Fracking: the what, where and how

Shale gas, a natural gas extracted from rock formations, has become an increasingly important source of energy over the past decade.

The U.S. shale gas industry has grown 45% a year from 2005 to 2010. And, as a proportion of America’s overall gas production, shale gas has increased from 4% in 2005 to 24% today. What’s more, the country now produces more gas than what it needs.