Energy versus well being: How much energy do we need to consume?

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There are no shortage of people confidently proclaiming how much energy the world will consume in future. We must at least triple or quadruple global energy consumption. Or perhaps we can lower it, as appears to be the wish of many green NGOs.

Who is correct?

Energy forecasts are of course no better than the predictions of the crazed prophets who once resided in the Middle East. So, as someone who recognises the absolute failure of previous forecasts and as someone who doesn’t believe they have powers of prophecy not granted to earlier “experts”, I will not bother answering my first question. Instead, I will show some simple numbers that should be the background to any discussion about the future of energy consumption.

Global primary energy consumption, or least the commercial varieties, came in at 12.7 billion tonnes of oil equivalent (toe). There are still a lot of people – too many – who rely on burning wood and dung for their energy, and this means the actual figure is a bit higher. But for now I will just round my number up to 13 billion toe.

In total, there are around 7.2 billion people on earth. So, split between them, 13 billion toe works out as 1.8 toe per-person. This is where things are now. How about the future?

Typical developed economies consume between 3 and 8 toe per-person. However, in reality the developed world is split between North America and the rest. Western Europeans and Japanese consume around 4 toe per-capita; North Americans consume close to 8 toe per-capita.

Americans however have little to show for this. By all measures, life-expectancy, infant mortality, you name it, Americans are no better off than their developed world counterparts who consume half as much energy. (Yes, Americans do have higher GDP, but what do they have to show for that either?) So, there does not seem to be any evidence based on these data points that consuming much more than 4 toe per-capita will make you better off.

Let’s see how this works out on a bigger scale. Below is a graph comparing life expectancy with per-capita energy consumption. (All data here is taken from the excellent Gapminder.)

lifeAs you can see very low energy consumption is more or less uniformly associated with lower life expectancy. However, increasing energy consumption above 3 or so toe per-capita does not appear to result in increasing in life span.

What about human development index?

hdiA similar story. HDI does not appear to increase much, if at all, once you hit European levels of per-capita energy consumption. But again, lower energy consumption has an impact.

And one final comparison. Energy consumption versus infant mortality (number of infants dying by the age of 5 for each 1000 born).

mortAs before, there is little benefit from energy consumption above the 3 to 4 toe per-capita mark. In fact, you could argue that above 2 toe per-capita things do not improve that much.

So various futures are possible. Everyone could consume energy like Western Europeans. On a planet of 9 billion people, that would mean global energy consumption almost tripling. And, of course, more rational energy consumption could reduce this figure significantly. However, it clearly appears unlikely that everyone can live like Western Europeans without global energy consumption rising. That would take a tripling of efficiency, which is probably unthinkable.

But, on the other hand, everyone could consume like North Americans. Global energy consumption would increase by a factor of six, and the planet would likely fry and we would have little to show for the frying. I am not going to predict which is more likely, but it is clear which is more desirable.


2 thoughts on “Energy versus well being: How much energy do we need to consume?

    Arthur said:
    February 21, 2015 at 1:07 am

    Excellent graphs. Questions: what do the blue lines and grey areas represent mathematically, and how did you create them? (Some sort of moving average and uncertainty range??) Would you be willing to share the source code? (I am trying to make the leap from Excel)


      Robert Wilson said:
      February 21, 2015 at 3:30 pm

      Thanks Arthur,

      The curve is just a standard loess smooth, and the shaded area is just a measure of the confidence in the model at that point.

      I wouldn’t Excel for anything other than converting Excel files into something that can be used in a proper system. These were done in R using the package ggplot2. Email me at if you want the source code. Though, I’m not 100% sure where it is on computer as I produced the plots and uploaded them to wordpress maybe a year ago.


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