Based on the actual values (dots in the chart) of world proved oil reserves and world oil production from 1980 to 2009, a graph is presented for two distinct cases. The first case (blue line) assumes that 2009 proved reserves of 1,342 billion barrels are practically it and will remain unchanged. The results are frightful. These reserves would have allowed for 62 years of 1980-level production, 50 years of 2011-level production and only 38 years of 2050-level production.

The alternative case (red line) considers that reserves will continue growing, as they did until now. The situation visibly improves. Proved preserves in 1980 would have permitted 30 years of 1980-level oil production. The reserves lifetime should increase to 41 years in 2011, and 50 years by 2050.

The chart provides an exclusively quantitative view of the issue, ignoring its economic side. For instance, if a ceiling is applied to extraction in order to protect reserves, prices are likely to rise, which will hinder consumption, therefore lengthening the reserves lifetime. However, the chart says loud and clear that reserves are not limitless – they will attain a maximum at some point. Having set the limit at 2,000 billion barrels, the curve evidently shows a slow but regular deceleration of the lifetime growth, which by 2050 approaches a plateau, foretelling an eventual world oil dry out.

We do not attempt to tell when the drying out will occur, this may happen a few decades sooner or later. Although it would be extremely useful to know the exact deadline, this piece of information is of shrinking importance compared to the key message that says that reserves exhaustion is inevitable, and that it may happen in a man's lifetime (see also Oil prices up & reserves down).

Sources: EIA - Energy Information Administration

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