Programs and Communities

Better methods are necessary to fully account for anthropogenic impacts on ecosystems and the essential services provided by ecosystems that sustain human life. Current methods for assessing sustainability, such as life cycle assessment (LCA), typically focus on easily quantifiable indicators such as air emissions with no accounting for the essential ecosystem benefits that support human or industrial processes. For this reason, more comprehensive, transparent, and robust methods are necessary for holistic understanding of urban technosphere and ecosphere systems, including their interfaces. Incorporating ecosystem service indicators into LCA is an important step in spanning this knowledge gap.

For urban systems, many built environment processes have been investigated but need to be expanded with life cycle assessment for understanding ecosphere impacts. To pilot these new methods, a material inventory of the building infrastructure of Phoenix, Arizona can be coupled with LCA to gain perspective on the impacts assessment for built structures in Phoenix. This inventory will identify the origins of materials stocks, and the solid and air emissions waste associated with their raw material extraction, processing, and construction and identify key areas of future research necessary to fully account for ecosystem services in urban sustainability assessments. Based on this preliminary study, the ecosystem service impacts of metropolitan Phoenix stretch far beyond the county boundaries. A life cycle accounting of the Phoenix’s embedded building materials will inform policy and decision makers, assist with community education, and inform the urban sustainability community of consequences.

An increase in population and need to protect the planet has created many initiatives and research goals in developing alternatives methods of fueling. Federal and state policies have provided a push for industries to find ways to of reducing their impact on the environment while maintaining competitiveness. In the sector of alternative fuels, large policies such as the Renewable Fuel Standards (RFS) in the United States are making goals to reduce vehicular fuel from coal and oil, and focus on alternative fuels such as ethanol and biodiesel. Along with the RFS and other federal policies, states are introducing independent initiatives to promote the use of alternative fuels.

Research has shown that other crops besides corn can feasibly be used to produce ethanol for fuel use. One of the major crops of interest currently is switchgrass (Panicum Virgatum L.) because of its ability to grow under a variety of weather conditions and soil types. Switchgrass does not require as much maintenance as corn and is a perennial grass that can have high yielding fields for up to 9 years.

This report focuses on the impacts from using switchgrass-derived ethanol to meet the state of Arizona’s policy to have government fleet vehicles operating on alternative fuels. The study uses a life cycle assessment (LCA) approach to evaluate 22 million gallons of ethanol produced in Arizona and stored at fueling stations for use. Impacts in land use, global warming, and water quality are evaluated using software tools and databases in Ecoinvent and Simapro.

The results of the study indicate that the cultivation and harvest phase of the process will contribute the most to negative environmental impacts. According to the study, application of heavy nutrient fertilizer and the machinery needed for the additional agriculture have the potential to contribute over 36 million moles of hydrogen and 89 million CTU eq. to the air, soil, and water.

The City of Phoenix Street Transportation Department partnered with the Rob and Melani Walton Sustainability Solutions Service at Arizona State University (ASU) and researchers from various ASU schools to evaluate the effectiveness, performance, and community perception of the new pavement coating. The data collection and analysis occurred across multiple neighborhoods and at varying times across days and/or months over the course of one year (July 15, 2020–July 14, 2021), allowing the team to study the impacts of the surface treatment under various weather conditions.