A collection of scholarly work published by and supporting the Center for Earth Systems Engineering and Management (CESEM) at Arizona State University.
CESEM focuses on "earth systems engineering and management," providing a basis for understanding, designing, and managing the complex integrated built/human/natural systems that increasingly characterize our planet.
Works in this collection are particularly important in linking engineering, technology, and sustainability, and are increasingly intertwined with the work of ASU's Global Institute of Sustainability (GIOS).
A Framework and Review for Using Life Cycle Assessment to Inform Eco-Labeling of Wild Caught Fisheries
Our objectives are to:
1. Review the LCA literature to determine the dominant environmental impact categories in
wild-caught fisheries in order to evaluate which phases are causing the greatest impacts.
2. Determine how these impacts can best be mitigated and develop a framework that seeks
to incorporates LCA into sustainable seafood guides so that consumers can make better-
This framework will include developing meaningful LCA impact categories for sustainable seafood guides. Despite their importance, we considered social factors beyond the scope of this paper.
The research topic for this assignment is shrimp farming in Thailand located throughout the coastal areas of the southern, eastern, and central regions of the country. Thailand’s huge shrimp export driven industry represents one of the largest in the world accounting for over twenty-five percent of food exports out of the country (Sriboonchitta & Wiboonpongse, n.d.).
Specific research questions include:
1. What are the current unsustainable practices in shrimp farm production?
2. In what part of the life cycle should intervention take place?
3. What does a sustainable shrimp farming practice look like in the future?
Our study calculates the estimated difference in water use, energy demands, and CO2 emissions of head lettuce associated with the production (land preparation and growing operations, chemical inputs, irrigation) and the transportation (diesel demand) to the Phoenix metro area from:
1. A local level, defined here as within Maricopa County, Arizona (AZ).
2. From the central coast of California (CA) in Monterey County.
Our research results demonstrate that local lettuce is more resource intensive than non-local or regional produce. Production in Maricopa County has significantly higher (more than double) energy demands and emissions than Monterey County. Irrigation and chemical inputs are the greatest contributors to energy demand in Maricopa, but it is primarily irrigation that contributes to emissions. Comparatively, transportation and chemical inputs are the greatest contributors to energy demand in Monterey, and it is primarily transportation that contributes to emissions.
This life cycle inventory suggests that we need to reconsider the “food miles” framing of the local food debate and whether local food production is a viable sustainable alternative to the current food system in the arid Southwest. However, we also recognize that factors beyond resource-use and emissions affect policymakers’ and consumers’ demands for local foods. Future studies ought to provide a more nuanced look at the issue that also includes social, psychological, and economic factors that influence food policies and purchases. These results have important implications for future water management and suggest the need to pursue more water efficient practices in AZ.
This study analyzes the feasibility of using algae cultivated from wastewater effluent to produce a biodiesel feedstock. The goal was to determine if the energy produced was greater than the operational energy consumed without consideration to constructing the system as well as the emissions and economic value associated with the process.
Four scenarios were created:
1) high-lipid, dry extraction.
2) high-lipid, wet extraction.
3) low-lipid, dry extraction.
4) low-lipid, wet extraction.
In all cases, the system required more energy than it produced. In high lipid scenarios, the energy produced is close to the energy consumed, and a positive net energy balance may be achieved with minor improvements in technology or accounting for coproducts. In the low lipid scenarios, the energy balance is too negative to be considered feasible. Therefore the lipid content affects the decision to implement algae cultivation.
The dry extraction and the wet extraction both require some level of mechanical drying and this makes the two methods yield similar results in terms of the energy analysis. Therefore, the extraction method does not dramatically affect the decision for implementing algae-based oil production from an energetic standpoint. The economic value of the oil in both high lipid scenarios results in a net profit despite the negative net energy. Emission calculations resulted in avoiding a significant amount of CO2 for high lipid scenarios but not for the low lipid scenarios. The CO2 avoided does not account for non-lipid biomass, so this number is an underestimation of the final CO2 avoided from the end products.
While the term "CO2 avoided" has been used for this study, it should be noted that this CO2 would be emitted upon use as a fuel source. These emissions, however, are not “new” CO2 because it has already been emitted and is being captured and recycled. Currently, literature is very divisive on the lipid content present in algae and this study shows that lipid content has a tremendous affect on energy and emissions impacts. The type of algae that can grow in wastewater effluent also should be investigated as well as the conditions that promote high lipid accumulation. The dewatering phase must be improved as it is extremely energy intensive and dominates the operational energy balance.
In order to compete, wet extraction must have a much more significant effect on the drying phase and must avoid the use of the human toxicants methanol and chloroform. Additionally, while the construction phase was beyond the scope of this project it may be a critical aspect in determining the feasibility these systems. Future research in this field should focus on lipid production, optimizing the belt dryer or finding a different method of dewatering, and allocating the coproducts.
A Consequential Life Cycle Assessment of the SCEIP Financing Program for Residential Photovoltaics in Sonoma County, CA: Determining the Life Cycle Carbon and Energy Cost Benefit
Sonoma County, CA is on an ambitious pathway to meeting stringent carbon emissions goals that are part of California Assembly Bill 32. At the county-level, climate planners are currently evaluating options to assist residents of the county in reducing their carbon footprint and also for saving money. The Sonoma County Energy Independence Program (SCEIP) is one such county-level measure that is currently underway. SCEIP is a revolving loan fund that eligible residents may utilize to install distributed solar energy on their property. The fund operates like a property tax assessment, except that it only remains for a period of 20 years rather than in perpetuity.
This analysis intends to estimate the potential countywide effect that the $100M SCEIP fund might achieve on the C02 and cost footprint for the residential building energy sector. A functional unit of one typical home in the county is selected for a 25 year analysis period. Outside source data for the lifecycle emissions generated by the production, installation and operations of a PV system are utilized. Recent home energy survey data for the region is also utilized to predict a “typical” system size and profile that might be funded by the SCEIP program. A marginal cost-benefit calculation is employed to determine what size solar system a typical resident might purchase, which drives the life cycle assessment of the functional unit. Next, the total number of homes that might be financed by the SCEIP bond is determined in order to forecast the potential totalized effect on the County’s lifecycle emissions and cost profile.
The final results are evaluated and it is determined that the analysis is likely conservative in its estimation of the effects of the SCEIP program. This is due to the fact that currently offered subsidies are not utilized in the marginal benefit calculation for the solar system but do exist, the efficiency of solar technology is increasing, and the cost of a system over its lifecycle is currently decreasing. The final results show that financing distributed solar energy systems using Sonoma County money is a viable option for helping to meet state mandated goals and should be further pursued.
Anticipatory LCA seeks to overcome the paucity of data through scenario development and thermodynamic bounding analyses. Critical components of anticipatory LCA include:
1) Laboratory-scale inventory data collection for nano-manufacturing processes and
preliminary performance evaluation.
2) Thermodynamic modeling of manufacturing processes and developing scenarios of
efficiency gains informed by analogous material processing industries.
3) Use-phase bounding to report inventory data in a functional unit descriptive of
Together, these analyses may call attention to environmentally problematic processes or nanotechnologies before significant investments in R&D and infrastructure contribute to technology lock in. The following case study applies these components of anticipatory LCA to single wall carbon nanotube (SWCNT) manufacturing processes, compares the rapid improvements in SWCNT manufacturing to historic reductions in the embodied energy of aluminum, and discusses the use of SWCNTs as free-standing anodes in advanced lithium ion batteries.
While the scientific study of religion is not new, the topic has yet to be approached by Lifecycle Assessment (LCA). This work demonstrates a method for assessing the personal “cost” of “manufacturing” a mature religious adherent, or, a believer committed to a particular faith. By measuring such inputs as personal importance of faith, prayer, religious service attendance, religious experiences, and scripture reading, an assessment can be made of the quantity of such inputs required to engender enduring religious devotion. Ultimately, this study has demonstrated that the data typically collected in longitudinal surveys are insufficient to adequately support any firm quantitative conclusions, but the method proposed is sound and can be exploited when data becomes available.
Meaningful sustainable consumption patterns require informed consumers who understand the actual impact of their actions on a quantitative and tangible basis. Life cycle assessment (LCA) is a tool well suited to achieving this goal, but has only been superficially applied to the analysis of plant-based diets. This analysis looks at a common component of plant-based meat alternatives: a wheat-based protein known as seitan, which is a common substitute for beef. A comparative consequential analysis shows the overall change in environmental impact when 1000 servings of seitan displace 1000 servings of beef. The functional unit for comparison is one serving of seitan or one serving of beef and the system boundaries include production but not distribution, consumption or disposal. Life cycles are created for seitan and beef in the LCA modeling software SimaPro and an analysis is run using the Eco-indicator 99 methodology. The beef life cycle is created using complete existing LCA data, while the seitan life cycle is created using LCA data for constituent materials and processes.
Findings indicate that beef is much more environmentally impactful than seitan, but the largest difference is found in land use change. Significant data quality and uncertainty issues exist due to the data being incomplete or not representative for US processes and the use of proxy processes to estimate industrial processing. This analysis is still useful as a screening tool to show rough differences in impact. It is noted that despite seitan having a lower environmental impact than beef, increasing seitan production will probably have the effect of increasing overall environmental impacts, as beef production is not likely to decrease as a result. Massive changes in consumer purchase patterns are required before reductions in impact can be expected. Recommendations for future work include expanding system boundaries and obtaining industry specific data for seitan production.