As industry, science, government, and the public struggle over environmental policy, what does the engineering profession have to offer? A practical vision, says a Columbia metallurgical engineer, of the full effects of resource use

Sustainable development
and industrial ecology

Nickolas J. Themelis

F or several years I have been interested in a movement broadly known as "sustainable development." I had long read writings like Silent Spring, the Club of Rome's Limits to Growth, and Hardin's "Tragedy of the Commons," but like most engineers I went on working within my field: high-temperature reactions and the analysis of processes for extracting metals from mined ores and concentrates. I did work on projects related to SD such as the Noranda process for producing copper from sulfide concentrates,1 which combines smelting and converting in a single reactor, conserving fossil fuel, and recycling vast amounts of metallic "wastes." However, the companies that spent millions to build Noranda process reactors and the engineers who developed this method were motivated by short-term commercial objectives, not by SD considerations. Engineers are by inclination pragmatic people who want to know the specific job to be done; they tend to let others ponder the meaning of life and the near- or long-term future of humanity.

I became aware of this latter question in 1993 when the Mining and Metallurgical Society of Finland asked me to address its 50th anniversary meeting,2 assessing the recent history and future prospects of metal extraction. Metallurgy dates back nearly 6,000 years, to the copper smelters of the Timna valley in Israel. Copper, silver, and gold were the first metals used by mankind, because they were found in their native metallic state. Chunks of metal found in ashes taught the first pyrometallurgists to use fire to convert minerals to metals and alloys. Metals have been so integral to civilization that periods in the history of various peoples are marked by terms such as the Bronze Age and the Iron Age.

Civilization's effects, stamped in copper

Next to iron, copper has historically been the most important functional metal. Between the beginning of the 20th century and 1929, the world's annual copper production quadrupled, increasing modestly by 1950 and then quadrupling again by 1990.3 While preparing my keynote lecture, I was amazed to find that during the 50-year life of this Finnish society, humanity had consumed more copper than in the previous 60 centuries. Copper is now used principally in heat exchangers and in electrical and water conduits; in contrast to gold and silver, which can be hoarded by the rich, most of a nation's copper consumption is by the majority of the people. Therefore, copper use can serve as a measure of a country's material standard of living.

Copper consumption ranges from about 10 kg per capita for the United States and other developed nations to 0.2 kg per capita in India (1990 data).4 The world average consumption is about 2 kg per person annually. Therefore, to bring the rest of the world to the material level of the developed nations, we would have to raise current global production by 400 percent. From what we know about ore resources and grades, such production -- about 50 million tons per year -- cannot be attained.

On the basis of ore grade (metal concentration in mined ore), global ore resources are dwindling rapidly. The average grade of mined ores has decreased more than twofold since 1950; in the case of copper, about 200 to 300 tons of ore must be processed -- and many more hundreds moved aside -- to produce one ton of metal. Accordingly, the energy and other costs needed to produce a unit of metal have increased with time, despite great strides in exploration, mining, and mineral-processing technologies.

Emeritus professor Herbert Kellogg of Columbia's Henry Krumb School of Mines pointed out in 1978 that the imminent threat to global mineral supplies was not their eventual exhaustion but the skyrocketing cost of recovering metal from progressively lower-grade minerals.5 In effects that Kellogg called "the tyrannies of ore type and ore grade," energy consumption per unit of metal produced increases logarithmically with decreasing ore grade; direct pyrometallurgical or hydrometallurgical processing of the ores of the future will require up to 1,000 times as much energy. To meet the needs of the 21st century, we will need much more metal for the 80 percent of humanity in the developing world; it will be harder to find and much more energy-intensive. Product design for dematerialization, recycling, and elimination of dispersive uses of metals appear to be the only solutions.

Studies by Columbia's Earth Engineering Center underscore the need to recycle all materials humanity uses, not just metals.6 Except for fossil fuels, most materials we use are potentially recyclable, yet the United States leads the world in consuming virgin materials (in part because we maintain the cost of fuel far lower than in other developed nations, which tax gasoline use heavily). On a global scale, the prices of virgin, non-renewable materials are low because they do not yet include the capital cost of gradual depletion of the natural resources that provide these materials. The Earth's assets are simply not being preserved for future generations -- and this remains unlikely under the present systems of economic analysis, which count the depletion of a nation's oil or copper resources as an increase in GNP rather than a reduction in national natural capital.

Because global production of materials is not burdened by such "long-term" charges, materials are used extravagantly, from automobiles to rapidly obsolescent computers. Closer to home, we see entire buildings, such as Columbia's Ferris Booth Hall, a seemingly recent and decent structure, dissolving into waste to make place for a newer, bigger, better building. When materials are valued properly, there will be more effort to adapt and retrofit rather than demolish and rebuild. A good example is the revitalization of the old Schermerhorn building by the Center for Environmental Research and Conservation (CERC).

By now, the United States and other nations have recognized the need for SD. The driving force for doing so has not been resource conservation but the evident adverse effects of the profligate use of materials. Foremost examples are the depletion of the ozone layer and global warming, the subject of an international conference co-sponsored by the Earth Engineering Center in May 1997. In a way, humanity is fortunate to have had these prime paradigms of our extravagance in using natural resources; otherwise, we might have continued treating resources as unlimited until worse disasters occurred.

The formation of the Global Systems Initiative and its recent transformation to the Earth Institute highlight the need for active academic participation in SD. A number of the Earth Institute's components (including CERC, Lamont-Doherty, and various other economics, law, policy, journalism, and public health groups) are already active in identifying, observing, and mitigating anthropogenic effects on the Earth. In addition, the School of Mines, the first mining and metallurgical department in the United States, has now been designated by the School of Engineering and Applied Science as the Department of Earth and Environmental Engineering, the first of its kind in the world. Every academic discipline, like every thoughtful citizen, can make a contribution to SD; the role of engineers is pivotal.

Industry: can history's villain be the future's catalyst?

Industry -- the foremost target of environmental advocates -- sets its priorities by those of the purchasing public, as government sets its own by the electorate's votes. For example, U.S. consumers responded to the 1973 OPEC oil crisis by moving to smaller cars, and government by setting lower speed limits and higher energy-efficiency standards for the automobile industry. The industry responded admirably by producing smaller cars and more efficient engines, but the public's recent return to large vehicles is reversing these gains.

Scientists and engineers have invented and nurtured modern technology, and industry is its implementer. The benefits to humanity include a longer life span, increased mobility, decreased manual labor, and more leisure time; the flip-side effects have been resource depletion and environmental degradation. Industry is our agent of change, and we all share credit for the good and blame for the bad. Enter Industrial Ecology.

This concept, the fruit of intellectual debate in the 1980s, holds that all disciplines need to work together to reconcile the conflicting goals of economic development and environmental quality. If ecology is defined as the branch of biology concerned with the relations between organisms and their environment, IE examines the intereffects between industrious humanity and the rest of the living and inanimate systems of planet Earth. A general definition of IE is "the study of the flows of materials and energy in industrial and consumer activities; the effects of these flows on the environment; and the influence of economic, political, regulatory, and social factors on the flow, use, and transformation of resources."7

Environmental impact, either for a nation or our species as a whole, can be expressed as the product in a master equation comprising three terms: population, gross domestic product per capita (economic growth), and environmental impact per dollar of GDP. Citizens in every field can advance the goals of SD. The engineering profession can contribute by working to reduce the last term of this equation, the effects of technology on natural resources and on environmental quality.

For engineers, the study and application of IE can be restated simply as follows: the design, construction, and use of industrial processes and products with full knowledge of the environmental consequences. The IE mode of operation examines processes and products (including buildings, infrastructure, transport, and communication systems) from both perspectives: commercial competitiveness and environmental interactions. Industrial activities must be performed with full consideration of where the feed materials come from and what happens to the products and byproducts of the activity.

Like its synonymous branch of biology, IE rejects the concept of waste. Nature, with time, reuses all materials highly efficiently. In the industrial world, discarding materials that were extracted from the Earth at high cost, like copper, is unwise. What we call wastes are residues that we have not yet learned to reuse efficiently. At present one ton of used computers, which originally had a value of close to $200,000, has a scrap market value of only $60 (and many used computers actually end in landfills, at a "tipping fee" cost of $50 per ton, for lack of adequate collection and reprocessing systems). Restoring value to all that squandered material is a considerable engineering challenge.

In less than a decade, IE has become much more than a concept and a lofty definition. It includes new methodologies, such as Life Cycle Assessment (LCA) and Design for the Environment, which some companies have incorporated into existing computer-aided design and manufacturing systems. In LCA, the process or product designer is guided through assessment of all stages in the life of the product, including feed materials, primary processing, manufacturing, use, and recycling or disposal. Engineers provided with measures (e.g., environmental load units) for assessing each candidate material or component can make better decisions in selecting the right material and process, for both the market and the environment.

The most important lesson from the application of IE is that environmental control need not be the "end-of-pipe" cost burden of the past but the conservation of natural capital, the prevention of pollution, and the source of commercial advantage. Engineers in all disciplines, who for decades have built bridges of imagination between scientific knowledge and practical applications, can be instrumental in humanity's slow but unavoidable shift from unbridled to sustainable development.

Related links...

  • Society for Mining, Metallurgy, and Exploration

  • Mining History Network, University of Exeter, U.K.

  • The Copper Page, Copper Development Association

  • Gil Friend, The New Bottom Line (concrete examples of IE)

  • GNET: the environmental technology, business, and clean-up network

  • Earth Pledge Foundation, New York

  • Center of Excellence for Sustainable Development: Industrial Ecology

  • Program for the Human Environment, Rockefeller University

  • Society of Environmental Toxicology and Chemistry

  • Life Cycle Assessment (commercial: SimaPro LCA software)

  • Ecocycle: newsletter on product life-cycle management

  • Industrial Ecology: Some Directions for Research

  • The Virtual Ecology of Industry, PHE, Rockefeller

  • Work and Environment Initiative, Cornell

  • Center of Excellence for Sustainable Development

  • Green Institute

  • Environmental Industry, Extended Enterprise Service

  • Civano OnLine (ecologic community in Arizona)

  • MIT Program on Technology, Business, and Environment

  • The World Wide Web Virtual Library: Sustainable Development

  • Development: Internet Resources Collection, Institute for Global Communications

  • Communications for a Sustainable Future, University of Colorado

  • International Institute for Sustainable Development

  • Center for Excellence in Sustainable Development: site map

  • Centre Entreprise-Environment, Université Catholique de Louvain, Belgium

  • Nicholas Gertler, "Industrial Ecosystems: Developing Sustainable Industrial Structures," Indigo Development

  • IndEco Strategic Consulting, Inc.

  • Journal of Industrial Ecology

  • Global Business Network Book Club Reviews: Hardin Tibbs, Industrial Ecology: An Environmental Agenda for Industry

  • Ecological Operating Systems, Gil Friend and Associates

  • Industrial Ecology references, Technology, Business, and Environment program, MIT

  • Industrial Ecology Center, U.S. Army, Picatinny Arsenal, N.J.

  • SD/IE white paper, Institute of Electrical and Electronics Engineers

  • Fifth international meeting, International Society for Ecological Economics

  • Center for Environment and Development, Norwegian University of Science and Technology, Trondheim

  • Business Industrial Ecology table of contents, CESD

  • The Electronic Network of Environmental Professionals (environmental industry forum in LISTSERV e-mail format)

  • Report: "Global Change and Sustainable Development: Critical Trends," United Nations Department for Policy Coordination and Sustainable Development


    1. Themelis NJ, McKerrow GC, Tarassoff P, Hallett GD. The Noranda process for the continuous smelting and converting of copper concentrates. J. of Metals (April 1972): 25-32; Tarassoff P. Process R&D: The Noranda process. Metall. Trans. B, 15B (1984): 411-432.

    2. Themelis NJ. The golden age of extractive metallurgy. Vuoritellisuus Bergshanteringen, Helsinki, 51, no. 2 (1993): 90-95; Themelis NJ. Pyrometallurgy near the end of the 20th century.J of Minerals, Metals and Materials Society 46 (Aug. 1994): 51-57.

    3. Prain R. Copper: The Anatomy of an Industry (London: Mining Journal Books, 1975).

    4. American Bureau of Metal Statistics, Non-ferrous Metal Data, 1974-1990 series (Secaucus, NJ: 1974-1990); Universal World Atlas (Rand McNally, 1991): 233-256.

    5. Kellogg HH. Towards a materials conservation ethic. Metall. Trans. B, 9B (1978): 491-500.

    6. Wernick IK, Ausubel JH. National materials flows and the environment. Annual Reviews of Energy and Environment 20 (1995): 462-492.

    7. Allenby BR, Richards DJ (eds). The Greening of Industrial Ecosystems (Washington: National Academy Press, 1994), 211; IE-UNEP (Oct. 1995): 44.

    NICKOLAS J. THEMELIS, Ph.D., is director of the Earth Engineering Center, Stanley-Thompson professor of Chemical Metallurgy, and acting chairman of the Henry Krumb School of Mines at Columbia University. The School of Mines, the first mining and metallurgical department in the United States, has now been designated by the Fu Foundation School of Engineering and Applied Science as the Department of Earth and Environmental Engineering, the first of its kind in the world.

    Photo Credits: Photos and special effects, Howard R. Roberts