Ecologically Beneficial Outdoor Art Installation

There's nothing I'd be more interested in. Through my class, I have met some very interesting people with very interesting ideas and ongoing projects. The work done by artist types is often perceived as being flighty and impractical, and the work done by environment-saving types is often perceived as being boring, serious, and too practical. Why not combine both and make something that is not only interesting and beautiful to look at, but also *helps* the environment?