- John Feeney - Himself (Environmental writer)
- Sara Morello - Herself
- Malcolm Potts - Himself (University of California at Berkeley)
- William N. Ryerson - Himself (Population Media Center)
- Peter Sawtell - Himself (Eco-Justice Ministries)
- Laura S. Scott - Herself (author of Two Is Enough)
- Negussie Teffera - Himself (Population Media Center)
- Mathis Wackernagel - Himself (Global Footprint Network)
- Lyuba Zarsky - Herself (Monterey Institute of International Studies)
- Robert Walker - Himself (Population Institute)
-
Christophe Fauchere
- Joyce Johnson
Capítulo disponible en las siguientes plataformas: