Browsing by Subject "Climate Change"

Now showing 1 - 20 of 34

A Nuclear State of Mind: Identifying the Impact of Climate Change on Nuclear Security
(2024-05-01) Jaffery, Zulfikar; Nordhougen, Greg; Padmanabhan, Sam; Woyda, Trevor
There is a broad assumption that nuclear energy is ready to solve climate change without a proper understanding of how climate change will impact the civilian nuclear energy industry. It is this assumption that is interrogated within the research and analysis portions of this literature review. The sweeping assumption that nuclear energy is ready for global dependence would have dangerous implications if it were wrong. Even if it is right, the process required to reconfigure the energy industry in order to prepare it for the world’s demand for energy would still necessitate incredible strides. This literature review hopes to shine a spotlight on some of the unanswered questions while offering a vignette of the industry as it currently sits today.
Assessment of the Karner Blue Butterfly’S Response and Managed Relocation Under Climate Change
(2020-06) Li, Yudi
The Karner blue butterfly (Lycaeides melissa samuelis), an endangered species in decline from habitat loss, may be further threatened by climate change. Evaluating how climate shapes the dynamics and the distribution of Karner blue is helpful for developing adaptation plans. The demographic models generally used for insect populations are either density-dependent or are applied to population presence-absence data. The bulk of this thesis is concerned with the creation of scale-based, mixed density-dependent and density-independent (“endo-exogenous”) models for this butterfly based on the long-term count data shared by other Kaner blue researchers. The endo-exogenous models showed that both density dependence and environmental factors were important drivers of Karner blue population trends and that populations in different regions and the species’ bi-voltine generations have differing responses to climate (chapter 1). These models were then used to examine extinction risk and distribution shift under several scenarios of climatic change (elevated temperature and increased precipitation variance) by 2050. The predictions displayed relatively poor efficiency of local management on the populations of Central Wisconsin and Indian Dunes National Park under climate change, and they were projected to have high occupancy in the northern Midwest, especially Minnesota. These results suggested that some populations would benefit from managed relocation and that it would be possible to reintroduce the Karner blue back to Minnesota. To further identify target sites for relocation, the distributions of 179 utility-scale solar energy (USSE) were overlapped with model projections. There were 35 solar facilities located on sandy soil, and some of these were within the range of high occupancy of Karner blue populations, suggesting that if planted with native vegetation, including wild blue lupine (sole host plant of the Kaner blue), and converted into solar-pollinator habitats, USSE might have the potential to be developed as a refugia of this butterfly (chapter 2).
Caring Too Much is a Start. MFA Thesis University of Minnesota, Department of Art
(University of Minnesota, Department of Art, 2018-05) Limerick, Reb L
Change Detection with Climate Data Application
(2015-08) Lu, Ying
This thesis has two major components: Change Detection and Hurricane Trajectory Prediction. In Change Detection, we generalize the scope of the existing change detection framework, and propose change detection algorithms in the context of exponential family distribution, generalized extreme value distribution and so on. We also propose a novel and efficient approach to detect extreme change through order statistics. Performance of the proposed methodologies are assessed through simulation study. For Hurricane Trajectory Prediction, we propose a collection of models(neighborhood methods, time series etc), and ensemble them to predict the hurricane's upcoming locations. We analyze the prediction performance through historical hurricanes, and discuss its advantages and disadvantages.
City of Minneapolis - Climate Change Impacts and Adaptation Strategies
(Hubert H. Humphrey School of Public Affairs, 2013-05-20) Emanuele, Andrew; Rockway, Andrew; Rubenstein, Georgia; Schmitt, Kelly
Climate Change Adaptation policies in Himalayan Region of Nepal. Comparative analysis of INDCs between Nepal, India, and Peru
(2017) Gurung, Tashi, Wongdi
The Himalayas are also known as the third pole as they comprise the third largest amount of snow on the earth after the Arctic and Antarctica. They are also known as The Water Towers of Asia. With global climate change, the temperatures on the Tibetan Plateau in the Himalayas are rising substantially compared to other regions. The Himalayan people are far from being the top contributors to this climate change, yet they suffer its hardest consequences. Studies show that communities struggle to adapt to the changing environment because of limited information, poor or no access to services, lack of infrastructure, lack of capacity on the part of the central government, an unfavorable geographical location, lack of external support etc. Hence, rural mountain communities in developing nations such as Mustang in Nepal have very low adaptive capacity. In addition to the many existing problems like poverty, the changing climate has exacerbated the numerous difficulties of day-to-day life of people in the mountains. This is just as much an environmental problem as it is a policy and social justice problem. Mustang, a mountainous district in northern Nepal, is not immune to the impact of climate change. This paper focuses on how different adaptation policies and strategies can help the Himalayan region of Nepal adapt better to the constantly changing environment and assuage the impacts exacerbated by climate change. The challenges in Nepal are not unique: other mountainous regions in developing countries have begun to develop strategies to adapt to a changing climate. India and Peru provide two useful comparative cases. Recommendations and reforms for Nepal are discussed after comparative analysis of INDCs (Intended Nationally Determined Contributions) prepared by Peru and India.
Climate Change and Future Forests of the Boundary Waters Canoe Area Wilderness: An assessment of Temperate Tree Abundance, Earthworm Invasion and Understory Regeneration Trends
(2019-07) Chaffin, David
The forests of the Boundary Waters Canoe Area Wilderness (BWCAW) are dominated by boreal tree species at their southern range limit, making them particularly sensitive to climate change. Numerous studies have modeled potential climate change induced tree species range shifts across northern Minnesota and the BWCAW, projecting declines for boreal tree species and increases for northern temperate tree species currently at low abundances in the wilderness. The coarse resolution of these models, their lack of some biological interactions and the unprecedented velocity of projected future climate change could lead to over and/or under estimates of tree species range shifts at the scale of the BWCAW. To better understand potential forest successional shifts within this ecologically important wilderness we assessed 1) the abundance and spatial distribution of northern temperate tree species, 2) the stage, pattern, and extent of earthworm invasion in the wilderness, and 3) the impact of seasonal temperature, overstory composition, earthworm invasion and soil moisture potential on the understory relative density of ten boreal and northern temperate tree species. We found that red maple (Acer rubrum) is the most abundant temperate tree species in the BWCAW by orders of magnitude across all size classes, with its spatial distribution strongly correlated with an existing west to east summer temperature gradient. Conversely, our results raise questions about whether adequate seed sources of other temperate species are currently present in the wilderness to support a successful boreal to temperate transition. Earthworm invasion in the BWCAW is widespread, yet incomplete. Modeling results indicate the spatial pattern of earthworm invasion in the wilderness is driven by anglers dumping unused earthworm fishing bait at campsites. We predict that 33% of total land area in the BWCAW is currently invaded by earthworms. Lastly, our results indicate that summer temperature is a key driver of differences in understory relative density of boreal and northern temperate tree species across the mixed-boreal forests of the BWCAW, but that earthworm invasion and areas with increased soil moisture availability may support the short-term resistance of boreal tree species under future warmer and drier conditions.
Climate Change and Tallgrass Prairies: Exploring the Interaction of Extreme Weather and Invasion in Managed Prairie Systems
(2020-12) Ratcliffe, Hugh
Climate change will increasingly shift seasonal timing and increase the frequency and intensity of extreme events like drought and severe wet conditions, all of which threaten to amplify other global change drivers like invasion. Consequently, understanding how conservation management actions like prescribed burning interact with climate is increasingly pressing for invasive management. Although prescribed burning has been widely demonstrated to increase native plant diversity and suppress a number of invasive species, understanding under what current and future conditions burning will be most effective remains an ongoing focus of applied prairie ecology research. Earlier springs and extended growing seasons will shift the timing and availability of resources and niche space, which may disproportionately advantage invasive species and also influence the outcome of burning. Furthermore, northern tallgrass prairies will experience intensified extreme precipitation patterns characterized by more precipitation falling in fewer events interspersed with longer dry periods and amplified evapotranspiration. Because moisture availability functions as a key determinant of prairie composition, theory and evidence suggest drought conditions will hinder invasion, whereas wetter conditions will enhance invasion. Here, I conducted two analyses exploring the effect of weather on prairie invasion dynamics from 2010-2019 in 25 observed prairie sites and 267 transects spread throughout Minnesota, USA. First, I estimated the effects of burning, start time of the growing season, and their interaction. Second, I estimated how an increase in extremely wet or dry months altered invasive abundance and influenced the effectiveness of burning. For the first analysis, I determined that burning reduced both total invasive and invasive cool season grass abundance, and that this reduction persisted over time for invasive cover but quickly waned for frequency. Additionally, I found that growing season start does indeed influence community composition but that later starts rather than earlier increased invasive abundance. For the second analysis, I found that a greater occurrence of abnormally wet months increased invasive abundance and minimal evidence that abnormally dry conditions hinder invasion. Furthermore, I did not observe additive interaction effects of drought and prescribed burning but did find that an increase in the number of wet months reduced the effectiveness of burning. Together, these results suggest that, although earlier spring timing is unlikely to be a primary mechanism driving increased invasion, more frequent extremely wet and dry months may intensify invasive dominance and hinder our ability to suppress invasion species via prescribed burning. Ultimately, I propose that future research should seek to better understand abiotic controls on invasive species’ phenologies, how precipitation seasonality influences invasive performance, and also identify potential thresholds in ecological processes to understand whether responses in community invasion dynamics are abrupt or gradual.
Climate Change and Tallgrass Prairies: Exploring the Interaction of Extreme Weather and Invasion in Managed Prairie Systems
(2020-12) Ratcliffe, Hugh
Climate change will increasingly shift seasonal timing and increase the frequency and intensity of extreme events like drought and severe wet conditions, all of which threaten to amplify other global change drivers like invasion. Consequently, understanding how conservation management actions like prescribed burning interact with climate is increasingly pressing for invasive management. Although prescribed burning has been widely demonstrated to increase native plant diversity and suppress a number of invasive species, understanding under what current and future conditions burning will be most effective remains an ongoing focus of applied prairie ecology research. Earlier springs and extended growing seasons will shift the timing and availability of resources and niche space, which may disproportionately advantage invasive species and also influence the outcome of burning. Furthermore, northern tallgrass prairies will experience intensified extreme precipitation patterns characterized by more precipitation falling in fewer events interspersed with longer dry periods and amplified evapotranspiration. Because moisture availability functions as a key determinant of prairie composition, theory and evidence suggest drought conditions will hinder invasion, whereas wetter conditions will enhance invasion. Here, I conducted two analyses exploring the effect of weather on prairie invasion dynamics from 2010-2019 in 25 observed prairie sites and 267 transects spread throughout Minnesota, USA. First, I estimated the effects of burning, start time of the growing season, and their interaction. Second, I estimated how an increase in extremely wet or dry months altered invasive abundance and influenced the effectiveness of burning. For the first analysis, I determined that burning reduced both total invasive and invasive cool season grass abundance, and that this reduction persisted over time for invasive cover but quickly waned for frequency. Additionally, I found that growing season start does indeed influence community composition but that later starts rather than earlier increased invasive abundance. For the second analysis, I found that a greater occurrence of abnormally wet months increased invasive abundance and minimal evidence that abnormally dry conditions hinder invasion. Furthermore, I did not observe additive interaction effects of drought and prescribed burning but did find that an increase in the number of wet months reduced the effectiveness of burning. Together, these results suggest that, although earlier spring timing is unlikely to be a primary mechanism driving increased invasion, more frequent extremely wet and dry months may intensify invasive dominance and hinder our ability to suppress invasion species via prescribed burning. Ultimately, I propose that future research should seek to better understand abiotic controls on invasive species’ phenologies, how precipitation seasonality influences invasive performance, and also identify potential thresholds in ecological processes to understand whether responses in community invasion dynamics are abrupt or gradual.
Climate change, Covid-19, and Environmental Injustice: Understanding the Root Causes and Connections
(2021-07-28) Badithela, Athreyi S
It is speculated that there is a link between climate change, covid-19 and environmental injustice, three of the major problems the world presently faces. This paper explores that link and examines ways that understanding this link might be used to address, and possibly solve, these issues. Focusing on climate change solutions, I devised and conducted an informal survey of some of my fellow students and friends based on the idea that fighting climate change can lead to reducing future pandemic risks. In analyzing this data, I found that these University of Minnesota students believe that there is a lack of awareness regarding the implementations of climate change solutions by both society and the government.
Climate Change, the COVID-19 Pandemic, and Environmental Injustice: Understanding the Root Causes and Interactions
(2021-07-28) Izar Helfenstein Fonseca, Luisa
The following article outlines the findings of a University of Minnesota Undergraduate Research Program whose purpose was to determine the connections and intersections between three of the biggest threats to human health today, climate change, the COVID-19 pandemic, and environmental injustice. A thorough review of the relevant literature on the three topics was made and the data and information gathered were analyzed. The objective was to find the common threads between the three topics of interest. The findings show that climate change and its effects, such as extreme weather events and air pollution, are harmful to human health and disproportionately impact marginalized communities throughout the world. They are also connected to the emergence and spread of new and old infectious diseases, such as COVID-19, which once again impact poor neighborhoods and communities of color far more intensely, exacerbating social and racial segregation and contributing to the rise in deaths and poverty among these populations. Addressing the three crises in an integrated manner and with government support will be crucial to fighting climate change and offering help to the populations most in need.
College Student Environmental Activism: How Experiences and Identities Influence Environmental Activism Approaches
(2016-05) King, Laura
College student environmental activism is one way students civically engage in addressing social issues. This study explores the environmental activism of twelve college students and how their experiences outside of college and in college influenced their activism. In addition, how students’ identities influenced their approach to activism was considered. Each participant approached environmental activism in their own unique way. The way in which students engaged with environmental activism was shaped by their childhood experiences, their worldview, and experiences in College both in and out of the classroom. The identities of participants influenced how they were involved and why they were involved in the current social movement. Students conceptualized the environmental movement and their role in it in different ways. The current movement focused less on saving wilderness and more on addressing climate change and related social issues. The activities participants engaged in fell on a continuum from volunteerism to advocating for social change. Students’ environmental activism was supported by family, peers, K-12 education, and spending time in nature as children. In college, students emphasized the importance of peer networks, interactions with faculty members, and experiences in classes. Students’ identities intersected in unique ways and influenced why they were involved in and how they approached environmental activism. Students discussed the way in which their identities of gender, race, and class shaped their involvement. In addition, some students viewed their sexuality, spirituality, and being a young person as key influencers. Students said their biographic availability enabled them to be involved in environmental activism. Student environmental activists were concerned about oppression and privilege related to how the environmental movement addresses social change.
The Effect Of Climate Change On Mercury In Boreal Peatlands
(2023-09) Pierce, Caroline
Mercury is a ubiquitous pollutant that accumulates in peatlands, an ecosystem highly sensitive to climate change. Methylmercury (MeHg) is a neurotoxin that is capable of biomagnifying in food webs. We examined the effects of increasing temperature and elevated atmospheric carbon dioxide (CO2) on the concentration of total mercury (THg) and MeHg in peatland soil. This research was performed at the Spruce and Peatland Responses Under Changing Environments (SPRUCE) experiment, an ecosystem-scale manipulation in an ombrotrophic bog in northern Minnesota, USA, which includes five temperature levels (ambient plus above- and below-ground warming), with ambient or enhanced CO2 concentration. Increased temperature led to decreased MeHg concentrations in peat and increased THg and MeHg in porewaters. This decrease in peat MeHg, and increases in THg and MeHg in porewater could be caused by more rapid decomposition of the peat leading to mercury mobilization, increased methylation/demethylation rates, or increased gaseous mercury emission. The response to elevated atmospheric CO2 was limited to the surface depths of peat. Total mercury and MeHg decreased in the peat and increased in the porewater. There are no known direct effects of CO2 on mercury cycling so this finding is likely due to changes in other response variables such as the lowering of the water table or changes in the proportion of different plant species. Overall, we observed that temperature and CO2 had significant but subtle effects on THg and MeHg retention in peat. Our findings indicate that mercury concentrations in peat may decrease with climate change which may shift the system from a mercury sink to a mercury source.
Enhancing Climate Action: Exploring Human Rights Approaches in the Implementation of the Loss and Damage Fund
(2024-05-01) Kantaria, Natia
Climate change is a major challenge facing humanity. The need to address it is unfortunately not matched by sufficient action. Countries either fail to reach agreements, implement policies or stick to their commitments. The recognition of climate change as a human rights issue in UN resolutions, by the Human Rights Council and the recent judgment of the European Court of Human Rights in KlimaSeniorinnen v. Switzerland opens up new possibilities to ‘help’ countries to take action and stick to their commitments. In light of this development, this paper explores how the inclusion of human rights principles into climate change action could enable more possibilities to ensure that countries stick to their commitments. Utilizing a mixed-methods approach, and focusing on the Loss and Damage Fund (LDF) as the case, the paper examines in how far human rights principles are part of the LDF make-up and in how far their further addition can ensure states stick to their commitments. Drawing from academic and gray literature, as well as the author's firsthand experience as a practitioner and observer at the 28th Conference of the Parties, the paper concludes that meaningful integration of human rights principles, including references to international human rights law, can create more avenues for states to make them liable. Consequently, this paper underscores the importance of integrating these principles into climate change actions and develops policy recommendations to advance the enjoyment of basic human rights.
Evaluating the Impact of Vegetation and Future Climate Change on Groundwater Recharge using a Land-Surface Model
(2022-01) Anurag, Harsh
Understanding groundwater recharge is critical for accurate assessment of our valuable groundwater resources. Unfortunately, it’s also one of the most difficult fluxes of hydrological cycle to quantify because it’s influenced by several interacting factors including climate, topography, soil, land-use and vegetation. This thesis uses an integrated land-surface model to understand various factors that impact recharge. Vegetation, through evapotranspiration (ET), controls the amount of water reaching the water table and becoming recharge. Thus, changes in vegetation growth can in turn impact groundwater recharge. Currently, vegetation representation in most recharge modeling studies is specified using climatological leaf area index (LAI) values. This kind of year-to-year repeating vegetation parameterization cannot capture seasonal and inter-annual vegetation responses to dynamic meteorological conditions and can thus neglect the corresponding impact on recharge. The first part of this thesis uses Community Land Model (CLM) to investigate the sensitivity of recharge to seasonal and interannual varying vegetation in Minnesota (USA) across different climate, hydrogeology, and ecoregions. We found that although year-to-year varying vegetation does not affect long-term climatological recharge estimates, it can drive disproportionately large variability in annual and seasonal recharge. Results also show that across the precipitation gradient, vegetation leaf-out in Minnesota is highly sensitive to springtime temperature anomalies, and this phenological response can trigger notable changes in ET and subsequently recharge. Along with characterizing recharge responses to vegetation dynamics, understanding and predicting recharge under future climate conditions is also critical, as climate change is imposing additional stresses on our water resources. In the second part of this thesis, we used Minnesota as a testbed to understand how recharge will respond to changing climate in upper-latitude, low-elevation temperate settings. We compared the simulated future recharge (2026-2055) under two emissions scenarios (RCP4.5 and RCP8.5) with baseline historical conditions (1976-2005) and found that despite consistent projections of higher precipitation, state-average recharge will mostly decline or remain about the same due to warming-induced ET increases. Results also demonstrate that in addition to precipitation and temperature change, moisture feedbacks on ET and the influence of hydrogeological properties and frozen ground dynamics on runoff is essential to consider when quantifying climate change impacts on recharge in temperate zones. The final part of this thesis focuses on snowfall-induced seasonally frozen ground changes and its impact on spring recharge. We conducted simulation experiments with varying snow inputs to test the hypothesis that a smaller snowpack will allow for higher partitioning to runoff versus recharge due to greater ground frost. Results show that smaller snowpacks did lead to lower spring recharge amounts relative to precipitation compared to larger snowpacks, but not due to greater partitioning to runoff as initially hypothesized. Instead, relative recharge decreased alongside relative runoff when snowfall was less, because more of the infiltrated water was lost to ET as the surface soil ice thawed earlier and meltwater infiltrated into the root zone earlier. Overall, the findings in this thesis enhances our understanding of processes controlling groundwater recharge in upper to mid-latitude, low-relief settings such as Minnesota. As demand of groundwater continues to increase, understanding this important process by which aquifers are replenished is imperative for effective and sustainable groundwater resource management.
Evolutionary impacts of assisted gene flow: Fitness consequences of hybridization along a geo-climatic gradient in an annual prairie legume
(2024-02) Pain, Rachel
Rapid climate change, alongside substantial habitat fragmentation, presents new challenges for biodiversity conservation in the tallgrass prairie. Therefore, capacity for adaptation in situ will be necessary for long-term population persistence. Populations with larger genetic variation likely have greater capacity for adaptation, but limited population sizes and restricted gene flow decrease this potential. Assisted gene flow (AGF) aims to increase adaptive capacity by introducing genetic material from populations that have undergone selection in warmer or drier environments. However, the addition of genetic diversity from geographically and genetically distant populations may disrupt local adaptation and ultimately decrease population performance. Here, I study how hybridization between populations over a geo-climatic gradient impacts their evolutionary capacity in response to warming temperatures. I used Chamaecrista fasciculata, a buzz-pollinated prairie annual to investigate the immediate and longer-term consequences of assisted gene flow in the Minnesota tallgrass prairie. In Chapter 1, I found that local gene flow increased population fitness compared to long distance or no gene flow scenarios in both ambient and warmed conditions and that the offspring of long-distance hybridization were limited by their capacity to germinate in Minnesota. In Chapter 2, I assessed how hybridization along this geo-climatic gradient impacted the capacity for ongoing adaptation and its dependence on environmental conditions. I found that the VA(W) of hybrids was more clearly expressed in warming conditions compared to the focal populations, thus providing evidence of capacity for adaptation in hybrid populations exposed to warmer temperatures. In Chapter 3, I evaluated the impact of hybridization on floral trait plasticity. Although I detected plasticity in almost all floral traits and found no significant difference in trait values between populations, the effect of those traits on population fitness differed significantly between populations. Together these chapters provide an empirical examination of the theoretical expectations of gene flow on a complex landscape and provide substantial evidence of the importance of maintaining genetically variable populations in a changing climate.
Examining Collective-Efficacy As A Framework For Watershed Scale Resource Management
(2017-10) Perry, Vanessa
This dissertation explores a collective-efficacy theoretical framework as it relates to climate change and extreme weather response and water and stormwater management in a northern Minnesota coastal community. A multi method research approach was implemented in two sub-watersheds of the Lower St. Louis River Basin near Duluth, Minnesota that included 27 interviews, two focus groups, a workshop, and bio-physical modeling of potential climate impacts. Perceived collective-efficacy to make decisions and take action to manage natural resources and potential future resource impacts from climate and extreme weather impacts emerged as a prominent theme in analysis. This dissertation explores collective-efficacy in the study community through three approaches, 1) perceived collective-efficacy for resource management and climate and extreme weather response as it relates to relationship to place, 2) the use of a collective-efficacy framework throughout a sequential community-based, multi methods, natural resource management study, and 3) the application of collective-efficacy principals in an applied tool for use in local decision making. An exploration of collective-efficacy in local communities can help identify barriers to effective decision making and opportunities for progress in climate and extreme weather preparedness. This work both builds the body of literature on climate response related collective-efficacy research and offers an applied path for stakeholders working collectively to address challenging natural resource management issues.
First We Must Consider Manoomin/Psiŋ: Impacts of Climate and Land Cover Change on Wild Rice
(2023) Nyblade, Madeline
In the upper Laurentian Great Lakes region, Indigenous communities have experienced declines of wild rice (Ojibwemowin: Manoomin; Dakodiapi: Psiŋ; Latin: Zizania palustris), a sacred aquatic plant and food central to their culture. Through tribal-university collaboration, we analyzed Manoomin/Psiŋ density and harvest data along with case studies to show Manoomin/Psiŋ available for tribal harvest has declined regionally by 6±4% to 7±2% per year, complicated by local multi-year cycles and relationships. Our analysis of this data in relation to key environmental conditions reveals both climate and land cover change as drivers of this decline. Increasing precipitation during early summer, as well as decreasing winter temperatures, snowfall, and lake ice, with the changing climate all negatively impact Manoomin/Psiŋ density. Land cover change with U.S. colonization causes harm as well: the resulting increased croplands, pastures, and urban areas, as well as the shifting forest types, all negatively impact Manoomin/Psiŋ. This decline has infringed on Indigenous lifeways by reducing off-reservation harvest by Indigenous people, a right guaranteed by treaties with the US government. Since time immemorial, Indigenous nations have been taking care of Manoomin/Psiŋ, charting a course of Manoomin/Psiŋ stewardship that can be followed to protect this important being in the face of threats from climate and land cover change.
Food Systems and Climate Change: A Comparison of Global Emission Estimates, A Systems Framework for Mitigation Efforts, and Intersections of Mitigation Efforts with Sustainable Development Goals
(2022-08) Colgan, Kimberly
Global food systems are estimated to contribute approximately one-third of anthropogenicgreenhouse gas (GHG) emissions, and alone, are large enough to make the goals of the Paris Climate Agreement unattainable. The need for the rapid reduction of GHG emissions in our food systems is well established, with calls for food systems transformation focusing on the intersection of climate, food security, public health, sustainability, and social reform as people do not have equal access to nutrition, land, or economic benefit. The multifaceted nature of our food systems crisis requires thoughtful and expansive solutions. This dissertation strives to understand the contribution of the global food system to GHG emissions today and in the future, explore recommendations to reduce food system GHG emissions using a systems thinking framework, and how these interventions may affect broader sustainability goals. In my three chapters, I: (1) synthesize and explore estimates of global food system GHG emissions in the past and future; (2) explore interventions and expert recommendations to mitigate food system emissions through a systems thinking lens, and use systems change frameworks to propose more transformational recommendations; and (3) explore how interventions to mitigate food system emissions might affect the achievement of the United Nations Sustainable Development Goals (SDGs). I find that: (1) existing estimates for global food system GHG emissions are often too aggregated to contribute to understanding what drives climate damages, while there are no global food system GHG emission projections for the future that include post-production emissions; (2) there is a mismatch between expert calls for food systems transformation to mitigate GHG emissions and expert recommendations, but we can expand our expert recommendations to mitigate food systems utilizing systems change frameworks to create better, more transformational recommendations; and (3) that there are likely to be environmental- and economic-benefits of interventions to mitigate food system emissions, but advancement on justice-centered SDGs is likely only if policies center on reducing inequalities, and marginalized and vulnerable populations are included and empowered at the forefront of mitigation policy planning and implementation. Food system mitigation interventions that are inclusive, holistic, and interdisciplinary that are designed to consider all the SDGs initially are likely to bring us closer to the transformational food system changes necessary to meet the goals of the Paris Agreement, achieve sustainable diets, and reduce inequalities in our food systems. Overall, my work suggests that climate mitigation research would benefit from: current food system emissions estimates that are sufficiently disaggregated to illuminate what is ultimately driving climate damages in our global food system; projections of comprehensive GHG emissions that include the entire life cycle of our global food system; a new focus in our recommendations and efforts on interventions that have higher potential to achieve desired food system transformations; and include aspects of sustainability beyond climate change mitigation to ensure our future efforts to reduce GHG emissions do not exacerbate the existing inequalities in our current food system.
Genecology and Phenotypic Selection in Whitebark Pine (Pinus albicaulis) and Ponderosa Pine (Pinus ponderosa) Under Warm-Dry Climate
(2015-08) Warwell, Marcus
To study patterns of adaptation to the contemporary climate and phenotypic selection under future predicted climate in whitebark pine (Pinus albicaulis), seedlings from 49 populations representative of the interior northwestern USA were grown in two low-elevation, common-garden field tests over a 12-year period. The primary objectives were to: 1) assess genetic variation in growth and survival among populations (Chapter 1); 2) model this genetic variation in relation to climate at the seed source (Chapter 1); 3) describe phenotypic selection on growth rhythm (Chapter 2); and 4) model growth rhythm in relation to climate of seed source (Chapter 2). Results showed moderate genetic divergence in growth and survival among populations that corresponded with climatic clines. Populations originating from locations with earlier spring warming exhibited greater inherent growth under favorable conditions, while populations originating from locations with lower spring precipitation exhibited greater survival under drought conditions. Selection on measures of growth rhythm was detected and varied between experimental sites and among years. More complex selection on measures of growth rhythm was observed on the experimental site with more favorable growing conditions. Curved directional selection and stabilizing selection tended to occur in earlier years and was chiefly associated with mortality in the year of expression. Differences among seed sources in growth rhythm were mild and were explained to a moderate extent (r2 = 0.08 - 0.28) by variation in temperature or precipitation among seed origins. Individuals originating from milder climates tended to elongate slightly longer through the growing season and exhibit slightly higher shoot elongation rates. To study phenotypic selection of ponderosa pine (Pinus ponderosa Doug.) in response to predicted future climate, seedlings were grown from seed in the field using three drought-imposed treatments under a climate warmer and drier than the climates of seed origins. The seedlings originated from 36 maternal trees from Priest River Experimental Forest, ID and 3 provenances (8 maternal trees per provenance) representative of the interior northwestern USA. The primary objectives were to 1) evaluate the magnitude, form and temporal dynamics of selection on seed and seedling traits in response to variation in the timing of growing-season drought for a single provenance and (2) assess differences in selection among provenances representative of the interior northern USA (Chapter 3). Differences in selection among treatments and provenances on traits associated with drought adaptation were detected and described. For the Priest River provenance, mortality differed among families within provenances. Selection via differential mortality in the year of emergence was particularly strong, while selection in subsequent years was far less pronounced. The form of selection was influenced by timing of drought. Differences in the magnitude and form of selection were also detected among provenances. In addition, patterns of variation for selection among provenances corresponded with dryness of seed origin. These results suggested that during the seed-to-seedling stage, populations within the region will likely differ in their selection response to changes in the timing of growing-season drought.

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