THE CARBON CYCLE 1.What are some ways Carbon cycles on Earth? 2.What process takes C out of the atmosphere and plants use it for sugars? 3.What’s it called when ‘dead’ C is returned to the Earth?
1. What’s the Carbon Cycle The same C is used repeatedly on earth. It cycles between the earth, ocean, and the atmosphere.
2. How do plants use CO2? Plants pull CO2 from the atmosphere and use it to make food –— photosynthesis. The C becomes part of the plant (stored food).
3. How does it get to us? When organisms eat plants, they take in the C and some of it becomes part of their own bodies.
4. What happens when plants and animal die? most of their bodies are decomposed and C atoms are returned to the atmosphere or soil. Some are not decomposed fully and end up in deposits underground (oil, coal, etc.).
Check for Understanding What’s it called when CO2 is removed from the atmosphere and plants use it to make sugars? Where do fossil fuels come from?
5. How does C get from the ground to the atmosphere? C in rocks and underground deposits is released very slowly into the atmosphere. This process takes many years (millions or billions).
6. What about C in oceans? Additional C is stored in the ocean. Many animals pull C from water to use in shells, etc. Animals die and C is deposited at the bottom. Oceans have most of Earth’s C.
The Carbon Cycle
7. How are humans involved with C? Fossil fuels release C very slowly Burning anything releases more C into atmosphere — especially fossil fuels Increased CO2 in atmosphere increases global warming Fewer plants mean less CO 2 removed from atmosphere
8. What can humans do to reduce C in the atmosphere? Burn less, especially fossil fuels Promote plant life, especially trees
Check for Understanding The ________ contains the most C on Earth. What are two ways cutting down trees for firewood are bad for Earth with carbon?