Prelab Preparation

Copy enough worksheets and background information for each student in the class. Each student will need access to a calculator to perform this activity.

Safety Precautions

This classroom activity is considered nonhazardous.

Lab Hints

• This laboratory activity may be completed during class with use of the Internet. The Internet is not essential but it will assist students in determining mileage for trips.
• Depending on the level of your students, assistance may be needed with the calculations. For example, some students may find it difficult to estimate how many miles they travel on average per year. You may guide them by listing typical travel or presenting an example. Remind them they are not expected to remember every location they traveled over the past year but to get an idea of the average.
• Students may need to enlist the help of their parents in determining annual travel mileage.
• It will be necessary to instruct students to read through the activity the day before so they can get information from utility bills and/or get help from their parents.
• CO₂ emissions for plastic and glass usage are averages, they are not individualized. They are intended to give students a general idea of the CO₂ emissions involved.

Teacher Tips

• This activity is an excellent tool to use to wrap up studies regarding environmental pollution. Students will discover the impact of their actions on the environment.
• Flinn Scientific offers several environmental study kits in the Earth Science section of our catalog. These kits study topics such as acid rain, soil testing, water pollution, etc.

Answers to Prelab Questions

1. Sam purchased paint, a paint brush and a ladder from the store. Would this purchase contribute to Sam’s primary footprint or his secondary footprint? Explain.

   Sam’s purchases contribute to his secondary footprint. While these goods do not give off CO₂ themselves their production and/or disposal does.

2. Peter needs to travel 57 miles each way to meet with a client for his job. How many metric tons of CO₂ will be released as a result of this trip? Hint: Assume the vehicle receives 25 miles per gallon.

   The total mileage traveled is 114 miles. The car Peter drives gets 25 miles per gallon so 114 miles/25 miles per gallon uses 4.56 gallons of fuel. Therefore 4.56 gallons multiplied by 0.002421 metric tons of CO₂ per gallon. A total of 0.01099 metric tons of CO₂ were released as a result of Peter’s trip.

3. Ashley is planning a trip to visit her friend Amy over the holiday weekend. Amy lives 120 miles away. Assuming that either a train or the bus could be used for travel which mode of travel would contribute the least carbon dioxide, CO₂, to Ashley’s carbon footprint?

   Since average values are used, regardless of the distance a train emits less CO₂. In practice it depends on several other factors (e.g., occupancy of the vehicle, type of driving [several stops versus constant travel]).

Sample Data

Residential Emissions Data Table

*Keep in mind students may not have data for all categories depending on what type of energy their house uses. The data table is completed for reference purposes.

Answers to Questions

1. Based on the information in Data Table 1 and the information obtained in the Residential Emissions Data Table, calculate your daily CO₂ emissions as well as your annual CO₂ emissions. Record in the Residential Emissions Data Table.

   Students may not have data for every category. All are presented to give a general idea of the approximate values.
   Electricity—
   7.3973 kWh x 0.0006214 metric tons CO₂/kWh = 0.0046 metric tons of CO₂ per day 0.0046 metric tons of CO₂ per day x 365 days = 1.6778 metric tons of CO₂ annually
   Natural Gas—
   0.9165 CCF x 0.005431 metric tons CO₂ per CCF = 0.0049 metric tons of CO₂ per day 0.0049 metric tons of CO₂ per day x 365 days = 1.8208 metric tons of CO₂ annually
   Heating Oil—
   0.3452 gallons x 0.0101468 metric tons CO₂/gallon = 0.0204 metric tons of CO₂ per day 0.0204 metric tons of CO₂ per day x 365 days = 1.2785 metric tons of CO₂ annually
   Propane—
   0.3699 gallons x 0.00552 metric tons of CO₂ per gallon = 0.0020 metric tons of CO₂ per day 0.0020 metric tons of CO₂ per day x 65 days = 0.7300 metric tons of CO₂ annually

2. Explain how you calculated the annual distance traveled for each mode of transportation listed in the Transportation Data Table.

   Auto travel was calculated based on a 23 mpg vehicle travelling 20 miles round trip to gymnastics clubs twice a week. Club meets throughout the school year (35 weeks) for a total of 1400 miles a year. Also approximately 50 miles are traveled per week to do errands for a total of 4,000 miles a year.
   Air travel was calculated based on one round trip from Chicago, Illinois to Orlando, Florida.
   Rail travel was based on three 60-mile round trips from the suburbs to Chicago.
   Bus travel was calculated based on the distance from the bus stop to school being 3.75 miles. At two trips a day, five days a week in a 35-week school year the total mileage is 1,312 miles.

3. Based on the information in Data Table 2 of the Background section and the information calculated in the Transportation Data Table, calculate your volume of fuel consumed by car travel (based on mpg). Calculate the annual CO₂ emission. Record in the Transportation Emissions Data Table.
   Car Travel
   4,000 miles traveled per year/23 miles per gallon = 173.91 gallons of gasoline
   173.91 gallons of gasoline x 0.002421 metric tons of CO₂ per gallon = 0.42104 metric tons of CO₂ annually
   Air Travel
   1,982 miles x 0.000268 metric tons CO₂ per mile = 0.53117 metric tons of CO₂ annually
   Rail Travel
   180 miles x 0.000109 metric tons of CO₂ per mile = 0.01962 metric tons of CO₂ annually
   Bus Travel
   1,312 miles x 0.000177 metric tons of CO₂ per mile = 0.232224 metric tons of CO₂ annually
   Bus Travel > 20 miles
   100 miles x 0.000082 metric tons of CO₂ per mile = 0.0082 metric tons of CO₂ annually
4. Add your annual CO₂ emissions from the Residential, Transportation and Hospitality Data Tables. This is your annual carbon footprint. Record below.

   Student answers will vary. Based on sample calculations this person’s carbon footprint would be 6.864 metric tons of CO₂ per year.

5. Calculate the percentage each component contributes to your overall carbon footprint. Prepare a pie chart to show the amount (percent) contributed by each aspect of your daily life.
   {12805_Answers_Figure_1}
   Based on a household that does not use heating oil or propane.
6. Compare your carbon footprint with those of three of your classmates. How do your carbon footprints differ?

   All of our carbon footprints were somewhat similar. One classmate’s carbon footprint is much higher as he does not ride the bus and gets a car ride to and from school every day.

7. What activities are different that could be modified to have the greatest impact on reducing your carbon footprint.

   All of our carbon footprints could be reduced by riding a bicycle to and from school when the weather permits. It would also help to turn off lights, computers, etc., when not in use.

8. What other activities, not included on this worksheet, may also contribute to your carbon footprint?

   Consuming goods also increases our carbon footprint. If we only need three pair of jeans we should not buy more. Those jeans contribute to our carbon footprint in both their production and disposal.

References

Household Emissions Calculator Assumptions and References. Environmental Protection Agency. http://www.epa.gov/climatechange/emissions/ind_assumptions.html Emission Facts: Average Carbon dioxide

Emissions Resulting from Gasoline and Diesel Fuel. Environmental Protection Agency. http://www.epa.gov/otaq/climate/420f05001.htm

About IPCC. Intergovernmental Panel on Climate Change. http://www.ipcc.ch/about/index.htm

Introduction

The term “carbon footprint” is widely used by the media, environmentalists and even the general public. What does the phrase mean and how is the quantity calculated? Perform this activity to determine your annual carbon footprint!

Concepts

• Carbon footprint
• Carbon dioxide emissions
• Environmental pollution

Background

The term carbon footprint is a measure of the impact our activities have on the environment and it is used to evaluate or describe how our activities affect climate change. A carbon footprint is measured by greenhouse gases produced by an activity and is expressed in terms of kilograms of carbon dioxide (CO₂) equivalent.

A carbon footprint is comprised of two parts—the primary footprint and the secondary footprint. The primary footprint measures our direct emissions of CO₂ from the burning of fossil fuels, including domestic energy consumption and transportation. The secondary footprint measures the indirect CO₂ emissions from the whole lifecycle of products we use. It takes into account all of the emissions associated with the manufacturing of an item and their eventual breakdown. Everything we purchase contributes to our carbon footprint.

In addition to carbon dioxide, several other greenhouse gas emissions also contribute to global warming. In order to compare the emission of different gases on a scale, greenhouse gases are often measured based on their carbon dioxide equivalent. Carbon dioxide equivalents are calculated by multiplying the weight of the gas of interest (in metric tons) by its estimated global warming potential. Global Warming Potential (GWP) provides a method for converting emissions of various gases into a common measure. The GWP allows scientists to combine the radiative impacts of various greenhouse gases into a uniform measure in carbon dioxide equivalents. Hence the title of the calculation is the carbon footprint. It compares the environmental impact of all greenhouse gas emission in terms of carbon.

Numerous calculators are available online to estimate a carbon footprint. These programs require individuals to enter several pieces of personal data into the calculators. Such programs often base the calculations on factors (e.g., mileage traveled per year by various modes of transportation, the size of living quarters, the type and volume of energy used in the home). Calculators quickly provide individuals with their carbon footprint. It is often unclear, however, how our everyday activities are calculated to produce this carbon footprint. Where do the calculators obtain their data and how is it measured?

GWP values are determined by the Intergovernmental Panel on Climate Change (IPCC). The IPCC is a scientific intergovernmental organization established by the World Meteorological Organization (WMO) and the United Nations Environment Program (UNEP). The IPCC was created because climate change is a complex issue. Policymakers require an objective source of information regarding sources that cause climate change and its potential environmental and economic consequences. The scientific content is accumulated by experts of member countries of WMO and UNEP throughout all regions of the world. Since research for the IPCC is done throughout the world, the scientific information should be gathered in a policy-neutral manner.

The data obtained by the IPCC is very detailed and accounts for all possible variables. In order to calculate accurate values several pieces of specific information are required. For example, automobile emissions are obtained based on fuel consumption, exhaust emission legislation classes, average speed traveled, average trip distance, climatic conditions and evaporation distribution. The data is entered into complex calculus equations to determine the most precise CO₂ emission or CO₂ equivalent.

It is not feasible for the average person to gather and compute such complex equations. Often time data varies from one source to another. Emissions from transportation sources often are not consistent from one calculator to another. Automobile emissions vary depending on the method used to obtain the data. The United States Federal Highway Administration bases its estimates on tailpipe emissions only. Other sources base their emission values for the full life cycle of the fuel, including extraction, processing, and transportation. Emissions from air travel are also somewhat difficult to calculate. They are often not included in carbon footprint calculations as the emissions depend on aircraft type, length of trip, occupancy rates and weight of cargo. The same can be said for rail and bus travel. Carbon footprint calculators use average values and are intended to give individuals a general idea of their carbon footprint. The numerical values used in this activity were obtained from the Environmental Protection Agency.

Experiment Overview

The purpose of this laboratory activity is to calculate and analyze your annual primary carbon footprint.

Materials

Prelab Questions

1. Sam purchased paint, a paint brush and a ladder from the store. Would this purchase contribute to Sam’s primary footprint or his secondary footprint? Explain.
2. Peter needs to travel 57 miles each way to meet with a client for his job. How many metric tons of CO₂ will be released as a result of driving the car this amount of miles? Hint: Assume the vehicle receives 25 miles per gallon.
3. Ashley is planning a trip to visit her friend Amy over the holiday weekend. Amy lives 120 miles away. Assuming that either a train or a bus could be used for travel, which mode of travel would contribute a lower amount of CO₂ to Ashley’s primary carbon footprint?

Safety Precautions

This classroom activity is considered nonhazardous.

Procedure

Residential CO₂ Emissions

1. Obtain a copy of your household electric bill.
2. Locate the number of kilowatt hours used (kWh) and divide the kilowatt hours by the number of days in the billing cycle.
3. Divide the daily kilowatts used by the number of people in your household to obtain your daily electrical usage. Record this number in the Residential Emissions Data Table of the Calculating Your Carbon Footprint Worksheet.
4. Depending upon which energy sources your home, skip the corresponding steps indicated below. If your home does not use— Natural gas, skip steps 5 and 6. Heating oil, skip steps 7 and 8. Propane, skip steps 9 and 10. Mark the appropriate boxes in the data table with N/A as needed.
5. Obtain a copy of your natural gas bill. Locate the volume of natural gas consumed in CCF (100 ft³) and divide the CCFs of natural gas by the number of days in the billing cycle.
6. Divide the daily natural gas usage by the number of people in your household. Record this number in the data table.
7. Obtain a copy of your most recent heating oil statement. Locate the volume of heating oil consumed in gallons. Divide the gallons of heating oil consumed by the number of days in the billing cycle.
8. Divide the daily heating oil usage by the number of people in your household. Record this number in the data table on the worksheet.
9. Obtain a copy of your propane gas bill. Locate the volume of propane consumed in gallons. Divide the gallons of propane by the number of days in the billing cycle.
10. Divide the daily propane usage by the number of people in your household. Record this number in the data table on the worksheet.

11. Estimate the average annual mileage you travel by car and record the value in the Transportation Emissions Data Table.
12. Estimate the average annual mileage you travel via airplane and record the value in the data table.
13. Estimate the average annual mileage you travel via train and record the value in the data table.
14. Estimate the average annual mileage you travel via bus and record the value in the data table.

15. Calculate the annual CO₂ emitted by the purchase of newspapers.
16. Calculate the annual CO₂ emitted from the purchase of magazines.
17. Calculate the annual CO₂ emitted from the use of glass materials.
18. Calculate the annual CO₂ emitted from the use of plastic materials.

Student Worksheet PDF

12805_Student1.pdf