The greenhouse gas effect – what does CO₂ do?

The greenhouse gas effect is caused by gases in the Earth’s atmosphere trapping heat from the sun. Without the Earth’s atmosphere, the planet would be much colder. Carbon dioxide (CO₂) is one of these natural gases – it is part of our air. We exhale CO₂ with every breath we take. In addition to natural sources, CO₂ is produced by all kinds of combustion processes. Car exhaust fumes, for example, consist largely of CO₂. Man-made greenhouse gases are the main cause of climate change. You can investigate the greenhouse gas effect caused by CO₂ with this experiment. Since it is a bit more complicated, have your parents help you.

Before you get started

If you are experimenting at home:
1. Let your parents know and discuss the experiments with them beforehand.
2. Do not eat or drink at your workspace.
3. Wash your hands thoroughly before and after the experiment.
4. Be careful and cautious with the materials.

Graphic figure boy pouring liquid in flask

two Erlenmeyer flasks with digital thermometers under a lamp

You will need

2 identical glass jars with a small opening at the top
2 digital thermometers
Strong adhesive tape ‏(duct tape)
Effervescent tablets ‏(for example, vitamin tablets) or baking soda
Household vinegar
A heat lamp ‏(a desk lamp with a bulb that gives off a lot of heat will also work)
Stopwatch

Let’s get started!

close up of two Erlenmeyer flasks in front of stand

1. Set-up

Attach the digital thermometers to two glass jars (jar 1 and jar 2) using adhesive tape. The tips of the thermometers should be 5 cm above the bottom. Place the jars 5 cm apart. Take 2 effervescent tablets and place them in jar 2. Measure the temperature in the two jars and write it down. The temperature in both jars should be about the same at the beginning. Jar 1 should later represent the atmosphere without additional CO₂ and jar 2 should represent an atmosphere with a high CO₂ concentration.

close up of lamp above two digital thermometer heads

2. Mount the lamp

Place the two glass jars in a place free of drafts directly under a lamp so that the lamp is about 35 cm above the jars. The lamp represents the sun in the experiment. The lamp should have a bulb that gives off a lot of heat, such as those used as heat lamps in terrariums.

close up of Erlenmeyer flask with foaming liquid at bottom

3. Produce CO₂ and measure temperature

Caution: Keep your distance from the hot lamp!
First switch on the lamp and then carefully pour 50 ml of vinegar over the effervescent tablets. Immediately start the stopwatch. Measure the temperature in both glasses after 2, 4, 6, 8 and 10 minutes and write down the values. Compare the temperatures. Were you able to measure a difference? If not, repeat the experiment and change the distance between the lamp and the glasses, for example.