Over on www.theoildrum.com today there is fantastic article by Cutler Cleveland called “10 Fundamental Principles of Net Energy Analysis.” Cutler is one of the world’s very few experts on this subject, which I wrote about in THE PARTY’S OVER back in 2003.

It takes energy to get energy, and our net energy profit is what enables us to run human societies. The larger the profit ratio, the more complex a society we can build and manage (that’s a bit of an oversimplification, but it’s not too far off the mark). Fossil fuels gave us energy that was cheap and abundant—it took us only a trivial amount of effort in exploration and drilling to obtain an enormous energy return on our energy investment.

The peaking of world oil production is an easily understandable problem. Perhaps less readily grasped are the consequences of society losing ground in the net energy race. Alternatives to oil generally have a lower energy return on energy invested (EROEI). For oil itself, the energy profit from exploration is falling fast, and secondary and tertiary oil recovery methods also often entail a lower EROEI.

In agrarian society, most of the population had to be involved in food (i.e., energy) production in order to support a minority of specialists in management, violence, and psychological conditioning (i.e., kings, soldiers, and priests). With fossil fuels, we could afford to expand the middle class: full-time division of labor grew to encompass tens of thousands of unique job descriptions.

As net energy declines, society must simplify itself again. More of us will need to grow food.

The moral of the story is inescapable: if you want to survive in the new economy of the 21st century, develop a range of practical skills; learn to use, make, and repair tools of various kinds and degrees of complexity; and hone your gardening ability.