Global cities have recognized the need to reduce greenhouse gas (GHG) emissions and have begun to take action to balance of the carbon cycle. This thesis examines the nuances of quantification methods used and the implications of current policy for long-term emissions. Emissions from waste management, though relatively small when compared with building and transportation sectors, are the largest source of emissions directly controlled by municipal government. It is important that municipalities understand the implications of methodological selection when quantifying GHG emissions from waste management practices. The “Waste-in-Place” methodology is presented as the most relevant for inventorying purposes, while the “Methane Commitment” approach is best used for planning. Carbon sinks, divided into “Direct” and “Embodied”, are quantified using the Greater Toronto Area (GTA) as a case study. “Direct” sinks, those whose sequestration processes occur within urban boundaries, contribute the largest share of carbon sinks with regional forests providing a significant proportion. “Embodied” sinks, those whose sequestration processes (or in the case of concrete, the processes that enable sequestration) are independent of the urban boundary, can contribute to the urban carbon pool, but greater uncertainty exists in upstream emissions as the management/processing prior to its use as a sink are generally beyond the consumer’s purview. The Pathways to Urban Reductions in Greenhouse gas Emissions (or PURGE) model is developed as a means to explore emissions scenarios resulting from urban policy to mitigate climate change by quantifying future carbon sources/sinks (from changes in building stock, vehicle stock, waste treatment and urban/regional forests). The model suggests that current policy decisions in the GTA provide short-term reductions but are not sufficient in the long term to balance the pressures of economic and population growth. Aggressive reductions in energy demand from personal transportation and existing building stock will be necessary to achieve long-term emissions targets.

Decision-makers in cities have realized their pivotal role in addressing climate change, and they are responding accordingly. This thesis presents three papers that explore the process of responding to climate change in cities, highlighting the situation in selected global cities with varying economies and development priorities. The methodology for conducting an urban greenhouse gas inventory in three Chinese cities is detailed in the first paper, illustrating issues of economic development and climate change mitigation in a transitional economy. Next, the greenhouse gas emissions savings of various strategic mitigation plans are quantified for Toronto, demonstrating the aggressive actions needed in developed cities to approach carbon neutrality. The third paper explores issues associated with climate change in three developing cities, emphasizing the need for synergic development incorporating strategies for both mitigation and adaptation. The thesis concludes with an overview of the importance of innovation and further research to future responses to climate change.

Global cities have recognized the need to reduce greenhouse gas (GHG) emissions and have begun to take action to balance of the carbon cycle. This thesis examines the nuances of quantification methods used and the implications of current policy for long-term emissions. Emissions from waste management, though relatively small when compared with building and transportation sectors, are the largest source of emissions directly controlled by municipal government. It is important that municipalities understand the implications of methodological selection when quantifying GHG emissions from waste management practices. The “Waste-in-Place” methodology is presented as the most relevant for inventorying purposes, while the “Methane Commitment” approach is best used for planning. Carbon sinks, divided into “Direct” and “Embodied”, are quantified using the Greater Toronto Area (GTA) as a case study. “Direct” sinks, those whose sequestration processes occur within urban boundaries, contribute the largest share of carbon sinks with regional forests providing a significant proportion. “Embodied” sinks, those whose sequestration processes (or in the case of concrete, the processes that enable sequestration) are independent of the urban boundary, can contribute to the urban carbon pool, but greater uncertainty exists in upstream emissions as the management/processing prior to its use as a sink are generally beyond the consumer’s purview. The Pathways to Urban Reductions in Greenhouse gas Emissions (or PURGE) model is developed as a means to explore emissions scenarios resulting from urban policy to mitigate climate change by quantifying future carbon sources/sinks (from changes in building stock, vehicle stock, waste treatment and urban/regional forests). The model suggests that current policy decisions in the GTA provide short-term reductions but are not sufficient in the long term to balance the pressures of economic and population growth. Aggressive reductions in energy demand from personal transportation and existing building stock will be necessary to achieve long-term emissions targets.

Decision-makers in cities have realized their pivotal role in addressing climate change, and they are responding accordingly. This thesis presents three papers that explore the process of responding to climate change in cities, highlighting the situation in selected global cities with varying economies and development priorities. The methodology for conducting an urban greenhouse gas inventory in three Chinese cities is detailed in the first paper, illustrating issues of economic development and climate change mitigation in a transitional economy. Next, the greenhouse gas emissions savings of various strategic mitigation plans are quantified for Toronto, demonstrating the aggressive actions needed in developed cities to approach carbon neutrality. The third paper explores issues associated with climate change in three developing cities, emphasizing the need for synergic development incorporating strategies for both mitigation and adaptation. The thesis concludes with an overview of the importance of innovation and further research to future responses to climate change.

New Zealand's greenhouse gas inventory is dominated by the agricultural trace gases, CH4 and N2O instead of CO2, which is dominant on a global scale. While the majority of the anthropogenic CH4 is emitted by ruminant animals as a by-product of enteric fermentation, N2O is mainly produced by microbial processes occurring in the soil. In grazed pastoral soils, N2O is generated from N originating from dung, urine, effluent applied to land, biologically fixed N2 and fertiliser. The amount of emission depends on complex interactions between soil properties, climatic factors and management practices. Increased intensification of pastoral agriculture in New Zealand, particularly in dairying has led to an increased production of farm dairy effluent. Traditionally, direct disposal of nutrient rich farm dairy effluents (FDE) into water bodies was an acceptable practice in New Zealand, but with the introduction of the Resource Management Act (1991), discharge of effluents into surface waters is now a controlled activity and many Regional Councils encourage the land irrigation of effluents to protect surface water quality. While the impact of grazing and FDE irrigation on groundwater contamination through leaching and runoff of nutrients has been studied extensively, there has been only limited work done on the effect of these practices on air quality as affected by N2O emission. This thesis examines the effects of various factors, such as compaction due to cattle treading, and the nature, application rate and time of effluent application on N2O emission in relation to the changes in the soil physical properties and C and N transformation from a number of small plot and field experiments. The results were then used, together with data from the literature, to predict the emissions from effluent irrigated pastures using a process-based model. In grazed pastures, animal treading causes soil compaction, which results in decreased soil porosity and increased water filled pore space that stimulate the denitrification rate as well as influence the relative output of N2O and dinitrogen (N2) gases. A field plot study was conducted to determine N2O emission from different N sources as affected by soil compaction. The experiment comprised two main treatments (uncompacted and compacted) to which four N sources (natural cattle urine, potassium nitrate, ammonium sulphate and urea at the rate of 600kg N ha-1) and a control (water only) were applied. Compaction was obtained through driving close parallel tracks by the wheels of the vehicle. The changes in the soils physical properties (bulk density, penetration resistance (PR), soil matric potential and oxygen diffusion rate (ODR) due to the compaction created by the wheel traction of the vehicle were compared with the changes in these properties due to the treading effect of grazing cattle, which was monitored in another field experiment. The N2O fluxes were measured using a closed chamber technique. The compaction at the grazing trial and at the wheel traction experimental plot caused significant changes in soil bulk density, PR, soil matric potential and ODR values. Overall, the bulk density of the compacted soil was higher than the uncompacted soil by 6.7% (end of 3 weeks) and 4.9% (end of 1 week) for the field experiment and the grazing trial, respectively. Results suggest that maximum compaction occurred in the top 0-2 cm layer. Compaction caused an increase in N2O emission, which was more pronounced in the nitrate treatment than in the other N sources. In the case of the compacted soil, 10% of the total N applied in the form of nitrate was emitted, whereas from uncompacted soil this loss was only 0.7%. N2O loss was found to decrease progressively from the time of application of N treatments. Total N2O emission for the three month experimental period ranged from 2.6 to 61.7 kg N2O-N ha-1 for compacted soil and 1.1 to 4.4 kg N2O-N ha-1 for uncompacted soil. In the second field plot experiment, the results of N2O fluxes from treated farm dairy effluent (TFDE), untreated farm dairy effluent (UFDE), treated piggery farm effluent (TPFE) and treated meat effluent (TME) applied to 2m x 1m plots for 'autumn' (February-April) and 'winter' (July-September) are described. Effluent irrigation resulted in higher emissions during both the seasons indicating that the supply of C and N through effluent irrigation contributed to increased N2O emission. The highest emissions were observed from TPFE (2.2% of the applied N) and TME (0.6% of the applied N) during the autumn and winter seasons, respectively. Emissions generated by the TFDE application were the lowest of the four effluent sources but higher than the water and control treatments. The effect of effluent irrigation on N2O emission was higher during the autumn season than the winter season. The effect of key soil and effluent factors such as water filled pore space (WFPS), nitrate, ammonium and available C in soil and effluents on N2O emission was examined using regression equations. The third field plot experiment examined the effect of four TFDE application rates (25mm, 50mm, 75mm and 100mm) on N2O emission. Treatments were added to 2m x 1m plots lined with plastic sheet to restrict the flow of effluent. The N2O emission increased with the increasing effluent loading rate, with the emission ranging from 0.8 to 1.2% of the added N. This can be attributed to the increasing addition of N and C in the soil with the increasing application rate of the effluent. Besides, providing C and N substrates, the effluent application increased the WFPS of the soil, thereby creating conditions conducive for dentrification and N2O emission. A field experiment was conducted at the Massey University No 4 Dairy farm in which N2O emission and related soil and environmental parameters were monitored for two weeks following the TFDE applications over an area of 0.16 ha in September 2003 (21mm), January 2004 (23mm) and February 2004 (16mm). Emissions were measured by a closed chamber technique with 20 chambers for each treatment, in order to cover the variability present in the field. N2O emissions increased immediately after the application of the effluent, and subsequently dropped after about two weeks. The total N2O emitted from the effluent application after the first, second and third irrigation was 2%, 4.9% and 2.5%, respectively of the total N added through the effluent. The higher emission observed during the second effluent irrigation event was due to high soil moisture content during the measurement period. Moreover effluent was applied immediately after a grazing event leading to more N and C input into the soil through excretal deposition. In this experiment the residual effect of effluent application on N2O emission was also examined by monitoring emissions 12 weeks after the effluent application. The emissions from the control and effluent irrigated plots were similar, indicating that there was no residual effect of the effluent irrigation on N2O emissions. In a separate field study, N2O emission was monitored at the Massey University No 4 Dairy farm to examine the effect of a grazing event of moderate intensity on N2O emission. The treatments consisted of a grazed and an ungrazed control. The fluxes from the grazed site were much higher than for the ungrazed site with the total emissions from the former site being 8 times higher than the latter site for the entire experimental period. A modified New Zealand version of denitrification decomposition model (DNDC), a process based model, namely "NZ-DNDC", was used to simulate N2O emission from the TFDE application in the field experiment. The model was able to simulate the emission as well as the WFPS within the range measured in the field. But simulated emissions from the TFDE were slightly lower than measured values. Improvements in the parameterisation for effluent irrigation are likely to further improve the N2O simulations.

Made available in DSpace on 2014-12-17T14:08:44Z (GMT). No. of bitstreams: 1 RafhaelAH_DISSERT.pdf: 3286080 bytes, checksum: f7d63c2f5fde3101ddffb2cd1417b11d (MD5) Previous issue date: 2011-02-17 / Efforts in research and development of new technologies to reduce emission levels of pollutant gases in the atmosphere has intensified in the last decades. In this context, it can be highlighted the modern systems of electronic engine management, new automotive catalysts and the use of renewable fuels which contributes to reduce the environmental impact. The purpose of this study was a comparative analysis of gas emissions from a automotive vehicle, operating with different fuels: natural gas, AEHC or gasoline. To execute the experimental tests, a flex vehicle was installed on a chassis dynamometer equipped with a gas analyzer and other complementary accessories according to the standard guidelines of emission and security procedures. Tests were performed according to NBR 6601 and NBR 7024, which define the urban and road driving cycle, respectively. Besides the analysis of exhaust gases in the discharge tube, before and after the catalyst, using the suction probe of the gas analyzer to simulate the vehicle in urban and road traffic, were performed tests of fuel characterization. Final results were conclusive in indicating leaded gasoline as the fuel which most contributed with pollutant emissions in atmosphere and the usual gasoline being the fuel which less contributed with pollutant emissions in atmosphere / Nas ?ltimas d?cadas tem se intensificado os esfor?os em pesquisa e desenvolvimento de novas tecnologias para redu??o dos n?veis das emiss?es de gases poluentes na atmosfera. Neste contexto, destacam-se os modernos sistemas de gerenciamento eletr?nico do motor, os novos catalisadores automotivos e a utiliza??o de combust?veis renov?veis que contribuem para o menor impacto ambiental. A presente pesquisa teve como prop?sito a an?lise comparativa das emiss?es gasosas de um ve?culo automotivo, funcionando com diferentes combust?veis: g?s natural, AECH, ou gasolina. Para execu??o dos testes experimentais, um ve?culo flex foi instalado em um dinam?metro de chassi equipado com analisador de gases e demais acess?rios complementares ao atendimento das diretrizes das normas de emiss?o e procedimentos de seguran?a. Os ensaios foram realizados de acordo com as normas NBR 6601 e NBR 7024, que definem o ciclo de condu??o urbano e estrada, respectivamente. Al?m da an?lise dos gases de escapamento no tubo de descarga, antes e ap?s o catalisador, utilizando a sonda de aspira??o do analisador de gases, para simula??o do ve?culo em tr?fego urbano e estrada, foram realizados testes de caracteriza??o dos combust?veis. Os resultados finais foram conclusivos em apontar a gasolina aditivada como o combust?vel que mais contribuiu com as emiss?es de poluentes na atmosfera e a gasolina comum sendo o combust?vel que menos contribuiu com as emiss?es de poluentes na atmosfera

abstract: In the U.S., high-speed passenger rail has recently become an active political topic, with multiple corridors currently being considered through federal and state level initiatives. One frequently cited benefit of high-speed rail proposals is that they offer a transition to a more sustainable transportation system with reduced greenhouse gas emissions and fossil energy consumption. This study investigates the feasibility of high-speed rail development as a long-term greenhouse gas emission mitigation strategy while considering major uncertainties in the technological and operational characteristics of intercity travel. First, I develop a general model for evaluating the emissions impact of intercity travel modes. This model incorporates aspects of life-cycle assessment and technological forecasting. The model is then used to compare future scenarios of energy and greenhouse gas emissions associated with the development of high-speed rail and other intercity travel technologies. Three specific rail corridors are evaluated and policy guidelines are developed regarding the emissions impacts of these investments. The results suggest prioritizing high-speed rail investments on short, dense corridors with fewer stops. Likewise, less emphasis should be placed on larger investments that require long construction times due to risks associated with payback of embedded emissions as competing technology improves. / Dissertation/Thesis / M.S. Sustainability 2011

Submitted by Lucienne Costa (lucienneferreira@ufcg.edu.br) on 2018-09-12T17:38:44Z No. of bitstreams: 1 MARIA JOSICLEIDE FELIPE GUEDES – TESE (PPGRN) 2018.pdf: 5583855 bytes, checksum: 596a8968a2b1827271eb605c4751fa06 (MD5) / Made available in DSpace on 2018-09-12T17:38:44Z (GMT). No. of bitstreams: 1 MARIA JOSICLEIDE FELIPE GUEDES – TESE (PPGRN) 2018.pdf: 5583855 bytes, checksum: 596a8968a2b1827271eb605c4751fa06 (MD5) Previous issue date: 2018-02-23 / O biogás gerado pela biodegradação anaeróbia dos Resíduos Sólidos Urbanos (RSU) se configura como uma fonte alternativa de energia, entretanto, vem sendo desperdiçado em muitos aterros sanitários, na forma de emissões de Gases do Efeito Estufa (GEE) à atmosfera. A geração e emissão de gases são influenciadas por fatores associados às características operacionais dos aterros e dos resíduos, bem como aqueles relacionados às condições meteorológicas locais; os quais podem interferir na quantidade e qualidade dos gases gerados. Nessa perspectiva, o estudo das emissões de biogás se constitui em uma importante contribuição para a gestão de aterros sanitários, permitindo avaliar a eficiência das camadas de cobertura de solo compactado, além de permitir a otimização do sistema de drenagem dos gases e a recuperação energética do metano. Dentro desse contexto, o objetivo desta pesquisa foi estudar as emissões de biogás em aterro de Resíduos Sólidos Urbanos no semiárido brasileiro, no que concerne aos aspectos qualiquantitativos, a fim de gerar uma base de dados para apoiar a gestão sustentável desses empreendimentos. Esse estudo foi conduzido em uma célula de RSU, denominada de Célula 2, que se constitui em um aterro em escala real e está localizada no Aterro Sanitário em Campina Grande-PB. A operação da Célula 2 compreendeu o período entre 27/dezembro/2015 e 8/maio/2016, quando foi executada a camada de cobertura final de solo compactado. A massa total de RSU na Célula 2 foi de, aproximadamente, 62 mil toneladas, com uma taxa média de disposição de resíduos em torno de 465 t.dia-1. A metodologia da pesquisa englobou um plano de monitoramento das emissões de gases na Célula 2, o qual consistiu em medições: i) no sistema de drenagem vertical de biogás; ii) na interface soloresíduo; e iii) na camada de cobertura de solo compactado. Por meio dos resultados obtidos nesta pesquisa, foram verificadas concentrações médias de CH4, nos 9 (nove) drenos verticais (DV) de gases, superiores a 50% no período monitorado. A vazão total de CH4 variou na faixa de 59 a 17 Nm³.h-1, no período de 270 a 570 dias após o encerramento da Célula 2, implicando em uma redução dessa vazão de 70% durante esse intervalo de tempo. A taxa de captação de biogás por tonelada de resíduos aterrados variou de 15 a 4 Nm³.t-1.ano-1 (entre 270 e 570 dias). As emissões superficiais de metano pela camada de cobertura da Célula 2 totalizaram uma vazão inferior a 2 Nm³.h-1, no período de estiagem. Porém, a vazão de CH4 pela camada de cobertura foi significativamente inferior à vazão pelos DVs, correspondendo a um percentual inferior a 9% no período em análise. Os principais fatores que contribuíram para esse desempenho foram o elevado grau de compactação médio obtido para a Célula 2, a ausência de pressões diferenciais de gases na interface solo-resíduo, a eficiência do sistema de drenagem vertical de gases e a baixa permeabilidade do solo à água e ao ar. As estimativas da vazão de CH4 realizadas para a Célula 2, por meio do Landfill Gas Emissions Model, são compatíveis com uma potência máxima de 80 kW, disponível até 2047. Entretanto, as estimativas teóricas de vazão de biogás não refletiram o comportamento dos dados experimentais, visto que, nessas avaliações, não foi identificado o decaimento expressivo da vazão de metano, decorridos 570 dias de monitoramento da Célula 2. Portanto, faz-se necessário estudar possíveis soluções para ativar o potencial energético teórico dos resíduos na célula investigada. / The biogas generated by anaerobic biodegradation of Municipal Solid Waste (MSW) is an alternative energy source, however, it has been wasted in many landfills, in the form of emissions of Greenhouse Gases (GHG) to the atmosphere. The generation and emission of gases are influenced by factors associated with the operational characteristics of landfills and waste, as well as those related to local meteorological conditions; which may interfere with the quantity and quality of the generated gases. In this perspective, the study of biogas emissions is an important contribution of landfills management, allowing to evaluate the efficiency of the compacted soil cover layers, besides allowing the optimization of the gas drainage system and the methane energy recovery. Within this context, the objective of this research was to study the biogas emissions in Municipal Solid Waste landfill in the Brazilian semi-arid region, regarding qualitative and quantitative aspects, in order to generate a database to support the sustainable management of these enterprises. This study was conducted in a MSW cell, denominated Cell 2, built in a real-scale landfill and is located in the Campina Grande-PB Landfill. The operation of Cell 2 comprised the period between December 27, 2015 to May 8, 2016, when the final soil cover layer was executed. The total MSW mass of MSW in Cell 2 was approximately 62 thousand tons, with a mean waste disposal rate of around 465 t.day-1. The research methodology encompassed a gas emissions monitoring plan in Cell 2, which consisted of measurements: i) in the vertical biogas drainage system; ii) at the soil-residue interface; iii) in the compacted soil cover layer. Through the results obtained in this research, average concentrations of CH4, in the 9 (nine) Gas Drains (DV), higher than 50% in the monitored period. The total CH4 flow ranged from 59 to 17 Nm³.h-1, in the period from 270 to 570 days after the closure of Cell 2, implying a reduction of this flow by 70% during this time interval. The rate of capture of biogas per tonne of landfill residues varied from 15 to 4 Nm³.t- 1.year-1 (from 270 to 570 days). The surface emissions of methane by the cover layer of Cell 2 totaled a flow lower than 2 Nm³.h-1, during the dry season. However, the CH4 flow through the cover layer was significantly lower than the flow rate for the DVs, corresponding to a percentage lower than 9% in the period under analysis. The main factors that contributed to this performance were the high degree of average compaction obtained for Cell 2, the absence of gas differential pressures at the soil-residue interface, the efficiency of the vertical gas drainage system and the low permeability of the soil to water and air. The CH4 flow accomplished for Cell 2, using the Landfill Gas Emissions Model, are compatible with a maximum power of 80 kW, available until 2047. However, the biogas flow theoretical estimates did not reflect in the behavior of the experimental data, since in these evaluations, the significant decay of the methane flow was not identified after 570 days of monitoring of Cell 2. Therefore, it is necessary to study possible solutions to activate the theoretical energetic potential of the residues in the investigated cell.

Master of Science / Architectural Engineering and Construction Science / Russell J. Murdock / The purpose of this study is to identify and explore relationships between the building industry, building energy usage, and how both the industry and the energy usage correspond to greenhouse gas (GHG) emissions in the United States. Building energy codes seek to reduce energy usage and, subsequently, GHG emissions. This study specifically seeks to determine the impact that most current U.S. building energy codes could have on national GHG emissions if widespread adoption and enforcement of those codes were a reality. The report initially presents necessary background information about GHG emissions is first discussed. This establishes the current state of global GHG emissions, the position of the U.S. within the global scale, and what portion of the contribution can be attributed to the building industry. The report also describes the current issues and benefits of building energy codes. An overview of building energy codes evaluation is included, with explanation of the energy analysis used to determine the effectiveness of new building energy codes. In order to determine how to improve the building energy code system, an analysis of ANSI/ASHRAE/IES Standard 90.1-2013 (equivalent to 2015 IECC, the most recent standard available) is conducted to reveal unrealized GHG emission reductions that are expected with adoption and compliance to the newest code. Standard 90.1-2013 is analyzed due to the national popularity of the code relative to other building energy codes. This analysis includes compilation of energy usage intensity, square footage, and current code adoption data throughout the United States. Results showed that the excess GHG emission savings from enhanced adoption and compliance was not significant on a national scale. However, in terms of GHG emissions currently saved by building energy codes, the extra savings becomes more significant, proving that increased adoption and compliance is a worthwhile pursuit. Recommendations are then made for how to increase adoption and compliance. This information will give policymakers improved understanding of the current state of the industry when crafting laws regarding GHG emissions and building energy codes. Furthermore, findings from this study could benefit specific states that are attempting to lower GHG emissions.

Thesis (MTech (Information Technology))--Cape Peninsula University, 2016. / Climate change imposes indisputable burdens on economic development by significantly causing damage to the environment. In the transportation sector, carbon dioxide emissions from vehicles are seen as top environmental pollutants around the world and in South Africa. Despite increasing environmental issues, many people, including business leaders, generally think of environmental issues as disconnected from their everyday business lives and behavioural patterns. The Republic of South Africa as a member of the United Nations Framework Convention on Climate Change (UNFCCC) encourages any practices and processes that will control, reduce or prevent anthropogenic emissions of greenhouse gases. The adoption of telecommuting for travel reduction can impact positively on environmental sustainability by reducing the amount of commuter driving and thus reducing carbon emissions. Telecommuting is an arrangement where an employee works from home or out of office using telecommunication links (internet, email and/or telephone) to reduce commuting to and from the office, enhance productivity in the organisation, and reduce office space requirements. However, despite the well documented benefits of telecommuting, the uptake of telecommuting in South Africa is slow. This study falls under the Green Information Technology research field. The aim of the study is to identify the reasons behind the slow adoption of telecommuting in South African organisations. The study followed embedded multiple-case studies. Qualitative data were collected from nine companies using semi-structured interviews with 19 participants comprising of Information Technology (IT) and Human Resource (HR) managers, telecommuters and non-telecommuters. The companies were selected to be as diverse as possible in the operating sector and both purposive and snowball strategies were used.