Today, the average person on the planet consumes power at the rate of about 2,500 watts, or to put it a different way, uses 600 calories per second. About 85 per cent o f that comes from burning coal, oil and gas, the rest from nuclear and hydro (wind, solar and biomass are mere asterisks on the chart, as is the food you eat). Since a reasonably fit person on an exercise bicycle can generate about fifty watts, this means that it would take 150 slaves, working eight-hour shifts each, to pedal you to your current lifestyle. (Americans would need 660 slaves, French 360 and Nigerians 16.) Next time you lament human dependence on fossil fuels, pause to imagine that for every family o f four you see in the street, there should be 600 unpaid slaves back home, living in abject poverty: if they had any better lifestyle they would need their own slaves. That is close to a trillion people.
You can take this reductio ad absurdum two ways. You can regret the sinful profligacy o f the modern world, which is the conventional reaction, or you can conclude that were it not for fossil fuels, 99 per cent of people would have to live in slavery for the rest to have a decent standard of living, as indeed they did in Bronze Age empires.
The US Department of Agriculture estimated in 2002 that each unit of energy put into growing maize ethanol produces 1.34 units of output, but only by counting the energy o f dried distillers’ grain, a by-product of the production process that can go into cattle feed. Without that, the gain was just 9 per cent. Other studies, though, came to lesspositive conclusions, including one estimate that there was a 29 per cent loss of energy in the process. Drilling for and refining oil, by contrast, gets you a 600 per cent energy return or more on your energy used. Which sounds the better investment?
The plants and animals that dominate the earth today channel more of the sun’s energy through their bodies than their ancestors of the Cambrian period (when, for example, there were no plants on land). Likewise, human history is a tale of progressively discovering and diverting sources of energy to support human lifestyle.
Domesticated crops captured more solar energy for the first farmers; draught animals channelled more plant energy into raising human living standards; watermills took the sun’s evaporation engine and used it to enrich medieval monks. ‘Civilisation, like life, is a Sisyphean flight from chaos,’ as Peter Huber and Mark Mills put it. ‘
The chaos will prevail in the end, but it is our mission to postpone that day for as long as we can and to push things in the opposite direction with all the ingenuity and determination we can muster. Energy isn’t the problem. Energy is the solution.’