This Earth Day, give your students this report card and have them evaluate how "green" their school / classroom / home is.
There are three different report cards: one for the whole school, one for the classroom, and one for the home. You could either have all students complete both the school and classroom report card, or divide your class into two groups and have one group complete the school card, and one group complete the classroom card. Students could then compare the results to see how their classroom compares to the school. Home report cards could be taken home for students to complete with their parents.