Jeff Bridges as Self / Narrator (voice)

Piers Sellers as Self - NASA Astronaut & Research Scientist

Wesley Clark as Self - General, US Army (ret.); Former NATO Supreme Allied Cmdr.

Oren R. Lyons as Self - Dist Prof of American Studies, Onondaga Council of Chiefs

Timothy Morton as Self - Philosopher & Author, 'Humankind'

Bob Inglis as Self - Former Congressman (R), South Carolina

Rich Pancost as Self - Professor of Biogeochemistry

Ruth Gates as Self - Marine Biologist; Dir. Hawaii Institute of Marine Biology

Renée Lertzman as Self - Author, ‘Environmental Melancholia’

Leonard Mlodinow as Self - Physicist

Bruce Hood as Self - Prof of Developmental Psychology, Univ of Bristol, UK

Mark Plotkin as Self - Ethnobotanist, Amazon Conservation Team

Amy Jacobson as Self - Evolutionary Anthropologist, Human Behavioral Ecologist

Daniel Goleman as Self - Psychologist, Science Journalist, Author

Stephan Lewandowsky as Self - Professor of Cognitive Psychology, University of Bristol

Nate Hagens as Self - Director, Instit. for the Study of Energy & Our Future

Joseph Tainter as Self - Professor of Anthropology, Author

Ugo Bardi as Self - Prof of Physical Chemistry, Univ of Florence, Italy

Paul Roberts as Self - Journalist; Author, 'The Impulse Society'

Ian Robertson as Self - Cognitive Neuroscientist, Trinity College, Univ of Dublin