National Geographic: Now that oil prices have dropped to levels not seen since 2009, helped by a flood of oil flowing from hydraulic fracturing or fracking wells in North Dakota and Texas, it's time to ask the question: How long can the U.S. oil boom last?
In the short term, the price drop threatens profits from fracking, which is more expensive than conventional drilling. Sure enough, permit applications to drill oil and gas wells in the U.S declined almost 40 percent in November.
But in the long term, the U.S....