P R O J E CT G U T S
CL I M AT E C H AN G E U NI T
Climate Change in a Bottle
Experiment adapted from the Teaching Channel Series, “Climate Change in a Bottle”.
https://www.teachingchannel.org/videos/climate-change-lesson-1
Background
Our atmosphere works like a greenhouse, keeping our planet warm by keeping
heat from escaping into the atmosphere. This heat is generated from the sun’s
energy; 30% of that energy bounces back into space but 70% is absorbed and
converted into heat. This heat is also known as infra-red radiation. Some of the
gases that make up our atmosphere can intercept the heat and trap it, which is
how our planet gets warmer. This is called the greenhouse effect and it’s
necessary for life on our planet. However, by pumping more of these gases into
the atmosphere, like Carbon Dioxide, the planet starts warming up and the
climate changes. This global warming could cause coastal flooding, increased
storms, and force us to change the way we live.
The Experiment: Introduction
In this experiment we will find out how temperature is influenced by increased
carbon dioxide (CO2). All of the bottles will be closed and a thermometer
introduced to the inside. The sun’s energy will be represented by light from the
lamp. We will simulate climate change in closed bottles and find out whether
increasing CO2 will increase the temperature in our bottles.
To this end the students will set up an experiment comparing the temperature
between a bottle with Carbon Dioxide added to it and a control bottle (with just
normal air).
Introduce global warming to the students. Ask them how they might design an
experiment to show global warming using two bottles. After this, explain the
experiment you will be running. Discuss what you might expect to happen.
Explain the importance of having a control bottle; the control gives us something
to compare our CO2 bottle to. Have the students come up with a hypothesis
and a prediction and write these down on their worksheets. For example, in this
experiment:
Hypothesis: increasing CO2 in the atmosphere will cause temperatures to rise.
Prediction: the bottle with CO2 added will have a higher temperature than the
control bottle once the experiment is finished.
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CLIMATE CHANGE UNIT
The Experiment: Materials
In order to simulate climate change in the lab, you will need a few different
ingredients per experiment:
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Two small plastic bottles (about half a liter), empty, label removed,
identical
Marker to label the bottles
Black tape
Two thermometers
Vinegar
Baking soda
One glass bottle (small)
One large and one small funnel
One balloon for CO2
Data sheets
Timer (for whole group)
One lamp between the bottles or two lamps (one by each bottle)
Optional: scissors and soil and duct tape
The Experiment: Set-Up
1. Take two plastic bottles – make sure they have caps!
2. Check to make sure they are dry inside – water will absorb CO2 and change
our results!
3. Label one bottle A (air) and the other C (CO2).
4. Take the cooking thermometer and pierce the side of the bottle, close to the
top.
5. Insert the cooking thermometer through the small hole until it is stable. Make
sure you can see the temperature reading. Also, make sure the end of the
thermometer is in air – NOT touching the bottom or side of the bottle.
6. Put tape around the bottle and the opening where the thermometer goes
into the bottle. Try to seal the opening as much as you can to avoid CO2
leaking out later.
7. Take the glass bottle and pour 50 ml of vinegar in it through the big funnel.
Take a balloon and pour 1 teaspoon of baking soda in it through the small
funnel. Carefully place the balloon over the mouth of the plastic bottle so
that it is air-tight and the baking soda falls into the bottle. The baking soda
will react with the vinegar, producing CO2, which will fill the balloon. Shake
the bottle a bit more to get all the CO2 you can.
8. When the balloon is full, take it off the bottle top and pinch it shut.
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CLIMATE CHANGE UNIT
The Experiment: Set-Up (cont’d)
7. Quickly transfer the balloon to the plastic
bottle you’ve decided will contain extra
CO2, and squeeze gently so that the gas
transfers to the soda bottle. The CO2 will
sink to the bottom of the bottle and push
out ordinary air. Remove the balloon and
put the bottle cap back on so that the
gas is trapped inside!
8. Place the lamp in front of the two bottles,
making sure it is at the same distance
between each bottle.
Running the Experiment
1. Run one experiment together. Give each student a task from the set-up and
running experiment sections so they each have a role to do in both.
2. Designated students should take the experimental material and set it all up
according to the instructions.
3. Students set to measure temperature and those set to record temperature
should take their places.
4. Turn on the thermometers and let them stabilize. Set them to Celsius. They
should show temperatures that are roughly the same. If they don’t, give them
more time and if they are still different, write down what the difference is.
5. Wait until the timer is ready, and everyone countdown from 10.
6. Turn on the lamp! At the first minute, the teacher will ring a bell, and everyone
will take the first measurement.
7. Take measurements every minute for fifteen minutes – try to be as accurate
as possible.
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CLIMATE CHANGE UNIT
Results
1. Have the students analyze their results. They can graph the two bottles
temperature changes on the graph paper at the back of their worksheets.
Ask them what they think the results mean. Is the slope different between the
two bottles? Were the final temperatures different?
2. If the temperature change occurred, explain to them that even if it was just a
small change, it can have a huge impact on our planet. Each degree of
warming could result in a sea level increase of about 5 feet!
3. If no temperature change occurred, have the students think about what that
means. Did something go wrong with the experiment? How could they
increase their confidence in their results? Introduce the concept of replicates
– repeating the experiment many times helps scientists trust their results. Other
factors that might affect the results could be the thermometers not being
well-matched or not functioning properly, the lamp being closer to one bottle
than another, human error, etc.
4. Brainstorm about what other similar experiments the students could run, for
example, by incorporating plants - plants absorb CO2.
5. How would they model this experiment in StarLogo TNG? Brainstorm with the
students.
Tips
1. In order to read the thermometer, the lamp needs to be partially elevated
(for example, on a pair of text books) so that the light does not shine up into
the eyes of the person recording temperatures.
2. Excess water in the bottles will absorb CO2 and affect the result. Try to dry the
bottles thoroughly, or if they have water, make sure they have the same
amount. Try to keep the bottles identical to each other EXCEPT for the CO2.
3. If you have larger bottles, fill up a balloon with CO2 twice to allow for the
greater volume.
4. For the generation of CO2 you can use a glass flask from your science labs if
you have one available.
5. If you want to run additional experiments or to modify this one, for example
by adding soil to the bottles, you can pour soil into both bottles using the
larger funnel. If you want to add plants, you will need to cut off the top fourth
of the bottle, use a larger bottle, and tape it shut before proceeding with the
rest of the experiment.