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.

We can still determine the number of years until the reserves run dry. We start by using known values for 2006 as indicated above. Next, we select the expected percentage increase in annual oil consumption and in discoveries. Obviously if we continually use less or the same amount than we discover, we will never run out. But, we are on a finite Earth so this is not a realistic future.

Our saving grace so far is that we continually find new reserves. Yet, these aren’t infinite. For example, the North Sea oil reserves, recently developed, are already nearing depletion. Further, 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. Thus, future reserves won’t have the same benefit to society as current proven reserves. All this should be enough of a cause to consider making viable, worthwhile plans for the future.

BP recently released its 2011 Statistical Review of World Energy. With it, and some data from we can update the rates. On average, from 2003 to 2010, the rate of consumption has been increasing at +2.9%, a whopping increase. As well, the rate of depletion of reserves is -0.38% which is very close to nil.

As always there are some caveats. Principle amongst these is that we rely upon nationalized industries for many reserve figures. On inspection, one sees that for the last 10-15 years, the oil reserves of almost all none-Western countries have either remained the same or increased. This is a neat trick considering their appreciably high extraction rate.
In any case, lets make a few more assumptions. For one, assume that the three fossil fuels; oil, natural gas and coal will continue to comprise 87% of our primary energy. As well, assume that they are equally interchangeable. That’s a stretch but useful for calculating depletion. With this, and assuming that the rate of consumption and reserve depletion remains, then we will completely exhaust our fossil fuels by 2042.

Are you ready for this?