So how much natural gas does the US have? Depends whom you ask.

What we have here is a failure among gas industry advocates to sing the same song from the same song book.

The Dallas Morning News reported Friday that T. Boone Pickens said US natural gas supply will probably dry up in about 30 years. After that, the country will need some other transportation fuel, such as fuel cells or batteries.

"Natural gas is just a bridge," he said in a speech at the University of Texas. "Twenty-five, 30 years is what we're going to get out of it." He said pretty much the same thing a few weeks ago at the first meeting of the House Natural Gas Caucus.

The newspaper noted that the Texas oilman has spent $62 million of his money promoting a plan to persuade Americans to use natural gas instead of gasoline or diesel to get where they want to go. He also wants the country to rely more on wind power.

On Tuesday, Chris McGill, the Managing Director Policy Analysis at the American Gas Association, said on AGA's blog that there is more than a 100 years of natural gas supply at current production levels. He based his assertion on findings by 2008 Potential Gas Committee and the US Energy Information Administration.

"These are not short-term phenomena," McGill insisted. "They are indications that natural gas is poised to serve a growing market of low-carbon fuel requirements. America, this is the real deal."

Could be, but some news organizations reported last week that US electric utilities aren't convinced huge increases in US natural gas output mean it's time to make bigger bets on the fuel.

Several utility executives said they're cautious about ramping up the use of gas to generate electricity. Utilities have been stung before by the fuel's volatile prices, and they remain reluctant to make long-term commitments to gas by building or expanding plants.

Companies such as Duke Energy, Xcel Energy and American Electric Power see sizable risks to new supplies, including emerging environmental issues, possible global exports and uncertainties over production costs.

This public dispute over gas supplies probably isn't going to do much to assure utility executives that gas is the way to go. Likewise, the conflicting messages probably aren't reassuring to members of Congress who are trying to figure out what role natural gas should play in addressing climate change.