Onder andere met: Leonardo DiCaprio (Narrator), Kenny Ausubel (Himself), Thom Hartmann (Himself), Wangari Maathai (Herself), Sandra Postel (Herself), Paul Stamets (Himself), David Orr (Himself), Stephen Hawking (Himself), Oren Lyons (Himself), Andrew C. Revkin (Himself (as Andy Revkin)), Sylvia Earle Ph.D. (Herself (as Sylvia Earle)), Paul Hawken (Himself), Janine Benyus (Herself), Stuart Pimm (Himself), Paolo Soleri (Himself)