Logo cartOrder Online    cartEmail Updates    cartContact   
logo HometransChapterstransCool StufftransGlindextransDr. Art?


Greenhouse Effect

Background: Dr. Art's Guide to Science, pages 137-139, 232-234.

The greenhouse effect plays a very important role in the flow of energy into and out of the Earth system. By viewing a physical simulation of this phenomenon or creating their own simulation, participants can gain a deeper understanding of the greenhouse effect.

Equipment and Supplies:
Demonstration Mode - One object representing each of the following (the objects can be different color balloons, paper cut-outs, molecular models, etc.): Sun, planet Earth, packet of light energy, packet of heat energy, oxygen molecule, nitrogen molecule, carbon dioxide molecule.
Inquiry Mode - Sets of objects representing the same things as for Demonstration Mode. One set per group of participants.

Safety Issues:

Demonstration Mode- 15 minutes
Inquiry Mode - 50 minutes

Procedures: Demonstration Mode

  1. Model a light wave traveling at relatively high frequency from the sun to Earth. In a wavelike motion, walk the light wave (e.g., a yellow balloon) from the sun to Earth. Do not include any effects of atmospheric gases.
  2. Model absorption of the light energy, its conversion to heat and its departure from Earth to outer space. For example, exchange the yellow balloon for a red balloon. Walk the heat wave away from planet Earth, again using a wavelike motion but this time of a lower frequency (fewer up and down motions; longer wavelength). Do not include any effects of atmospheric gases.
  3. Describe what you have done as modeling the flow of energy into and out of the Earth system.
  4. Now include the atmospheric gases nitrogen, oxygen and carbon dioxide. Model a light wave traveling from the sun and show that it does not interact with any of the atmospheric molecules. Model the heat wave leaving Earth and that it interacts with carbon dioxide but not with oxygen or nitrogen.
  5. Model the interaction of the heat wave with a carbon dioxide molecule as an absorption of energy and a re-radiation of that heat energy back to planet Earth where it is absorbed and re-radiated back out. This can be repeated several times.
  6. Describe the greenhouse effect as a natural phenomenon that currently helps keep Earth at a comfortable temperature. Describe the effects of human actions in increasing the current greenhouse effect, thereby threatening to change the global climate.

Procedures: Inquiry Mode

  1. Provide materials that will enable each group of participants to develop and illustrate a working model of the greenhouse effect.
  2. Have each group share its model. At the end, encourage constructive critiques of the models to bring out the main concepts.
  3. Combine the best features to illustrate all the essential concepts or do the demonstration mode described above.

Appendix/Further Explorations

  1. Ask a family member or a friend if they have heard about the greenhouse effect and whether it is a good thing or a bad thing. Ask them to explain their answer. If their answer has wrong information, explain what you have learned about the greenhouse effect.
  2. Human actions are increasing the amount of greenhouse gases in the atmosphere. You can learn more about these different gases. Here are some good questions to investigate:
  • What greenhouse gases are increasing as a result of human activities?
  • What human activities cause each gas to increase?
  • What other effects on the environment are caused by those activities?
  • Can those activities be accomplished with reduced environmental effects?

Internet resources that can help you answer these questions include: