"It's a mistake to rush headlong into this, " said Fred Krupp, president of the Environmental Defense Fund.

CNN: SHARE THIS

As president of the Environmental Defense Fund, Fred Krupp helped establish a market-based cap-and-trade system to limit acid rain pollution in the late 1980s.

FORBES: Market Man

They include such domestic energy enthusiasts as former Al Gore aide and secretary of the Pennsylvania Department of Environmental Protection Kathleen McGinty, and Fred Krupp, president of the Environmental Defense Fund.

FORBES: Energy: What's All The Fracking Fuss About?