Carbon Cycles
Figure 1. Diagram of the carbon cycle.Copyright National Aeronautical and Space Administration http://earthobservatory.nasa.gov
Students are introduced to the concept of energy cycles by learning about the carbon cycle. They learn how carbon atoms travel through the geological (ancient) carbon cycle and the biological/physical carbon cycle. They consider how human activities disturb the carbon cycle by emitting carbon dioxide into the atmosphere. They discuss how engineers and scientists are working to reduce carbon dioxide emissions. Lastly, with the associated activities students draw connections between the past and present to consider how they can help the world through simple energy conservation measures.
Human activities during the past 100 years, particularly fossil fuel burning and deforestation, are releasing unnatural amounts of carbon dioxide (CO2) into the atmosphere. Today, people are concerned about the rising CO2 concentration in the atmosphere and its impact on global climate change. Many engineers are working to reduce CO2 emissions. For example, environmental engineers study carbon sequestration — the processes that remove carbon from the atmosphere. Mechanical and electrical engineers design buildings, homes, cars and appliances that use less energy. Other engineered devices, such as solar panels and wind turbines, generate electricity from natural sources and do not emit CO2 into the atmosphere.
After this lesson, the student will be able to:
- Identify the main differences between the geological carbon cycle and the biological/physical carbon cycle.
- Describe how human activities have affected the carbon cycle.
- Explain how engineers are working to understand and rebalance the carbon cycle.