The Comparison of Climate Change Rates in Rural versus Urban Areas in Tennessee An analysis of climate data was performed in three counties in Tennessee. The goal of this study is to identify the different rates of climate change in counties of varying urbanization levels. Davidson County, which contains the city of Nashville, is used as the most urban county. Two counties outside Nashville, Sumner and Dickson Counties, are used as a moderately urban county and a rural county, respectively. The level of urbanization was adopted from Tennessee Advisory Commission on Intergovernmental Relations' Index of Relative Rurality. Yearly average temperature and daily mean temperature for the warm season (May through October) were collected on each county from the years of 1960-2020 via the PRISM Climate Group at Oregon State University. A Mann-Kendall (MK) trend test was used for each individual county’s data to determine if the series had a monotonic upward trend, meaning overall temperature increase. The hypothesis of this analysis is that the most urban county will have the highest rate of warming due to the urban heat island (UHI) effect. The analysis of the yearly average temperature data for the three counties showed that Davidson and Sumner had higher Sen’s slopes and Kendall’s Taus, which were the prominent factors examined to determine the extent of climate change. Comparatively, Dickson County was found to have a lower Sen’s slope and Kendall’s Tau, which implies a lower overall rate of warming. Significance was found within all the results, since P-values were α Laina Caywood: Environmental Health, East Tennessee State University. Ying Li: Environmental Health, East Tennessee State University. Andrew Joyner: Department of Geosciences, East Tennessee State University.

Traditional agricultural practices often result in gaseous losses of nitrous oxide (N2O), ammonia (NH3), and carbon dioxide (CO2), representing a net loss of nutrients from agricultural soils, which negatively impacts crop yield and requires farmers to increase nutrient inputs. By adopting best management practices (BMPs; i.e., no-tillage, cover crops, sub-surface manure application, and proper manure application timing), there is great potential to reduce these losses. Because N2O and CO2 are also greenhouse gases (GHGs), climate change mitigation via BMP adoption and emissions reductions would be an important co-benefit. However, adopting a no-tillage and cover cropping system has had setbacks within the Northeast, primarily due to concerns regarding manure nitrogen (N) losses in no-tillage systems as well as uncertainty surrounding the benefits of cover crops. This thesis used two field-trials located in Alburgh, Vermont to assess differences in (i) GHG emissions from agricultural soils, (ii) nitrate and ammonium retention, (iii) corn yield and protein content, and (iv) N uptake and retention via cover crop scavenging under a combination of different BMPs. Chapter 1 evaluates the effects of different reduced-tillage practices and manure application methods (i.e., vertical-tillage, no-tillage, manure injection, and broadcast manure application) on reducing N2O and CO2 emissions, retaining inorganic N, and improving crop yields. Greenhouse gas measurements were collected every other week for the growing season of 2015-2017 via static chamber method using a photoacoustic gas analyzer. Results from this study showed that tillage regimes and manure application method did not interact to affect any of the three research objectives, although differences between individual BMPs were observed. Notably, vertical tillage enhanced CO2 emissions relative to no-tillage, demonstrating the role of soil disturbance and aeration on aerobic microbial C transformations. Manure injection was found to significantly enhance both N2O and CO2 emission relative to broadcast application, likely due to the formation of anerobic micro-zones created from liquid manure injection. However, plots that received manure injection retained greater concentrations of soil nitrate, a vital nutrient for quality crop production, thereby highlighting a major tradeoff between gaseous N losses and N retention with manure injection. Chapter 2 evaluates the effects of tillage practices and timing of manure application to increase N retention with the use of cover crops in order to mitigate GHG emissions, enhance soil nitrate and ammonium retention, and improve cropping system N uptake. Treatments at this field trial consisted of a combination of the presence or absence of cover crops, no-tillage or conventional-tillage, and spring or fall manure application. Greenhouse gas emissions were measured every other week via static chamber method using a gas chromatograph for the growing season of 2018. Results from this study showed that the presence of cover crops enhanced both N2O and CO2 emissions relative to fallow land, irrespective of tillage regime and manure application season, likely as a result of greater N and carbon substrates entering the soil upon cover crop decomposition. Due to enhanced N2O emissions with cover crops, cover crops did not retain significantly greater inorganic N in the system upon termination.

Large areas of northern peatlands have been drained and afforested in the second half of the 20th century with significant impacts on important ecosystem services, including loss of biodiversity and potential changes in C storage. A considerable effort is currently invested into restoring original peatland function and ecosystem services, with an increasing area of newly restored peatland areas over recent years. However, the effect of restoration on the greenhouse gas (GHG) budget is unknown. This study is the first quantification of CO2, CH4 and N2O fluxes from forest-to-bog restoration sites spanning 0 to 17 years in age. Further, the impact of afforestation on peat decomposition is measured in situ, and the impact of afforestation on the biochemical composition of the peat in relation to CO2 and CH4 fluxes is investigated. Results show that forest-to-bog restoration is successful from a GHG perspective, since all three major GHG fluxes of the restoration sites are changing along the chronosequence towards the fluxes from near pristine bog sites. The peat decomposition rate under the forest plantations is a big part of the total soil respiration at 126.8 ± 14.7 g C m-2 y-1 (44% of total soil CO2 efflux) and our results indicate a slowing down of peat decomposition towards the near pristine bog. CH4 fluxes increase with restoration age, whilst all sites remain a small sink for N2O. I observed changes in peat quality and nutrient availability in the pore water under forests. Different CO2 fluxes between vegetation-free peat cores from different sites for the same temperature and water level show that these differences in peat quality and nutrient availability shape the biogeochemical processes in the peatlands. However only small differences in CH4 fluxes between sites were evident, suggesting that on its own (and in absence of biotic interactions under field conditions), forestry effects on CH4 flux are limited.

This study is made to understand the opportunities and challenges SMEs have to adopt GHG calculation tools. Adoption of GHG calculation tools are common by large organizations and have proven as a consequence to lower their GHG emissions, motivate their employees and establish sustainability goals. Even thou a large amount of large organizations have adopted GHG calculation tools, this is very rare in SMEs. Using the theoretical framework called Rogers diffusion of innovation theory and a survey, the factors behind why or why not SMEs have adopted GHG calculation tools were studied. The results showed that only 9% of SMEs have adopted GHG calculation tools and the reason for this is lack of resources, competence and data. The analysis showed that the characteristics of an organization that affects this the most are leadership, education and regulations. In order to overcome the challenges, organizations should prioritize to have a leadership that motivates employees to engage in sustainability actions. Organizations should enable skill development in the field of sustainability to increase the competence. This would enable more organization to adopt GHG calculation tools and most likely lower their GHG emissions.

Greenhouse gasses, such as carbon dioxide and methane absorb and emit heat radiation, which contribute to global warming. Human activities such as increased emissions through burning of fossil fuels and deforestation drive this climate threat. International treaties such as the Paris agreement, enables stakeholders to mitigate effects of climate impact and create new sustainable markets. Various carbon offset projects on the voluntary market are an attempt to neutralize climate impact. In this report we identify five main project types for carbon offsets: i) forestry and land use, ii) renewable energy and energy effectivization, iii) transport, iv) waste handling and v) household devices. These project types are evaluated against UNs 17 sustainable development goals. The results show a net positive impact on goal 13, Climate action, for all project types, which is congruent with the focus on carbon offsetting. The results also show that impact varies depending on how the project is deigned. Climate offsetting has enabled multiple stakeholders to contribute to climate change mitigation. Despite many global benefits, carbon offsets have been subject to criticism in cases where the concept is not used as intended. There are currently no clear guidelines as to when focus for companies should shift from internal reduction to external reduction through offsetting. Validation of carbon offsets is another problematic aspect, as there is no one standard for the market to secure the quality of projects.

Manguezais são ambientes costeiros que proveem diversos recursos para ecossistemas adjacentes devido à alta produtividade decorrente da decomposição de matéria orgânica e principalmente da constante ciclagem de carbono, realizada pelas comunidades microbianas presentes nos sedimentos. Desde a década de 70, com o aumento da liberação de gases pela queima de combustíveis fósseis, diversas anormalidades, como o aumento da temperatura e acidificação dos oceanos, têm sido observadas. Com base na hipótese de que as mudanças climáticas provocam alterações na diversidade microbiana associada à decomposição da matéria orgânica em sedimentos de manguezais, estimulando a liberação de Gases do Efeito Estufa (GEE), o presente estudo teve como objetivo avaliar a dinâmica da diversidade microbiana sob alteração das condições climáticas durante o processo de decomposição, correlacionando-a com a emissão de GEE. Microcosmos destrutivos contendo material orgânico proveniente das principais espécies vegetais encontradas nos manguezais do Estado de São Paulo (Rhizophora mangle, Laguncularia racemosa e Avicennia schaueriana) foram incubados em condições simulando as mudanças climáticas (aumento de temperatura e pH). Amostragens do material em decomposição (para sequenciamento da região 16S rRNA e quantificação do gene mcrA) e de gases foram coletadas durante 45 dias. As variações no tempo resultaram em impactos significativos no aumento da α diversidade e na composição da comunidade, inicialmente com maior abundância de Gammaproteobacteria para todas as espécies vegetais independente das variações nas condições climáticas. Análises do tipo PCoA evidenciaram o processo de sucessão em decorrência do tempo na β diversidade, indicando o aumento da incidência de Deltaproteobacteria ao final do processo. As emissões de GEE variaram em função da fonte de material orgânico e observou-se relação entre a emissão de metano (CH4) e a presença do gene mcrA em duas das espécies vegetais estudadas, admitindo-se que o aumento na população de Deltaproteobacteria tenha controlado sua emissão. Apesar da quantidade de estudos relacionados à decomposição de matéria orgânica, à diversidade microbiana e à emissão de gases em manguezais, poucos apresentam uma abordagem como a proposta pelo presente trabalho, que busca compreender melhor a relação entre os três processos, relacionando-os a um quarto evento, as alterações climáticas, que são um problema imanente da atualidade. / Mangrove are coastal environments that provide resources for adjacent ecosystems due to its high productivity that comes from decay of organic matter and carbon cycling, made by microbial communities in sediments. Since the increase of gas release due to fossil fuel burning in the 1970\', many abnormalities have been observed such as temperature and acidification increase. Base on the hypothesis that climate change modifies microbial diversity associate to decay of organic matter in mangrove sediments, changing the emission of Greenhouse Gases (GHG) rate, the goal of this research is to evaluate the dynamics of microbial diversity under the climate change conditions during de decay process, correlating with the emission of GHG. Destructive microcosms containing organic matter from the main plant species found in mangroves throughout the State of São Paulo, Brazil (Rhizophora mangle, Laguncularia racemosa e Avicennia schaueriana) were incubate simulating climate changes (increase in temperature and pH). Sampling of decaying material (for sequencing of 16S rRNA region and quantification of the mcrA gene) and of gasses were collected for 45 days. The variation in time resulted in important increases of α diversity impacts and in the community composition, initially with greater abundancy of Gammaproteobacteria for all plant species despite of the climate conditions variations. The PCoA analysis bespeak the chronological sequence in β diversity, indicating the increase of Deltaproteobacteria at the end of the process. The GHG emission varied in function of the organic matter source and the relation between methane (CH4) release and the presence of the mcrA gene in two of the plant species studied, if the increase in the Deltaproteobacteria population controlled its emission. Despite the great number of studies about the decay of organic matter and emission of gases in mangroves, few present an approach like this work, which aims to understand the relation between these three processes and the climate changes, a pressing problem nowadays.

This thesis is divided into two parts. The first evaluates the role of the built environment in life-cycle energy consumption, by comparing different neighborhood and city styles. Through a holistic modeling and accounting framework, this work identifies the largest energy-consuming sectors, among residential and commercial buildings, personal vehicles and transit trips, and supporting infrastructure (roads, sidewalks, parking lots, water pipes, street lighting). Life-cycle energy calculations include operational energy use (e.g., gasoline for vehicles, electricity and natural gas for buildings) and embodied energy used to produce materials and construct buildings and infrastructure. Case study neighborhoods in Austin, Texas, and larger-scale regional models suggest that building energy demands comprise around 50% of life-cycle energy demands, while transportation demands (from driving and infrastructure alike) contribute around 40%, across all cases. However, results also suggest that population density and average residential unit size play a major role in defining per-capita energy consumption. Operational demands made up about 90% of life-cycle energy demands, suggesting that v most urban energy savings can be obtained from reduced personal vehicle trips and more efficient vehicles and buildings. Case study comparisons suggest that neighborhoods and regions with greater density and higher share of multi-family housing units tend to reduce operational (and thus life-cycle) energy demands with less travel demand and decreased home and work energy use, per capita. The second part of this modeled plug-in electric vehicle (PEV) emissions impacts in Texas, by considering four possible vehicle adoption scenarios (where PEVs make up 1, 5, 10, and 25% of total passenger vehicles). The analysis anticipates PEV electricity demand and emissions rates, based on current Texas power grid data. Results indicate that PEV emissions depend significantly on which specific power plants are used to power the vehicles, but that PEVs' average per-mile emissions rates for NO[subscript x], PM, and CO₂ are all likely to be lower than today's average passenger car, when today's average mix is used. Power produced from 100% coal plants could produce 14 times as much NO[subscript x], 3,200 times as much SO₂, nearly 10 times as much CO₂ and CO₂eq, 2.5 times as much PM₁₀, and VOCs, and nearly 80 times the NO₂ compared to a grid with 100% natural gas plants. / text

Grasslands comprise the greatest biome by land area, are sensitive to environmental factors affected by climate change, and can impact future climate change through their ability to store and release greenhouse gasses (GHGs). I performed two studies: 1) evaluated the effects of increased temperature and precipitation on slug herbivory/abundance and pasture forage production; 2) quantified different homeowner lawn system effects on soil-to-atmosphere GHG emissions. Climate change will likely affect pasture forage production, with implications for slug herbivory and abundance. I found little evidence that slugs have or will have significant effects on pasture production or plant community. Warming altered the abundance of slugs and modified seasonal trends, increasing slug abundance in spring/winter and reducing it in late-summer/fall, through both direct effects and changes in plant community and forage quality. Home lawns vary in levels of management, influencing the exchange of GHGs. I quantified the effects of three common home lawn systems of central Kentucky on GHG emissions, but found no significant differences in CO2, N2O, and NH3 fluxes. My research suggests that slug herbivory is not a dominant ecological process in Kentucky pastures and that common home lawn systems have similar soil-to-atmosphere GHG emissions.

The aim of this study was to understand the link beween greenhouse gasses emissions (CH4 and N2O) microbial activity and nutrient content in soil from different types of soil in Svalbard. Warming can cause release of large amounts of carbon and nitrogen in form of greenhouse gasses from soil into the atmosphere. This might strengthen the greenhouse effect and thus global climate change. We measured release of greenhouse gases from soil. At the same time, soil sampling was conducted at five different localities in August in the years 2014 and 2015. Soils were found to have low nutrient content and unfavourable C/N ratio to support vegetation growth. Areas were not a significant source of emissions of greenhouse gasses from soil to the atmosphere.

Manguezais são ambientes costeiros que proveem diversos recursos para ecossistemas adjacentes devido à alta produtividade decorrente da decomposição de matéria orgânica e principalmente da constante ciclagem de carbono, realizada pelas comunidades microbianas presentes nos sedimentos. Desde a década de 70, com o aumento da liberação de gases pela queima de combustíveis fósseis, diversas anormalidades, como o aumento da temperatura e acidificação dos oceanos, têm sido observadas. Com base na hipótese de que as mudanças climáticas provocam alterações na diversidade microbiana associada à decomposição da matéria orgânica em sedimentos de manguezais, estimulando a liberação de Gases do Efeito Estufa (GEE), o presente estudo teve como objetivo avaliar a dinâmica da diversidade microbiana sob alteração das condições climáticas durante o processo de decomposição, correlacionando-a com a emissão de GEE. Microcosmos destrutivos contendo material orgânico proveniente das principais espécies vegetais encontradas nos manguezais do Estado de São Paulo (Rhizophora mangle, Laguncularia racemosa e Avicennia schaueriana) foram incubados em condições simulando as mudanças climáticas (aumento de temperatura e pH). Amostragens do material em decomposição (para sequenciamento da região 16S rRNA e quantificação do gene mcrA) e de gases foram coletadas durante 45 dias. As variações no tempo resultaram em impactos significativos no aumento da α diversidade e na composição da comunidade, inicialmente com maior abundância de Gammaproteobacteria para todas as espécies vegetais independente das variações nas condições climáticas. Análises do tipo PCoA evidenciaram o processo de sucessão em decorrência do tempo na β diversidade, indicando o aumento da incidência de Deltaproteobacteria ao final do processo. As emissões de GEE variaram em função da fonte de material orgânico e observou-se relação entre a emissão de metano (CH4) e a presença do gene mcrA em duas das espécies vegetais estudadas, admitindo-se que o aumento na população de Deltaproteobacteria tenha controlado sua emissão. Apesar da quantidade de estudos relacionados à decomposição de matéria orgânica, à diversidade microbiana e à emissão de gases em manguezais, poucos apresentam uma abordagem como a proposta pelo presente trabalho, que busca compreender melhor a relação entre os três processos, relacionando-os a um quarto evento, as alterações climáticas, que são um problema imanente da atualidade. / Mangrove are coastal environments that provide resources for adjacent ecosystems due to its high productivity that comes from decay of organic matter and carbon cycling, made by microbial communities in sediments. Since the increase of gas release due to fossil fuel burning in the 1970\', many abnormalities have been observed such as temperature and acidification increase. Base on the hypothesis that climate change modifies microbial diversity associate to decay of organic matter in mangrove sediments, changing the emission of Greenhouse Gases (GHG) rate, the goal of this research is to evaluate the dynamics of microbial diversity under the climate change conditions during de decay process, correlating with the emission of GHG. Destructive microcosms containing organic matter from the main plant species found in mangroves throughout the State of São Paulo, Brazil (Rhizophora mangle, Laguncularia racemosa e Avicennia schaueriana) were incubate simulating climate changes (increase in temperature and pH). Sampling of decaying material (for sequencing of 16S rRNA region and quantification of the mcrA gene) and of gasses were collected for 45 days. The variation in time resulted in important increases of α diversity impacts and in the community composition, initially with greater abundancy of Gammaproteobacteria for all plant species despite of the climate conditions variations. The PCoA analysis bespeak the chronological sequence in β diversity, indicating the increase of Deltaproteobacteria at the end of the process. The GHG emission varied in function of the organic matter source and the relation between methane (CH4) release and the presence of the mcrA gene in two of the plant species studied, if the increase in the Deltaproteobacteria population controlled its emission. Despite the great number of studies about the decay of organic matter and emission of gases in mangroves, few present an approach like this work, which aims to understand the relation between these three processes and the climate changes, a pressing problem nowadays.