Our oily food

Posted on September 28, 2009


On September 29 a new Swedish magazine is launched, “Power – The Climate Magazine” (Klimatmagasinet Effekt). It deals with climate and sustainability issues. In the first issue I have been asked to write about food and oil (in Swedish) and below is the English translation:

Our oily food

In one of his first speeches as USA’s president, Barack Obama declared that, “No single issue is as fundamental to our future as energy”. This is the same viewpoint that I have had since the mid-1990s. Energy is the foundation for our daily bread, our warm home and our work. If our energy security crumbles then our society will also crack.

An important part of my working day is to teach in energy systems civil engineering at Uppsala University. Currently it is the university’s most sought after variety of engineering education. When I introduce my course on energy technology I discuss with the students what is most fundamental to our lives. We soon agree that is it food, shelter and community. Crudely put, the rest of what we do is not much more than “killing the time in between”.

A large proportion of our time is dedicated to earning money for food and accommodation. Our National Food Administration recommends that we eat food providing 2,500 kilocalories (kcal) per day. Kcal is a unit for measurement of energy. To obtain and prepare this amount of food takes around five times as many kcal as in the food itself. This is provided by, principally, oil and natural gas. Agriculture, transport, preparation, trade and food preparation – all these require oil and gas. If these numbers apply globally then as much as 40% of all oil and natural gas use goes to provision of food.

In the debate that is occurring in the run-up to the climate change meeting in Copenhagen in December we hear discussion of the ways in which future carbon dioxide emissions from oil and natural gas can be reduced. Many experts think that we must reduce emissions to a level far below those that are currently required to feed the world’s population. If, at the same time, one considers that the world’s population is increasing then this means that food production by today’s methods will require even more oil and gas. Therefore, it is not unexpected that the world’s poorest nations want to put food on the meeting’s agenda. Every responsible environmental opinion leader should also have food at the top of their agenda. In a world where people are already starving, how can we justify using political means to shut off the fossil fuel supply that fills the world’s larder without simultaneously discussing alternatives to our current methods of food provision?

The research group, Global Energy Systems at Uppsala University has studied in detail the energy content of 129 of the world’s agricultural products and their byproducts – i.e. agriculture’s total bioenergy production (read the relevant Master thesis at www.fysast.uu.se/ges). Globally, this is about 20,000 TWh per day. This is nearly as much energy as is consumed daily by transport worldwide. Of the total harvest, nearly 90% is edible but some must be conserved as seed stock for the following year’s harvest, some is lost during storage and some is used for animal feed and so on. In our calculations we have also kept in mind that 3% of our food comes from the oceans. We have concluded that the energy content of the world’s food that is currently available for human consumption is 7,225 TWh per day. The food we actually consume contains nearly as much energy. In other words, the global food reserves available to provide for a rapidly growing population are very small – approximately 2% more than current consumption.

How to rescue our climate for future generations is considered by many to be the most important question. The figure of 350 ppm is given as a permissible upper threshold for atmospheric carbon dioxide concentration. But the future’s greatest challenge is that too many people must share too little energy. It is time that we began discussing the figure of 2500 kcal and how, in future, the world’s population will be provided with its daily bread without having it soaked in oil.

Kjell Aleklett is Professor of Physics at Global Energy Systems, Uppsala University. He also blogs on energy issues at aleklett.wordpress.com.

Posted in: Dagsaktuellt