The atmospheric greenhouse effect

We invite you to watch a brief video demonstration of the developer conducting the experiment you’ll be facilitating with your students.

Create or have a set of students create an experimental structure for holding the plastic "atmosphere" layers using popsicle sticks like in the photo or other materials you may have like the activity developers used.

1. Glue 4 popsicle sticks together into a square
2. Glue 4 popsicle sticks as legs
3. Glue another 4 popsicle sticks into a square for base of structure

Set up 4 stations as follows:

1. Stations 1 and 2 include links to simulations and/or videos; if students are using physical worksheets, we recommend either setting up a computer with the simulation/video already pulled up at these stations or sharing those resources in an announcement to the class so they can access them easily on their own devices.
2. Station 3: Infrared thermometer, popsicle stick tower, and plastic films. Teachers will be directly facilitating Station 3.
3. Station 4: Independent research station. If students do not have their own devices such as Chromebooks, set up a computer that students can use to research information on the planets.

Make a connection between what students learned in Activity 1 about types of light and infrared radiation. Describe IR radiation as heat or thermal radiation. Remind students this is what surfaces (in this case the hand) emit into the atmosphere.

Demonstrate how to properly use the infrared thermometer, showing how to point it (distance from the object), read values, and understand emissivity differences between different materials.

a. Remind students that the thermometer measures surface infrared radiation, not air temperature.

b. Remind students of safety when using the infrared thermometer.

Place a hand at the bottom of the popsicle structure, against the table, with their palm facing up.

Hold the thermometer just above the structure.

Take a temperature reading of their hand without any films in place.

Place the first (0.002 inch) thickness of plastic sheeting onto the popsicle stick structure. Make sure they handle the films with the edges only.

Check that each layer is smooth and laying evenly. This part of the experiment simulates the atmospheric “optical thickness”.

Hold the thermometer just above the plastic sheeting and take a measurement of the heat emitted from the hand through the sheeting.

Make sure the student’s hand is kept the same distance from the sheeting and the thermometer each time.

Record in the table below (also found in the student guide).

Repeat for each plastic thickness.

If time allows, students may want to experiment with layering multiple films at once to get new thicknesses.

If time allows, different students can try measuring temperature with different hands.

Have students describe their observations in terms of atmospheric thickness, and relate that back to the greenhouse effect.

Students will chart their data on the following graph as part of the discussion & conclusion section after the class comes back together.

Have students graph their data from Station 3 using the chart provided.

Guide students to identify patterns. They should expect that more layers correspond to lower measured temperatures that eventually approach the room temperature, meaning less heat emitted from the palm can reach the thermometer.

Have students connect their data from Station 3 to the information they gathered about Mars, Venus, and Earth in Station 4, and match each layer from Station 3 with a planet in Station 4.

Help students define optical thickness based on their evidence, which is the idea that a thicker atmosphere absorbs and re-emits more infrared radiation to prevent heat from escaping efficiently.

Host a discussion on the definition of greenhouse effect. Have students connect the ideas of optical thickness with the greenhouse effect.

Have students connect greenhouse gases to the Molecules and Light simulation. They should observe that some molecules (greenhouse gases) allow visible light to pass through, but interact with/scatter infrared light.

Encourage students to come up with final conclusions supported by their data.

Help students brainstorm: What careers might involve studying how energy moves through the atmosphere or analyzing climate data, and what skills from this activity would be useful in those jobs?