Andrew Hoffman

Holcim (US) Professor of Sustainable Enterprise at the University of Michigan

Michael Shellenberger

Founder & President of Environmental Progress; Expert on Energy, Climate, Security, Human Development and Politics

Ric O'Barry

Wildlife Activist, Author & Founder of the Dolphin Project; Star of the Academy Award-Winning Documentary "The Cove"

Calum Worthy

Canadian Actor & Environmental Activist

Bindi Irwin

Wildlife Conservationist & Daughter of Steve Irwin; Season 21 Contestant on "Dancing With the Stars"

Kent Connaughton

Regional Forester of the USFS Pacific Northwest Region

Cassandra Moseley

Director of the Ecosystem Workforce Program in the Institute for a Sustainable Environment at the University of Oregon

Brian Palik

Team Leader / Research Ecologist for the Center for Research on Ecosystem Change at the USDA Forest Service Northern Research Station

Jon Waterhouse

Explorer at National Geographic Society

Michael Lombardi

Diving Scientist, Technologist & Environmentalist

Christiana Figueres

Expert on Global Climate Change; Former Executive Secretary of the UN Framework Convention on Climate Change

Naomi Oreskes

Geologist & Earth Science Historian

Laura Stachel, M.D., M.P.H

Co-Founder of WE CARE Solar, a Company that Fights to Combat High Maternal Mortality Rates in Developing Countries

David Trimble

Director of Natural Resources and Environment at the Government Accountability Office.

Jonathan Trent

Former Director of Offshore Membrane Enclosures for Growing Algae; Founder of UpCycle Systems

Gus Speth

Environmental Lawyer and Advocate; Vermont Law Professor

Mark Tercek

Former President & CEO of The Nature Conservancy

Harvey Wasserman

Journalist, Author, Democracy Activist & Advocate for Renewable Energy

Shailene Woodley

Actress & Environmental Activist

Carl Pope

Senior Advisor to UN Envoy for Cities and Climate; Former CEO and Chairman of the Sierra Club

Carl Safina

Ecologist & Writer

Emmanuelle Chriqui

Actress Known for "Entourage;" Social Advocate for Colon Cancer, Environmental Issues & Human Rights in Congo

John Passacantando

Former Executive Director of Greenpeace USA

Laurie David

Producer, Activist Author,The Family Dinner: Great Ways To Connect With Your Kids One Meal At A Time

Chad Pregracke

Founder of Living Lands & Waters, CNN's Hero of the Year for 2013, Environmental Speaker & Bestselling Author

Yann Arthus-Bertrand

Photographer & Videographer

Scott Simon

NPR "Weekend Edition" Host

Windy City

Michael Psilakis

Greek-American Chef, Restauranteur & Cookbook Author; Owner of MP Taverna & Kefi

Live to Eat: Cooking the Mediterranean Way

Anita Archer

Educational Consultant, Author of "Explicit Instruction: Effective and Efficient Teaching"

Ryne Sandberg

Former Major League Baseball Second Baseman

Ryno!