How Long Will the Oil Age Last?

Quick, how many years will it be before the world runs out of oil? Don’t know? Join the club. Actually, choose one of several clubs, each of which vehemently disagrees with the others on how much usable crude is left on the earth. The question is far from an academic exercise: This year oil hit a near record-high $40 a barrel, and Royal Dutch/Shell Group downgraded its reserves by 4.5 billion barrels.

Popular Science