As of January 1, 2006, proven world oil reserves were estimated at 1293 billion barrels to 15 billion barrels. However proved reserves, are estimated quantities that can be recovered under present technology and prices. Oil reserves are compiled from voluntary survey responses and do not always reflect the most recent information.

World oil consumption by sector is illustrated in Figure 4.4. Much of the world's incremental oil demand is projected for use in the transportation sector, Figure 4.5, where there are few competitive alternatives to petroleum. There is not much incremental change predicted to take place by sectors between 2003 and 2030; however, several of the technologies associated with unconventional liquids (gas-toliquids, coal-to-liquids, and ethanol and biodiesel produced from energy crops) are expected to meet a growing share of demand for petroleum liquids during the projection period. Of the projected increase in oil use in the reference case over the 2003–2030 period, one-half occurs in the transportation sector (Figure 4.5). The industrial sector accounts for a 35% share of the projected increase in world oil consumption, mostly for chemical and petrochemical processes.