Limits to Growth in Energy Consumption?

Sometimes a single sentence is enough to kick your brain into thinking about things in a different way than you have before. This rant was keyed off the sentence “There is no limit to the amount of energy an industrialized society will use per capita”. I’d never really thought of it in precisely this way before, nor did it seem to me to be obviously true or false.

It is certainly true that I consume more energy than my father did, and his father, and so on back to the formation of industrialized society. The availability of inexpensive electricity and fossil fuels, and the general usefulness of them make their use almost obligatory. The food I eat isn’t grown locally: much of it is shipped from hundreds of miles away.

As I thought about this, I tried to consider myself as a single energy exchanger. A human might expend about 2000 kilocalories of energy in a day. If we sum up the total energy consumed as we go about our day, and we look at the ratio of energy burned by our bodies to those expended on our behalf, is there any real lower bound on this ratio? If so, then what factors affect this ratio?

The limits are mostly economic. If energy is expensive, we realize that we can make due with less. We tend to conserve resources which are precious. We begin to make tradeoffs:
we buy smaller cars, more efficient appliances, and turn off lights. We also try to improve the efficiency of energy generation, storage and transmission to lower the overall cost.

What this means for the future is the interesting question. If one believes that breakthroughs in energy technology will mean the continued growth of cheaper energy sources, then it seems likely that society will continue to develop new means to use that energy to do work, even if the work is only marginally useful. On the other hand, if you believe that the increasing population will cause us to exhaust our non-renewable energy resources and breakthroughs in renewable sources aren’t able to keep up, we will begin to reach our limits of energy growth.

When I first read The Limits To Growth in the eighties, it didn’t really click with me that there was this indisputable growth in the desire of industrialized societies to use energy. If populations are climbing and simultaneously energy use per capita is climbing, but most of our energy resources are non-renewable, then something has got to give. The interesting question becomes: how can an industrialized society place an upper bound on the amount of energy it is willing to expend on behalf of individuals, and what quality of life will be represented at that level?

I don’t have any answers, just questions. It was therefore not surprising that some googling
turned up some interesting ideas.

The Wikipedia turned up the work of Donella Meadows on leverage points to intervene in systems. The work of Joseph Tainter on Complexity, Problem Solving and Sustainable Societies seems to be most directly applicable.