Bill Richardson

Former Governor of New Mexico; Former U.S. Energy Secretary

Leonardo DiCaprio

Award-Winning Actor & Environmentalist

Leonardo DiCaprio winning Best Actor

Christiana Figueres

Former Executive Secretary, United Nations Framework Convention on Climate Change (UNFCCC)

Emmy Rossum

Actress Known for Showtime's "Shameless," Singer-Songwriter & Equal Pay Advocate

Shameless star Emmy Rossum explains her decision to leave ...

Sheryl Crow

Singer-Songwriter; Known for Hits "The First Cut Is The Deepest" and "Soak Up The Sun"

Arnold Schwarzenegger

Actor, Producer, Director, Writer; California’s 38th Governor; Host of "Celebrity Apprentice"

Arnold Schwarzenegger's Motivational Speech

John Browne

Former CEO of BP & Author of "The Glass Closet: Why Coming Out Is Good Business"

John Browne Explains the Brexit Effect - YouTube

Amin Toufani

Director of Strategy at Singularity University

William Nordhaus

Nobel Prize Winner; Sterling Professor of Economics & Professor, School of Forestry and Environmental Studies at Yale

Gov. Mike Leavitt

Founder & Chairman of Leavitt Partners, Former Governor of Utah

Emmanuelle Chriqui

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

Daniel Yergin

Vice Chairman of Cambridge Energy Research Associates, Pulitzer Prize-Winning Author

Patricia Arquette

Academy Award-Winning Actress Known for "Boyhood"; Activist, Humanitarian & Author

Equal Pay Trailblazer: Patricia Arquette

Mark Ruffalo

Actor, Director, Producer & Screenwriter; Known for "The Avengers" & "Shutter Island;" Environmental Activist

Mark Ruffalo Talks "Hulk" In 'The Avengers'