"North America stands at an energy crossroads. As cheap, plentiful conventional oil becomes a luxury of the past, we now face a choice: to set a course for a more sustainable energy future of clean, renewable fuels, or to develop ever-dirtier sources of transportation fuel derived from fossil fuels -- at an even greater cost to our health and environment."
Source:
http://www.nrdc.org/energy/dirtyfuels.asp
"There is no such thing as clean coal...(paraphrasing) If I put liquid coal in my Prius and drove it, I'd be producing the same lifecycle CO2 emissions as a Hummer."
Source (Video):
http://www.youtube.com/v/NC8OhWBwDqE&hl=en