"The natural gas boom has led to cleaner power and greater energy independence," President Obama declared in his State of the Union address Tuesday night. "That's why my administration will keep cutting red tape and speeding up new oil and gas permits."

The president is right. The United States sits atop seas of natural gas, a fuel that drives electric turbines, warms homes, heats water and even powers some big trucks. Much of this gas is in unconventional deposits that drillers have only begun to tap. Now that they have, the price of the fuel has plummeted and the United States has gone from a gas importer to a potential exporter, with decades of supply left.

Natural gas also burns cleaner than coal, which had been the dominant fuel used in electricity generation until the vast new gas fields opened up. Burning gas produces substantially less carbon dioxide, the main driver of global warming, than does coal, and it doesn't pollute the air with coal's toxic cocktail of particulates and gases.

Turning off coal-fired power plants while ramping up gas-burning facilities is one of the trends behind the recent drop in U.S. carbon emissions -- the Environmental Protection Agency (EPA) just announced that power-plant emissions dropped 4.6 percent in 2011 alone.

The country can't use natural gas forever, because it still produces some carbon dioxide. But gas can, for a time, serve as a low-cost alternative to dirtier fossil fuels in a program to steadily green the economy. Particularly when combined with a smart climate policy, such as a carbon tax, the availability of lots of natural gas is a national blessing.

But extracting unconventional gas is controversial, in part because it involves fracking -- pumping a mixture of water and other substances deep underground to fracture rock formations, freeing trapped gas. Environmentalists have mobilized against the practice, despite its potential to help reduce carbon emissions.

So, whereas Obama is promising to fast-track development, many of his fellow Democrats are dragging their feet.