Name:__________________________________________ Date:________ Period:____
Greenhouse Effect Simulation
Score: ____/ 15 pts
http://phet.colorado.edu/en/simulation/greenhouse
EQ: What is the greenhouse effect? Is it good or bad for the Earth?
Objective: To describe how the “greenhouse effect” affects temperature on the Earth and to use evidence to
support whether the “greenhouse effect” is good or bad for Earth.
Introduction: Global warming is perhaps the “hottest” topic in today’s headlines. The cause of warming is
usually blamed on the “greenhouse effect” or “greenhouse gases.” The following simulation will allow you to first
examine how the “greenhouse effect” works in a greenhouse. You will then experiment with a simulation of the
Earth’s atmosphere where the concentration of greenhouse gases can be varied. Finally, you will use the results of
the two simulations to describe how the “greenhouse effect” is good or bad for the Earth.
Directions: Steps in bold require a written response. A double asterisk is placed in front of any questions
requiring an answer in the form of a complete sentence.
Before diving into the whole issue of global warming, try to picture sitting in an enclosed car on a cold but sunny
day . . . pretty comfortable, isn’t it? Now try to imagine sitting in that same car on a hot, sunny day. Don’t hold
that image for too long. You’ll fry just thinking about it.
1. **Hypothesize why the inside of a car feels so much warmer than it surroundings on sunny days.
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2. Go to www.google.com Search for “phet greenhouse effect”. Click the first link. Click the neon green
“run now” box. A warning box will pop up in the bottom left of your browser, click “Keep.” Then click on
the drop down menu under the triangle and select “Open.”
Part I: A Greenhouse Simulation
3. Select the “Glass Layers” tab. Then look at the Legend in the top right corner.
4. What do the yellow stars represent? _____________________________
5. What do the red stars represent?
_____________________________
6. Both yellow and red stars represent forms of energy in the form of photons: the yellow are visible light, the
red are heat (infrared light).
7. Record the approximate temperature before adding glass panes. Temp = __________
8. Add one glass pane
9. **What do the sunlight photons do when they hit the glass from the top? _______________________
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10. **What do the infrared photons do when they hit the glass from the bottom? Be specific. ________
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11. What is the new temperature inside the greenhouse? Temp = _____
12. What happens to the temperature as additional glass panes are added? ________________________
13. ** Before proceeding to the “greenhouse effect” tab, predict how a greenhouse with glass panes
trapping heat is similar or different than our atmosphere. .
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14. Select the “Greenhouse Effect” tab.
15. Look on the right side where it says “Greenhouse Gas Composition” These are the gases that have a
greenhouse effect.
16. Look at the “atmosphere during” box on the right. Make sure “today” is selected.
17. Write the names of these gases here: (not the numbers) 1. ______ 2. ______ 3. ______ 4._______
18. The thermometer represents an average global temperature.
19. What is the average global temperature for the “today” simulation? Temp = ________
20. Is the behavior of photons more similar to the greenhouse with or without glass panes?
_________
21. In the “atmosphere during” box, select “adjustable concentration. ”Reduce the greenhouse gases to “None”.
22. Now, is the behavior of photons more similar to the greenhouse with or without glass panes? ______
23. What is the average global temperature with no greenhouse gas? Temp = _______
24. Increase the greenhouse gas concentration to “Lots”.
25. What is the average global temperature with lots of greenhouse gas? Temp = _____
26. **Consider the behavior of the photons, why does the temperature increase with more greenhouse
gas? _________________________________________________________________________________
27. Experiment with other periods in earth’s history or add clouds. Record at least two observations below.
a. _____________________________________________________________________
b. _____________________________________________________________________
Part II THIS IS THE MOST IMPORTANT PART OF THE LAB
Write at least two complete sentences for each of the following questions.
1. How does the “greenhouse effect” affect the temperature of the earth?
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2. How is the “greenhouse effect” similar to blankets on a bed?
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3. Is the “greenhouse effect” good or bad for the earth? Explain why.
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