22 February 2012
Norman Pagett writes:
Few of us ever stop to consider the embodied energy in what we eat. Why would we? Calories have become purely the currency of dietary fads, something to be limited in our constant battle with obesity. We have been well fed for so long that we imagine that supermarket shelves will always be amply stocked to support our affluent comfort.
We literally owe our lives to technology that uses 10 calories of energy input to provide a single calorie of energy output in the food we eat. That embodied energy in food represents all the mechanical input of our farming system: the tractors, fertilizer and transport. It includes the diesel in the trucks that deliver to your supermarket several times a day, and the fuel in your car when you go shopping. The cumulative energy intrinsic to so many food processes – growing, packaging, distribution and delivery – is so cheap in historic terms that most of us could buy sufficient basic food for a week for what we earn in an hour or two, and in many cases far less than that.
However, cheap food is an illusion created by energy sources that we have come to regard as inexhaustible. Our technology allows us to turn oil into food, and the wealth of the world is bidding for diminishing supplies of both. The cost of oil has quadrupled in the last decade, and prices and availability of many basic foodstuffs are becoming increasingly volatile because of it. Peak energy inevitably brings with it peak food.
In order to survive and thrive, an adult ideally needs to take in around 2500 calories a day; and for most of the history of mankind, we have expended as much energy in finding and catching food as we have got from consuming it. Man had a sustainable existence but no more than that, and no energy surplus was generated; energy returned on energy invested (EROEI) was 1:1. That equation meant you lived or died by what you could catch and eat.
Then around 10,000 years ago we learned how to plant crops and harvest them, and domesticate animals for their stronger muscle power and convenient meat supply. We stopped chasing our energy supplies and cultivated them instead, and found we could grow more than was necessary for mere survival. Over time, primitive farming techniques improved and began to provide more surplus food/energy. The surplus was not great, but if nine families or individuals could supply the energy needs of 10; that tenth unit was then available to develop a skill not related to food production.
The specialisation of the tenth individual might, say, have been metalworking, a skill that leveraged muscle power through the heat derived from charcoal to rework metal ores. Although still at a primitive level, carbon energy input began to support the beginnings of society and what we came to regard as our economy, enabling the production of tradable goods ranging from pots to weapons. Our society has been supported by hydrocarbon energy inputs ever since, at every level. We still make pots and weapons but our vastly increased energy input has given us our modern industrial infrastructure; the difference is only one of scale.
The metalworker’s sustenance was provided by a skill which did not produce food, but which others with different abilities were willing to pay for. If 20 measures of wheat bought one sword, it’s an easy step to streamline the transaction and create money as an intermediary. Money then becomes a token of energy in a convenient (and portable) form, usually gold, silver or copper. Money enabled the transfer of energy; you might sell your labour in one place, then buy the results of someone else’s work in another location. Although this was an exchange of energy at the most fundamental level, the skill acquired an accepted value that was directly and irreversibly linked to muscle power leveraged by hydrocarbon energy input.
Money supported basic trading systems for millennia, but nation-states could only sustain their fiscal stability and economic growth through energy inputs in various forms (almost always involving conflict), with gold as the commonly accepted standard by which labour could be bought and sold. The great empires of Egypt and Rome and the eighteenth and nineteenth century expansion of the Americas could be said to have functioned on the trading of the muscle power of enslaved human beings.
Money, if it was backed up by sufficient energy resources, became power because you could buy an army with it (of slaves or soldiers) to get more of the same. It is perhaps no coincidence that the ending of slavery occurred at almost exactly the same time as the spread of machinery, which did more work and was cheaper to buy and maintain.
The economic system that functioned by converting energy (via money) into food was already well established in the eighteenth century, but was accelerated in an invention that gave human muscle power colossal leverage. Concentrated hydrocarbon energy was released through the burning of coal in James Watt’s steam engine, which powered the industrial revolution. Mankind entered a new high energy/food era with the principle that the more energy is burned, the wealthier everybody becomes.
Once the steam engine had drilled the first commercial oilwell in 1859 in Titusville, Ohio, the oil industry took off and dragged humanity with it. By 1880, John D Rockefeller was worth $30 billion at today’s values, with profits coming from business in heating, lighting and machine lubrication and not yet from road transport. Rockefeller was undoubtedly clever and known for his ruthless business methods, but the real source of his wealth was the geological accident that had stored 150 million years’ worth of sun-energy. All he, and others, had to do was tap into it sell it.
Humanity had started to burn its inheritance, calling it profit and wealth. We continue to burn our inheritance, but now we call it growth and GDP. On the back of fossil fuel wealth, we have grown infrastructure, economies, cities, nations and a global population that has grown from 1 billion to 7 billion in 250 years. EROEI has been skewed by the energy input of oil, coal and gas, which provided the means to pump clean water into cities and sewage out, and boost food production and its transport. Instead of a paltry 1:1 of our ancestors, humanity has got colossal returns on energy invested. By the mid twentieth century it took the energy of only 1 barrel of oil to extract and distribute the energy of 100; that meant the leverage of human effort was 100:1. Now returns are only around 15:1 for conventional oil and as low as 3:1 for new sources like the Alberta tarsands.
The end of the era of cheap fossil fuels is bringing with it the end of the era of cheap food, and these are the ultimate causes of the destabilisation of economies that we are now witnessing across the world. World population has expanded to seven billion but young people now face a future without jobs or enough to eat. We might see this as a problem centred on the Middle East and southern Europe, but the 44 million people on food aid in the USA are symptoms of the same problem. Without an increasing input of cheap hydrocarbon energy our lives as we have lived them can no longer be supported.