Study Background: Researchers at ASU have determined that significant energy and environmental benefits are possible in the Phoenix metro area over the next 60 years from transit-oriented development along the current Valley Metro light rail line. The team evaluated infill densification outcomes when vacant lots and some dedicated surface parking lots are repurposed for residential development. Life cycle building (construction, use, and energy production) and transportation (manufacturing, operation, and energy production) changes were included and energy use and greenhouse gas emissions were evaluated in addition to the potential for respiratory impacts and smog formation. All light rail infill scenarios are compared against new single family home construction in outlying areas.

Overview of Results: In the most conservative scenario, the Phoenix area can place 2,200 homes near light rail and achieve 9-15% reductions in energy use and emissions. By allowing multi-family apartments to fill vacant lots, 12,000 new dwelling units can be infilled achieving a 28-42% reduction. When surface lots are developed in addition to vacant lots then multi-family apartment buildings around light rail can deliver 30-46% energy and environmental reductions. These reductions occur even after new trains are put into operation to meet the increased demand.

In his writings over the past decade, Brad Allenby has proposed (at least) 16 principles of sustainable engineering (see references) that are collectively known as the Earth Systems Engineering and Management (ESEM) principles. These principles have merit and applicability in many disciplines and domains of discourse, but are sometimes awkward to use due to the quantity of words required to accurately express their meaning. In light of this, it has become necessary to formulate a simplified list of “abbreviated tags” for ease of reference in conversation and concise writing. This list of tags also makes the principles immediately accessible to those who may want to pursue the more thorough definitions offered by Allenby. The following tags have been proposed for use when a concise phrasing is required. The citation provided after the tag is, in my opinion, the most complete expression of Allenby’s thought on this principle. It can be used when citing the principle in written assignments or publications.

Public transportation systems are often part of strategies to reduce urban environmental impacts from passenger transportation, yet comprehensive energy and environmental life-cycle measures, including upfront infrastructure effects and indirect and supply chain processes, are rarely considered. Using the new bus rapid transit and light rail lines in Los Angeles, near-term and long-term life-cycle impact assessments are developed, including consideration of reduced automobile travel. Energy consumption and emissions of greenhouse gases and criteria pollutants are assessed, as well the potential for smog and respiratory impacts.

Results show that life-cycle infrastructure, vehicle, and energy production components significantly increase the footprint of each mode (by 48–100% for energy and greenhouse gases, and up to 6200% for environmental impacts), and emerging technologies and renewable electricity standards will significantly reduce impacts. Life-cycle results are identified as either local (in Los Angeles) or remote, and show how the decision to build and operate a transit system in a city produces environmental impacts far outside of geopolitical boundaries. Ensuring shifts of between 20–30% of transit riders from automobiles will result in passenger transportation greenhouse gas reductions for the city, and the larger the shift, the quicker the payback, which should be considered for time-specific environmental goals.

This study seeks to examine how the introduction of residential solid oxide fuel cells (SOFC) will affect urban air quality. Both the life-cycle and operations emissions profiles of an SOFC are compared with the baseload electricity generating technologies that widespread adoption of SOFCs would replace – coal fired, natural gas combined cycle, and nuclear. The monetary impacts from use phase emissions are then assessed in five water-vulnerable cities in which SOFCs would likely be adopted in order to increase local resilience to electricity failures as a result of water shortages. The SOFC system under study is a 1 kWe system of planar design intended for residential CHP. The excess heat from the SOFC is used to heat domestic hot water. Analysis of the SOFC system life-cycle includes raw materials extraction and processing, component manufacturing, SOFC manufacturing, natural gas fuel processing and distribution, SOFC use, as well as energy used in these processes. Life-cycle analysis of the baseload power systems is bounded similarly. Emissions tracked for this study include SOx, NOx, VOCs, PM10, and PM2.5.

Sustainable mobility policy for long-distance transportation services should consider emerging automobiles and aircraft as well as infrastructure and supply chain life-cycle effects in the assessment of new high-speed rail systems. Using the California corridor, future automobiles, high-speed rail and aircraft long-distance travel are evaluated, considering emerging fuel-efficient vehicles, new train designs and the possibility that the region will meet renewable electricity goals. An attributional per passenger-kilometer-traveled life-cycle inventory is first developed including vehicle, infrastructure and energy production components. A consequential life-cycle impact assessment is then established to evaluate existing infrastructure expansion against the construction of a new high-speed rail system. The results show that when using the life-cycle assessment framework, greenhouse gas footprints increase significantly and human health and environmental damage potentials may be dominated by indirect and supply chain components. The environmental payback is most sensitive to the number of automobile trips shifted to high-speed rail, and for greenhouse gases is likely to occur in 20–30 years. A high-speed rail system that is deployed with state-of-the-art trains, electricity that has met renewable goals, and in a configuration that endorses high ridership will provide significant environmental benefits over existing modes. Opportunities exist for reducing the long-distance transportation footprint by incentivizing large automobile trip shifts, meeting clean electricity goals and reducing material production effects.