Leland Melvin

Engineer, Former NASA Astronaut & Former NFL Wide Receiver

Tamron Hall

Award-Winning Journalist; Former National News Anchor for NBC News; Host of the "Tamron Hall Show"

Watch Where They Hide

Eric Stonestreet

Actor & Comedian, Best-Known for "Modern Family"

Cesar Millan

Host of The Dog Whisperer; Author of Cesar's Way

Philippe Cousteau

Explorer, Social Entrepreneur & Environmental Advocate; Grandson of Captain Jacques-Yves Cousteau

David Suzuki

Environmentalist & Scientist; Co-Founder of the David Suzuki Foundation

Amy Smart

Actress, Environmentalist & Co-Founder of Smart House Collections

Kelly Wearstler

Interior and Fashion Designer

Moby

Musician, DJ, Photographer

Alison Victoria

Interior Designer; Host of HGTV's "Kitchen Crashers"

Vandana Shiva

World-Renowned Environmental Leader

Shaun Tomson

Former World Champion Surfer, Environmentalist & Motivational Speaker

Kevin Nealon

Former Cast Member of 'Saturday Night Live'; Co-Star on Showtime's "Weeds"

Martin Sheen

Award-Winning Actor Known for "The West Wing" & "Grace and Frankie;" Social Activist & Humanitarian

Alan Cumming

Emmy-Winning Actor Who Stars in "The Good Wife"

Anna Paquin

Actress Best Known for "True Blood" and for the X-Men Franchise

Torrey DeVitto

Actress, Model, Ambassador for NHPCO & Advocate

Joey Lawrence

Actor, Singer & TV Host; Known for his Role in "Melissa & Joey"

Roselyn Sanchez

Puerto Rican Singer-Songwriter, Model, Actress, Producer and Writer; Carmen Luna in "Devious Maids"

Eric Roberts

Actor Known for his Roles in "Runaway Train," "The Dark Knight" and "Heroes"