It produces less carbon dioxide for a unit of energy than coal or oil, so the climate will benefit to the degree that gas replaces either of those: it will mostly substitute for coal, though some oil too, especially if gas-powered trucking becomes widespread.

ECONOMIST: Natural gas

China is already investing billions of dollars to substitute hydropower (which counts as a renewable energy source) for coal and gas in electricity generation.

FORBES: Pollution And Prosperity

Cheap US gas is already driving down the price of the biggest substitute for generating electricity, coal, freeing it up for export to Europe, where it is displacing Europe's relatively highly-priced gas.

BBC: Burning issues for the world's future