5C Class Spotlight: Life Cycle Assessment (LCA)

BY: LAUREN D’SOUZA

In my opinion, the most unique aspect of attending one of the five Claremont Colleges is the ability to take classes at the other four esteemed institutions. As a tour guide at Claremont McKenna, I tout this proudly on all my tours, mentioning one class in particular: Professor Tanja Srebotnjak’s Life Cycle Assessment (LCA) course.

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I am a government and history major at CMC, particularly interested in environmental law and policy. I often mention to those in my tour group that I am by no means an engineer, a materials scientist, a coder, or a professional in any STEM field. However, I know that Harvey Mudd is world-renowned for the aforementioned fields, existing as one of the few STEM-focused liberal arts colleges in the nation.

Feeling the need to expand my horizons beyond my comfort zone of reading constitutional law and analyzing historical documents, and wanting to take a class with the terrific “Prof S,” I registered for Engineering 190X: Life Cycle Assessment and Sustainable Environmental Design, (now offered as Engineering 038) in the fall of my sophomore year.

Life Cycle Assessment, commonly abbreviated as LCA, is a materials engineering technique used to analyze the impacts of goods and services from cradle to grave. The final report analyzes every step of a product’s creation and disposal, including raw materials acquisition and processing, manufacturing, distribution, use and maintenance, and end-of-life management or recycling.

Life Cycle of a Plastic Water Bottle.

Life Cycle of a Plastic Water Bottle.

life cycle water bottle divided into LCA areas

Life Cycle of a Plastic Water Bottle, divided into an LCA’s five primary areas.

LCA reports are divided into four parts: (1) goal and scope definition, (2) inventory analysis, (3) impact assessment (where the majority of input and output analysis occurs), and (4) interpretation. There are several software programs that help an analyst conduct an LCA and calculate impacts; the program we used in Professor Srebotnjak’s class was SimaPro. SimaPro can also calculate more specific LCA reports, such as only analyzing a product or process’s water footprint or carbon footprint.

Professor Srebotnjak, who is also the director of the Hixon Center, has studied and conducted LCAs for much of her professional career. Because this is her area of expertise, I thought Prof S did an exceptional job at teaching this complex field of research and applications to students who had little to no knowledge of it beforehand. Through a combination of lectures covering the theory and methods of LCA, in-class conversations and activities, and labs using SimaPro, we were all able to learn the key components of an LCA, how LCAs are used in practice, and how to conduct an LCA independently.

One of the most exciting and interesting components of the course was our final project. During the last five weeks of the course, we worked in groups to become “green entrepreneurs,” acting as environmental consultants to conduct an LCA on any product or process we chose.

My partner, Ramita Kondepudi HMC ’18, and I assessed the impacts of Amazon packaging (the boxes, fillers, tape, and labels) and transport, comparing different scenarios to find out whether or not it was more “environmentally-friendly” to package multiple Amazon orders in one package or to send them separately. Although we approached the project with the assumption that sending multiple orders in one package would have fewer environmental impacts, we were surprised to find that the differences in impacts for the specific controlled scenario we created were actually negligible. You can read our final report in detail, Life Cycle Assessment of Ordering Amazon Packages in Bulk to the Harvey Mudd College Mailroom (PDF).

Our report taught us the value of conducting an LCA—LCAs can often disprove myths about perceived environmental impacts. Because LCAs address each stage of a product or process’s life cycle, LCA reports can give a more holistic look at a product’s real effect on the environment, including which stage has the largest impact.

For example, Life Cycle Assessment of Hand Drying Systems (PDF) conducted by the Materials Systems Laboratory at MIT compares seven systems for drying hands, including electric air dryers, standard paper towels, and recycled paper towels. In the impact assessment phase of the LCA, the researchers found that a standard air dryer actually had the highest overall environmental impact (measured in global warming potential or GWP), even higher than virgin paper towels, because of the impacts of the electricity needed to power the dryer.

Global Warming Potential of seven different hand drying systems.

Global Warming Potential of seven different hand drying systems.

Now, Professor Srebotnjak teaches the class as a lower level engineering elective, available to all students, regardless of grade level or home institution. Although there were upperclassmen engineering majors in my class, I was still able to understand the course and its objectives as a non-STEM major. I highly recommend this course for any student interested in environmental engineering, environmental consulting, or product stewardship—it is a fantastic way to learn about a unique and expanding field in materials systems.