In 2000 a Saudi oil geologist named Sadad I. Al Husseini made a startling discovery. Husseini, then head of exploration and production for the state-owned oil company, Saudi Aramco, had long been skeptical of the oil industry's upbeat forecasts for future production. Since the mid-1990s he had been studying data from the 250 or so major oil fields that produce most of the world's oil. He looked at how much crude remained in each one and how rapidly it was being depleted, then added all the new fields that oil companies hoped to bring on line in coming decades. When he tallied the numbers, Husseini says he realized that many oil experts "were either misreading the global reserves and oil-production data or obfuscating it."
Where mainstream forecasts showed output rising steadily each year in a great upward curve that kept up with global demand, Husseini's calculations showed output leveling off, starting as early as 2004. Just as alarming, this production plateau would last 15 years at best, after which the output of conventional oil would begin "a gradual but irreversible decline."
That is hardly the kind of scenario we've come to expect from Saudi Aramco, which sits atop the world's largest proven oil reserves—some 260 billion barrels, or roughly a fifth of the world's known crude—and routinely claims that oil will remain plentiful for many more decades. Indeed, according to an industry source, Saudi oil minister Ali al-Naimi took a dim view of Husseini's report, and in 2004 Husseini retired from Aramco to become an industry consultant. But if he is right, a dramatic shift lies just ahead for a world whose critical systems, from defense to transportation to food production, all run on cheap, abundant oil.