Until recently, natural gas was the forgotten stepsister of fuels. It provides about a quarter of U.S. electricity and heats over 60 million American homes, but it's always been limited — more expensive than dirty coal, dirtier than nuclear or renewables. Much of Europe depends on gas for heating and some electricity — but the bulk of the supply comes from Russia, which hasn't hesitated to use energy as a form of political blackmail. The fuels of the future were going to be solar, wind and nuclear. "The history of natural gas in the U.S. has been a roller-coaster ride," says Tony Meggs, a co-chair of a 2010 Massachusetts Institute of Technology gas study. "It's been up and down and up and down."
Natural gas is up now — way up — and it's changing how we think about energy throughout the world. If its boosters are to be believed, gas will change geopolitics, trimming the power of states in the troubled Middle East by reducing the demand for their oil; save the lives of thousands of people who would otherwise die from mining coal or breathing its filthy residue; and make it a little easier to handle the challenges of climate change — all thanks to vast new onshore deposits of what is called shale gas.