جيف بريدجز

Self - Narrator (voice)

Piers Sellers

Self - NASA Astronaut & Research Scientist

Wesley Clark

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

Oren R. Lyons

Self - Dist Prof of American Studies, Onondaga Council of Chiefs

تيموثي مورتون

Self - Philosopher & Author, 'Humankind'

Bob Inglis

Self - Former Congressman (R), South Carolina

Rich Pancost

Self - Professor of Biogeochemistry

Ruth Gates

Self - Marine Biologist; Dir. Hawaii Institute of Marine Biology