Sources and sinks – energy and resource quality

In yesterday’s piece about “humanity’s carbon budget,” I followed Bill McKibben in comparing the constraints imposed by energy and climate. This is basically a story about sources and sinks — where our stuff comes from and where it goes to.

Decades ago, there was a lot of talk about resource constraints. The famous 1980 bet between Paul Ehrlich and Julian Simon, for instance, was all about resource availability, as measured through commodity prices.

More recently, we are learning that physical constraints imposed by the availability of resources may be less challenging than those imposed by the availability of sinks — like the capacity of the Earth’s atmosphere to store our carbon dioxide wastes. This latter, the climate challenge, is looking particularly daunting. Still, resource availability remains a critical factor in social and economic life, and there is plenty of analysis of these topics on websites like The Oil Drum.

With an eye to the systems view, here are some notes from the classic text Energy and Resource Quality: The Ecology of the Economic Process, by Charles Hall, Cutler Cleveland, and Robert Kaufmann.

The most important point about energy and its relationship to other resources in both biological and economic systems is not that “everything can be reduced to energy” (which is false) but rather that every material (and most nonmaterial) resource has an associated energy cost, so that every potentially limiting resource is limiting in part because its energy cost is too high. (p.8)

All the creatures of the Earth face a common constraint: the total solar energy income is relatively fixed, changing little from year to year or century to century. … In some special cases animal and even plant groups are what we call energy subsidized; they are able to exploit the solar energy that has been captured over a region larger than the one in which they live. … An interesting parallel exists between a subsidized animal community, such as the oyster reef, and modern industrial society in that both depend on energy subsidies in amounts much greater than the direct solar energy available to them. (p.9-10)

Living organisms maintain their organized states by capturing high-quality, low-entropy energy and matter from their environment, using it to grow, repair damage, and reproduce, and then releasing that energy back to the environment in the form of low-quality, high-entropy waste heat. (p.10)

The basic tenet of an energy-based approach to selection is that organisms act so as to maximize their reproductive potential by selection for the largest difference between energy gains and energy losses over time. (p.12)

Particular characteristics of the environment – what we call various attributes of resource quality – influence the energy costs and gains of living. A most important attribute of this is the trophic productivity of the environment, that is, the fundamental rate of energy fixation by the green plants of that environment or the additions from neighboring environments. (p.13)

We view the course of natural selection over the past there and one-half billion years as a series of energy investments into different life possibilities. … One of the important criteria for these energy investments is that they be favorable: a favorable investment is defined as one where more than 1 kcal is returned per kilocalorie invested and where a greater return on investment is achieved relative to alternative viable choices, thus favoring the survival of the organism and, ultimately, that investment pattern. … For an organism to have energy available for maintenance, growth, and reproduction, it must obtain more energy from its food than the amount of energy it uses to capture it. (p.16)

The amount of economic work possible depends on both the quantity and quality of energy directed to the task and the efficiency of the process. The process in which society invests some of its already extracted (surplus) energy to make available additional qualities of fuel is called an energy transformation process. This aspect of fuel quality is measured by energy return on investment (EROI). EROI is the ratio of the gross amount of fuel extracted in the energy transformation process to the economic energy required to make that fuel available to society. … We use EROI and the related ideas of economic work and output per unity of energy invested as the conceptual glue to bind the chapters of this book. (p.28-29)

The ability of the human economy to convert natural resources to useful structures depends on the natural energies used in the past to upgrade these elements to natural resources and the economic energies available to convert these resources to useful goods and services. … Energy is the only primary factor of production because it cannot be produced or recycled from any other factor – it must be supplied fro outside the human economic system, Labor, capital, and technology are intermediate inputs because they depend on a net input of free energy for their production and maintenance. (p.36-40)

We view technology as simply the specific methods by which energy is applied to upgrade and transform natural resources. (p.42)

The relationship between energy and human values … is not a strictly deterministic one. … The important point is that the type, quality, and quantity of natural resources, and fuel in particular, set general but definite limits on the development of human values and the physical implementation of human ideas. (p.70)

The United States and other industrialized nations are faced with a remarkable quandary not previously encountered in human history. Natural resource shortages and energy transitions have come and gone throughout history of civilization but never before has a society with such a sophisticated physical infrastructure and a high material standard of living been so dependent on a finite store of low-entropy matter and energy.

The question before us is a simple one: Can human technologies circumvent the declining quality of fossil fuels as it did in many (but not all) past resource shortages, and thereby allow economic growth to continue at rates comparable to those we’ve experienced since the Industrial Revolution? No definitive answer is available at this time. … Yet we cannot rule out the possibility that technical breakthroughs might make such growth possible. …

The relative risk and return of the two strategies can be analyzed by applying the logic behind Pascal’s wager (Daly, 1977). We can adopt the omnipotent technology hypothesis and later find it to be false, or we can reject it and later find out that the necessary technical breakthroughs do in fact exist. …

We must realize that the remarkable social achievements of the past 150 years could not have occurred without empowering labor with greater quantities of energy, particularly fossil fuels. In the future genius must work toward replacing the bludgeon of fossil fuel with the rapier of knowledge. (p.534)

Hall’s new book is Energy and the Wealth of Nations.

This post draws from one I wrote in 2009 on “Charles Hall: Energy, Biophysical Economics and EROI.”

  • Ted Wolf 27 Jul 2012, 5:23 pm

    A side point, but I wonder about the validity of the “sink” metaphor when applied to the atmosphere. When we “store our carbon dioxide wastes in the atmosphere,” we are adding massive quantities of a radiatively active gas to a dynamic system — rather different than parking something in “storage.” The static condition implied by “sink” may mislead in a dangerous way.

  • Howard Silverman 27 Jul 2012, 5:49 pm

    Indeed! Thanks, Ted.

    Also relevant: the widely differing rates at which carbon dioxide and other greenhouse gases leave the atmospheric system.

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