Surging oil and gas production is nudging the nation closer to energy independence. But new research suggests that the boom could peter out long before the United States reaches this decades-old goal. Many wells behind the energy gush are quickly losing productivity, and some areas could hit peak levels sooner than the U.S. government expects, according to analyses presented last week at a Geological Society of America meeting in Denver. “It’s a temporary bonanza,” says J. David Hughes, an energy expert at the Post Carbon Institute, a research group focused on sustainability. He studied two of the nation’s largest shale rock formations, now the source of huge amounts of oil and gas, and says they could start declining as early as 2016 or 2017. The reason: “sweet spots” — small areas with the highest yields. Hughes says these spots simply don’t last long. Unless more wells are drilled, the Bakken shale of North Dakota and Montana loses 44% of its production after a year, and the Eagle Ford shale of Texas loses 34%. Most of the nation’s major shale regions produce both oil and gas.