Human Energy Systems | Activity 4.2

Target Student Performance

Students identify carbon pools in Earth systems and investigate the fluxes associated with human use of one pool: fossil fuels.

Resources Provided

Recurring Resources


Print enough copies of the 4.2 Carbon Pools and Fossil Fuels Reading and Four Questions Handout so that each student has one copy of each. Prepare a computer and projector for the 4.2 Carbon Pools and Fossil Fuels PPT. You may want to print and post the Four Questions Large Poster for the rest of the unit.


1. Use the instructional model to show students where they are in the course of the unit.


Students will not have complete accounts of where the energy in fossil fuels comes from and where it goes after fossil fuels are burned. Check during this activity to see where their ideas are as you begin to discuss fossil fuels.


  • You may want to revisit the Powers of Ten 11 x 17 Poster (from the Systems and Scale unit) to refresh students’ memories about what we mean by “scale” when we zoom into fossil fuels.
  • Students may have questions at this point about the difference in the way we define “organic” in the Carbon TIME units, and other meanings of this word. Remind them that in the Carbon TIME units, “organic” things contain C-C and C-H bonds. “Inorganic” things do not contain C-C and C-H bonds. Fossil fuels contain C-C and C-H bonds that make them a rich source of energy for people—this means that fossil fuels are organic, even though they are not living. If students raise these questions, point out that our definition of organic is also not the same as the definition they might see in a grocery store to refer to food produced without using pesticides, fertilizers, antibiotics, or growth hormones.


Have students read in pairs and discuss Questions, Connections, Questions with their partners.

Extending the Learning
  • Have students record different ways they use fossil fuels in one day of their lives and bring their journals to class. Check to see if they make the connection that using electricity uses fossil fuels (assuming the electricity comes from a coal-fired power plant). At this point in the unit, they may not be able to make this connection, but it could serve as a way to introduce the idea for later discussion.
  • Have students research things that are made using fossil fuels and make a list of products. They might be surprised how many things they use every day are made from oil and petroleum!
  • The overview of fossil fuel formation is very short in this Lesson. As an extension activity, have students research in more detail how different fossil fuels are formed, how they are extracted from the Earth, and how we use them.