Prerequisite skills: Prerequisite skills and knowledge include skills in concept mapping, computation, skills knowledge of the mechanisms of the Greenhouse Effect and the carbon cycle, including sinks and sources of carbon dioxide.

Appropriate grade levels: High School, or upper Middle School levels. Prerequisite skills and knowledge could be sequenced to precede this activitiy, or taught at earlier grade levels.

Time needed: 2-4 classes over several weeks depending on the detail of data collected and analyzed.

Although carbon dioxide, methane, nitrous oxide, chlorofluoracarbons, and ozone collectively contribute to the greenhouse warming of the Earth, it is carbon dioxide that plays the largest (60%) single role in the warming process.
A variety of human activities, including deforestation, agriculture, the burning of fossil fuels, and cement production produce carbon dioxide. Of these activities, fossil fuel combustion accounts for about 85% of the carbon dioxide production per year. Energy usage in industrialized countries has been chiefly responsible for the observed 25% increase in atmospheric carbon dioxide concentration over the past 100 years. Population increase in less industrialized countries over the next 100 years, coupled with increased energy requirements as these countries develop, are likely to shift a substantial part of human C02 production to other world regions.
As the number of humans and fossil fuel use increase, all of us must share the responsibility for possible global climate change produced by the additional carbon dioxide in the atmosphere, and work toward reducing the impact such change might bring.
1. Engagement

Based on student knowledge of the carbon cycle, review the major human activities which contribute or remove carbon dioxide from the carbon cycle.
Because an individual contribution of carbon dioxide is mainly through the use of energy, have students list all the ways they use energy during the day. Summarize this list on the black board; make the list as exhaustive and inclusive as possible. Classify each energy use as to the type of energy used; e.g., a clock-radio uses electricity. Finally, trace the electrical energy type "electricity" to its local source; e.g., coal-fired power plant.

2. Explore

In this activity, students will calculate the average per person production of C02 for the local area through the use of gasoline, generation of electricity and use of natural gas. If other energy sources are used in your area, list them and try to determine the C02 produced from using them.

Make the following calculations for a typical household in your area and record this information on the data sheet. Ask for a student/parent volunteer, use your own household, or use a class average to provide the data.
A. Direct Use

1. Transportation

a. Cars - Find out how many miles the family car(s) were driven last year, and about how many miles per gallon of gas each car travels (the national average miles per gallon is 28 mpg). Divide the miles driven by the miles per gallon for each car. Each gallon of gas burned produces 20 pounds of C02 for cars and 21 pounds of C02 for trucks/vans.

b. Airplanes - Find out how many miles family members flew last year. Flying 1 mile produces one-half pound of C02 per person.

2. Household Use - Determine what the fuel source is for electricity generation in your area by calling the power company. Obtain monthly bills for electricity and natural gas for a year or use a March or October bill and multiply times 12. Determine the kilowatt hours and therms used in a year, and then the pounds of C02 produced by each fuel source using the chart.

B. Indirect Use

Carbon dioxide is also released into the air when the products we buy are produced and transported. It is estimated that this indirect production of carbon dioxide is equal to the direct production. Multiple the total direct production of C02 by two to get the Total Indirect Pounds of C02 produced by a typical family in your area. (Divide this number by the number of individuals in the family to get Total Pounds of C02 Produced per Person in your area.)

C. Total Production

Add the direct and indirect production of C02 .

3. Explain

Be certain students understand how and why the calculations were made and that concepts such as KWH are defined/understood. Discuss the following questions:

1. Calculate the pounds of C02 saved if your car(s) averaged 5 more mile per gallon.

2. If one acre of trees can use 2.6 tons of carbon dioxide per year, how many acres of trees would be needed to absorb the C02 produced by the average person in your area?

3. Discuss ways to reduce the use of fossil fuel consumption/C02 release in each production category, (transportation, household and indirect use).

4. Try to determine the average direct C02 production per person in your country.

5. What are the indirect sources of C02 from:

a. Transportation (i.e., clearing vegetation to build roads, cement production to build roads)

b. Household use

4. Elaborate

Summarize the data collected by constructing a bar graph of the Total Direct C02 Produced (A3), C02 Produced from Transportation (A1), and C02 Produced by Household (A2).

Write a paragraph as a class or in small groups which describes the lifestyle of your community and its geographical features which might lead to the numbers you calculated. Share this information with the other Globe-Phase II Trace Gas experiment schools.

When you have received information from the other globe schools, compare and discuss the results. In small groups construct one hypothesis as to why the differences exist in the data between schools and decide on data which might be used to support or reject your hypothesis. Collect these data from the other schools and use it to evaluate your hypothesis. For example transportation differences may depend on type of cars driven, distance from school, driving age, use of cars, etc.

References
Penn State - College of Education
http://www.ed.psu/dept/ci/sts/ toc.htms
Global Atmospheric Change - Investigation - Lesson 13

Environmental Science Activities by Dorothy B. Rosenthal, 1995, John Wiley and Sons, ISBN 0-471-07626-0

Global Warming - Social Studies Activities - High School, 1991, by Roberta Snow and Richard Golden, Climate Protection Institute, San Francisco, CA.