Jeffrey Ball

He’s reported on the auto and oil industries for The Wall Street Journal.

Michael Bloomberg

New York City’s mayor, he's issued a plan to cut the city’s greenhouse gas emissions 30% by 2030.

Jeff Goodell

A journalist and the author of Big Coal: The Dirty Secret Behind America's Energy Future.

Dan Kammen

A specialist in renewable research at the University of California, Berkeley, he’s an adviser to Sen. Barack Obama and Gov. Arnold Schwarzenegger.

Maryann Keller

She’s been an analyst of the U.S. auto industry for three decades and is the author of several books on the industry.

Vinod Khosla

He’s a leading venture capitalist who has invested hundreds of millions of dollars of his personal fortune in “green” start-ups.

Ling Wen

He’s CEO of Shenhua Energy, China’s largest coal company and the second-largest coal company in the world.

Beth Lowery

She’s General Motors’ vice president for environment, energy and safety policy

Mindy Lubber

She’s president of Ceres, an investors and environmental leaders network that works to help business develop environmentally responsible practices.

Rajendra Pachauri

An economist and chairman of the Intergovernmental Panel on Climate Change who’s been a much tougher advocate for climate change action than anyone expected.

T. Boone Pickens

A billionaire Texas oilman who’s investing $10 billion to build the world’s biggest wind farm in the Texas panhandle.

Jeffrey Sachs

An expert on global economics, he’s an outspoken proponent for climate change action.

Stephen Schneider

A Stanford University scientist, he’s long been arguing the dangers of climate change and in the end says he is optimistic that the world will start acting.

Jeroen van der Veer

He’s CEO of Royal Dutch Shell, the world’s second-largest oil company.

Sen. Joseph Lieberman and Sen. John Warner

Co-sponsors of legislation that was Congress’ first serious attempt to institute federally regulated limits on industrial carbon emissions.