Carbon In the Atmosphere - My Life as a Greenhouse Gas

Part C: What's My Carbon Footprint?

In Part B, you observed that the amount of carbon dioxide has been increasing in the atmosphere and that this increase corresponds with a rise in global temperature. The graph on the right tells us that fossil fuel emissions have also been increasing since the Industrial Revolution began, indicating that the burning of the hydrocarbons in fossil fuels is releasing carbon dioxide to the atmosphere. Furthermore, fossil fuel usage is expected to increase as the world's population continues to increase. So, what can individuals, organizations or governments do to reduce the amount of CO₂ in the atmosphere? Find out what a very large organization is doing - the U.S. Military! Watch Khaki Goes Green. As you watch, make note of the solutions they are developing to reduce their use of fossil fuels. Use your notes in the following discussion.

Because the U.S. Military is a large organization, their strategy to reduce carbon fossil fuel emissions could have a sizable impact. What about us—individuals and families? Can we make a difference? Watch Carbon Footprints-You Can Make a Difference to get some ideas then answer the Checking In questions below.

What's My Carbon Footprint?

In order to reduce carbon emissions, we first need to understand how much carbon we are creating. Carbon footprints can help us do that. What exactly is a carbon footprint and what does it tell us?
A comprehensive carbon footprint is made up of two parts.

• The primary carbon footprint is a measure of our direct emissions of CO₂ from the burning of fossil fuels – essentially all the greenhouse gases we individually produce in our day-to-day activities. This would include, for example, the energy needed to light and heat our homes, run our appliances, and drive our cars.
• The secondary carbon footprint includes the CO₂ emissions from products that we buy. For example, how many CO₂ emissions are created to make a steak, a shoe, a glass of milk, or a television? To put it simply, when we buy a product, CO₂ emissions will be caused on our behalf.

Now, it's your turn to determine your family's carbon footprint. There are many carbon footprint calculators available on-line, so you may have already determined your carbon footprint in another class or perhaps with your family. Today, you will use a carbon footprint calculator developed by The Nature Conservancy. This carbon footprint allows you to compare your carbon footprint with the footprints of average families in the United States and the World.

1. Access the Carbon Footprint Calculator.
2. In the "Get Started" section, input the number of people in your household and click on "calculate family." Make sure you read the information in this section.
3. Click on "more info" and read what it tells you about how the carbon footprint is calculated.
4. Click "continue" to go to the Home Energy section. Input your "Home Energy" information to the best of your knowledge. As you input your information, notice how figures in the right-hand column of the Home Energy page changes. The first number that comes up is your estimated impact on the atmosphere in terms of how many tons of CO₂ equivalencies you are releasing. Notice that as you input more information in the section below, you either reduce your impact or add to it. At the bottom of the page, two bar graphs tell you how you compare to the average U.S. household. At the end of the carbon footprint calculator, information in these bar graphs will be combined into two pie graphs. How do your "Home Energy" emissions compare to the U.S. average?
5. Click "continue" and input your "Driving and Flying" information. How do your "Driving and Flying" emissions compare to the U.S. average?
6. Click "continue" and input your "Food and Diet" information. How do your your "Food and Diet" emissions compare to the U.S. average?
7. Click "continue" and input your "Recycling and Waste" information. How do your "Recycling and Waste" emissions compare to the U.S. average?
8. Click "continue" to "Results." Review your results and answer the Checking In questions below.

Optional Extension

How heavy is my carbon footprint?

Many students carry a backpack filled with heavy books to and from school. How much would a backpack weigh for a single day of carbon emissions for a family who has a carbon footprint of 40 tons (metric) of CO2 equivalent per year? 40 metric tons of CO2eq is equivalent to 23809 pounds of carbon going into the atmosphere per year. Divide that number by 365 days in a year, and this family is putting 65 lbs of carbon into the atmosphere each day!

How can you help friends and family members visualize this? You will need a bathroom scale and any materials that will allow you to add weight to the backpack. Examples of weights are bricks, stones, heavy books, exercise weights, etc.

Next, fill the backpack with 65 lbs of weight and invite friends and family to carry around their carbon emissions for a day!