I read once about an idea of forcing every school in the US to have a small nature preserve - just some local trees and flowers and wild grasses. This would create habitats all across the nation which would serve to protect wild animals and give humans a chance, as they're growing, to develop a respect for nature.

Ever since then, I can't get the idea out of my head. It seems really nice. Excuse the pun, but this is one place where grassroots movements can have massively outsized effects.