The Greenhouse Effect - A Model

Procedure

1. Add dark colored sand or soil to the bottom of a clear plastic or glass container to a depth of about 2-3 cm

2. Using a spray bottle, dampen the surface of the soil

3. Use a piece of cardboard as a support to place a thermometer in the container, bulb end up. Make sure that the thermometer is positioned so that the scale can be seen.

4. Mount a lamp about 20-30 cm directly above the container so that the light shines on the thermometer

5. Turn the lamp off and allow the thermometer to return to room temperature

6. With the lid on the container, turn the lamp on and record the temperature every minute for 20 minutes.

7. Turn the lamp off and allow the thermometer to return to room temperature. Spray the soil again with water and repeat step 6.

8. Graph the data by plotting the temperature versus time.

9. Repeat the experiment using light colored soil or sand.

Questions

1. Explain why the temperature increased?

2. How can this activity be compared to the greenhouse effect on Earth?

3. What was the effect of spraying extra water in step 7 of the experiment?

4. What is the relationship between step 7 of the experiment and increased cloud cover on the Earth.

5. Was there any difference between dark and light soil? Explain.

6. What effect would a rise in average global temperature have on coastlines? This effect would result from two separate factors. Explain both.