US becomes largest natural gas producer

Over the past few decades, the U.S. has been increasingly dependent on imports to meet its growing hunger for energy. But technological advances have now led to a huge surge in domestic output - and the U.S. is now the world's largest natural-gas producer. And the impact of this is being felt not just domestically but across the globe. As part of a special series on America's energy revolution - Tom Ackerman reports from Texas.