Industrial Metabolism: Theory and Policy Robert U. Ayres

1. Industrial Metabolism:Theory and PolicyRobert U. Ayres Summary: Patrick Wilkinson Critique: James Silva

2. Overview • Introduction to Industrial Metabolism • The Materials Cycle • Measures of Industrial Metabolism • Policy Implications of the Industrial Metabolism Perspective

3. Introduction to Industrial Metabolism • Definition: “the whole integrated collection of physical processes that convert raw materials and energy, plus labor, into finished products and wastes in a (more or less) steady-state condition.” • Metabolism: Analogous to the process of a living organism • Takes in food for self/storage and excretes wastes. • Differences: • Organisms reproduce themselves, specialized, change over long period of time. • Firms produce products or services, not specialized, can change quickly

4. The Materials Cycle • Closed cycles are self-sustaining with no external sources or sinks and are in steady state. • Open cycles are unsustainable, using materials without replenishing sources. • Must stabilize or will ultimately fail • The Biological cycle is a closed cycle, while our industrial cycle is an open cycle.

5. The Material Cycle • “Industrial system of today”: Unsustainable • Can this stabilization be obtained with a “technological ‘fix’”? • If so, how? • If not, how long will the current system last? • Biological system • Has not always been a closed system • “Responded to inherently unstable situations (open cycles) by ‘inventing’ new processes (organisms) to stabilize the system by closing the cycles.” • Time scales • Biological system took billions of years • Industrial system does not have that much time

6. Measures of Industrial Metabolism • Recycling and dissipative loss are the “fates” of all waste materials • There are 3 classes of materials use • Those that are recyclable under present technology and cost • Those that are recyclable, but not under present tech. and cost • Those that are not recyclable • For the industrial system to function as a closed cycle, it must recycle or reuse nearly all materials

7. Measures of Industrial Metabolism • Examples of dissipative use: Class 3 materials • Sulfur • CFC’s • Ammonia • Phosphoric acid • Chlorine • Although can be classified as class 2 when used in plastics and solvents

8. Measures of Industrial Metabolism • Potentially recyclable materials • Are they being recycled and reused? • Recycle (reuse) vs. Dissipation of a material shows how far sustainability is from being reached

9. Policy Implications of the Industrial Metabolism Perspective • Industrial metabolism is “holistic” in theory • All interactions are considered together resulting in the best for the system as a whole • Short term solutions and policies, however, are being enforced • Such policies are usually more harmful and costly in the long run • Ex.’s Pollution and coal as a fuel • Air and water pollution reduced, but land disposal increased • Clean coal technology could extend coal as fuel, but effects of byproducts extended as well

10. Critique • Sulfur Example • Comparison: human vs. natural • Material Source vs. Material Path • A more “holistic view”

11. Sulfur Example • Example of Dissipative use • Nearly all sulfur mined is dissipated or discarded • Mostly used for sulfuric acid – used in non-recyclable chemicals • Thus sulfur mainly falls into the third category • But… plaster-of Paris

12. Comparison: human vs. natural • Where is the natural to compare with the anthropogenic? • What are the percentages referring to? • “In all cases, with the possible exception of nitrogen, the anthropogenic contributions exceed the natural flows by a considerable margin.” • Really?

13. Comparison: human vs. natural (Can you interpret this?)

14. Material Source vs. Material Path • Should be less concerned with how much of something is left than with what path used material takes • How much oil/steel/etc. is left to be extracted from natural sources is not a good measure of evaluation for industrial processes • A better way is to quantify how much recycling of material is going on: What do we do with what we use?

15. A more “holistic view” • Defines it more by what it is not • Contrasts with “narrowly conceived or short-run (myopic) ‘quick fix’ policies” • Longer pipelines for sewage • Air vs. water vs. land • Not an in-depth application paper • Less than 15 pages • The industrial system of tomorrow…?

16. Questions?