Greenhouse effect

The title of the Project: Greenhouse effect

This virtual laboratory is intended for use in chemistry classes on the following topics:

  • 11th grade. Chapter XIV. Green chemistry.

Purpose of the virtual laboratory work:

  • To study the effect of greenhouse gases on the temperature of the Earth’s surface.
  • To demonstrate how the greenhouse effect leads to global warming.
  • To raise awareness of the potential impacts of climate change.

Practical part

  1. Run the simulation. There are three modes available to you: “Waves”, “Photons” and “Layer Model”. Select the “Layer Model” mode. Click the “Start Sunlight” button to start the experiment.

  1. You will see the surface of the Earth and a continuous stream of red and yellow photons. Yellow photons are emitted by the sun, and red photons are infrared photons that the Earth’s surface emits in response to solar radiation. You can increase the number of photons and also slow down their speed.

  1. There is a surface thermometer on the left. Click on the arrow to change the temperature unit: degrees Celsius (°C), degrees Fahrenheit (°F) or Kelvin (K). You can also display or remove the thermometer from the screen.

  1. Display the Energy balance indicator and photon Flux meter on the screen by checking the boxes. The color of the arrows corresponds to the colors of the photons. You can move the meter from top to bottom to measure the photon flux near the earth’s surface or atmosphere.

  1. In the Sunlight section on the right side of the screen, you can adjust the following parameters:
  • Solar intensity: This determines the strength of the sunlight reaching the surface.
  • Surface albedo: This determines how much of the sunlight the surface reflects. The higher the albedo, the more light is reflected.

  1. In the Infrared section, you can add layers that absorb infrared radiation to the atmosphere and adjust their amount, along with the intensity of absorption (Infrared absorption).

Virtual experiment

  1. Click the Reset button and restart the simulation. Set the albedo to 0.3 to approximate Earth’s current average albedo.  Click on Flux Meter.  

8. Drag the flux meter to just above the surface.  Click on Start Sunlight, and let the sim run until the surface temperature stabilizes.  The Earth absorbs the sunlight photons (yellow) and then radiates infrared photons (red). 

9.  From the Flux Meter, record the units of both incoming and outgoing sunlight radiation in the table below.  Do the same for the infrared radiation.  Then, calculate the total incoming and outgoing radiation. 

10. Add one absorbing layer, and make sure the flux meter is below the absorbing layer.  Let the simulation run until the surface temperature stabilizes and record the data in the table below.  

    • How do the sunlight photons interact with the absorbing layer?
    • How do the infrared photons interact with the absorbing layer?

    1. Add another layer and record the data.  You can zoom out/in the Flux meter in some cases to have a better look. Finally, add a third layer and record the data.

    Table 1.

    # of LayersSunlight InInfrared InTotal InSunlight OutInfrared OutTotal OutSurface T
    0404134-18°C
    1
    2
    3       
    1. How did the surface temperature change as you added absorbing layers?  Explain why this happens.

    Conclusion

    By running the simulation, you observed that adding layers that absorb infrared radiation (heat) increased the Earth’s surface temperature. This mimics the real-world greenhouse effect, where greenhouse gases trap heat, leading to global warming. The more greenhouse gases in the atmosphere, the warmer the planet gets.