02 Greenhouse effect

Experiment: Observe the greenhouse effect in a jar

Create the greenhouse effect in jars using regular air and carbon dioxide.

Observe how the temperature changes when the jars are in the sun.

Time: 50 minutes

Level: Beginner

Materials

carbon dioxide (as from a Soda Stream or CO2 cartridges)
digital temperature sensors,
3 glass jars with lids (no labels or colored glass)
2 small rods (pencils, skewers, etc.)
putty such as “Blu Tack”
sunny window

Specifics and purchasing links are on this spreadsheet Materials list for CCSAE experiments

Science Notes

How does a real greenhouse work? A traditional green house is a clear glass enclosure for plants that require a warmer environment than the outside air. Solar energy comes in through the glass as light (radiation) and is absorbed by the air and materials in the greenhouse. The energy is re-emitted as heat energy, which does not pass through the glass as easily as the light energy came in. As a result, the air inside the greenhouse warms up and provides a warm environment for the plants.

How does that concept relate to the earth? The term "greenhouse effect" is a metaphor used to describe the excess warming of the earth due to the addition of "greenhouse gasses". The earth's atmosphere acts like the glass in a greenhouse, allowing sunlight in to be absorbed by the earth and converted to heat energy. Without the atmosphere and its greenhouse gasses, the earth would not hold heat and would not be able to support life as we know it. The additional carbon dioxide and other greenhouse gasses in the atmosphere are causing more heat to be absorbed in the atmosphere and on earth, and temperatures on earth to rise. This is sometimes called the "enhanced greenhouse effect".

Procedure

Step 1

Make holes in 2 of the jar lids. This can be done easily without a drill by making a small hole withy a pointy screw, then using a phillips head screwdriver or an awl to enlarge to fit the temperature probe.

Step 2

Insert the temperature probes and secure them in place with putty. When the lid is placed on the jar, the end of the probe should be in the middle of the jar, not touching the sides. For the jar without a lid, support and secure the temperature probe with pencils or similar items.

Step 3

Mark the jars with a small label as control, Air and CO2.

Leave the jars in a sunny window for a few minutes to let them get to the same temperature as the windowsill

Step 4

Add carbon dioxide to the jar marked CO2 and fasten the lid (CO2 gas is heavier than air so it will stay in the jar). Adjust the temperature probe so that it is centered in the jar and sealed well with the putty.

Seal the jar marked Air. Adjust the temperature probe so that it is centered in the jar and sealed well with the putty.

Step 5

Place all 3 jars in the sunny window and record the temperatures in each jar.

Take data every 5 minutes for 25 minutes.

Step 6

After the last reading, remove the jars from the sunlight, or block the sunlight.

Take data every 5 minutes for at least 15 minutes.

Step 7

Plot the data and observe. The Line Chart tool in Google Sheets was used for the example.

The data from our experiment is shown in the image.

It shows that:

The Control jar got warmer when in the sunlight and went back to its starting temperature soon after the sunlight was blocked.
The Air jar held a bit of heat after the sunlight was blocked.
The CO2 jar absorbed more heat during the 25 minutes in the sun, and it held more of the heat after the sunlight was blocked.

This experiment was adapted from the experiment shown on this video: Greenhouse Effect (II): Enhanced Greenhouse Effect

https://www.youtube.com/watch?v=EKrpa3eLBgQ

Draw your own conclusion (open this box to see our suggestions)

Suggestions:

Carbon dioxide gets warmer in the sun

The jar with carbon dioxide got warmer and stayed warmer

Identify the physical, chemical or biological mechanism that is happening (open this box after you have an idea)

The mechanism is the greenhouse effect

Greenhouse gasses are gasses in the earth’s atmosphere that absorb heat from the Sun.

High levels are causing more heat to be held in the Earth’s atmosphere.

Relate this mechanism to climate change

Find the arrow (→) in the framework that represents this mechanism (starts at the cause phenomenon and goes to the effect phenomenon). (Use your printed copy of the framework, or open the appropriate framework below. )

Pathway for Rising Sea Level.pdf

Pathway for Extreme and Changing Weather.pdf

Pathway for Changes to Atlantic Ocean Circulation.pdf

Pathway for Harmful Algal Blooms.pdf

Open this box to check your connection

Then go to the Explainer pages to learn more about the Cause and Effect phenomena

Connection 2

Cause: Increasing carbon dioxide in the atmosphere

What is happening: atmosphere is warming through an "enhanced" greenhouse effect.

Effect: Warmer air

The Earth’s atmosphere is holding more heat

We’d love to hear how you used this tool in your community, how the students responded, and your suggestions to improve the experiments and other resources. Contact us at ccsae@mit.edu.