change.
