YOUR NEXT CAR WILL BE A VOLT:

Carbon emissions in the U.S. have hit a 20-year low due to a supposedly environmentally unfriendly drilling technique that has created an abundance of cheap natural gas. The free market, it seems, does it better than the EPA.

Environmentalists find themselves between shale rock and a hard place after a little noticed technical report documented how the natural gas boom caused by the use of hydraulic fracturing, or fracking, has actually helped the environment in a major way while also creating jobs and economic growth.

The natural gas boom that fracking wrought has shaken up the global energy landscape. Now its effects are rippling toward the fuel tanks of U.S. cars and trucks, although a few leaps may be required for natural gas vehicles to go mainstream.

The natural gas industry is making a big push for passenger vehicles that can run on either natural gas or gasoline. As a demonstration, the industry group America's Natural Gas Alliance this summer unveiled six vehicle models retrofitted with these fuel systems for less than $3,000 apiece. And starting next year, Ford plans to equip a version of its best-selling pickup truck, the F-150, to run on either gasoline or compressed natural gas (CNG).

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