Experts fear day when oil runs low

Within a couple of hours last week, crude oil prices hit a record $56 a barrel, President Bush fretted publicly over world oil shortages and the Senate voted to open an Alaskan wildlife refuge to drilling.

The converging events drew attention to what administration officials call a temporary global energy crunch. But bigger worries also are bubbling to the surface – fears of a day of reckoning over world oil reserves