Chicago is a city that is now creatively keeping cooler in the face of global climate change and the urban island effect. The energy costs associated with cooling buildings have been on the rise as the city sees more and more 100-degree days. Residents who are more accustomed to snow than rain find themselves suffering the ill effects of living in overheated homes that never needed air conditioning in the past, and residents are filling emergency cooling centers like never before during the hottest days of the summer. Streets and alleys that are deluged with more rainwater than ever face flooding and erosion, as there has been nowhere for the runoff to go, until the city got smarter about staying cool.
Students will review information about the action being taken in Chicago to both mitigate the impact of rising temperatures in the city and find solutions that could benefit the environment. Priorities include lower emissions and less pollution due to runoff (rainwater), as well as the secondary benefits to the community like beautification. This environmentally friendly approach includes green roofs as well as “greener” streets and alleys.
Use the worksheet included in this lesson plan to pre-test students on related vocabulary. Student can complete the sheet individually or in a small group at the start of class or as a homework assignment. Students may also elect to draw answers to describe certain terms, such evaporation (a stage in the water cycle).
Possible responses include:
Climate change: A significant change, over an extended period of time, in the measures of climate. Changes in temperature, precipitation, or wind patterns are all examples.
Evaporation: The process by which water turns into a gas or vapor, from a liquid state. Evaporation can have a cooling effect. (Image of the water cycle can be found at: http://ga.water.usgs.gov/edu/watercycleevaporation.html)
Green roofs: A system in which plant life and/or a growing medium covers at least part of a roof so the building will be insulated, rainwater will be absorbed, the air temperature will be lowered, and the heat island effect will be mitigated (made milder).
“LEED certified”: Designed with energy efficiency in mind.
Permeable pavement: Pavement designed so that rainwater can pass through the pavement into the ground underneath, where it can naturally evaporate.
Permeable pavers: Pavers, or “bricks” arranged so that rainwater will pass through them, keeping alleys and streets cooler, since the water beneath will evaporate and cool the surface above it.
Rain garden: A small garden designed through landscaping to absorb runoff from rainwater in the soil beneath it, providing protection from flooding and drainage issues, an opportunity for the water to be filtrated, and a habitat for local wildlife.
Reflective pavement: Pavement that has been treated so that heat will not be absorbed and trapped, but will essentially bounce off the street, reducing the surface temperature of the roads.
Urban Heat Island Effect: When heat-retaining structures and the overall temperatures rise in a city at a rate higher than that of nearby rural areas, which have more open land, permeable surfaces, and green space. This can result in an increase in emissions of air pollutants, an increase energy consumption, and compromised health for residents.
Thermal radar: A device used to measure the surface temperature of roads, rooftops, and other areas that become much warmer as the overall temperature increases, even from a distance.
Review the vocabulary list with the larger group. What terms did the students already understand? What are some terms that will require further research and clarification? The pre-test is not to be graded, but to be used as a tool for focusing on the new information that will be presented. Students will later take notes on these topics after reviewing a variety of media.
Share the infographic with the class, either online or in a printed version (about 6 pages long), and have the students look for facts related to the terms they have just reviewed. Ask students to make a note of at least 10 facts from the image, and label those facts as (I) for an interesting fact, (H) for something hard to believe or surprising, (K) for facts they knew already, or (L) for what you’d like to learn more about.
Chicago has enough green roofs to cover about 95 football fields. (I)
Building with green roofs can save about $3,600 in energy costs. (H)
The downtown area is hotter than other parts of the city. (K)
If emissions are lowered over the next decade or two, there will be fewer very hot days in Chicago. (L)
Once students have used the infographic to take notes on the topic, share other forms of media* that have related details with the class. The full report, including a video (running time 10 minutes, 31 seconds) is available online. Students can also gather additional information on green roof from the photo gallery-Coping With Climate Change: Green Roofs of Chicago.
*Students with different learning styles may be drawn to different types of media, including photography, video, print or the infographic. If possible, consider grouping students with different approaches to learning in teams of about 4 to gather more facts about the issue.
Remind students to continue to take notes on details they have learned and/or ideas that are reinforced, in each component of the presentation. A goal of 20-25 facts is realistic for high school students. Remind students that the information may overlap in different parts of the report, but two experts may have a different perspective on the same topic, so it is worthwhile to listen to both points of view.
Ask students to take a position on green roofs and/or permeable pavement from the perspective of each of the following community members, and list several benefits, in writing. (This can also be completed for homework, or assigned to classmates working in small groups.)
- An older citizen with asthma, living in an apartment building who uses fans to cool the home on hot summer nights.
- An entrepreneur who is renovating a 20-story building. The lower floors will house offices and shops, and the higher floors will have luxury condominiums. This building hopes to rent out all of his space at high prices, and to turn a profit as quickly as possible.
- An accountant working for the city government, budgeting for the operating expenses in city hall. Taxpayers have been complaining that they are tired of high utility bills in their homes, and wonder why the city is “wasting” so much money cooling older buildings downtown, compared to previous years.
- An entomologist (person who studies insects) concerned that with the changes in climate around Chicago, certain rare species of insects will die out. The entomologist hopes for more hospitable environments for all wildlife, but mostly insects, in the downtown area, because the ecosystem is at risk.
- A community organizer planned to arrange a 3-day walk to benefit those who have a terminal illness this August, just before Labor Day. Detractors say that the heat from the streets downtown could make the walkers sick, and more medical tents will be needed for the volunteers who will be exposed to 100-degree temperatures due to the urban island effect, especially at the end of the day.
- A landscaper’s son is inheriting the family business. While he appreciates the work his parents have put into mowing lawns and trimming trees in the suburbs, using gas-powered mowers, he’s interested in using what he knows about vegetation to prevent flooding, create cooler communities, and beautify urban landscapes. Consider how his skills and interest in the environment could be utilized in a city like Chicago.
Scour your community for an appropriate site on which one could build a rain garden. Ideal locations are at least 10 feet from a house, on relatively flat land, away from areas where water tends to pond, and where there is full or partial sun. The slope should be less than 12% before consulting a professional for assistance, like a landscape architect. With the help of members of your community, design and/or build a rain garden, ideally using recycled materials.
For guidance on how to design your own, download a free manual such as the one provided at:
The District Department of the Environment, called Rain Gardens, A How-to Manual for Homeowners.