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Adding SUSTAINABILITY to the Engineer’s Toolbox: A Challenge for Engineering Educators
The next generation of engineers must be able to design with natural resources that have very different constraints for a wider variety and greater number of end users.
© 2007 American Chemical Society
CLIFF I. DAV IDSON H. SCOTT M ATTHEWS CHRIS T. HENDRICKSON MICH A EL W. BRIDGES CA RNEGIE MELLON UNIV ERSIT Y BR A DEN R. A LLENBY JOHN C. CRITTENDEN YONGSHENG CHEN ERIC W ILLI A MS A RIZONA STATE UNIV ERSIT Y DAV ID T. A LLEN CY NTHI A F. MURPH Y UNIV ERSIT Y OF TEX AS AUSTIN SH A RON AUSTIN U.S. EPA JUly 15, 2007 / Environmental Science & Technology n 4847
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zation has led to a fast-expanding and tremendously variable customer base. Concurrently, the availability of inexpensive natural resources appears to be contracting. Therefore, the next generation of engineers must be able to design with a narrowing and diminishing set of natural resources for a wider variety and greater number of end users. This represents a significant shift in the engineering paradigm and will require that designs be more flexible and robust. Anticipating and accounting for this change is the domain of sustainable engineering. Consistent with the new paradigm, Kates et al. recently noted the emergence of a scientific field known as sustainability science (1). This new discipline considers interactions between nature and society and encourages FIGURE 1 changes in these interactions along a more sustainable trajectory. Societies Changes in global population and ways of dealing with that consume large amounts of nonreenvironmental problems, 1950–present newable materials without recycling, use extensive quantities of nonrenewable energy, and produce wastes that 7 cannot be assimilated naturally by the Environmental, economic, and social sustainability: systems engineering environment are considered less sus6 tainable than societies that consume Green design: resource conservation and improved efficiency small quantities of materials and en5 ergy and produce smaller amounts of Modified operation/control for pollution prevention waste. Kates et al. proposed an initial 4 Dilution and end-of-pipe treatment set of core questions to focus research on nature–society interactions and sugRise of environmental interest 3 gested several tasks to promote a transiLittle concern tion to sustainability. 2 Most engineers in practice today were educated before debates about global warming, diminishing fossil fu1 els, and extinction of species became commonplace. Yet the importance of 0 having engineers who understand the 1930 1940 1950 1960 1970 1980 1990 2000 2010 long-term implications of societal acYear tions is well recognized. Professional engineering societies are currently deDefining the problem veloping a new language about what engineers of Engineers have always been responsive to the pubthe future should be required to know as the new lic about what is needed to improve the quality of century unfolds (2–4). life. Therefore, not surprisingly, as public attitudes Educational institutions are slow to change. Dehave changed over time, so has the role of engineers. spite evidence that human activities worldwide are One example of these changes is in the area of enviunsustainable over relatively short timescales, most ronmental protection, in which the lack of concern U.S. engineering programs have made only minor in the mid-20th century was replaced by calls for progress, if any, in increasing exposure of students action in the 1960s and eventually by widespread to sustainability issues (5). Part of the challenge is legislation. Engineers rose to the challenge by dedefining the new discipline: >350 different definiveloping the technology needed to satisfy the intions of sustainability currently exist (6). Most of the creasingly stringent rules, moving from taller stacks problem, however, is simply reaching the thousands and end-of-pipe technology to pollution prevention of educators who train the engineering workforce, and green design (Figure 1). But even greater chalwhich consists of ~70,000 B.S. graduates per year in lenges lie ahead. the U.S. (7). As implied by Figure 1, engineers have long benefited from a seemingly limitless supply of natural Challenges in engineering education resources from which to draw, including sources and Some headway was made at two workshops in July sinks for society’s wastes. Engineers have realized 2006 conducted by the newly established Center for these benefits while responding to a rather narrow Sustainable Engineering (CSE) at Carnegie Mellon set of customers—those in developed countries. University (CMU). CSE is a partnership of CMU; ArThis situation is about to undergo a rapid reversal. izona State University; and the University of TexAt the dawn of the 21st century, increasing globali as Austin (8). Attended by >60 engineering faculty Global population (billions)
any long-established paradigms for engineering design no longer hold true, because global population increases and standard-of-living improvements have led to a growing demand for world resources. New paradigms that consider the principles of sustainable development must now be incorporated into the design of products and processes. This poses a dilemma for engineering educators, who must rethink their courses and curricula to prepare the new graduates. Teaching engineers to think holistically and incorporate a complexity of new constraints is the challenge facing the nation’s engineering programs.
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members from across the U.S., plus several faculty members and graduate students from the three CSE partner institutions, the workshops explored critical questions in training engineers for the future. Discussions of overarching issues took place in plenary sessions, whereas challenges in specific topics were discussed in breakout groups. In this viewpoint article, we summarize the key challenges identified in the plenary sessions (see box to the right). We suggest focusing on these challenges as a guide for engineering programs that are considering revamping their curricula to incorporate principles of sustainability. Such principles are given in several prior publications (9–17). At the workshops, breakout groups on energy flows, material flows, water resources, and building design all noted the critical role that engineers can play in the design of sustainable systems. At their home institutions, workshop participants are now developing the educational tools to equip engineers to address sustainability challenges in courses that range from introduction to engineering to capstone design projects. Approaches include the development of short modules for classes as well as entire courses on sustainable engineering. Discussions at the workshops revealed several different means of incorporating sustainability concepts into engineering curricula. However, this heterogeneity in scope and methodologies can be both a liability and an asset. It can be problematic in that sustainability is not yet well defined in engineering terms. But in a field as diverse and fluid as sustainability science (1), experimenting with multiple approaches seems the only sound way to proceed.
Challenges for the engineering community A community of educators, well represented at the workshops and convinced of the importance of making good engineering and sustainability synonymous, is moving forward with major changes in engineering courses and curricula. A challenge for this emerging engineering community will be to effectively communicate successes and failures in incorporating sustainability topics into engineering curricula. The ongoing workshops at CSE are dedicated to this exchange in the U.S. A further challenge for this community will be to make these efforts more global. Education for sustainable development is desperately needed to solve problems in developing countries, where financial resources are lacking. Currently, the global engineering community invests a large fraction of its efforts in improving standards of living in industrialized regions or in the wealthiest parts of developing countries. Movement toward sustainability must include efforts to reduce poverty; social as well as environmental solutions must be part of a sustainable society. Some organizations, such as Engineers without Borders and Engineers for a Sustainable World, are beginning to tackle this problem.
Future perspectives Engineers of the future must be familiar with the concepts, language, and sources of information re-
lated to both natural and social sciences. They do not have to become experts in these domains, but they should be comfortable and fluent in dealing with such experts. Engineers must also have an awareness of major dilemmas that are best addressed by other disciplines. In addition, they must be able to develop first-order predictions about potential outcomes and changes to environmental, economic, and social systems that result from engineering decisions. Only then can the possibility of undesirable, unintended consequences be minimized.
Challenges to be addressed when sustain ability issues are incorporated into engineer ing curricula • Consider sustainability in all engineering decisions. Because all engineering affects the environment in some way, sustainability should be taught as an essential part of every decision. The eventual goal is to have sustainability principles considered routinely as elements of “good engineering”. • Account for humanistic issues. Engineers must have a solid understanding of issues beyond scientific and technical matters. Different viewpoints in ethics and social responsibility as well as cultural differences play a major role in sustainable-engineering decisions. • Account for the natural environment. A one-size-fits-all model is no longer acceptable when products and processes are designed. Consideration of local conditions and availability of materials and energy along with the design constraints can reduce adverse environmental impact. • Keep up-to-date. It is impossible in a 4-year university curriculum to teach more than a small fraction of what engineers on the job would need to know about sustainability. Natural curiosity and lifelong learning for all engineers are crucial as the field evolves. • Focus on process rather than endpoint. Defining endpoints for sustainable engineering problems is difficult. Thus, education in this discipline may be most effective by exploring processes by which solutions can be found. • Encourage diversity within the profession. End users will be from increasingly diverse cultures and socioeconomic groups as globalization continues, and therefore the engineering profession must expand its membership to achieve greater diversity. This will also promote better use of talent from currently underrepresented groups. In some ways, the incorporation of societal and environmental issues into engineering is not new. Engineered products and systems have always influenced and been influenced by the social and economic systems in which they are used. What is new is the role of the engineer in considering these influences. In this new century, when routine computation and manufacturing are becoming the province of machines, successful engineers must be able to integrate information across the scales and time horizons that are the province of sustainability. Engineers taught to design sustainable systems will be well prepared to face this new world of engineering. JUly 15, 2007 / Environmental Science & Technology n 4849
Cliff I. Davidson is a professor of civil and environmen tal engineering and of engineering and public policy and is director of CSE; H. Scott Matthews is an associate professor of civil and environmental engineering and of engineering and public policy; Chris T. Hendrickson is the Duquesne Light Co. Professor of Engineering; Mi chael W. Bridges is an assessment specialist at the Office of Technology for Education; all are at Carnegie Mellon University. Braden R. Allenby is the Lincoln Professor of Ethics and Engineering, a professor of civil and en vironmental engineering, and a professor of law; John C. Crittenden is the Richard Snell Presidential Chair Professor of Civil and Environmental Engineering; Yong sheng Chen is an associate research professor of civil and environmental engineering; and Eric Williams is an as sistant professor of civil and environmental engineering; all are at Arizona State University. David T. Allen is the Melvin H. Gertz Regents Chair in Chemical Engineering and Cynthia F. Murphy is a research associate in the Center for Energy and Environmental Resources; both are at the University of Texas Austin. Sharon Austin is a chemical engineer in the Economics, Exposure, and Technology Division, Office of Pollution Prevention and Toxics, EPA. Address correspondence about this article to Davidson at
[email protected].
Acknowledgments This work was funded by National Science Foundation grant DUE-0442618 and EPA grant X3832351-01-0, which are providing support for CSE.
References
(1) Kates, R. W.; et al. Sustainability Science. Science 2001, 292, 641–642. (2) World Federation of Engineering Organisations. Engineers and Sustainable Development; Rio+10 Report by the Committee on Technology. Cited in the WFEO Biennial Report 2001–2003; www.wfeo.org. (3) ABET Engineering Accreditation Commission. Criteria for Accrediting Engineering Programs; ABET, Inc.: Baltimore, MD, 2006; www.abet.org. (4) Frontiers of Environmental Engineering Education, NSF Workshop, Tempe, AZ, Jan 8–10, 2007. (5) CSE. EPA Benchmark Assessment Project, CSE, 2006. (6) Engineering Design for Sustainable Development. Centre for Sustainable Development, University of Cambridge, UK; www7.caret.cam.ac.uk/sustainability.htm. (7) National Science Teachers Association, www.nsta.org. (8) CSE, www.csengin.org. (9) Robert, K. -H.; et al. A Compass for Sustainable Development. Int. J. Sustain. Dev. World Ecol. 1997, 4, 79–92. (10) Anastas, P. T.; Zimmerman, J. B. Design Through the 12 Principles of Green Engineering. Environ. Sci. Technol. 2003, 37, 95A–101A. (11) Fiksel, J. Designing Resilient, Sustainable Systems. Envi ron. Sci. Technol. 2003, 37, 5330–5339. (12) Mihelcic, J. R.; et al. Sustainability Science and Engineering: The Emergence of a New Metadiscipline. Environ. Sci. Technol. 2003, 37, 5314–5324. (13) Vanegas, J. A. Road Map and Principles for Built Environment Sustainability. Environ. Sci. Technol. 2003, 37, 5363–5372. (14) Ritter, S. K. A Green Agenda for Engineering. Chem. Eng. News 2003, 81 (29), 30–31. (15) Allen, D. T.; Shonnard, D. R. Green Engineering; Prentice Hall: Upper Saddle River, NJ, 2002. (16) Graedel, T. E., Allenby, B. R. Industrial Ecology; Prentice Hall: Upper Saddle River, NJ, 2003. (17) Hendrickson, C. T.; et al. Environmental Life Cycle Assess ment of Goods and Services: An Input-Output Approach; Resources for the Future: Washington, DC, 2006.
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