the shale revolution

Nature | The vast reserves of US natural gas must be used judiciously to ease the transition to clean energy.

Several years ago, it looked as though the United States was running short of natural gas. Prices spiked as declining production in old fields collided with increasing industrial demand. Electric utilities shifted from 'clean' gas back to cheap coal, and suppliers began building terminals to import liquefied natural gas from abroad. Yet today, coal-fired power is again on the wane, ports for liquefied natural gas are idling below capacity, and the nation is awash with gas.

So what happened? Clearly, the threat of carbon regulation has curbed industry's appetite for coal, and the sagging economy has depressed energy demand across the board. But just as importantly, natural-gas production is again on the rise. Thanks to advances in drilling technology, including horizontal drilling and more effective rock fracturing, producers have at last unlocked the vast quantities of gas trapped underground in impermeable strata of shale.

The Potential Gas Committee, a volunteer group of industry, government and academic experts headquartered in Golden, Colorado, increased its estimate of recoverable gas reserves by 39% in its biennial report released last month, mostly because of shale gas. The new total, almost 60 trillion cubic metres, is equivalent to about a century's worth of gas at current usage rates.

Policy-makers everywhere should take note. Shale formations similar to those that have upended the US natural-gas market exist all over the world. Early explorations are already under way in Canada and several European countries, many of which are overly reliant on coal and politically risky Russian gas imports. And there is no reason to think the development will stop there.