The carbon cycle

• Carbon cycle

  The process by which carbon is continuously cycled through the environment
• Decomposers

  • Their role is to break down dead organic matter and return carbon to the atmosphere as carbon dioxide
• Carbon cycle

  1. Carbon dioxide in atmosphere

  2. Photosynthesis by plants and algae to make carbohydrates, fats and proteins

  3. Plants and algae respire, releasing some carbon dioxide back to atmosphere

  4. Plants and algae consumed by animals

  5. Animals respire, releasing carbon dioxide back to atmosphere

  6. Animals excrete waste and die

  7. Decomposers break down waste and dead remains, releasing carbon dioxide back to atmosphere

  8. Under certain conditions, carbon in dead remains can be converted to fossil fuels over millions of years

  9. Humans burn fossil fuels, releasing large amounts of carbon dioxide to atmosphere
• Photosynthesis is the only way carbon can enter the carbon cycle
• Respiration and breathing are not the same thing
• Decomposers are extremely important as they cycle materials through an ecosystem and return carbon to the atmosphere as carbon dioxide
• Decomposers also release mineral ions to the soil
• If decomposers cannot function effectively due to lack of oxygen, carbon in dead remains can slowly be converted to fossil fuels
• Over the last 200 years, humans have been burning huge amounts of fossil fuels, releasing large amounts of carbon dioxide to the atmosphere