What is "Environmental Art"?

Here are some definitions of environmental art:

1. From dictionary.com: "artistic works that are planned, often on a grand scale, to surround or to involve the participation of the spectator" 

2. Google search: 

1. The production of artistic works intended to enhance or become part of an urban or other outdoor environment.
2. The production of works of art by manipulation of the natural landscape.

 3. From greenmuseum.org

• Informs and interprets nature and its processes, or educates us about environmental problems
• Is concerned with environmental forces and materials, creating artworks affected or powered by wind, water, lightning, even earthquakes
• Re-envisions our relationship to nature, proposing new ways for us to co-exist with our environment
• Reclaims and remediates damaged environments, restoring ecosystems in artistic and often aesthetic ways

 My personal definition? 

Any art that either talks about the environment or utilizes the environment in the artwork itself. This also includes art that uses recycled materials.