Sustainability in Engineering Education and Research at U.S. Universities

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Sustainability in Engineering

Education and Research at U.S.

Universities

C Y N T H I A F . M U R P H Y * D A V I D A L L E N

University of Texas, Austin B R A D E N A L L E N B Y Arizona State University, Tempe J O H N C R I T T E N D E N

Georgia Institute of Technology, Atlanta C L I F F I . D A V I D S O N

C H R I S H E N D R I C K S O N H . S C O T T M A T T H E W S Carnegie Mellon University, Pittsburgh

Questionnaire results indicate that sustainable, or “green”,

engineering is securing its foothold in U.S. academic programs.

In December 2003, Environmental Science & Technology (ES&T) published a special issue on the Principles of Green Engineeringsengineering for sustainability. Two dozen papers described approaches to evaluating the environmental footprints of products and processes, green design methods and case studies, and education reform. The papers were organized using a framework of 12 principles of Green Engineering (1), which paralleled the 12 principles of green chemistry identified by Anastas and Warner (2) and appear in Table 1. The papers reflected growth in engineering research and education addressing sustainability, driven by societal attention to environmental issues, and increased funding for research in sustainable engineering.

After 5 years, it is reasonable to ask how well these principles of Green Engineering, or engineering for sustain-ability, have been incorporated into engineering education and research. To address this question, the Center for Sustainable Engineering (CSE), a collaborative initiative of the University of Texas at Austin, Carnegie Mellon University, and Arizona State University, benchmarked the extent to which sustainability concepts are being incorporated into the research and educational missions of colleges of engi-neering in the U.S. Although it is recognized that there are a number of sustainability efforts in the natural sciences and business schools, as well as stand-alone efforts in sustain-ability, this evaluation was limited to engineering programs for the scope of the analysis to be manageable and to facilitate inter-comparisons of programs.

The primary focus of the benchmarking effort was the distribution and analysis of two questionnaires regarding sustainable engineering education. The first questionnaire

focused on development of sustainable engineering at the program level. It was sent to the heads of all academic units within the U.S. that included at least one Accreditation Board for Engineering and Technology (ABET) program. More than 1300 letters were sent out to department and program heads, and nearly 300 responses were received (a 21% response rate). A more detailed questionnaire was sent to 327 additional engineering faculty identified as sustainable engineering champions. The identification of these individuals was based on recommendations from department and program heads, 10-year publication records from technical journals that focus on issues of sustainability (such as theJournal of Industrial EcologyandClean Technologies and Environmental Policy), and attendance at four separate workshops held by the Center for Sustainable Engineering in which>120 faculty members participated. A total of 137 valid responses from this smaller group were received, for a response rate of 43%. These results provide representation by at least one individual from 97 (27%) of all 365 U.S. institutions with engineering programs. Copies of both questionnaires are included in the Supporting Information (SI) for this paper.

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SAUNDERS

Environ. Sci. Technol.2009,43,5558–5564

55589ENVIRONMENTAL SCIENCE & TECHNOLOGY / VOL. 43, NO. 15, 2009 10.1021/es900170m 2009 American Chemical Society

Published on Web 07/06/2009

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While the overall representation of engineering programs is<30% in the results reported here, the representation of highly rated engineering programs is more extensive. Three-fourths (73%) of engineering schools with Ph.D. programs and that ranked in the top 100 had at least one department that participated in the questionnaire (ranking numbers are in ref3). Since more than 80% of the respondents reported some level of sustainable engineering course activity and 70% reported some sustainable engineering research activity, it is clear that teaching and research in sustainable engi-neering are part of the activities of most of the top 100 engineering programs in the U.S. As described in the full report, available at the CSE website (4, 5), the activity is most extensive at the largest institutions.

The findings from the benchmarking effort reported in this paper are presented in two major categories: (1) courses, course modules, and curricula, and (2) research. Since the findings are not a census of activities, the findings should be

considered directional rather than definitive. In addition, in conducting the benchmarking, a comprehensive definition of either “sustainability” or “sustainable engineering,” was, intentionally, not provided. The goal of the benchmarking was to have engineering programs self-identify the content that constitutes sustainable engineering. This means that there is some heterogeneity in the nature of the responses. While this reflects the state of the art in sustainable engineering educational practices, it increases the subjectivity of the findings.

Curricula, Courses, and Course Modules

More than 80% of the respondents, which as noted above include 73% of schools with Ph.D. programs that ranked in the top 100, reported some level of course activity. While most of the top 100 programs offer courses, a much smaller number of programs offer degrees. A total of one-quarter

TABLE 1

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System Scales and Topics, and Associated Green Engineering Principles

system size description topics(green engineering principle)

gate-to-gate decisions made within a single facility

or corporation by engineering and/or business units (i.e., site- or industry-sector-specific activities)

process design, including material and/or energy reduction3,4

material or chemical selection9

product design for a single phase of a product’s life (e.g., design for recycling)9,11

pollution prevention2

media-based (i.e., air, water, solid waste) regulations1

cradle-to-grave decisions made by different entities

over the life of a product or sector activity; activities are typically analyzed as sequential events (i.e., life cycle analysis)

resource availability and economics12

consumer behavior5,8

product utility5,7,8

reuse and recycling options4,7,9,11

product based legislation (e.g., WEEE) and standards (e.g., ISO 14000) life cycle inventory development10

inter-industry

(industrial symbiosis)

decisions made by two or more entities (corporations or other stakeholders), often involving multiple sectors; the analysis typically captures spatial as well as temporal effects and scales, although temporal scales may be compressed such that activities are presumed to occur in parallel (i.e., industrial ecology)

material flow analysis4,10

by-product synergy6,10

eco-industrial development10

multiple/nested LCA analysis6,10

input-output analysis (either physical or economic)10

extra-industry decisions made by multiple stakeholders,

including industry, non-governmental organizations (NGOs),

policy makers, consumers, etc.

policy development (current and historical)

consumption patterns and preferences5,8

eco-industrial development10

multiple/nested LCA analysis6,10

input-output analysis

(either physical or economic)10

1_{Principle 1: Designers need to strive to ensure that all material and energy inputs and outputs are as inherently}

nonhazardous as possible.2_{Principle 2: It is better to prevent waste than to treat or clean up waste after it is formed.} 3_{Principle 3: Separation and purification operations should be designed to minimize energy consumption and materials}

use. 4_{Principle 4: Products, processes, and systems should be designed to maximize mass, energy, space, and time}

efficiency.5_{Principle 5: Products, processes, and systems should be “output pulled” rather than “input pushed” through}

the use of energy and materials.6_{Principle 6: Embedded entropy and complexity must be viewed as an investment when}

making design choices on recycle, reuse, or beneficial disposition.7_{Principle 7: Targeted durability, not immortality, should}

be a design goal.8_{Principle 8: Design for unnecessary capacity or capability (e.g., “one size fits all”) solutions should be}

considered a design flaw.9_{Principle 9: Material diversity in multicomponent products should be minimized to promote}

disassembly and value retention.10_{Principle 10: Design of products, processes, and systems must include integration and}

interconnectivity with available energy and materials flows.11_{Principle 11: Products, processes, and systems should be}

designed for performance in a commercial “afterlife”.12_{Principle 12: Material and energy inputs should be renewable}

rather than depleting.

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(23%) of respondents (65 departments and 53 institutions) offer Bachelor’s or Master’s degree programs related to sustainability. Minors and certificate programs in sustain-ability were not specifically investigated for reasons including the fact that they are often not housed within engineering departments.

Curricula.To summarize the results of the benchmarking

effort in the area of curricula and degree programs, examples of specific programs and activities with features that are unusual are described. The goal of identifying these programs and practices of note is not to endorse specific approaches, but rather to identify potential pathways that the sustainable engineering education community may follow as it estab-lishes common practices.

At the graduate level, degree programs include inter- and intra-departmental programs and multi-institutional pro-grams. The University of Michigan (Ann Arbor) and Yale University (New Haven, CT) provide examples of inter-departmental curricula with joint Master’s degree programs: Michigan’s College of Engineering has partnered with its School of Natural Resources and Environment; Yale’s College of Engineering has partnered with its School of Forestry and Environmental Studies. Both of these programs are new, having launched in 2007. The Michigan program offers three tracks: sustainable energy systems, sustainable design and manufacturing, and sustainable water resources, with re-quired courses from both engineering and natural resources and a final Master’s report. The Yale program also involves core courses from both the School of Engineering (water resources, industrial ecology, and sustainable design) and the School of Forestry and Environmental Studies (envi-ronmental science, social ecology, economics, and policy and law).

A longer-standing program is offered through the De-partment of Engineering and Public Policy (EPP) at Carnegie Mellon University (Pittsburgh, PA). For more than 30 years, this program has offered Bachelor of Science (B.S.) and Doctor of Philosophy (Ph.D.) programs to students interested in both technical and policy dimensions of topics such as energy and environment. The undergraduate program is available

only as a double major with any of the traditional engineering departments or with computer science. The core of the program consists of selected courses in decision analysis, economics, statistics, and technical topics, plus two project courses where students work in teams on a current un-structured problem for an outside client. Graduate student requirements include courses in policy analysis, economics, and probability and estimation methods for engineering systems. Graduate students can pursue a single major in EPP or a double major. This program can be contrasted with the programs at Yale and Michigan in that it combines engineering, environment, and policy into programs that reside within the College of Engineering; most faculty in the EPP have dual appointments there and with one of the traditional engineering departments or computer science. Another approach to graduate engineering education in sustainability has been developed by the University of Pittsburgh. The Sustainable Engineering Fellowship program, funded through the National Science Foundation’s (NSF’s) Integrative Graduate Education and Research Traineeship (IGERT) Program, focuses on construction and water use, and includes topics such as new materials, reducing energy use, and life cycle design and planning. The program partners with the University’s Center for Latin American Studies and the University of Campinas in Sao Paulo, Brazil, to host an 8-month international experience in green construction and sustainable water use for the graduate students participating in the program.

At the undergraduate level, an unusually comprehensive approach to undergraduate education in sustainable engi-neering has been developed by Virginia Tech (Blacksburg). There students from any undergraduate engineering program can choose a concentration related to sustainable (green) engineering. Students take a total of 18 semester credit hours of courses with sustainable engineering content: 6 h within their major, 6 h of interdisciplinary electives, and 6 h that are core to the option. Depending on the specific engineering department, between 120 and 136 hours are needed for graduation; thus these courses constitute 13-15% of total required credits. The two core courses provide a general

FIGURE 1. Courses described by sustainable engineering (SE) champions were grouped into four categories: Sustainable Engineering (dedicated sustainable engineering courses), Traditional Engineering courses with sustainable engineering content, Cross-disciplinary courses offered jointly with a non-engineering department, and Sustainable Engineering Technology courses which addressed technologies viewed as enabling for sustainability.

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background in environmental science and an introduction to life cycle assessment (LCA) approaches to engineering problem solving. The consistent approach across all engi-neering departments and the common core courses, taken by engineers from all departments, make this program unusual.

A different approach, with a different undergraduate audience can be found at the University of Texas (Austin). Engineering faculty there have developed and taught uni-versity courses with no pre-requisites that are offered as part of a reform of the undergraduate core curriculum. The reform requires that all university students take “Signature Courses” that teach multi-disciplinary approaches to addressing complex and pervasive societal problems. A course titled “Sustaining a Planet” describes material and energy cycles in the natural world (e.g., the carbon cycle), how natural systems interact with and are modified by engineered systems (e.g., how carbon emissions from engineered systems perturb global carbon cycles), and how students’ lives fit into these systems. Signature courses have also been developed on more focused topics in sustainable engineering (e.g., energy systems). These courses provide insight into how sustainable

engineering topics can be delivered to broad audiences at the undergraduate level.

These exemplars of educational approaches at the gradu-ate and undergradugradu-ate levels illustrgradu-ate the diversity of activities captured in the benchmarking. While program structures are highly diverse, courses and course content show more of a consensus approach.

Courses and Course Modules.The benchmarking effort

indicates that courses and course modules are extensively used to incorporate sustainability content and concepts into engineering degree programs by four dominant means. The first and most common approach is to develop dedicated sustainable engineering courses; these tend to focus on the use of tools designed to address complex systems at relatively large scales (such as LCA). Another slightly less common approach is to integrate sustainable engineering concepts into traditional courses. Two additional approaches, each used in<15% of the courses reported in the benchmarking, focus on the technologies predicted to be important in developing sustainable engineering solutions (such as carbon capture or solar power) or offer courses in conjunction with

FIGURE 2. Coverage of topics at (a) gate-to-gate and (b) cradle-to-grave scales in sustainable engineering courses.

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a non-engineering department as a cross-listed or interdis-ciplinary course offering.

Figure 1 depicts the number of courses reported in the benchmarking in each of the four categories, along with the fraction of the course content that is dedicated to sustainable engineering. Nearly all (94%) of the courses categorized as dominated by sustainable engineering material were de-scribed as containing>50% sustainable (SE) content; the respondents were not given a definition of sustainable engineering when asked to assess the content of their courses, but were given examples of material that should be con-sidered as addressing sustainable engineering (e.g., entries in Table 1). More than two-thirds of courses categorized as traditional engineering with sustainable engineering content are described as having a>10% sustainable engineering focus; more than one-third have>25%.

Benchmarking information on the content of the material in the courses was assembled and organized in a variety of ways. One way of organizing the information is to recognize different scales of design; four categories, representing different scales, were used. The smallest scale, referred to as gate-to-gate, addresses the design of processes and manu-facturing of products (e.g., the design of an auto part). The next larger scale, referred to as cradle-to-grave, examines the entire life cycle of a product or process (e.g., the life cycle of a vehicle). At an even larger scale, the relationship between engineering designs and the infrastructures that support them (inter-industry, e.g., the roads and fuels that support vehicles) can be examined. A final scale, referred to as extra-industry, addresses the relationship between designs and social and cultural norms (e.g., the relationship between vehicle use and urban planning). Table 1 identifies these scales and gives examples of the types of topics covered at each scale. The topics identified in Table 1 are matched with the green engineering principles identified by Anastas and Zimmerman (1). All of the principles are represented along with some additional topics which are primarily at the inter-industry and extra-industry scales.

Most of the focus of sustainable engineering courses reported in this benchmarking tends to be at the gate-to-gate or cradle-to-grave scales. More than three-quarters of courses cover at least some of the topics listed in Table 1 at these two scales. In contrast, half of the courses contain no content at the inter-industry or extra-industry scales, and consequently some sustainable engineering and green engineering principles (e.g., principles 6 and 10) are frequently not covered in engineering curricula. As shown in Figure 2, there is some variability among engineering disciplines in the coverage of topics. For example, general engineering programs are less likely to cover regulations targeted at specific environmental media, while chemical and materials engineering programs are more likely than other engineering disciplines to cover pollution prevention. Despite these differences, there is an overall trend among engineering programs to cover gate-to-gate and cradle-to-grave scales, and the principles of green engineering in their courses.

The information on course content collected in the benchmarking effort can also be organized topically. Table 2 lists course themes that were identified by examining readings and texts associated with the courses. A full listing of the materials is available in the final report for the project (5). Energy and life cycle approaches emerge as particularly dominant themes, although more general system approaches and water resources are also common topical areas.

More detail concerning the topics covered in sustainable engineering courses is provided by a group of course modules available through the CSE. The CSE has organized workshops to bring together faculty members who are developing courses or sections of courses on sustainable engineering. Participants who attended one of the CSE workshops were

required to submit a module to an electronic library linked to the CSE web site (4). Current and planned modules address LCA, ecological footprints, introductory sustainable engi-neering, green construction, water and air quality, renewable energy, metalworking fluids, climate change, public under-standing of sustainable engineering, nanomanufacturing, infrastructure development, waste minimization, green materials, and sustainable design. These modules provide complementary, and in some cases, more detailed

informa-TABLE 2

.

Themes Observed in Books and Readings

theme no. of times dominant theme of reading or book no. of times addressed to a notable degree if addressed, % of time it was dominant theme

energy & power generation

84a ₂₀₃a _41%a

LCA (life cycle assessment) 67a ₁₄₈a _45%a business & economics 39a ₁₈₂a _21% industrial ecology 38a ₆₅ _58%a systems, metrics, & information management 38a 139a 27% water 36a ₇₁ _51%a industrial processes 33a 123a 27% humanities (philosophy, ethics, history) 31a ₁₀₉a _28%a

end of life and waste management

26a ₉₈a _27%

design 22a ₁₂₇a _17%

pollution prevention, fate & transport

22 80 28%a transportation 20 58 34%a policy 18 157a _11% biogeochemical systems (incl. ecology) 16 77 21% materials 16 69 23% building & construction 15 45 33%a urbanism and urban systems 14 36 39%a climate change 13 62 21% agriculture and land use 12 81 15% natural resources 10 97a _10% material flow analysis 6 16 38%a human health 2 49 4%

a_{Indicates top 10 in number of times the theme was}

addressed, number of times it was used as one of multiple themes, or the number of times it was the dominant theme.

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tion about content of courses than could be represented in benchmarking questionnaires.

Research

Research funding in sustainable engineering is substantial. The benchmarking effort identified roughly a quarter of a billion dollars in funding. The dominant sponsor of this research is the NSF and consequently median project sizes (∼$300,000) and durations (36 months) follow NSF norms. The funding is concentrated in top tier institutions; more than half of the research funding is found at top 40 Ph.D. granting institutions. Student participation in these research programs is extensive: more than 500 graduate and roughly 400 undergraduate students are actively engaged.

As shown in Table 3, topical areas for research are heavily concentrated in energy and power systems. However, publication and other dissemination of results are not primarily directed toward energy conferences and journals; readers may not be surprised to learn that the two dominant journals that sustainable engineering re-searchers monitor and publish in areES&Tand theJournal of Industrial Ecology.

The approaches that different institutions take in con-ducting sustainable engineering research can be categorized in the same manner as teaching in this area. Categories identified in the full benchmarking report include (1) integration of sustainable engineering concepts to evaluate or improve an existing infrastructure or industry sector, (2) development of technologies that will facilitate sustainable behavior and systems, (3) interdisciplinary efforts to address complex systems, and (4) sustainable engineering tool development and optimization.

Conclusion

The progress of sustainable engineering is at a critical juncture. As documented in the benchmarking study and summarized in this paper, there is significant “grass-roots” activity in education and research related to sustainable engineering. While individual programs are well structured and course materials are addressing common themes and topics, there is little overall organization at a national level. The principles of green engineering (1), and recommended bodies of knowledge in sustainable engineering, such as those developed by the American Academy of Environmental Engineers (6), provide frameworks for education and re-search. The path forward will require the development of a set of community standards for sustainable engineering. The benchmarking described here is an inventory of what is currently available and can serve as a resource as standards develop.

All of the authors are founding members of the Center for Sustainable Engineering. Cynthia Murphy is a research associate with the Center for Energy and Environmental Resources at the University of Texas at Austin. David Allen is the Gertz Regents Professor in Chemical Engineering and director of the Center for Energy and Environmental Resources at the University of Texas at Austin. Brad Allenby is Lincoln Professor of Engineering and Ethics, a professor of civil, environmental, and sustainable engineering, and founding director of the Center for Earth Systems Engineering and Management, at Arizona State University. John Crittenden is director of the Brook Byers Institute of Sustainable Systems at the Georgia Institute of Technology. Cliff Davidson is a professor of civil & environmental engineering and engineering & public policy at Carnegie Mellon University, and is director of the Center for Sustainable Engineering. Chris Hendrickson is the Duquesne Light Company Professor of Engineering and co-director of the Green Design Institute at Carnegie Mellon University. Scott Matthews is an associate professor in civil & environmental engineering and engineering & public policy at Carnegie Mellon and research director of the Green Design Institute. Please address correspondence regarding this article to [email protected].

Acknowledgments

The U.S. Environmental Protection Agency (EPA), through Grant Agreement X3-83235101, provided funding for this work. Although the research described in this article has been funded in part by the EPA, it has not been subjected to the Agency’s peer and policy review and therefore does not necessarily reflect the views of the agency, and no official endorsement should be inferred.

Supporting Information Available

Copies of the two questionnaires used to gather the data presented in this analysis. This information is available free of charge via the Internet at http://pubs.acs.org.

TABLE 3

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Projects

theme no. of projects with theme dominant no. of projects where theme is significant rank of theme in course readings

energy & power generation

61a ₇₇a ₁

industrial processes 25a ₄₂a ₇

materials 22a ₃₂a ₁₅a

end of life and waste management

20a

26a

9

building & construction 16a

20a 16a water 14a ₂₂a ₆ transportation 13a ₂₀a ₁₂ humanities (including education) 10a ₁₅ ₈ climate change 9 9 18a human health 9 15 22a pollution prevention, fate & transport

9 19 11 systems, metrics, & information management 9 24a ₅ biogeochemical systems (including ecology) 4 9 14 industrial ecology 3 5 4 agriculture and land use 2 5 19a business & economics 2 13 3 design 2 8 10 LCA

(life cycle assessment)

2 19 2 material flow analysis 2 2 21a urbanism and urban systems 2 4 17a

a_{Indicates top 8 dominant themes in projects and the 8}

themes that were most commonly identified as a

significant component of projects.

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Literature Cited

(1) Anastas, P. T.; Zimmerman, J. B. Design through the twelve principles of green engineering.Environ. Sci. Technol.2003,37 (5), 94A–101A.

(2) Anastas, P. T.; Warner, J.Green Chemistry: Theory and Practice; Oxford University Press: London, 1998.

(3) U.S. News & World Report. Best Colleges 2009: Premium Online Edition, Undergraduate Engineering Programs, 2008; accessed September, 2008 (available for a fee at http://colleges.usnews. rankingsandreviews.com/college/engineering).

(4) The Center for Sustainable Engineering (CSE); www.csengin.org. (5) Allen, D.; Allenby, B.; Bridges, M.; Crittenden, J.; Davidson, C.; Hendrickson, C.; Matthews, S.; Murphy, C.; Pijawka, D. Bench-marking Sustainability Engineering Education; Final Report EPA Grant X3-83235101-0, 2008; available at www.csengin.org. (6) American Academy of Environmental Engineers. Environmental

engineering body of knowledge summary report.Environ. Eng. 2008,44(3), 21–33.

ES900170M

Sustainability in Engineering Education and Research at U.S. Universities