A little-noticed rule requiring large ships to soon slash the air pollution they produce threatens to drive benchmark oil prices as high as $200 a barrel, send prices at the pump soaring to $6 or even $10 a gallon and crash the global economy just 17 months from now.

The doomsday scenario was described in a paper last week by Philip Verleger, an economist who advised two presidents and correctly forecast in 2007 that oil prices would sharply rise to levels that could trigger a financial crisis – a development experts saycontributed to the Great Recession. And in his latest prediction, he's not alone.