A process known as hydraulic fracturing
The wells draw from the Barnett Shale, a geological formation in the southwestern US state once thought too dense to be profitably tapped for energy. In 1997, crews deploying water under high pressure with chemicals and sand learned how to fracture the shale rock and release vast new supplies of natural gas - a process known as hydraulic fracturing, or fracking.
The technology has reshaped America's energy industry, with shale gas now produced in more than a dozen states. President Barack Obama is touting the expansion in natural-gas-generated electricity, which produces roughly half the carbon emissions of coal, as a bridge to the nation's energy future.
But natural gas is no long-term solution in the effort to shield the world from the most severe effects of climate change, or for meeting the difficult goal set by Obama and other world leaders to keep global temperature rises to within 2 degrees Celsius. Some experts say unfettered burning of natural gas, without adding systems to capture carbon emissions, will significantly undermine that effort.
"Gas may be the cleanest of fossil fuels, but it is still a fossil fuel," Maria van der Hoeven, executive director of the International Energy Agency, said in a July speech. "The widespread use of gas without emissions abatement would leave us with no chance of meeting our 2-degree climate goal."
The use natural gas to combat climate change is further eroded by leakage from the production, processing and transport of the fuel. Methane is the primary component of natural gas, and when vented rather than burned for energy, it acts as a short-lived but potent greenhouse gas.