Originally published in GreenSWord June 2005

"It has often been said that, if the human species fails to make a go of it here on Earth, some other species will take over the running.

In the sense of developing high intelligence this is not correct. We have, or soon will have, exhausted the necessary physical prerequisites so far as this planet is concerned. With coal gone, oil gone, high-grade metallic ores gone, no species however competent can make the long climb from primitive conditions to high-level technology.

This is a one-shot affair. If we fail, this planetary system fails so far as intelligence is concerned.

The same will be true of other planetary systems. On each of them there will be one chance, and one chance only. “(Prof Sir Fred Hoyle, 1964; ‘Of Men and Galaxies’)

Hoyle’s point, made 40 years ago, is that there is only one chance to progress from an industrial civilization to a sustainable advanced civilization.

One way of measuring the development of a civilization is to look at how much energy is available for use by each individual – the more advanced a civilization, the more energy (be it renewable or not) can be used by each citizen.

A worrying fact is that in global terms our per-capita energy use has peaked in the early 1980s. Since then growth in population has outstripped increases in world available energy supply. This may be an early sign of the decline of human civilization on a global scale.