One of the first questions to grapple with when trying to understand the interdependencies between Western nations and Middle Eastern oil producers is devilishly difficult: Just how much oil is out there? And the immediate answer is confusing, because a close look reveals that there is an awful lot yet to be pumped up.
Ever since the oil industry got its start in Pennsylvania in the late 19th century, people have wondered when the world would run out of "black gold." Doomsday predictions have been commonplace. The earliest U.S. government estimates believed that oil would be gone by 1925; updated predictions from the Department of the Interior in both the 1940s and 1950s argued that oil supplies would run out before 1970. The 1980s, 1990s, and early 21st century have all also been pinpointed, by both environmentalists and geologists, as periods in which the wells would finally peter out.
Each of these predictions might have been proven correct, if only the supply of oil was a static figure. But instead, like oil itself, the amount of oil remaining in the world, according to one analyst, is "totally fluid." Even as the world consumes more than 73 million barrels of oil per day, according to U.S. Department of Energy figures, the total available supply continues to grow.
The standing figure for proven and easily accessible oil reserves remains what it was in the 1980s -- 1 trillion barrels. That's more than double estimates from the 1940s, and the number doesn't even reflect improvements in technology that will let oil companies pull even more oil out the ground.
"When you drill you expect to get 30 percent of the oil [under the ground]," Butler says. "That's what the trillion barrels is based on; the 30-35 percent of what's available. But because technology has made great strides, you can now get 50 percent and in some cases -- in places such as the North Sea -- 70 percent."
In other words, there are actually more than 1 trillion barrels of proven reserves. "If you look at the series of estimates, it's an increasing series." says Butler. When they do it again in a few more years, I guarantee that they'll even find more."
In fact, the most recent U.S. Geological Survey estimates declare that the world holds 3 trillion barrels -- enough to satisfy world demand at the present level for about 100 years. These surveys could be overstating the potential, but there are also other sources of oil that remain untapped. Tar sands and shale rock formations hold substantial quantities of oil. Some experts estimate -- according to Bjorn Lomborg, author of "The Skeptical Environmentalist" -- that shale rock alone contains 242 times more oil than conventional petroleum resources.
As Saudi Arabia's former oil minister Sheik Yamani pointed out, the Stone Age came to an end not for lack of stones and the Oil Age will end, but not for a lack of oil."
With such an abundance of oil yet to be extracted, why can't the world wean itself from the Persian Gulf? At the very least, why couldn't the 506 million barrels of Saudi Arabian oil imported last year -- about 15 percent of total U.S. oil imports -- be found somewhere else, specifically the Caspian Basin?
The answer to both questions, as always with oil, comes down to price. With the current price of oil hovering around $22 per barrel, it is not yet economical to develop sources of oil that would reduce dependence on Mideast oil. And right now Mideast oil is cheap to produce, and production of it can easily be ramped up to keep prices down. Central Asian oil, for a variety of reasons, can't compete.
Next page: Central Asian oil, hard to get, expensive, and a big political mess