The impact that greenhouse gases have on the earth cannot be understated. Giving your students a hands-on experiment can be a great way to help them understand the impact that pollution has on global temperatures. Share a fun and engaging experiment that will demonstrate the concept of greenhouse gases and the effect they have on earth’s temperatures.
This activity comes from The American Association of Chemistry Teachers.
Grades: 6-8, 9-12
The “greenhouse effect” refers to the phenomena that traps heat within the atmosphere, much like a greenhouse that is designed to keep the interior warm. It is a natural process that warms the earth’s surface. While some of the heat and radiation from the sun is reflected back into space, much of it remains within the atmosphere and is absorbed by greenhouse gases.
Greenhouse gases include water vapor, carbon dioxide, methane, nitrous oxide, and other artificial chemicals. These gases absorb and re-radiate the warmth that comes from the sun. While this is an incredibly important process that helps to keep the surface of the earth warm, we are experiencing a potentially disastrous problem. Increased human activities that depend on the burning of fossil fuels such as coal, oil, and natural gas, are releasing more and more greenhouse gases into the atmosphere every year. And those gases don’t escape into space, they stay in the atmosphere. This is increasing the greenhouse effect and is leading to increasing global temperatures every single year.
The enhanced greenhouse effect is having a disastrous impact on ecosystems and communities around the world. Higher temperatures are leading to melting ice caps, coastal erosion, intense tropical storms, and a myriad of other dangerous side effects.
What You’ll Need
There are two main components to this activity: an experiment and a research project. Most materials are used for the experiment while the computers are necessary for the accompanying research project.
- 1 Tablets/Chromebook
- 3 tablets Alka-Seltzer
- 2 empty, clear 2-liter bottles
- 2 liters of Water
- 2 rubber stoppers with hole in the center that fit 2-liter bottle openings (use modeling clay if these are not available)
- 2 temperature sensors (use thermometers if these are not available)
- Heat lamp or 100 watt spotlight and bulb holder with clamp
What To Do
The American Association of Chemistry Teachers has created an incredibly detailed walkthrough of this simulation with added teacher notes, so I will provide a basic overview of the activity here.
As I said, there are two components of this activity. The main focus of the simulation is the hands-on experiment, but this activity requires a bit of waiting and data collection so an additional research project is included to fill in the time.
Here is the procedure for the experiment outlined by AACT:
- Fill each 2 liter bottle halfway with water, about 1 liter.
- Set-up and connect two temperature sensors for use.
- Push each of the temperature sensors through the center hole in a rubber
- Set up the heat lamp about 2 feet from the bottles, and adjust it so that the
light will shine directly on the bottles. Do not turn it on until the timer is
- Next, place the 3 Alka-Seltzer tablets in one of the bottles. This will be the
bottle with the increased amounts of greenhouse gases. The other bottle is
- Place the stoppers with the temperature sensors in the 2 liter bottles. Turn
on the light. Start the timer.
- Record the initial temperature of each bottle in the data table below.
- Also, plot the points for initial temperature on your double line graph on the
graph paper. The X-axis should be time and Y-axis should be temperature.
Don’t forget to create a key with color coding.
- Record the temperature of each bottle every 5 minutes until there are only 5
minutes left in your class period.
- While the experiment is taking place, use the tablet/Chromebook to complete
the questions and continue to plot the points for the double line graph.
Here are guiding questions that can be answered while groups are gathering data over the course of the activity.
Suggested websites include:
- What gases and percentages of each make up Earth’s atmosphere?
- What does the term “Greenhouse Effect” mean in regard to Earth’s
- What happened to the Alka Seltzer when it was placed in the water? What
type of change (chemical or physical) was it and how can you prove it?
- How have humans contributed to an increase in carbon dioxide levels in the
past 100 years?
- What natural events contribute to an increase in carbon dioxide levels?
- What happens to the air temperature when there is more carbon dioxide
- Describe the data from the experiment you just carried out with the 2-liter
- In your opinion, what should be done by humans to protect Earth’s
Connecting Concepts (NGSS)