On the heels of Cambridge Energy Research Associates study arguing that new oil finds are replacing declining production at existing oil fields, a BP economist said the world is more likely to switch away from oil as opposed to running out of the commodity in the decades ahead, Reuters reported.

BP plc (ADR) (NYSE: BP) Special Economic Advisor Peter Davies also told ministers from Britain's Parliament that world oil production is likely to peak -- but not due to any "peak oil" scenario involving declining recoverable supplies and/or declining production -- but rather due to declining demand, Reuters reported.

"I think we will run out of demand before we run out of supply," Davies said, Reuters reported. "There's a distinct possibility that global oil consumption could peak as a result of climate policies."

Existing oil field output is declining about 4.5% annually, but new fields are making up for that production decline, a study by Cambridge Energy Research Associates concludes, The Wall Street Journal reported Thursday. (Subscription required.)

The annual decline from existing fields is about 4 million barrels per day -- about the amount oil No. 4 oil producer Iran produces per day -- with new fields offsetting the loses. The study is based on data from 811 fields, The Journal reported.

Depletion rates are one measure that oil sector analysts use to gauge current productivity, proven reserves that can be extracted, and probable future production output.

The measure also provides evidence for the ongoing debate in oil circles regarding the ultimate size of oil supplies -- with exploration bulls arguing that oil is decades away from a production top, and others, peak oil theorists, arguing that global oil production is likely to peak in the decade ahead, if not sooner. The debate is complicated by the fact that reliable production data on field-by-field production is not available from several key oil-producing nations, including Saudi Arabia, Iran, Russia, and Venezuela.