Changes in environment can be natural or influenced by humans. Some changes are good, some are bad, and some are neither good nor bad. Pollution is a change in the environment that can influence the health, survival, or activities of organisms, including humans.

Trees, especially large deciduous shade trees, provide cooling shade during the warmer months of the year. Shade trees cool homes, office buildings, sidewalks, parking lots and many other urban and rural locations. We all understand how much cooler we feel sitting under a tree versus the hot sun on the sidewalk; however, just how much that tree can cool the air is a surprise to many of us. The temperature under a medium-sized tree is at least 3 to 4 percent cooler than the air around or above the tree. In fact, well-placed trees can reduce the need for air conditioning in a home or building by as much as 30 percent. This reduced need for artificial cooling produces a domino effect: reduced need for air conditioning -- less energy needed to run the air conditioner -- less fossil fuels needed (oil, coal) to fuel the air conditioner -- less pollutants created by the burning and mining of these fuels.

Awareness of the need to find a balance between urban development and a healthy urban ecosystem is important to our well being. The creation of heat islands can be a danger to our physical, psychological and economical health. A heat island is a term that refers to mostly urban areas with few trees and green areas. A large percent of the earth is covered in cement and asphalt. Trees and greenery can drastically reduce summer temperatures and minimize the "heat island effect."

Trees can also save us energy and money in the winter. Trees and shrubs planted near a home, school or office building can help block the cold winter winds and create a buffer around a building. This can reduce heating needs and related costs.


To have the students understand the many energy saving benefits of trees and how that relates to reducing air pollution.

You’ll need:

  • Copies of energy /pollution cycle charts (click here)
  • Magazine pictures, photos or student drawings of examples of tree growth and/or tree placement in your community or other communities that help save energy
  • Scissors, glue, tape, poster boards
Have students discuss whether they can identify heat islands in their community and what improvements can be made to solve the problem. They should be encouraged to look at their own backyard and note where trees are planted. Energy cycle mobiles or collages can be created. For students prek-1st grade, the energy cycle charts can be enlarged and cut apart, then pasted on separate poster board or paper (81/2 x 11). One student holds a happy face and a sad face. The other students march around forming the energy circle. The student with the faces decides whether the elements that compose the circle will make him/her happy or sad. Students take turns being the faces.

Use the
Treeture, Steward, as a possible guide, icon or symbol to help animate and enhance your lesson. His rap songs can be used in a class performance. The students can try to write their own "rap" about street trees and the animals that live in street trees. What do they see as they try to exist as part of the busy life in a town or city? See the Treeture, Professor Arbor E. Tum, for more about urban trees.

*The Treeture characters, as learning tools, can be adapted to any grade level. For example, students in grades K-1 could utilize coloring pages, finger puppets and collages. Stories, poems, creation of new Treetures characters, newsletters and plays could be fun and used as mentoring projects by the 5th and 6th graders for younger students. Another entertaining educational activity is to hold a Treeture Fair. This project has been successfully implemented in many schools. Each Treeture character can be enlarged and placed on an easel on a table with an appropriate experiment or example of its tree role.

  • Large trees can transpire around 30 gallons of water a day, helping to cool the air. You can observe how water moves through a leaf by picking a deciduous leaf and stem. Place it in a small amount of water with red food coloring. Watch as the red dye moves up the leaf. Leaves contain thousands of tubes to move water and food.
  • Research the effects on our environment of using fossil fuels such as oil and coal to power our heaters and air conditioners. What are the benefits of renewable energy?
  • Take action! Go on a field trip into your school campus/yard. Take a written inventory, draw a map, or even take photos of all the green plants/space around the school. Discuss with students the wealth or lack of trees, shrubs, etc. Where are the best places to plant trees and other greenery? Draw up a plan to present to school administrators for possible funding. Also contact NTT for a Community Tree Planting grant (1-800-846-8733.)
Totally True Treeture Trivia:
  • A single 70-foot shade tree cools as much as a three-ton air conditioner. (Living in the Environment, G. Tyler Miller, Jr., 1998.)
  • The shade of a tree can make the area under the leaves 3 to 4 degrees cooler than air above the tree. (USA Today \, June 7, 1999. Kevin V. Johnson.)
  • Energy use can be reduced 30-50 percent by painting building surfaces with light or reflective colors. (Growing Greener Cities Education Guide, American Forest, 1992.)
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