Physical Sciences and Mathematics Commons^™

Novel Materials Can Radically Improve Whole-System Environmental Impacts Of Additive Manufacturing, Jeremy Faludi, Cory M. Van Sice, Yuan Shi, Justin Bower, Owen M.K Brooks

Dartmouth Scholarship

Additive manufacturing often has higher environmental impacts per part than traditional manufacturing at scale, but new materials can enable more sustainable 3D printing. This study developed and tested novel materials for paste extrusion printing, and tested materials invented by others. Testing compared their whole-system environmental impacts to standard ABS extrusion, measured by life cycle assessment (LCA); testing also assessed material strength, printability, and cost. Materials were chosen for low print energy (chemical bonding, not melting), low toxicity, and circular life cycle (biodegradable, ideally sourced from waste biomaterial). Printing energy was reduced 75% (from 160 to 40 Wh/part), and embodied impacts …

Towards Sustainable Aquafeeds: Evaluating Substitution Of Fishmeal With Lipid-Extracted Microalgal Co-Product (Nannochloropsis Oculata) In Diets Of Juvenile Nile Tilapia (Oreochromis Niloticus), Pallab K. Sarker, Anne R. Kapuscinski, Ashley Y. Bae, Emily Donaldson, Devin S. Fitzgerald, Oliver F. Edelson

Dartmouth Scholarship

Microalgae companies increasingly seek markets for defatted biomass that is left over after extracting omega-3 rich oil for human nutraceuticals and crude oil for fuels. Such a protein-rich co-product is a promising alternative to unsustainably sourced fishmeal in aquaculture diets. We report the first evaluation of co-product of the marine microalga Nannochloropsis oculata(N. oculata co-product) for replacing fishmeal in diets of Nile tilapia, a globally important aquaculture species. We conducted a nutrient digestibility experiment with N. oculata dried whole cells and N. oculata co-product, followed by an 84-day nutritional feeding experiment with N. oculata co-product. N. oculata co-product, more nutrient-dense …

What Design Practices Do Professionals Use For Sustainability And Innovation?, Jeremy Faludi, Alice M. Agogino

Dartmouth Scholarship

Interviews with 27 professionals were performed to investigate what designers, engineers, and their managers value in sustainable design practices, and see how sustainable design practices might also provide innovation. Quantitative and qualitative analysis found that only 1/6th of design practices were valued for both sustainability and innovation; two often-mentioned practices were systems thinking and The Natural Step. Providing a new lens, broadening scope, and problem redefinition were some of the reasons these and other design practices were valued for both sustainability and innovation.

Golden Tools In Green Design: What Drives Sustainability, Innovation, And Value In Green Design Methods?, Jeremy Faludi

Dartmouth Scholarship

What do product design teams value in sustainable design methods? Specifically, what kinds of activities and mindsets comprise different design methods, and which ones do design teams believe drive sustainability, innovation, and other value? How could they be combined to improve sustainable design’s value to companies? This study was the first to deconstruct green product design practices into their constituent activities and mindsets to characterize them and hypothesize their potential synergies. It was also the first to empirically test and compare what practitioners value within three of these sustainable design practices—The Natural Step, Whole System Mapping, and Biomimicry. Others have …

Salting Our Freshwater Lakes, Hilary A. Dugan, Sarah L. Bartlett, Samantha M. Burke, Jonathan P. Doubek, Flora Krivak-Tetley

Dartmouth Scholarship

The highest densities of lakes on Earth are in north temperate ecosystems, where increasing urbanization and associated chloride runoff can salinize freshwaters and threaten lake water quality and the many ecosystem services lakes provide. However, the extent to which lake salinity may be changing at broad spatial scales remains unknown, leading us to first identify spatial patterns and then investigate the drivers of these patterns. Significant decadal trends in lake salinization were identified using a dataset of long-term chloride concentrations from 371 North American lakes. Landscape and climate metrics calculated for each site demonstrated that impervious land cover was a …

Recommending Sustainable Design Practices By Characterizing Activities And Mindsets, Jeremy Faludi

Dartmouth Scholarship

How do designers, engineers, and managers choose the best sustainable design method for their work? How can different design practices combine to complement each other? This study makes recommendations by deconstructing 14 design methods, guides, certifications, and other practices into their constituent activities and mindsets, then characterizing those activities and mindsets. For example, some of the seven activity categories are analysis, ideation, and goal-setting; some of the eight mindset categories are priorities, abstract versus concrete goals, and environmental versus social goals. Recommendations are given for matching sustainable design practices to different usage contexts by their constituent activities and mindsets. It …

What Green Design Activities And Mindsets Drive Innovation And Sustainability In Student Teams?, Jeremy Faludi, Alice Agogino, Sara Beckman, Alastair Isles

Dartmouth Scholarship

What sustainable design practices can also drive innovation, and what practices do people value? Previous analysis of sustainable design methods, and the opportunism of designers generally, has suggested that design methods should actually be examined at the level of their component activities and mindsets, as each of these provides different advantages that designers could mix and match. This study performed workshops of three sustainable design methods for a total of 327 students, then surveyed students about which activities or mindsets within each design method drove innovation value, sustainability value, and any other value. The design methods tested were The Natural …

Are There Environmental Benefits From Driving Electric Vehicles? The Importance Of Local Factors, Stephen P. Holland, Erin T. Mansur, Nicholas Z. Muller, Andrew J. Yates

Dartmouth Scholarship

We combine a theoretical discrete-choice model of vehicle purchases, an econometric analysis of electricity emissions, and the AP2 air pollution model to estimate the geographic variation in the environmental benefits from driving electric vehicles. The second-best electric vehicle purchase subsidy ranges from $2,785 in California to -$4,964 in North Dakota, with a mean of -$1,095. Ninety percent of local environmental externalities from driving electric vehicles in one state are exported to others, implying they may be subsidized locally, even when the environmental benefits are negative overall. Geographically differentiated subsidies can reduce deadweight loss, but only modestly.

Coupled Impacts Of Climate And Land Use Change Across A River–Lake Continuum: Insights From An Integrated Assessment Model Of Lake Champlain’S Missisquoi Basin, 2000–2040, Asim Zia, Arne Bomblies, Andrew W. Schroth, Christopher Koliba, Peter D.F. Isles, Yushiou Tsai, Ibrahim N. Mohammed, Gabriela Bucini, Patrick J. Clemins, Scott Turnbull, Morgan Rodgers, Ahmed Hamed, Brian Beckage, Jonathan Winter, Carol Adair, Gillian L. Galford, Donna Rizzo, Judith Van Houten

Dartmouth Scholarship

Global climate change (GCC) is projected to bring higher-intensity precipitation and higher- variability temperature regimes to the Northeastern United States. The interactive effects of GCC with anthropogenic land use and land cover changes (LULCCs) are unknown for watershed level hydrological dynamics and nutrient fluxes to freshwater lakes. Increased nutrient fluxes can promote harmful algal blooms, also exacerbated by warmer water temperatures due to GCC. To address the complex interactions of climate, land and humans, we developed a cascading integrated assessment model to test the impacts of GCC and LULCC on the hydrological regime, water temperature, water quality, bloom duration and …

Nonnative Forest Insects And Pathogens In The United States: Impacts And Policy Options, Gary M. Lovett, Marissa Weiss, Andrew M. Liebhold, Thomas P. Holmes, Brian Leung, Kathy F. Lambert, David A. Orwig, Faith T. Campbell, Jonathan Rosenthal, Deborah G. Mccullough, Radka Wildova, Matthew P. Ayres

Dartmouth Scholarship

We review and synthesize information on invasions of nonnative forest insects and diseases in the United States, including their ecological and economic impacts, pathways of arrival, distribution within the United States, and policy options for reducing future invasions. Nonnative insects have accumulated in United States forests at a rate of ~2.5 per yr over the last 150 yr. Currently the two major pathways of introduction are importation of live plants and wood packing material such as pallets and crates. Introduced insects and diseases occur in forests and cities throughout the United States, and the problem is particularly severe in the …

Temperature Sensitivity Of Mineral Soil Carbon Decomposition In Shrub And Graminoid Tundra, West Greenland, Julia I. Bradley-Cook, Chelsea L. Petrenko, Andrew J. Friedland, Ross A. Virginia

Dartmouth Scholarship

Background:

Shrub expansion is transforming Arctic tundra landscapes, but the impact on the large pool of carbon stored in high-latitude soils is poorly understood. Soil carbon decomposition is a potentially important source of greenhouse gases, which could create a positive feedback to atmospheric temperature. Decomposition is temperature sensitive, but the response to temperature can be altered by environmental variables. We focus on mineral soils, which can comprise a substantial part of the near-surface carbon stock at the landscape scale and have physiochemical characteristics that influence temperature sensitivity. We conducted a soil incubation experiment to measure carbon dioxide (CO₂) …

Biological Lignocellulose Solubilization: Comparative Evaluation Of Biocatalysts And Enhancement Via Cotreatment, Julie M. D. Paye, Anna Guseva, Sarah K. Hammer, Erica Gjersing

Dartmouth Scholarship

Feedstock recalcitrance is the most important barrier impeding cost-effective production of cellulosic biofuels. Pioneer commercial cellulosic ethanol facilities employ thermochemical pretreatment and addition of fungal cellulase, reflecting the main research emphasis in the field. However, it has been suggested that it may be possible to process cellulosic biomass without thermochemical pretreatment using thermophilic, cellulolytic bacteria. To further explore this idea, we examine the ability of various biocatalysts to solubilize autoclaved but otherwise unpretreated cellulosic biomass under controlled but not industrial conditions.

The Pathology Of Command And Control: A Formal Synthesis, Michael Cox

Dartmouth Scholarship

One of the most important theories in the study of environmental governance and policy is the pathology of command and control, which describes the negative consequences of top-down, technocratic governance of social and ecological systems. However, to date, this theory has been expressed somewhat inconsistently and informally in the literature, even by the seminal works that have established its importance and popularized it. This presents a problem for the sustainability science community if it cannot be sure of the precise details of one of its most important theories. Without such precision, applications and tests of various elements of the theory …

Trade-Offs Between Three Forest Ecosystem Services Across The State Of New Hampshire, Usa: Timber, Carbon, And Albedo, David A. Lutz, Elizabeth A. Burakowski, Mackenzie B. Murphy, Mark E. Borsuk

Dartmouth Scholarship

Forests are more frequently being managed to store and sequester carbon for the purposes of climate change mitigation. Generally, this practice involves long-term conservation of intact mature forests and/or reductions in the frequency and intensity of timber harvests. However, incorporating the influence of forest surface albedo often suggests that long rotation lengths may not always be optimal in mitigating climate change in forests characterized by frequent snowfall. To address this, we investigated trade-offs between three ecosystem services: carbon storage, albedo-related radiative forcing, and timber provisioning. We calculated optimal rotation length at 498 diverse Forest Inventory and Analysis forest sites in …

Coast-To-Interior Gradient In Recent Northwest Greenland Precipitation Trends (1952–2012), G J. Wong, E C. Osterberg, R L. Hawley, Z R. Courville, D G. Ferris, J A. Howley

Dartmouth Scholarship

The spatial and temporal variability of precipitation on the Greenland ice sheet is an essential component of surface mass balance, which has been declining in recent years with rising temperatures. We present an analysis of precipitation trends in northwest (NW) Greenland (1952–2012) using instrumental (coastal meteorological station) and proxy records (snow pits and ice cores) to characterize the precipitation gradient from the coast to the ice sheet interior. Snow-pit-derived precipitation near the coast (1950–2000) has increased (~7% decade⁻¹, p < 0.01) whereas there is no significant change observed in interior snow pits. This trend holds for 1981–2012, where calculated precipitation changes decrease in magnitude with increasing distance from the coast: 13% decade⁻¹ (2.4 mm water equivalent (w.e.) decade⁻²) at coastal Thule air base (AB), 8.6% decade⁻¹ (4.7 …

The Price Of Snow: Albedo Valuation And A Case Study For Forest Management, David A. Lutz, Richard B. Howarth

Dartmouth Scholarship

Several climate frameworks have included the role of carbon storage in natural landscapes as a potential mechanism for climate change mitigation. This has resulted in an incentive to grow and maintain intact long-lived forest ecosystems. However, recent research has suggested that the influence of albedo-related radiative forcing can impart equal and in some cases greater magnitudes of climate mitigation compared to carbon storage in forests where snowfall is common and biomass is slow-growing. While several methodologies exist for relating albedo-associated radiative forcing to carbon storage for the analysis of the tradeoffs of these ecosystem services, they are varied, and they …

Iarc Monographs: 40 Years Of Evaluating Carcinogenic Hazards To Humans, Neil E. Pearce, Aaron Blair, Paolo Vineis, Wolfgang Ahrens, Aage Andersom, Josep M. Anto, Bruce K. Armstrong, Andrea A. Baccarelli, Frederick A. Beland, Amy Berrington, Pier Alberto Bertazzi, Linda S. Birnbaum, Ross C. Brownson, John R. Bucher, Kenneth P. Cantor, Elisabeth Cardis, John W. Cherrie, David C. Christiani, Pierluigi Cocco, David Coggon, Pietro Comba, Paul A. Demers, John M. Dement, Jeroen Douwes, Ellen A. Eisen, Lawrence S. Engel, Richard A. Fenske, Lora E. Fleming, Tony Fletcher, Elizabeth Fontham, Francesco Forastiere, Rainer Frentzel-Beyme, Lin Fritschi, Michel Gerin, Marcel Goldberg, Philippe Grandjean, Tom K. Grimsrud, Per Gustavsson, Andy Haines, Patricia Hartge, Johnni Hansen, Michael Hauptmann, Dick Heederik, Kari Hemminki, Denis Hemon, Irva Hertz-Picciotto, Jane A. Hoppin, James Huff, Bengt Jarvholm, Daehee Kang, Margaret R. Karagas

Dartmouth Scholarship

Background: Recently, the International Agency for Research on Cancer (IARC) Programme for the Evaluation of Carcinogenic Risks to Humans has been criticized for several of its evaluations, and also for the approach used to perform these evaluations. Some critics have claimed that failures of IARC Working Groups to recognize study weaknesses and biases of Working Group members have led to inappropriate classification of a number of agents as carcinogenic to humans.

Objectives: The authors of this Commentary are scientists from various disciplines relevant to the identification and hazard evaluation of human carcinogens. We examined criticisms of the IARC classification process …

Does Material Choice Drive Sustainability Of 3d Printing?, Jeremy Faludi, Zhongyin Hu, Shahd Alrashed, Christopher Braunholz, Suneesh Kaul, Leulekal Kassaye

Dartmouth Scholarship

Environmental impacts of six 3D printers using various materials were compared to determine if material choice drove sustainability, or if other factors such as machine type, machine size, or machine utilization dominate. Cradle-to-grave life-cycle assessments were performed, comparing a commercial-scale FDM machine printing in ABS plastic, a desktop FDM machine printing in ABS, a desktop FDM machine printing in PET and PLA plastics, a polyjet machine printing in its proprietary polymer, an SLA machine printing in its polymer, and an inkjet machine hacked to print in salt and dextrose. All scenarios were scored using ReCiPe Endpoint H methodology to combine …

The Action Cycle/Structural Context Framework: A Fisheries Application, D. G. Webster

Dartmouth Scholarship

There is a growing consensus that environmental governance is a wicked problem that requires understanding of the many linkages and feedbacks between human and natural systems. Here, I propose an action cycle/structural context (AC/SC) framework that is based on the concept of responsive governance, in which individuals and decision makers respond to problems rather than working to prevent them. By linking agency and structure, the AC/SC framework points out two key problems in the realm of environmental governance: the profit disconnect, whereby economic signals of environmental harm are dampened by endogenous or exogenous forces, and the power disconnect, whereby those …

A Sustainable Design Method Acting As An Innovation Tool, Jeremy Faludi

Dartmouth Scholarship

Product companies generally see sustainability as a burden limiting their design process, similar to cost or safety limits. A method for sustainable design was created, attempting to turn sustainability from a burden into an innovation tool with inherent business value. The method combines creative whole-systems thinking with quantitative sustainability metrics. It facilitates innovation by the creation of visual whole-system maps that encourage more thorough and more radical brainstorming. It facilitates sustainability by using quantitative measurements, such as lifecycle assessment or point-based certification systems, to set priorities and choose final designs. The method has been anecdotally tested in classes at four …

Noble Gases Identify The Mechanisms Of Fugitive Gas Contamination In Drinking-Water Wells Overlying The Marcellus And Barnett Shales, Thomas H. Darrah, Avner Vengosh, Robert B. Jackson, Nathaniel R. R. Warner, Robert J. Poreda

Dartmouth Scholarship

Horizontal drilling and hydraulic fracturing have enhanced energy production but raised concerns about drinking-water contamination and other environmental impacts. Identifying the sources and mechanisms of contamination can help improve the environmental and economic sustainability of shale-gas extraction. We analyzed 113 and 20 samples from drinking-water wells overlying the Marcellus and Barnett Shales, respectively, examining hydrocarbon abundance and isotopic compositions (e.g., C2H6/CH4, δ13C-CH4) and providing, to our knowledge, the first comprehensive analyses of noble gases and their isotopes (e.g., 4He, 20Ne, 36Ar) in groundwater near shale-gas wells. We addressed two questions. (i) Are elevated levels of hydrocarbon gases in …

Climate Change And Forest Fires Synergistically Drive Widespread Melt Events Of The Greenland Ice Sheet, Kaitlin M. Keegan, Mary R. Albert, Joseph R. Mcconnell, Ian Baker

Dartmouth Scholarship

In July 2012, over 97% of the Greenland Ice Sheet experienced surface melt, the first widespread melt during the era of satellite remote sensing. Analysis of six Greenland shallow firn cores from the dry snow region confirms that the most recent prior widespread melt occurred in 1889. A firn core from the center of the ice sheet demonstrated that exceptionally warm temperatures combined with black carbon sediments from Northern Hemisphere forest fires reduced albedo below a critical threshold in the dry snow region, and caused the melting events in both 1889 and 2012. We use these data to project the …

Comparative Efficiency And Driving Range Of Light- And Heavy-Duty Vehicles Powered With Biomass Energy Stored In Liquid Fuels Or Batteries, Mark Laser, Lee R. R. Lynd

Dartmouth Scholarship

This study addresses the question, "When using cellulosic biomass for vehicular transportation, which field-to-wheels pathway is more efficient: that using biofuels or that using bioelectricity?" In considering the question, the level of assumed technological maturity significantly affects the comparison, as does the intended transportation application. Results from the analysis indicate that for light-duty vehicles, over ranges typical in the United States today (e.g., 560-820 miles), field-to-wheels performance is similar, with some scenarios showing biofuel to be more efficient, and others indicating the two pathways to be essentially the same. Over the current range of heavy-duty vehicles, the field-to-wheels efficiency is …

Benthic And Pelagic Pathways Of Methylmercury Bioaccumulation In Estuarine Food Webs Of The Northeast United States, Celia Y. Chen, Mark E. Borsuk, Deenie M. Bugge, Terill Hollweg

Dartmouth Scholarship

Methylmercury (MeHg) is a contaminant of global concern that bioaccumulates and bioamagnifies in marine food webs. Lower trophic level fauna are important conduits of MeHg from sediment and water to estuarine and coastal fish harvested for human consumption. However, the sources and pathways of MeHg to these coastal fisheries are poorly known particularly the potential for transfer of MeHg from the sediment to biotic compartments. Across a broad gradient of human land impacts, we analyzed MeHg concentrations in food webs at ten estuarine sites in the Northeast US (from the Hackensack Meadowlands, NJ to the Gulf of Maine). MeHg concentrations …

Unintended Outcomes Of Farmers' Adaptation To Climate Variability: Deforestation And Conservation In Calakmul And Maya Biosphere Reserves, Claudia Rodriguez-Solorzano

Dartmouth Scholarship

Minimizing the impact of climate change on farmer livelihoods is crucial, but adaptation efforts may have unintended consequences for ecosystems, with potential impacts on farmers’ welfare. Unintended outcomes of climate adaptation strategies have been widely discussed, however, empirical exploration has been neglected. Grounded in scholarship on climate adaptation, environmental governance, social–ecological systems, and land-use change, this paper studies whether farmers’ climate adaptation contributes to deforestation or forest conservation. The paper draws on interviews with 353 farmers from 46 communities in Calakmul Biosphere Reserve in Mexico and Maya Biosphere Reserve in Guatemala. Farmers in the area of study have implemented adaptation …

Profiting From Regulation: Evidence From The European Carbon Market, James B. Bushnell, Howard Chong, Erin T. Mansur

Dartmouth Scholarship

We investigate how cap-and-trade regulation affects profits. In late April 2006, the EU CO2 allowance price dropped 50 percent, equating to a €28 billion reduction in the value of aggregate annual allowances. We examine daily returns for 552 stocks from the EUROSTOXX index. Despite reductions in environmental costs, we find that stock prices fell for firms in both carbon- and electricity-intensive industries, particularly for firms selling primarily within the EU. Our results imply that investors focus on product price impacts, rather than just compliance costs and the nominal value of pollution permits.

Sustainable Design Education Through A Self-Directed Online System, Jeremy Faludi, Adam Menter

Dartmouth Scholarship

Sustainable design and engineering is an important topic, yet it is under-represented in educational institutions; moreover, it must be taught to practicing professionals, not just students. A free online system has been created to address both problems at once, providing educational materials for educators and also providing a self-paced program for professionals or students to earn a certificate in sustainable design. Called the Autodesk Sustainability Workshop, it is a collection of video tutorials and supporting materials (PDF reference guides, slide decks, quizzes, and other resources) that can be used either by individuals themselves or by educators (either in schools or …

Using Economic Instruments To Develop Effective Management Of Invasive Species: Insights From A Bioeconomic Model, Shana M. Mcdermott, Rebecca E. Irwin, Brad W. Taylor

Dartmouth Scholarship

Economic growth is recognized as an important factor associated with species invasions. Consequently, there is increasing need to develop solutions that combine economics and ecology to inform invasive species management. We developed a model combining economic, ecological, and sociological factors to assess the degree to which economic policies can be used to control invasive plants. Because invasive plants often spread across numerous properties, we explored whether property owners should manage invaders cooperatively as a group by incorporating the negative effects of invader spread in management decisions (collective management) or independently, whereby the negative effects of invasive plant spread are ignored …

Growing A Sustainable Biofuels Industry: Economics, Environmental Considerations, And The Role Of The Conservation Reserve Program, Christopher M. Clark, Yolanda Lin, Britta G. Bierwagen, Laurence M. Eaton, Matthew H. Langholtz, Philip Morefield, Caroline E. Ridley, Laura Vimmerstedt, Steve Peterson, Brian W. Bush

Dartmouth Scholarship

Biofuels are expected to be a major contributor to renewable energy in the coming decades under the Renewable Fuel Standard (RFS). These fuels have many attractive properties including the promotion of energy independence, rural development, and the reduction of national carbon emissions. However, several unresolved environmental and economic concerns remain. Environmentally, much of the biomass is expected to come from agricultural expansion and/or intensification, which may greatly affect the net environmental impact, and economically, the lack of a developed infrastructure and bottlenecks along the supply chain may affect the industry's economic vitality. The approximately 30 million acres (12 million hectares) …

Modeling Biofuel Expansion Effects On Land Use Change Dynamics, Ethan Warner, Daniel Inman, Benjamin Kunstman, Brian Bush, Laura Vimmerstedt, Steve Peterson

Dartmouth Scholarship

Increasing demand for crop-based biofuels, in addition to other human drivers of land use, induces direct and indirect land use changes (LUC). Our system dynamics tool is intended to complement existing LUC modeling approaches and to improve the understanding of global LUC drivers and dynamics by allowing examination of global LUC under diverse scenarios and varying model assumptions. We report on a small subset of such analyses. This model provides insights into the drivers and dynamic interactions of LUC (e.g., dietary choices and biofuel policy) and is not intended to assert improvement in numerical results relative to other works.

Demand …