World Environment Day is in June, and this year’s theme is “Connecting People to Nature.” The goal is to encourage us to get outdoors and into nature, to appreciate its beauty and importance and to inspire others to protect the Earth that we share. For World Environment Day, take students outside to explore trees - Earth’s natural air filters - and learn how to identify trees by their bark.



  1. To get started, talk about the various ways trees impact the environment and what students can do to protect and save trees in their local community (see “Lesson” below).
  2. Take students on a field trip to the local park to explore trees.
  3. Once they’ve found a tree, have students lay a white sheet of paper against the bark and rub the entire area of paper using the crayon or chalk. Remind students to press firmly in order to get the pattern of the bark on the paper.
  4. Once finished, have students compare the different bark patterns. If available, let them use field guides to identify the trees they’ve rubbed.


Trees provide a variety of benefits for the environment, including clean water, air temperature control and wildlife habitat. However, their main benefit is clean air. Trees absorb carbon dioxide and other potentially harmful gases from the air, trap particulates on their leaves and bark and release oxygen. How much oxygen? One large tree can supply a day’s supply of oxygen for four people. In fact, a 2013 study found that trees save an average of one life every year per city by filtering fine particulates out of the air.

There were three trillion trees on Earth in 2015, but humans remove 15 billion and only plant 1.6 billion trees a year. Check out seven ways kids can save trees and, as a result, help protect the environment.

This activity was adapted from Summer Program Tips, Strategies & Activities for School-Agers 5-14 Years-Old.