Let's look at actual numbers from:
world oil stats
world gas stats.
World oil reserves at the end of 1998 was 143,400,000,000 tonnes.
World oil consumption in 1998 was 3,037,500,000 tonnes.
Results unless something has changed dramatically in the last 2 years:
~47 years reserves (45 now).
Natural gas reserves at the end of 1998: 146,390,000,000,000 cubic metres.
Natural gas consumption in 1998: 1,846,700,000,000 cubic metres.
Results:
~79 years reserves (77 now).
This is fossil fuel not only in the ground but proven to be economical to extract at today's prices. If the price increases, there will be more incentive for exploration and we have a lot of undiscovered or currently unprofitable oil in the ground. Moreover, some old wells would be reactivated and refineries constructed. A lot of oil will become available if the polar ice cap melts within the next 10 years.
We do need to change our energy use but there's no need to panic from an exploration-production-consumption point of view yet. Environmental issues are another matter.
Beds Are Burning (Midnight Oil)