Spinning wheels of the carbon cycle: Carbon from gasoline to plant material

Yaffa Grossman, Beloit College
Tim Tibbits, Monmouth College
Skip Wittler, Ripon College


Students will determine the quantity of carbon dioxide released by driving 100 km in their vehicle of choice and then determine the amount of photosynthetic activity required during that time period to offset this carbon dioxide production. The speed limit for this trip is 100 km/hour. A list of plants and their photosynthetic characteristics will be provided.

Learning Goals

Improve problem solving, critical thinking, and quantitative skills
Develop facility with unit conversions between English and metric system, and among forms of carbon- containing compounds
Reinforce understanding of carbon cycle including photosynthesis, respiration, and carbon content of fossil fuels
Develop "back of the envelope" rules of thumb for carbon dioxide related activities

Context for Use

Intro Botany, Biology, Ecology, Environmental Studies classes
Best used by groups of students rather than individuals
Any class size
Start as exercise in lab or lecture and complete report as homework

Description and Teaching Materials

Students work in groups to select a type of vehicle and using the (incomplete) information provided, determine the quantity of carbon released by driving 100 km at 100 km/hr and how much plant material would be required to offset the carbon produced. Faculty member supports students through a group discussion of this process.

Students develop a flow chart for solving the problem, find information complete calculations using web sources and provided materials, and then write report report in IMRAD (introduction, methods, results, and discussion) format. Students will be asked to include information on how the plant material could be used so that it continues to sequester carbon over the long term and to reflect on how this information might affect their future actions.

Students need access to computers

Web sites
CO2 emissions: http://www.epa.gov/oms/climate/420f05001.htm
Fuel economy of different types of vehicles
Different types of liquid fuels
Gas consumption rates- use EPA mileage charts
Leaf level photosynthesis estimate
Respiratory loss estimate
Leaf to tree scale

Plant types
Landscape tree
Pine plantation
Prairie (carbon sequestered soil)

Climate, growing degree days, light level

Teaching Notes and Tips


Formative assessment: Faculty member checks in with student groups during discussion.
Summative assessment: evaluation of report; student evaluations

References and Resources

To be developed.