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Activity Guide
The One Degree Factor: The Carbon Dioxide Game


  • This activity may be short enough to conduct with drop-in audiences.


A fun, active, outdoor game for helping students visualize how human activities amplify the natural greenhouse effect.


Students will:

  • Demonstrate the greenhouse effect by showing how CO2 in the atmosphere holds heat and insulates Earth.
  • Show how human activities affect the concentration of greenhouse gases in the atmosphere.


Science, Physical Education


abiotic, greenhouse effect


20 minutes


  • An open area
  • Chalk
  • 1 bucket
  • Yellow 3x5 cards labeled “LIGHT,” (can be labeled by the students) (one per student)
  • Red 3x5 cards labeled “HEAT,” (can be labeled by the students) (one per student)
  • A small bag with the words “What do humans do?” written on it.
  • Action cards representing human actions that affect CO2 levels in the atmosphere. (Feel free to add your own).


This activity supports the following National Academy of Sciences Science Education Standards (Grades 5-8):

  • Unifying Concepts and Processes—Systems, order, and organization
  • Unifying Concepts and Processes—Constancy, change, and measurement
  • Standard B: Physical Science—Transfer of energy
  • Standard D: Earth and Space Science—Structure of the earth system
  • Standard E: Science and Technology—Understandings about science and technology
  • Standard F: Science in Personal and Social Perspectives—Science and technology in society


Climate is one of the most influential abiotic factors on our planet. Nevertheless, studying climate and climate change presents unique challenges to educators. For example, how to bring the vast and multifaceted concept of climate change down to a level where students can explore it in a hands-on interactive way and how to address the role that humans play in climate change. By the time they reach middle school, most students have heard of global warming and the greenhouse effect. They have some idea that rising global temperatures are attributed to human activities that have significantly increased the levels of heat-trapping gases in the atmosphere.

It is important that students also understand that the greenhouse effect is an important natural phenomenon that keeps the planet at a relatively uniform temperature. Incoming solar energy from the sun passes through our atmosphere as short wave radiation where some of it warms Earth’s surface. Part of this solar energy radiates off Earth’s surface as long wave radiation and heat that is held by heat-trapping gases in the atmosphere.

These gases, which include carbon dioxide, methane, water vapor and others, create an atmospheric layer that insulates the planet and maintains a surface temperature that allows life to flourish. Without this greenhouse effect, Earth would be a cold and inhospitable place-a nippy minus 20˚C (-4˚F).

Human activities such as deforestation and burning fossil fuels however release stored carbon dioxide and other greenhouse gases into the atmosphere. As these gases accumulate, they contribute to the creation of a thicker blanket, resulting in a gradual increase in Earth’s temperature. This important natural process becomes problematic when there is an abnormally rapid increase in heat-trapping gases in the atmosphere. When greenhouse gases accumulate too rapidly in the atmosphere, and the climate warms dramatically over a short amount of time, some life will not be able to adapt to the swift changes.

The Carbon Dioxide Game is a fun, active way to explain the greenhouse effect and the human contribution to global climate change. The game can be played with groups of up to 30 students, ages 10 and older.


1. Select an open, outdoor area in which to play the game.

2. Draw two concentric circles on the ground, 1.5 meters (5 feet) in diameter, and a larger one about 6 meters (20 feet) in diameter. The smaller circle represents Earth and the larger one represents Earth’s atmosphere.

3. Select two students to be CO2 molecules.

4. Have the other students (representing the sunbeams) each take a yellow 3x5 card and label it LIGHT and take a red 3x5 card and label it HEAT.

5. Place the red cards labeled HEAT into the bucket and put the bucket into the inner circle of Earth.

6. Cut apart the action cards provided and add any of your own. Divide the cards into those that add and those that remove carbon dioxide molecules. Put only the cards that add molecules into the bag labeled “What do humans do?”


The object of the game is for the sunbeams to enter the atmosphere (carrying their yellow cards labeled LIGHT over their heads), tag Earth (by touching the inner circle with a foot or hand and exchanging their yellow for a red card labeled HEAT). Then they must try to escape the atmosphere, holding their red cards, without being tagged by a CO2 molecule. Heat cardholder sunbeams, who are tagged, must stand still in the atmosphere, representing that their heat is being held in the atmosphere. Those who avoid being tagged bounce back out of the atmosphere into space.

The game is played in several rounds. Each round lasts approximately 30 seconds and during that time the sunbeams try to tag Earth only once. This simulation recreates the greenhouse effect: energy from the sun reaches Earth as short wavelength (LIGHT) and then radiates back into space at a longer wavelength (HEAT). CO2 and other gases and particles in the atmosphere hold some of the radiating heat energy.

1. For Round 1, choose two students to be CO2 molecules, and place them anywhere in Earth’s “atmosphere.” Once the student “molecules” are in the atmosphere, they cannot move their feet. The rest of the students are sunbeams representing light energy from the sun. (The bag is not used for this round.)

2. After the first round, have the escaped sunbeam students—those with red cards labeled HEAT, line up to review how many sunbeams (how much long—wave heat energy) have been trapped. Discuss how this may affect the temperature of the planet. Remind students that a certain amount of CO2 is necessary to keep the planet consistently warm enough to support life. During the first round, most of the heat energy will have escaped the atmosphere because CO2 levels are low. Before continuing the game, clear all the trapped sunbeams out of the atmosphere (have them put their red cards back in the bucket) but keep the two CO2 molecule students in the outer circle.

3. For Round 2, increase the number of CO2 molecules in the atmosphere. Do this by reaching into the “What do humans do?” bag and pulling out an action card. For this round, include only cards that add CO2 to the atmosphere. After a student reads the card, increase the number of CO2 molecules in the game (dictated by card) and play again. As before, the CO2 molecules stand in place in the atmosphere while the sunbeams rush in.

4. For the third and subsequent rounds, put all of the action cards in the bag. CO2 levels will now rise and fall depending on which card is drawn. Discuss what happens each time. The game should demonstrate that when you increase the amount of CO2, more heat is held-as illustrated by the tagged sunbeams holding HEAT cards standing in the atmosphere-and Earth warms up. The action cards demonstrate how even small-scale actions affect the amount of greenhouse gas that we emit into the atmosphere.

(Note: It is important to clarify that this is a simplified simulation and that such actions as using energy efficient technology or alternative forms of transportation do not actually remove carbon dioxide from the atmosphere. Rather, they contribute less than do their more commonly used counterparts. Eliminating actions that normally add greenhouse gases also stems the increase but does not reduce existing gases. Some actions, such as planting trees, can indeed reduce carbon dioxide emissions.)

5. Review how heat energy from the sun is held in Earth’s atmosphere. Discuss how human actions, particularly burning fossil fuels, can amplify the greenhouse effect by putting more CO2 into the atmosphere. The game can be a springboard into a variety of other explorations such as researching alternative energy sources, discussing sustainable lifestyles, and examining the different choices humans can make in relation to the environment.


Ask students to draw a diagram illustrating the greenhouse effect. Illustrate or list actions that influence carbon dioxide emissions into the atmosphere both positively and negatively.

Needs Improvement—Diagram is incorrect. Student identifies one or no actions that influence carbon dioxide emissions.

Satisfactory—Diagram generally reflects the process of greenhouse gases holding heat and warming the atmosphere. Student identifies at least two actions that contribute to increasing and reducing greenhouse gases.

Excellent—Diagram reflects in detail how greenhouse gases hold heat and warm the atmosphere. Student identifies three or more actions that affect greenhouse gases emissions and those actions reflect both increases and reductions.


  • Visit one or more of the Web sites listed in the MORE INFORMATION section and investigate ways to reduce carbon dioxide emissions.
  • Design and implement a campaign to reduce the group’s contributions to global warming. Consider extending the campaign to the school or community.


Travel Matters includes an emissions calculator to determine greenhouse gas contributions as a result of daily transportation practices. www.travelmatters.org/education/youth

10% Challenge includes a pledge program to reduce greenhouse gases by 10%, emissions calculator, and suggestions for reducing greenhouse gas contributions. www.10percentchallenge.org/

Safe Climate.Net, a project of the World Resources Institute, includes a carbon dioxide footprint calculator. www.safeclimate.net/calculator/

Climate Change Education includes links and information for youth, teens, and teachers. www.climatechangeeducation.org

Marian Koshland Science Museum of the National Academy of Science is an interactive site with information on the greenhouse effect and global warming. www.koshland-science-museum.org


This activity was created by educator Sashi Kaufman while working at the Ferry Beach Ecology School in Saco, Maine. It has been revised by the Sea Studios Foundation.

Adapted with permission from Green Teacher #70, Spring 2003. Green Teacher, P.O. Box 452, Niagara Falls, NY 14304, (888) 804-1486. www.greenteacher.com .

PHOTO CREDIT: Eric Hermann

Note to Teachers: This lesson and others relating to National Geographic’s Strange Days on Planet Earth can be found online at www.pbs.org/strangedays/

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