Ahmed Hassan

Celebrity Landscaper & TV Host of DIY's Yard Crashers, Blog Cabin, Turf War

Alexis Ohanian

Co-Founder of Initialized Capital & Co-Founder of Reddit; Entrepreneur, Investor, Activist & Bestselling Author

Alexis Ohanian Carthage College Commencement Address 2014

Amber Jenkins

Applied Science Engineer, NASA’s Jet Propulsion Laboratory; Editor, NASA Climate Change Website

Amory Lovins

Co-Founder & Chairman Emeritus of Rocky Mountain Institute

Ashley Judd

Actress, Activist & Humanitarian

Bill Kurtis

TV Journalist, Producer, Narrator and News Anchor; Host of A&E's "Investigative Reports," "American Justice" and "Cold Case Files"

Bill Nye

"The Science Guy"; Science Communicator, TV Presenter & Mechanical Engineer; Climate Change Activist

Blythe Danner

Emmy Award-Winning Actress & Activist

Bunker Roy

Founder of Barefoot College

Caroline Casey

Founder of Kanchi & The Ability Awards

Dan Barber

Multi-Award-Winning Chef, Agronomist, Environmentalist, Author & Co-Owner of New York's Blue Hill Restaurant

Dan Barber - From Seed to Table - Aspen Ideas: Health 2023

Daniel Kraft, M.D.

Physician-Scientist; Founder of Exponential Medicine; Chair for Medicine & Neuroscience at Singularity University

Darcy Winslow

Former Nike Global Sustainability Guru and Managing Partner at The Academy for Systemic Change

Dean Kamen

Founder of FIRST; President of DEKA Research & Development Corporation

Dennis Avery

Former Director, Center for Global Food Issues at the Hudson Institute

Dr. Michio Kaku

World-Renowned Futurist & Theoretical Physicist

Ed Rendell

Former Governor of Pennsylvania; NBC News Political Analyst & Author

Gary Snyder

Poet, Essayist, Lecturer and Environmental Activist

Geoffrey West

Theoretical Physicist, Distinguished Professor & Past President of Santa Fe Institute

Ian Somerhalder

Actor Known for "The Vampire Diaries"; Animal & Environmental Advocate; Founder of The Ian Somerhalder Foundation

James E. Hansen

Adjunct Professor Directing the Program on Climate Science, Awareness and Solutions of the Earth Institute at Columbia University; Former Director at NASA Goddard Institute for Space Studies

Jason Clay

Senior Vice President of Food & Markets at WWF

Jody Williams

Humanitarian and Nobel Peace Prize Winner and Chairman of the International Campaign to Ban Landmines

John Ratzenberger

Emmy-Nominated Actor, Entrepreneur & Philanthropist

Lamman Rucker

Actor, Education Activist, Green Living Advocate & Entrepreneur

Lisa Gansky

Corporate Advisor, Marketing Expert & Author of "The Mesh: Why the Future of Business Is Sharing"

Lisa Ling

Award-Winning Journalist & Producer for CBS News

Louie Schwartzberg

Award-Winning Cinematographer, Director, Photographer and Filmmaker

Marc Abrahams

Creator of the Ig Nobel Prizes

Mark Lynas

Environmental Writer; Author of "Our Final Warning: Six Degrees of Climate Emergency"