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oil pump jack

Nothing happens without energy. Howard T. Odum created a framework of energy flow, conversion, storages and feedback that built systems ecology into a general systems theory. That provided ecosystem science with a rigorous disciplinary basis. Odum and his intellectual progeny see that understanding how energy makes everything happen is so important, not only for the design of durable, healthy agroecosystems but for the future of our species and for the future of civilization, that Odum created a new term – emergy (that’s with an M).

Emergy is simply the full accounting of the energy cost of everything we produce from the morning conflakes to fighter bombers to energy itself.

Emergy accounting starts with the extraction of raw materials and continues up the production and supply chain to the end product.  In an age of dirt-cheap energy, few took an interest in counting up the energy costs of everything. Now, when the energy cost of the fossil energy itself, essential to modern civilization, is permanently rising, it causes production to peak and go into permanent decline. That brings to an end the industrial era. Oil Geologists, natural resource scientists and systems ecologists have been trying to make the public aware for decades, and hit a brick wall of denial.

Here is a key reason emergy accounting is so important. As defined above, emergy is the energy invested in anything produced. The energy return on energy invested (emergy) known by the acronym  EROEI is all important. It is a critical determinant and constraint on the level of our material standard of living. EROEI is a ratio: energy return/emergy. You can also think of it as net energy: gross energy produced minus emergy. It is simple to understand – it’s like business accounting. If your farm grosses $1 million, that is not profit. If your expense is $1 million, your profit is zero, right?

Now let’s apply EROEI accounting to our situation. Industrial civilization as we know it cannot run without oil. At the height of the oil age in the US 1930s, oil EROEI was 100/1: an energy cost of one barrel of oil for a net energy return of 99 produced and processed. Cheap as water – stick in a pipe and get a gusher. Now it has declined to 11/1 for US conventional oil production and steadily dropping, and less than 4/1 in unconventional oil like fracking. Corn ethanol EROEI is 1/1. That means it adds NO net energy to the economy. The only reason it is produced is subsidies. That is where the global economy is headed as EROEI of all fossil energy sources continues to drop. No more net energy – no more industrial economy.

A group of Odum’s intellectual progeny led by Charles Hall has studied the EROEI of various energy sources, with an emphasis on those claimed to be able to replace fossil fuels. They are finding that EROEI of “renewables” in nations which have devoted serious investment like Germany and Spain is nearly zero, far from the EROEI needed to replace oil’s EROEI of 100/1 in the heyday of the oil consumption that built the industrial economy. In sum, humanity has harvested the low hanging fruit – of fossil energy and most other raw materials necessary to industrial civilization.

Not long into this century, even global oil EROEI will be so low that oil can no longer power any industrial economy, including conventional and most organic agriculture. The energy cost (emergy) of food is huge in our oil age society. Over 90% of that energy cost is fossil fuel, mostly oil. We are eating oil, as it were. For those who pay attention, visible signs have existed since at least 1970 that the wheels are coming off the US industrial economy. First it began to slow down; now it is shrinking or propped artificially in places (e.g., weapons industry) by enormous debt. So much for “Saudi America”. So much for what most (well-intentioned) people call ’sustainable agriculture’.

What has this to do with sustainable agriculture? For longevity, natural ecosystems historically have far outperformed human managed ones in the modern age and every other age in the last 5000 years. All two dozen major civilizations since the advent of agriculture have crashed and burned from overshoot of carrying capacity and depletion of their resource base, or were overrun by peoples who still had resources to spare. Despite lip service to learning from nature, only academic renegades and outliers like the Odum brothers, Holling, Wes Jackson, John Todd, Peter Rosset, Alan Savory, Miguel Altieri and Steven Gliessman learned enough ecosystem science to make serious contributions to improving agricultural sustainability to where food production might outlast the industrial, fossil fuel age. At least Altieri and Gliessman made the effort to write the first agroecology texts. These people are all outliers because almost no attempt has been made in academia to put agricultural science on a rigorous disciiplinary basis, which is ecosystem science/systems ecology. Howard Odum has led the way in systems ecology by creating a general framework for the study of the complex systems in our planetary universe, based on the laws of energy and matter known as the laws of thermodynamics.

As the industrial era comes to a close, those who survive the energy descent will do so because they have designed food production the way natural systems operate: almost no inputs of finite resources including energy, near 100% mineral cycling inside the system, efficient capture and recapture of sun and water flow through ecosystems, biomimicry to maximize symbiosis within an intelligently designed species diversity, understanding and respect for nature’s laws of carrying capacity and thermodynamics.

Regarding design for the right kind of diversity, as Albert Howard said, Nature never farms without animals. As French sheep dairyman José Bové says, No manure, no food. It’s a question of scale. Feedlot agriculture puts the civilization into overshoot. Some of the best biomimicry use of animals is described in Franklin King’s Farmers of Forty Centuries, agroecosystems that supported one of the highest human carrying capacities ever with almost no external inputs but sun and rain.


Karl North has been a student, a farmer, a business owner, and a teacher. As a student, his strongest focus for over 50 years has been systems ecology and political economy (the power relations in social systems). 

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