Summer's still in full swing, but only about a month left and it's back to school time for some people. An even smaller group will be deciding on which colleges and universities should they attend--and in some cases, the school's carbon footprint and environmental education programs may be a deciding factor. Dorm Scout has a list of the top 20 greenest venues for higher education in the world, including EARTH University, which may set off green lights for people who make the environment their number one concern. It probably won't be their only one, though, considering that the school is in Costa Rica. Location might have something to do with wanting to go there, don't you think?