- Fred W. Allendorf
- Ecumenical Patriarch Bartholomew I
- Mary Catherine Bateson
- His Holiness Pope Benedict XVI
- Thomas Berry
- Wendell Berry
- Marcus J. Borg
- J. Baird Callicott
- Courtney S. Campbell
- F. Stuart Chapin III
- Robin Morris Collin
- Michael M. Crow
- Dalai Lama
- Avner de-Shalit
- Alison Hawthorne Deming
- Brian Doyle
- David James Duncan
- Massoumeh Ebtekar
- Jesse M. Fink
- James D. Forbes
- Dave Foreman
- Thomas L. Friedman
- James Garvey
- Norman Habel
- Thich Nhat Hanh
- Paul Hawken
- Bernd Heinrich
- Linda Hogan
- bell hooks
- Dale Jamieson
- Derrick Jensen
- Martin S. Kaplan
- Angayuqaq Oscar Kawagley
- Stephen R. Kellert
- Robin W. Kimmerer
- Barbara Kingsolver
- Shepard Krech III
- Ursula K. Le Guin
- Hank Lentfer
- Carly Lettero
- Oren Lyons
- Wangari Muta Maathai
- Sallie McFague
- Bill McKibben
- Katie McShane
- Curt Meine
- Stephanie Mills
- N. Scott Momaday
- Kathleen Dean Moore
- Hylton Murray-Philipson
- Gary Paul Nabhan
- Seyyed Hossein Nasr
- Michael P. Nelson
- Nel Noddings
- Barack Obama
- David Orr
- Ernest Partridge
- Pope John Paul II
- John Perry
- Rolf O. Peterson
- Edwin P. Pister
- Carl Pope
- Robert Michael Pyle
- David Quammen
- Daniel Quinn
- Kate Rawles
- Tri Robinson
- Libby Roderick
- Holmes Rolston III
- Deborah Bird Rose
- Jonathan F.P. Rose
- Rosmarin
- Carl Safina
- Scott Russell Sanders
- Lauret Savoy
- Nirmal Selvamony
- Ismail Serageldin
- Peter Singer
- Sulak Sivaraksa
- Fred Small
- Gary Snyder
- James Gustave Speth
- Alana Summers
- Brian Swimme
- Bron Taylor
- Paul B. Thompson
- George Tinker
- Joerg Chet Tremmel
- Quincy Troupe
- Mary Evelyn Tucker
- Jose Galizia Tundisi
- Beth Turner
- Brian Turner
- Kaylynn Sullivan TwoTrees
- Steve Vanderheiden
- John A. Vucetich
- Kimberly A. Wade-Benzoni
- Sheila Watt-Cloutier
- Xin Wei
- Alan Weisman
- Terry Tempest Williams
- Jack E. Williams and Cindy Deacon Williams
- E. O. Wilson
- Ming Xu