Browsing by Author "Tessum, Christopher"

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    Life Cycle Air Quality and Climate Impacts of Conventional and Alternative Light-Duty Transportation in the United States
    (2014-12) Tessum, Christopher
    This dissertation explores the air quality, climate, and environmental injustice aspects of potential strategies for reducing the environmental impacts of the light-duty vehicles in the United States. To improve the accuracy of life cycle air quality impact assessment, I add process-specific spatial and temporal information to an existing attributional life cycle emissions inventory (LCI) model. I then combine this emissions model with an advanced air quality model to find that powering vehicles with corn ethanol or with coal-based or "grid average" electricity increases monetized environmental health impacts by 80% or more relative to using conventional gasoline. Conversely, EVs powered by low-emitting electricity from natural gas, wind, water, or solar-power reduce impacts by 50% or more. I additionally explore how alternative vehicle fuel production and use would affect disparities in environmental health risks among race, ethnicity, and income groups, known as environmental justice. To do this I develop and apply a new air quality model, the Intervention Model for Air Pollution (InMAP), which is well-suited to investigate these environmental injustice issues because it can be used with high enough spatial resolution to resolve intra-urban differences in pollution concentration and to track the long-range transport of pollution at the same time. I find that the scenarios that cause the greatest improvements in overall air quality-related health impacts compared to the business-as-usual gasoline scenario---electric vehicles powered by natural gas or wind, water, or solar power---also yield substantial improvements in environmental justice.
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    Tank to Wheel Emissions of Ethanol and Biodiesel Powered Vehicles as Compared to Petroleum Alternatives: White Paper
    (Center for Transportation Studies, University of Minnesota, 2010-06) Tessum, Christopher; Marshall, Julian D.; Hill, Jason
    Air quality modeling of the air pollution effects of alternative fuels must be supported with data on the tailpipe emissions of those fuels relative to conventional fuels. Here a literature review is presented of the tailpipe and evaporative emissions from 85% ethanol (E85), 10% ethanol (E10), and 20% biodiesel (BD20) compared to conventional fuels. It is found that E85 causes both positive and negative changes in emissions relative to gasoline, depending on the pollutant, and the changes in some pollutants have an uncertain sign. E10 and BD20 in general exhibit smaller changes in emissions compared to E85, the impacts of which cannot be fully known without air quality modeling.