39 research outputs found

    A social-ecological-technological systems framework for urban ecosystem services

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    As rates of urbanization and climatic change soar, decision-makers are increasingly challenged to provide innovative solutions that simultaneously address climate-change impacts and risks and inclusively ensure quality of life for urban residents. Cities have turned to nature-based solutions to help address these challenges. Nature-based solutions, through the provision of ecosystem services, can yield numerous benefits for people and address multiple challenges simultaneously. Yet, efforts to mainstream nature-based solutions are impaired by the complexity of the interacting social, ecological, and technological dimensions of urban systems. This complexity must be understood and managed to ensure ecosystem-service provisioning is effective, equitable, and resilient. Here, we provide a social-ecological-technological system (SETS) framework that builds on decades of urban ecosystem services research to better understand four core challenges associated with urban nature-based solutions: multi-functionality, systemic valuation, scale mismatch of ecosystem services, and inequity and injustice. The framework illustrates the importance of coordinating natural, technological, and socio-economic systems when designing, planning, and managing urban nature-based solutions to enable optimal social-ecological outcomes

    Life-cycle Environmental Inventory of Passenger Transportation in the United States

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    Energy use and emission factors for passenger transportation modes typically ignore the total environmental inventory which includes vehicle non-operational components (e.g., vehicle manufacturing and maintenance), infrastructure components, and fuel production components from design through end-of-life processes. A life-cycle inventory for each mode is necessary to appropriately address and attribute the transportation sector’s energy and emissions impacts to reduction goals instead of allowing tailpipe emissions to act as indicators of total system performance. The contributions of U.S. passenger transportation modes to national energy and emissions inventories account for roughly 20% of U.S. totals, mostly attributed to gasoline consumption. Furthermore, world consumption of primary energy amounted to 490 EJ in 2005 with the U.S. responsible for 110 EJ, or 21% of the total. This means that passenger transportation in the U.S. accounts for roughly 5% of global primary energy consumption annually. With a predominant fossil fuel energy base, the impacts of U.S. passenger transportation have strong implications for global energy consumption, U.S. energy security, and climate change. Furthermore, criteria air pollutant emissions from transportation (passenger and freight) are also significant, accounting for 78% of national CO, 58% of NOX, 36% of VOCs, 9% of PM2.5, 2.6% of PM10, and 4.5% of SO2 emissions. These emissions often occur near population centers and can cause adverse direct human health effects as well as other impacts such as ground-level ozone formation and acid deposition. To appropriately mitigate environmental impacts from transportation, it is necessary for decision makers to consider the life-cycle energy consumption and emissions associated with each mode. A life-cycle energy, greenhouse gas, and criteria air pollutant emissions inventory is created for the passenger transportation modes of automobiles, urban buses, heavy rail transit, light rail transit, and aircraft in the U.S. Each mode’s inventory includes an assessment of vehicles, infrastructure, and fuel components. For each component, analysis is performed for material extraction through use and maintenance in both direct and indirect (supply chain) processes. For each mode’s life-cycle components, energy inputs and emission outputs are determined. Energy inputs include electricity and petroleum-based fuels. Emission outputs include greenhouse gases (CO2, CH4, and N2O) and criteria pollutants (CO, SO2, NOX, VOCs, and PM). The inputs and outputs are normalized by vehicle lifetime, vehicle mile traveled, and passenger mile traveled. A consistent system boundary is applied to all modal inventories which captures the entire life-cycle, except for end-of-life. For each modal life-cycle component, both direct and indirect processes are included if possible. A hybrid life-cycle assessment approach is used to estimate the components in the inventories. We find that life-cycle energy inputs and emission outputs increase significantly compared to the vehicle operational phase. Life-cycle energy consumption is 39-56% larger than vehicle operation for autos, 38% for buses, 93-160% for rail, and 19-24% for air systems per passenger mile traveled. Life-cycle greenhouse gas emissions are 47-65% larger than vehicle operation for autos, 43% for buses, 39-150% for rail, and 24-31% for air systems per passenger mile traveled. The energy and greenhouse gas increases are primarily due to vehicle manufacturing and maintenance, infrastructure construction, and fuel production. For criteria air pollutants, life-cycle components often dominate total emissions and can be a magnitude larger than operational counterparts. Per passenger mile traveled, total SO2 emissions (between 350 and 460 mg) are 19-27 times larger than operational emissions as a result of electricity generation in vehicle manufacturing, infrastructure construction, and fuel production. NOX emissions increase 50-73% for automobiles, 24% for buses, 13-1300% for rail, and 19-24% for aircraft. Non-tailpipe VOCs are 27-40% of total automobile, 71-95% of rail, and 51-81% of air total emissions. Infrastructure and parking construction are major components of total PM10 emissions resulting in total emissions over three times larger than operational emissions for autos and even larger for many rail systems and aircraft (the major contributor being emissions from hot-mix asphalt plants and concrete production). Infrastructure construction and operation as well as vehicle manufacturing increase total CO emissions by 5-17 times from tailpipe performance for rail and 3-9 times for air. A case study comparing the environmental performance of metropolitan regions is presented as an application of the inventory results. The San Francisco Bay Area, Chicago, and New York City are evaluated capturing passenger transportation life-cycle energy inputs and greenhouse gas and criteria air pollutant emissions. The regions are compared between off-peak and peak travel as well as personal and public transit. Additionally, healthcare externalities are computed from vehicle emissions. It is estimated that life-cycle energy varies from 6.3 MJ/PMT in the Bay Area to 5.7 MJ/PMT in Chicago and 5.3 MJ/PMT in New York for an average trip. Life-cycle GHG emissions range from 480 g C02e/PMT in the Bay Area to 440 g C02e/PMT for Chicago and 410 g C02e/PMT in New York. CAP emissions vary depending on the pollutant with differences as large as 25% between regions. Life-cycle CAP emissions are between 11% and 380% larger than their operational counterparts. Peak travel, with typical higher riderships, does not necessarily environmentally outperform off-peak travel due to the large share of auto PMT and less than ideal operating conditions during congestion. The social costs of travel range from 51 cent (in 2007 cents) per auto passenger per trip during peak in New York to 6 cents per public transit passenger per trip during peak hours in the Bay Area and New York. Average personal transit costs are around 30 cents while public transit ranges from 28 cents to 41 cents. This dissertation was completed with Professor Arpad Horvath serving as the advisor. This document supercedes the University of California, Berkeley, Center for Future Urban Transport papers, vwp-2007-7 and vwp-2008-2. Additional project information can be found at http://www.sustainable-transportation.com.Environment

    Infrastructure and the cognitive ecosystem: an irrevocable transformation

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    Disruption of legacy infrastructure systems by novel digital and connected technologies represents not simply the rise of cyberphysical systems as hybrid physical and digital assets but, ultimately, the integration of legacy systems into a new cognitive ecosystem. This cognitive ecosystem, an ecology of massive data flows, artificial intelligence, institutional and intellectual structures, and connected technologies, is poised to alter how humans and artificial intelligence understand and control our world. Infrastructure managers need to be ready for this paradigm shift, recognizing their systems are increasingly being absorbed into an emerging suite of data, analytical tools, and decisionmaking technologies that will fundamentally restructure how legacy systems behave and are controlled, how decisions are made, and most importantly how workers interact with the systems. Infrastructure managers must restructure their organizations and engage in cross-organizational sensemaking if they are to be capable of navigating the complexity of the cognitive ecosystem. The cognitive ecosystem is fundamentally poised to change what infrastructures are, necessitating the need for managers to take a close look at the functions and actions of their own systems. The continuing evolution of the Anthropocene and the cognitive ecosystem has profound implications for infrastructure education. A sustained commitment to change is necessary that restructures and reorients infrastructure organizations within the cognitive ecosystem, where knowledge is generated, and control of services is wielded by myriad stakeholders

    Vulnerability of California roadways to post-wildfire debris flows

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    Post-wildfire debris flows represent a significant hazard for transportation infrastructure. The location and intensity of post-fire debris movements are difficult to predict, and threats can persist for several years until the watershed is restored to pre-fire conditions. This situation might worsen as climate change forecasts predict increasing numbers of wildfire burned areas and extreme precipitation intensity. New insights are needed to improve understanding of how roadways are vulnerable to post-fire flows and how to prioritize protective efforts. Using California as a case study, the vulnerability of transportation infrastructure to post-fire debris flow was assessed considering geologic conditions, vegetation conditions, precipitation, fire risk, and roadway importance under current and future climate scenarios. The results showed significant but uneven statewide increases in the number of vulnerable roadways from the present to future emission scenarios. Under current climate conditions, 0.97% of roadways are highly vulnerable. In the future, the ratio of vulnerable roadways is expected to increase 1.9–2.3 times in the representative concentration pathways (RCPs) 4.5 emission scenarios, and 3.5–4.2 times in the RCP 8.5 emission scenarios. The threat of post-fire debris flow varies across the state, as precipitation changes are uneven. The vulnerability assessment is positioned to (a) identify, reinforce, and fortify highly vulnerable roadways, (b) prioritize watershed fire mitigation, and (c) guide future infrastructure site selection

    Greenhouse gas and air quality effects of auto first-last mile use with transit

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    With potential for automobiles to cause increased greenhouse gas emissions and air pollution relative to other modes, there is concern that using automobiles to access or egress public transportation may significantly increase the environmental impacts from door-to-door transit trips. Yet little rigorous work has been developed that quantitatively assesses the effects of transit access or egress by automobiles. This research evaluates the life-cycle impacts of first-and-last mile trips on multimodal transit. An environmental life-cycle assessment of transit and automobile travel in the greater Los Angeles region is developed to evaluate the impacts of multimodal transit trips by utilizing existing transportation life-cycle assessment methods. First-last mile automobile trips with transit may increase multimodal trip emissions significantly, mitigating potential impact reductions from transit usage. In some cases, multimodal transit trips with first-last mile automobile use may have higher emissions than competing automobile trips. In the near-term, first-last mile automobile trips in some Los Angeles transit services may account for up to 66% of multimodal greenhouse gas emissions, and as much as 75% of multimodal air quality impacts. Fossil fuel energy generation and combustion, low vehicle occupancies, and longer trip distances contribute most to increased multimodal impacts. Supply chain analysis indicates that life-cycle air quality impacts may occur largely locally (in Los Angeles) or largely remotely depending on the propulsion method and location of upstream life-cycle processes. Reducing 10% of transit system greenhouse emissions requires a shift of 23–50% of automobile first-last mile trips to a neutral emissions mode

    Policy Making Should Consider Time-Dependent Greenhouse Gas Benefits of Transit-Oriented Smart Growth

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    Cities are developing greenhouse gas (GHG) mitigation plans and reduction targets on the basis of a growing body of knowledge about climate change risks, and changes to passenger transportation are often at the center of these efforts. Yet little information exists for characterizing how quickly or slowly GHG emissions reductions will accrue given changes in urban form around transit and whether benefits will accrue quickly enough to meet policy year targets (such as reaching 20% of 1990 GHG emissions levels by 2050). Achieving GHG reductions through integrated transportation and land use planning is even more complicated for cities because changes in emissions can occur across many sectors (such as transportation, building energy use, and electricity generation). With the use of the Los Angeles, California, Expo Line, a framework was developed to assess how financing schemes could affect the rate of building redevelopment and resulting life-cycle GHG emissions from travel and building energy use. The framework leveraged an integrated transportation and land use life-cycle assessment model that captured upfront construction of new development near transit and the long-term changes in household energy use for travel and buildings. The results show that for the same amount of development around the Expo Line, it is possible either to meet state GHG goals by 2050 (if aggressive redevelopment happens early) or not meet those goals by 2050 (if significant redevelopment does not start for decades). The time-based approach reveals how redevelopment schedules should be considered when strategies for meeting future GHG emissions targets are set
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