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Real World Physics Problems Newsletter - Oil Amount, Issue #19
May 28, 2015

Amount Of Fossil Fuel In World

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Source: Wikimedia via Mailtosap

Have you ever wondered how much oil there is in the world?

Before I answer this first consider that there are two main types of oil. The first type is conventional oil, which can easily be pumped out of the ground and up to the surface. The second type is unconventional oil, which is much harder to extract from the ground. It consists of heavy oil, and oil found in oil sands and shale rock. When we add it all up we get about 10 trillion barrels in total worldwide. That is a lot of oil.

It's hard to imagine how much 10 trillion barrels is. For instance, one might wonder how many Olympic swimming pools that much oil would fill up. Or you might wonder if it's enough to fill up a small lake.

The way I approached this question was to imagine a large cube containing all the oil in the world (10 trillion barrels in all), and then calculate how big the cube would be. It turns out that the cube would have side lengths of about 12 kilometers! That's the size of a city, and the height of this cube would be greater than Mount Everest!

And here's another interesting fact. We have only used about 10% of the total oil in the world so far, or 1 trillion barrels from the beginning of the Industrial Revolution to the present. So we still have a great deal of oil left.

In addition to oil there are two other important fossil fuels that we use as an energy source. They are coal and natural gas. The total amount of coal in the world is about 11,000 billion tonnes. Using an average coal density of about 800 kg/m3, this is equal to about 1400 cubic kilometers. This works out to be a cube (of coal) with side lengths of about 11 kilometers.

The total amount of natural gas in the world is about 10,000 trillion cubic feet. This works out to be a cube (of gas) with side lengths of about 66 kilometers.

So now you have a visual idea of how much fossil fuel there is in the world. And the amazing thing is that these three very large cubes (which represent the total amount of worldwide oil, coal, and natural gas) would be barely visible from outer space. Relative to the size of our planet they are small dots in comparison. But they have provided the energy to build our civilization to the point it is at now, with much, much more left over.

Until next time.


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