Earth Science Week Classroom Activities

A Cool Roof

Activity Source:

Geological Society of America. Adapted with permission.

According to the U.S. Energy Information Administration, approximately 79% of the energy used in the United States comes from burning fossil fuels (i.e., coal, petroleum, and natural gas). Because fossil fuels are nonrenewable, it is important that we conserve them, otherwise they will become more expensive, and we might eventually run out of them (

Think about all the things that use energy in your home (air conditioners, heaters, refrigerators, lights, TVs, etc.). Brainstorm simple actions you can take to reduce energy use (conserve energy). During warmer months, keeping buildings cool with air conditioning can use a lot of energy. Let’s explore how simple innovations, such as the color of a building, particularly its roof, might affect air conditioning needs and energy consumption.


  • A bright, sunny day (or a heat lamp)
  • Black construction paper
  • White construction paper
  • Thermometers (2)
  • Clock or timer
  • Graph paper
  • Aluminum foil (optional)



  1. Visit the U.S. Environmental Protection Agency (EPA) website ( and look at Figure 1: Heating and Cooling Degree Days in the Contiguous 48 States, 1895–2020. The red line represents “cooling degree days”, which is a measure of the amount of time that the weather was warm enough to run fans and air conditioners.

a. What pattern do you notice in “cooling degree days” over the last 100 years? Over the last 30 years?

b. What might cause this pattern?

c. What does this pattern suggest about the usage of air conditioning?

d. How can we reduce the need for air conditioning and thus reduce energy consumption?


  1. Fold a piece of black construction paper around one thermometer and white construction paper around another thermometer. Fold the paper so you can slide the thermometer out to read the temperature.

  2. Place these a few feet apart in a sunny area or under a heat lamp (be sure the two setups are about the same distance from the lamp).

  3. Write down the initialtemperature on both thermometers and predict what you think will happen to the temperature on each.

  4. Record the temperatures from each thermometer every 5 minutes, for at least 30 minutes or until the temperature on both thermometers stops changing.

  5. On graph paper, draw a double line graph of temperature vs. time. Be sure to include a title, key, and labels on the x and y axes.


  1. Which color construction paper had the largest increase in temperature? Why do you think this happened?

a. Predict how the results would differ from a thermometer wrapped in aluminum foil.

b. If possible, test your prediction.

2. Many roofs are dark in color. How might changing roofs to a lighter color affect energy costs when it comes to using air conditioning? What about when using heat in colder months?

3. What else might be done to homes to reduce energy usage? What potential problems might be caused by such changes?


For more lessons from GSA, visit ​


SEP :Analyzing and Interpreting Data; Constructing Explanations and Designing Solutions

DCI :ESS2.A: Earth’s Materials and Systems

CCC :Energy and Matter; Cause and Effect


7 : Affordable and Clean Energy

9 : Industry, Innovation, and Infrastructure