We Will Never Run Out of Oil

The Oil Supply - The Doomsday Scenarios are Flawed

Oil pumpjack
Matthew D White / Getty Images

You may have read that the world's oil supply will run out in a few decades. In the early 80s, it was not uncommon to read that the supply of oil would be gone for all practical purposes in just a few years. Fortunately these predictions weren't accurate. But the notion that we will exhaust all the oil under the surface of the earth persist. There may well come a time when we no longer use oil remaining in the ground because of the impact of hydrocarbons on climate or because there are cheaper alternatives.


Mistaken Assumptions

Many predictions that we will run out of oil after a certain period of time are based a flawed understanding of how the reserve supply of oil should be assessed. One typical way of making the assessment uses these factors:

  1. The number of barrels we can extract with existing technology.
  2. The number of barrels used worldwide in a year.

The most naive way to make a prediction is to simply do the following calculation:

Yrs. of oil left = # of barrels available / # of barrels used in a year.

So if there are 150 million barrels of oil in the ground and we use 10 million a year, this type of thinking would suggest that the oil supply will run out in 15 years. If the predictor realizes that with new drilling technology we can gain access to more oil, he will incorporate this into his estimate of #1 making a more optimistic prediction of when the oil will run out. If the predictor incorporates population growth and the fact that demand for oil per person often rises he will incorporate this into his estimate for #2 making a more pessimistic prediction.

These predictions, however, are inherently flawed because they violate basic economic principles. 

We Will Never Run Out of Oil

At least not in a physical sense. There will still be oil in the ground 10 years from now, and 50 years from now and 500 years from now. This will hold true no matter if you take a pessimistic or optimistic view about the amount of oil still available to be extracted.

Let's suppose that the supply really is quite limited. What will happen as the supply starts to diminish? First we would expect to see some wells run dry and either be replaced with new wells that have higher associated costs or not be replaced at all. Either of these would cause the price at the pump to rise. When the price of gasoline rises, people naturally buy less of it; the amount of this reduction being determined by the amount of the price increase and the consumer's elasticity of demand for gasoline. This does not necessarily mean that people will drive less (though it is likely), it may mean that consumers trade in their SUVs for smaller cars, hybrid vehicles, electric cars or cars that run on alternative fuels. Each consumer will react to the price change differently, so we would expect to see everything from more people bicycling to work to used car lots full of Lincoln Navigators.

If we go back to Economics 101, this effect is clearly visible. The continual reduction of the supply of oil is represented by a series of small shifts of the supply curve to the left and an associated move along the demand curve. Since gasoline is a normal good, Economics 101 tells us that we will have a series of price increases and a series of reductions in the total amount of gasoline consumed.

Eventually the price will reach a point where gasoline will become a niche good purchased by very few consumers, while other consumers will have found alternatives to gas. When this happens there will still be plenty of oil in the ground, but consumers will have found alternatives that make more economic sense to them, so there will be little, if any, demand for gasoline.



Not necessarily. There already exists plenty of alternatives to the standard internal combustion engine. With gasoline less than $2.00 a gallon in most areas of the United States, electric cars are not very popular. If the price were significantly higher, say $4.00 or $6.00, I'd expect to see quite a few electric cars on the road. Hybrid cars, while not a strict alternative to the internal combustion engine, would reduce the demand for gasoline as these vehicles can get twice the mileage of many comparable cars. Advances in these technologies, making electric and hybrid cars cheaper to produce and more useful, may make fuel cell technology unnecessary. Keep in mind that as the price of gasoline rises, the car manufacturers will have an incentive to develop cars which run on less expensive alternative fuels in order to win the business of consumers fed up with high gas prices. An expensive government program in alternative fuels and fuel cells seems unnecessary.


When a useful commodity, such as gasoline, becomes scarce, there is always a cost to the economy, just as there would be a benefit to the economy if we discovered a limitless form of energy. This is because the value of the economy is roughly measured by the value of the goods and services it produces. Remember that barring any unforeseen tragedy or deliberate measure to limit the supply of oil, the supply will not drop suddenly, meaning that the price will not rise suddenly.

The 1970's were much different because we saw a sudden and significant drop in the amount of oil on the world market due to a cartel of oil producing nations deliberately cutting back on production in order to raise the world price.

This is quite a bit different than a slow natural decline in the supply of oil due to depletion. So unlike the 1970's, we should not expect to see large lines at the pump and large overnight price increases. This is assuming that the government does not try to "fix" the problem of a declining oil supply by rationing. Given what the 1970's taught us, this would be very unlikely.

In conclusion, if markets are allowed to function freely the supply of oil will never run out, in a physical sense, though it's quite likely that in the future gasoline will become a niche commodity. Changes in consumer patterns and the emergence of new technology driven by increases in the price of oil will prevent the oil supply from ever physically running out. While predicting doomsday scenarios may be a good way to get people to know your name, they are a very poor predictor of what is likely to happen in the future.

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