When I was in college, I did a series of lessons called “the pollution solution” with a 2nd grade class. We did science projects, read books, and wrote about the pollution of water, land and air. For the last lesson, I drew the human body. I pointed to the lungs and asked if the earth were a body, what would the lungs represent? They knew it was the air. We revisited health lessons and talked about how smoking is bad for our lungs and it made sense that pollution in the air is bad for the earth. Next I pointed to the blood vessels.