1. CenUSA Bioenergy High School Curriculum Lesson 2
The Carbon Cycle
CenUSA Bioenergy High School Curriculum
Lesson 2

2. What is the Carbon Cycle?
The carbon cycle is a way we can understand the complex movement of all carbon atoms between air, water, soil, rocks, and living things.
The image above is a simplified diagram of the living carbon cycle. Many other factors are not included, such as ocean absorption and fossil fuel emissions, but it can be seen how carbon cycles through the atmosphere, plants, and animals because of photosynthesis and respiration.

3. How do plants and animals contribute to the carbon cycle?
Movement of carbon between the biosphere, atmosphere, oceans, and geosphere.
Series of complex processes through which all of the carbon atoms in existence rotate.
Plants absorb carbon dioxide from the atmosphere and combine it with water they get from the soil to make the substances they need for growth.
The process of photosynthesis turns carbon atoms from carbon dioxide into sugars.
Animals, such as rabbits, eat plants and use the carbon to build their own tissues.

4. Effects of Carbon on the Environment
Carbon moves from fossil fuels to the atmosphere when fuels are burned.
When humans burn fossil fuels to power factories, power plants, cars and trucks, most of the carbon enters the atmosphere as carbon dioxide gas.
Each year, five and a half billion tons of carbon is released by burning fossil fuels. That’s the weight of 100 million adult African elephants!
Of the huge amount of carbon that is released from fuels, 3.3 billion tons enters the atmosphere. The rest mostly becomes dissolved in seawater.

5. Global Climate Change
Carbon moves from the atmosphere to the oceans. The oceans, and other bodies of water, soak up some of the carbon from the atmosphere.
Carbon dioxide is a greenhouse gas and traps heat in the atmosphere. Without it and other greenhouse gases, Earth would be a frozen world.
Humans have burned so much fuel that there is approximately 30% more carbon dioxide in the air today than there was about 150 years ago.
More greenhouse gases such as carbon dioxide in our atmosphere can cause our planet to become warmer.