Ben Casselman:

In 2008, I moved to Dallas to cover the oil industry for The Wall Street Journal. Like any reporter on a new beat, I spent months talking to as many experts as I could. They didn’t agree on much. Would oil prices — then over $100 a barrel for the first time — keep rising? Would post-Saddam Iraq ever return to the ranks of the world’s great oil producers? Would China overtake the U.S. as the world’s top consumer? A dozen experts gave me a dozen different answers.
 But there was one thing pretty much everyone agreed on: U.S. oil production was in permanent, terminal decline. U.S. oil fields pumped 5 million barrels of crude a day in 2008, half as much as in 1970 and the lowest rate since the 1940s. Experts disagreed about how far and how fast production would decline, but pretty much no mainstream forecaster expected a change in direction.