I would get everyone to plant a tree, somewhere in the surrounding area. Then, get your school to begin to grow its own food, you can begin a program to have students look after the garden for sustainability and biology courses. Have all the food produced used in school lunches so the school can save money while feeding its children healthy organic food. Also, get your school to recycle a lot more, and even possibly invest in alternative fuel sources. There are so many things your school can do to become more sustainable and lessen its impact on the environment. You can even get people to get together to pick up trash and help fund raise for environmental organizations.