Time Until Oil Depletion

We can make an excellent approximation to the time when the world’s supply of oil runs out. The time to depletion is simply the supply divided by the rate of consumption. From British Petroleum both these values are available. They are;

Supply or proven reserves amounts to: 1 208 200 million barrels at the end of 2006, and
Global consumption of oil in 2006 was: 83.719 millions of barrels of oil a day

However, math is never simple. Here, we must consider that the rate of consumption and the rate of discovery of new reserves constantly changes. As long as we find reserves at a faster rate than we consume the energy, our future energy supplies will not be in doubt. The following chart gives an indication of the year over year change in these values for oil.

This chart almost looks magical. We are continually extending the date to when all the reserves get consumed.  Why? For the most part it is because we develop technology which can draw more from reserves that were once considered depleted. Fracking is an example of a developing technology which has recently brought a lot more natural gas to market.

Nevertheless, there will be a time when we can’t extract any more, when the reserves run dry. For your own benefit, try changing the error values in the below form to see how small changes in rate affect the number of years before reserves are fully gone.


The above demonstrates that only big changes make big differences. Hopefully though, you realize that as we are on a finite Earth then there must come an end. That is, non-renewable energy sources are exactly that, non-renewable. Thus to sustain our civilization in the future, we need renewable energy sources.

Our saving grace to date is that we have been finding new reserves or developing new technologies for exploiting old reserves; technologies like fracking. However, any new finds are always in a location that is more difficult to access. Hence, we will need more energy just to extract the energy. This factor, also known as the Energy Returned On Energy Invested or EROEI, is thus getting closer to one. Simply put, future reserves, while perhaps large, will not have the same EROEI as previous and current reserves. All this should be enough of a cause to consider making viable, worthwhile plans for the future.