Essa pesquisa tem como objetivo propor um novo referencial metodológico para estimar a linha de base para projetos de MDL a serem conectados ao sistema interligado nacional SIN, a partir de uma visão do mix futuro das fontes energéticas que serão responsáveis pelas gerações de energia, nos próximos dez anos. Objetiva também aplicar essa nova abordagem para calcular as emissões deslocadas pelas atividades de projetos de MDL, através do cálculo do fator de substituição, medido em tCO2/MWh. Este fator estima a redução das emissões decorrente da substituição de parte da energia gerada pelas usinas térmicas convencionais, pela entrada no sistema de usinas que geram energia limpa e/ou pela redução da demanda agregada do sistema elétrico pela implementação de programas/medidas de eficiência energética pelo lado da demanda Para tanto, usando um modelo que simula o equilíbrio entre a oferta elétrica e os requisitos de energia previstos para o horizonte de 10 anos de energia calcula-se, inicialmente, as emissões dos GEE do sistema elétrico sem considerar a entrada do projeto de MDL. Na seqüência, as emissões do sistema elétrico são novamente calculadas, considerando a entrada do projeto MDL. Atualmente a linha de base do SIN é calculada, mensalmente, com base no Tool to calculate the emission factor for an eletricity system, que é uma ferramenta metodológica aprovada pelo CE do MDL, para determinar o fator de emissão de sistemas elétricos interligados. Essa ferramenta determina o fator de emissão de atividades de projetos que substituem eletricidade gerada na rede elétrica. Sustenta-se nesta pesquisa que é pouco provável, pelo menos no SIN, que as condições observadas em anos recentes e/ou atuais se reproduzam no futuro. Ao contrário do que ocorria até poucos anos atrás, em que a expansão do sistema elétrico era basicamente assentada em empreendimentos hidrelétricos, na atualidade desenha-se uma clara tendência à fossilização da matriz do setor elétrico nacional. Os resultados do trabalho mostraram que há uma tendência de elevação das emissões do SIN, embora o comportamento do Fator de Substituição, em termos anuais apresente variações importantes, em função das reais necessidades do despacho das térmicas inflexíveis que servem ao SIN a cada ano. No entanto, considerando todo o período estudado, os resultados encontrados são coerentes com o aumento da participação das UTE emissoras dos GEE no mix futuro das fontes energéticas que fornecerão eletricidade ao SIN. Os valores obtidos dos fatores de substituição (FSSINp) para todos os experimentos, entre 2008 e 2017, são significativamente superiores à linha de base do SIN de 2007, calculada com base no Tool to calculate the emission factor for an electricity system. / This research has as a goal propose a new methodological reference to assess the baseline for CDM projects designed to be connected to the national connected system SIN, coming from a foreseen sight of the energetic sources mix that will be responsible for the energy generation, in the next ten years and apply the news approach to calculate the emissions move to distinct amounts of entry energies of SIN, either by generation of new plants that do not generate emissions of GHE, except concern nuclear plants, or by the reduction of future demand of electrical energy, originated from the implantation of programs/measures of energetic efficiency considering demand. The factor of emission replacement factor of the electrical system measures the energy movement generated by the plants that serve the electrical system by the entrance of new plants that do not generate emissions of GHE. Thus, using a model that simulates the balance between supply and requirements for electric energy provided to the horizon of 10 years of energy it is estimated, initially, the GHG emissions of the electric system without considering the input of the CDM project. Following the emissions of the electric system are again calculated, considering the entry of the CDM project. Currently, the SIN baseline is calculated, monthly as a base tool to calculate the emission factor for an electricity system, which is a methodological tool approved by the CDM Executive Board, to determine emission factor of electrical systems. This thesis sustains that it is unlikely, at last in the SIN that the conditions noticed in recent years and/or conditions, will reproduce in the future. On the contrary of what has occurred a few years ago, in which the expansion of the electrical system was basically set up in hydro electrical enterprise, nowadays there is a trend toward fossilization of matrix of national electrical sector. The results of the study showed that there is a trend of increased emissions of SIN, but behavior of Factor Substitution in the year, vary in important ways, depending on the needs of the order of thermal inflexible to serve the SIN each year. However, considering the whole period studied, the results are consistent with the increased participation of the GHG emission UTEs in future mix of energy sources that will provide electricity to the SIN. The values of the factors of substitution (FSSINp) for all experiments, between 2008 and 2017 are significantly above the baseline of SIN, 2007, calculated on the Tool do calculate the emission factor for an electricity system.

Rapid, human-forced climate change as a result of greenhouse gases is threatening the fabric of human civilisation itself. It is clear that we need to alter our development and poorer countries will need to develop while limiting their emissions, but it is not clear what sustainable development would entail. Climate change policy solutions have pivoted on carbon trading, under the auspices of the Clean Development Mechanism (CDM), but this too has failed to limit growth in carbon emissions. This report looks at the operations of the CDM in South Africa as a source of climate finance meant to facilitate sustainable development. Though South Africa has emphasised its commitment towards a low-carbon transition, in practice its national planners seek to preserve energy-intensive mineral and industrial sectors. This research draws on both primary and secondary documents as well as interviews with carbon professionals to conclude that CDM projects have played a limited role in South Africa, but has tended to reproduce the existing minerals and energy complex within the country.

Dentre os ecossistemas terrestres, o solo constitui um dos principais reservatórios de carbono (C). As práticas de preparo agrícola alteram esse compartimento, acelerando o processo de oxidação da matéria orgânica do solo, o que favorece a emissão de gases do efeito estufa. O presente trabalho foi desenvolvido em um experimento de longa duração localizado na Fundação ABC em Ponta Grossa (PR) sob diferentes sistemas de manejo do solo: plantio convencional (PC), preparo mínimo (PM), plantio direto (PD) e plantio direto escarificado (PDE), dispostos em blocos ao acaso. Os objetivos foram, determinar: a) os estoques de C e nitrogênio (N) do solo; b) a quantidade e qualidade dos resíduos culturais; e c) quantificar as trocas gasosas de CO2 e N2O entre o solo-atmosfera. As amostragens foram realizadas de outubro de 2003 a novembro de 2004 na sucessão aveia branca/soja/trigo. Os estoques de C e N do solo foram determinados após a colheita das culturas e não apresentaram diferença estatística entre épocas de cultivo e tratamentos. O PD apresentou os maiores estoques médios de C e N, e o PC os menores valores. As taxas de seqüestro de C, na camada 0-20 cm nos tratamentos estudados em comparação ao PC (15 anos de implantação), foram de: 0,55; 0,66 e 0,46 Mg ha-1ano-1 para PM, PD e PDE, respectivamente. As massas secas e os estoques de C e N dos resíduos culturais foram maiores na época da colheita das culturas, e superiores nos tratamentos PD e PDE. Os teores de C dos resíduos não tiveram diferença estatística entre as médias dos tratamentos. Os resíduos de soja apresentaram, em todos os tratamentos, maior teor de N e menor de hemicelulose. As variações no Quociente holocelulose/lignocelulose (QCL), Índices ligno-celulósico (ILC) e de decomponibilidade (ID) foram pequenas, evidenciando pouca variação entre os resíduos da rotação. As médias diárias das emissões de CO2 do solo variaram de 24 a 248 mg m-2 h-1 aumento progressivo, de novembro/03 (semeadura da soja) a fevereiro/04, devido ao crescimento das raízes que incrementou a taxa de respiração do solo. Não foi observada correlação significativa entre as emissões de CO2 e N2O com o ciclo diário da temperatura. As médias anuais de emissão de CO2 e N2O foram iguais nos horários 8:00, 12:00h e 17:00h. Os fluxos de N2O variaram de 3 a 53 µg m-2, e a maior freqüência observada com saturação de água no solo em torno de 60%, após as adubações nitrogenadas em junho/2004 no PC e PM e em julho/2004 no PD e PDE. O revolvimento do solo pela gradagem e incorporação dos resíduos culturais no PC e PM, não alteraram significativamente as emissões de CO2 e N2O. Os tratamentos estudados não apresentaram diferença nas médias anuais de emissão de CO2 e N2O do solo. Dentre todas as variáveis estudadas, comparando os tratamentos PC, PM, PD e PDE, o PD destacou-se por apresentar maior estoques de C e N no solo em relação aos demais tratamentos. / Between the terrestrial ecosystems, the soil is one of the most important pools of carbon (C). Agricultural tillage practices alter the contents of this element, accelerating the process of organic matter oxidation, inducing greenhouse gases emissions. The present research was carried out in a long-term experiment located at Fundação ABC in Ponta Grossa (Paraná State, Brazil) under different soil management systems: conventional (CT), minimum (MT), no-till (NT) and no-till harrowed (NTH), randomly displayed in blocks. The objectives were to determine: a) soil C and nitrogen (N) stocks; b) quantity and quality crop residues; c) quantify the CO2 and N2O gasses fluxes from the soil to the atmosphere. Sampling activities were performed between October 2003 and November 2004 in the succession white oat/soybean/wheat. Soil C and N stocks were determined after the crops were harvested and showed the same distribution of soil C and N for all treatments, no significant statistically difference among cultural seasons and treatments was observed. NT system presented the highest mean soil C and N stock values, and the CT had the smaller values. Soil C sequestration rates in the 0-20 cm, in the treatments in comparison with the CT with 15 years of adoption, were 0,55; 0,66 and 0,46 Mg ha-1year-1 for MT, NT and NTH, respectively. Dry matter and C and N stocks of crop residues were higher in the harvest season, and presented high values for NT and NTH. Carbon contents in crop residues were maintained in the same magnitude and showed no significant statistically difference. Soybean residues just presented, in all treatments, higher N concentration and smaller hemicelulose contents. The holocelulose/lignocelulose quotient (HLQ), ligno-celulosico (LCI) and decomposition (DI) indexes were small, evidencing in this work, little variation between the crop residues analised. The soil CO2 CO2 daily average emissions varied from 24 to 248 mg m-2 h-1 and presented a progressive increase of November/03 (sow of the soy) to February/04, indicating that the soil respiration passed to be constituted of the organism soil and root plants. Correlation was not observed between the emissions of CO2 and N2O with the daily cycle of the temperature. The same annual averages of emission of CO2 and N2O were observed in the schedules 8:00, 12:00 and 17:00 hours. The N2O flow varied from 3 to 53 g m-2, and the largest frequency observed with water filled pore space around 60 %, and after the nitrogen fertilization in June 2004 in CT and MT and in July 2004 in NT and NTH. Soil tillage with plow and incorporation of the cultural residues in CT and MT, didn't alter the emissions of CO2 and N2O significantly. The studied treatments didn\'t present difference in the annual averages of emission of CO2 and N2O of the soil during 2003 and 2004 years. Between the studied variables, comparing the treatments CT, MT, NT and NTH, NT system stranded out from the other treatments by present higher soil C and N stocks.

<p>Kukuruzovina je žetveni ostatak i potencijalni supstrat za proizvodnju biogasa. Direktivom 2018/2001 definisan je tzv. RED metod za obračunavanje ušteda emisija gasova s efektom staklene bašte&ndash; GHG. Metod je primenjiv za silažu kukuruza i stajnjak kao supstrat za proizvodnju biogasa, ali se na neadekvatan način obračunavaju emisije GHG za kukuruzovinu. Cilj je bio da se predlože unapređenja RED metoda kojima bi se prevazišli identifikovani problemi, kao i da se ispita uticaj primene unapređenog metoda na ocenu ušteda emisija GHG energetskog iskorišćenja biogasa iz kukuruzovine, tj. na ocenu održivosti. Uštede emisija GHG za sve razmatrane slučajeve primene RED metoda u osnovnoj i unapređenoj formi, imale su vrednost nižu od postavljenog kriterijuma od 70 %, tj. nisu održivi. Predloženo je da se RED metod unapredi ukidanjem pravila da se ne obračunavaju emisije GHG pre ubiranja žetvenih ostataka i da je potrebno da se navede da je ostatak fermentacije ko-produkt proizvodnje i korišćenja biogasa, kao i da je primena alokacije emisija GHG na biogas i ostatak fermentacije obavezna u slučaju primene ostatka fermentacije na polja sa kojih nisu ubirani žetveni ostaci.</p> / <p>Corn stover is a crop residue and potential substrate for biogas production. Directive<br />2018/2001 defines so-called RED method for determination of greenhouse gas (GHG)<br />emission savings. In the case of energy utilization of biogas produced from corn stover,<br />savings are calculated in an inadequate manner. The objective was to suggest the<br />improvements of the RED method in order to overcome the identified problems, as well<br />as to investigate the impact of the application of the improved method on the evaluation<br />of GHG emission savings, i.e. the the sustainability evaluation. The results of the GHG<br />emission savings, using the basic and the improved forms of RED method, show that all<br />considered cases had a value lower than the set criterion of 70%, i.e. they are not<br />sustainable. It was suggested to improve the RED method by abolishing the rule that<br />GHG emissions prior to collection of crop residue are not accounted. Also, it should be<br />noted that the digestate is a co-product of biogas production as well that the application<br />of the GHG emissions allocation to biogas and the digestate is mandatory in the case<br />when digestate is used on fields other than those used for substrate provision.</p>

Climate changes and global warming are topics of scientific debate. The increase of greenhouse gases has been pointed out as one of the main causes of the changes. The study aimed to evaluate the associative effect of monensin (M) with different levels of tannins (T) on feeding, digestive and rumen fermentation (ex-situ technique) parameters as well as on anaerobic biodigestion of waste. In a 2 x 4 factorial arrangement, 8 cannulated Nellore cows were distributed in 2 contemporary 4 x 4 Latin squares and received 8 experimental diets which differed in the level of inclusion of T of A. mearnsii extract (0.0, 0.75, 1.5, and 2.25% DM) and M which was daily administered to each cow (about 32 mg/kg DM) of one square. To evaluate the production of biogas, experimental batch-type anaerobic biodigesters were used in a completely randomized design. The data were analyzed by the Statistical Analysis System (SAS 9.3, Institute Inc., 2013). The results have shown little interaction between M and T. Regarding the feeding, digestive and N balance parameters, the T linearly reduced DM and water intake, the total apparent digestibility of DM, CP, TDN and OM; for the NDF and ADF the reduction was quadratic. The T linearly reduced rumen disappearance rate by linearly reduce both passage and digestion rates. T also linearly reduced urinary urea excretion, but both additives had no effect on the synthesis and efficiency of microbial protein synthesis. M reduced the proportion of N excreted in feces, but had no effect on N balance, whereas T linearly increased fecal N and linearly reduced urinary and retained N. Regarding the parameters of rumen fermentation, no significant effect of M was observed on CH4 production, but on the reduction of acetate:propionate ratio. T linearly reduced the production of CH4 and total SCFA. Regarding anaerobic biodigestion, M and T reduced the nutrient removal efficiency. M and T had independent effects on rumen metabolism, however, the use of T of A. mearnsii extract up to 2.25% DM is a safe option for cattle, with potential to mitigate rumen CH4. The combined use of M and T reduced the potential of biogas production by reducing the nutrient use efficiency. M inhibited the effect of T on the reduction of nutrient use efficiency of the waste through antagonistic interaction. / As mudanças climáticas e o aquecimento global são temas de debate científico da atualidade. O aumento de gases de efeito estufa é apontado como uma das principais causas das mudanças. O estudo teve como objetivo avaliar o efeito associativo da monensina (M) com diferentes níveis de inclusão de taninos (T) sobre os parâmetros ingestivo, digestivo e fermentação ruminal (técnica ex-situ), bem como sobre a biodigestão anaeróbia de dejetos. Em arranjo fatorial 2 x 4, 8 vacas Nelore, canuladas foram distribuídas em 2 quadrados latinos contemporâneos 4 x 4 e receberam 8 dietas experimentais que diferiram no nível de inclusão de T do extrato da A. mearnsii (0,0, 0,75, 1,5 e 2,25% da MS) e M que foi administrada diariamente a cada vaca (cerca de 32 mg/kg de MS) de um quadrado. Para avaliar a produção de biogás foram utilizados biodigestores anaeróbios do tipo batelada, em delineamento inteiramente casualizado. Os dados foram analisados pelo Statistical Analysis System (SAS 9.3, Institute Inc., 2013). Os resultados mostraram pouca interação entre M e T. Quanto aos parâmetros ingestivo, digestivo e balanço de N, os T reduziram linearmente o consumo da MS e água, a digestibilidade aparente total da MS, PB, NDT e MO e quadraticamente a da FDN e FDA. Os T reduziram linearmente a taxa de desaparecimento ruminal pela redução linear das taxas de passagem e digestão. Os T reduziram linearmente a excreção de uréia urinária, mas ambos aditivos não tiveram efeito sobre a síntese e eficiência da síntese de proteína microbiana. A M reduziu a proporção de N fecal, mas não teve efeito sobre o balanço do mesmo, enquanto que os T aumentaram linearmente o N fecal e reduziram linearmente o N urinário e retido. Em relação a fermentação ruminal, não foi observado efeito da M sobre a produção de CH4, mas sim, redução da relação acetato:propionato. Os T reduziram linearmente a produção de CH4 e AGCC. Em relação a biodigestão anaeróbia, a M e T reduziram a eficiência de remoção de nutrientes. A M e T tiveram efeitos independentes sobre o metabolismo ruminal, porém, o uso de T do extrato da A. mearnsii até 2,25% de MS é seguro para bovinos, com potencial para mitigar o CH4 entérico. O uso combinado de M e T reduziu o potencial de produção de biogás pela redução da eficiência do uso de nutrientes. A M inibiu o efeito dos T sobre a redução da eficiência biodigestiva dos dejetos através da interação antagonista.

Road traffic dominates in domestic Swedish transportation and is highly dependent on fossil fuels, petrol and diesel. Currently, the use of renewable fuels in transportation accounts for less than 6% of the total energy use in transport. The demand for bioethanol to fuel transportation is growing and cannot be met through current domestic production alone. Lignocellulosic ethanol derived from agricultural crop residues may be a feasible alternative source of ethanol for securing a consistent regional fuel supply in Swedish climatic conditions.  This licentiate thesis focuses on regional transport fuel supply by considering local small-scale ethanol production from straw. It presents the results of investigations of regional transport fuel supply with respect to minimising regional CO2 emissions, cost estimates for transport fuel supply, and the availability of lignocellulosic resources for small-scale ethanol production. Regional transport fuel demand between the present and 2020 is also estimated. The results presented here show that significant bioethanol can be produced from the straw and Salix available in the studied regions and that this is sufficient to meet the regions’ current ethanol fuel demand.  A cost optimisation model for regional transport fuel supply is developed and applied for two cases in one study region, one when the ethanol production plant is integrated with an existing CHP plant (polygeneration), and one with a standalone ethanol production plant. The results of the optimisation model show that in both cases the changes in ethanol production costs have the biggest influence on the cost of supplying the regional passenger car fleet with transport fuel, followed by the petrol price and straw production costs.  By integrating the ethanol production process with a CHP plant, the costs of supplying regional passenger car fleet with transport fuel can be reduced by up to a third. Moreover, replacing petrol fuel with ethanol can cut regional CO2 emissions from transportation by half.

Intercropping, defined as two or more crops grown on the same land area at the same time, is a sustainable alternative to sole crops. Intercropping has been associated with multiple benefits, such as increased nutrient and soil organic carbon (SOC) cycling, decreased soil erosion and increased carbon (C) sequestration. A common intercropping practice is to integrate cereal and legume crops such as maize (Zea mays L.), and soybean (Glycine max (L.) Merr.). Most studies on intercropping have focused on yield, weed control, and land use efficiency in the tropics. Few studies have researched C and nitrogen (N) dynamics in temperate intercrops, with respect to soybean and maize residue stabilization. Soil from Balcarce, Argentina, was incubated for 140 days with soybean, maize, or no residue. Throughout the incubation, results illustrated the effect of residue application upon the soil, specifically through significantly higher amounts of light fraction (LF) C and LFN concentrations, soil microbial biomass (SMB) C and SMBN concentrations, higher microbial diversity, lower N2O production rates, in addition to distinct isotopic values in soil fractions and CO2 (p<0.05). Furthermore, it was observed from δ15N-TN and δ15N-LF that treatments with soybean residues included had higher N cycling (p<0.05), emphasizing the importance of including N-fixing legumes in complex agroecosystems. Significant changes over time in SMB and SMCS characteristics, and isotope values (p<0.05) indicated the preferential utilization of relatively young and easily accessible litter. Furthermore, the loss of labile material over the incubation resulted in more recalcitrant forms (such as older C and lignin) to be utilized. Slightly higher SOC, TN, LFC and LFN concentrations, as well as lower CO2 production rates suggested 2:3 (rows of maize:rows of soybean) as a more desirable intercrop design for C sequestration. The 1:2 intercrop design was observed to be more beneficial for microbial community structure, furthering the idea that intercropping is a beneficial alternative to sole cropping. This study improves knowledge in residue stabilization and C sequestration in complex agroecosystems, providing encouragement for the implementation of more sustainable management practices.

The aim of this study is to determine the predictability of river discharge in several major rivers on time scale varying from weeks to a century. We investigated predictability considering relationship between SST and Ganges and Brahmaputra River discharge. On seasonal time scales, statistically significant correlations are found between monthly equatorial Pacific SST and the summer Ganges discharge with lead times of 2-3 months due to oscillations of the ENSO phenomena. In addition, there are strong correlations in the southwest and northeast Pacific. The Brahmaputra discharge shows weaker relationships with tropical SST. Strong correlations relationships are found with SST in the Bay of Bengal but these are the result of very warm SSTs and exceptional Brahmaputra discharge during the summer of 1998. When this year is removed, relationships weaken everywhere except in the northwestern Pacific for the June and July discharge. Second goal is to project the behavior of future river discharge forced by the increasing greenhouse gases and aerosols from natural and anthropogenic sources. Three more rivers, the Yangtze, Blue Nile, and Murray-Darling rivers are considered. The original precipitation output from CMIP3 project has large inter-model variability, which limits the ability to quantify the regional precipitation or runoff trends. With a statistical Quantile-to-Quantile (Q-Q) technique, a mapping index was built to link each modeled precipitation and observational discharge. We also use the climatological annual cycle to choose the ¡°good¡± models. With the same indices, the future 21st century discharges of the first four rivers are simulated under different SRES scenarios. The Murray-Darling River basin does not have the similar seasonal cycle of discharge with modeled precipitations. We choose to project basin averaged precipitations instead. The Yangtze, Ganges, Brahmaputra River mean wet season discharges are projected to increase up to 15-25% at the end of the 21st century under A1B and A2. The risks of flooding also reach to a high level throughout the time. Inter-model deviations increase dramatically under all scenarios except for COMMIT. With large uncertainty, the Blue Nile River discharge and Murray-Darling River basin annual precipitation do not suggest a sign of change on multi-model mean.

This thesis presents a detailed study of life cycle greenhouse gas (GHG) emissions intensity during the uranium mining-milling phase of the nuclear fuel cycle for three paired uranium mine-mill operations in northern Saskatchewan (SK). The study period runs from 2006 – 2013 for two of the three pairs, and from 1995-2010 for the third. The life cycle analysis has been conducted based on the ISO 14040:2006 standard using a Process Chain Analysis methodology. This study differs from previous studies of GHG emissions intensity during the uranium mining-milling phase of the nuclear fuel cycle in two key respects. First, it has a very large system boundary which includes the uranium exploration and mine-mill decommissioning phases. Second, it utilizes a life cycle inventory database to include many processes which would normally fall outside of the system boundary due to their small individual contributions. These differences contribute to a more accurate result. The production-weighted average life cycle GHG emissions intensity is estimated as 45 kg CO2e/kg U3O8 at an average ore grade of 9.12% U3O8 based on relative U3O8 production volumes at Mine-Mill A, B, and C from 2006 to 2010. The 95% confidence interval for the production-weighted average result ranges from 42 to 49 kg CO2e/kg U3O8, indicating that overall uncertainty in the result is low. Life cycle GHG emission intensity for the three uranium mine-mill pairs are 84, 66, and 35 kg CO2e/kg U3O8 at average ore grades of 0.71%, 1.54%, and 11.5% U3O8 respectively. Nearly 90% of life cycle GHG emissions are associated with operation of the uranium mine-mills, primarily from energy consumption during operation (69% of total) transport of materials and personnel (7.0%), and use of reagents (5.6%). Remaining processes each individually account for less than 5% of the total. In calculating emissions from electricity consumption, the base-case emission intensities reported above use a province-wide electricity emission factor because the utility does not differentiate its emissions by region. However, the facilities included in this study are all located in Northern Saskatchewan, which is powered exclusively by hydropower. Application of a regional emission factor reduces the production-weighted average life cycle GHG emission intensity to 26 kg CO2e/kg U3O8 with a 95% confidence interval of 25 to 29 kg CO2e/kg U3O8. This represents a 42% reduction in life cycle GHG emission intensity from the base case. Due to the high uranium ore grades found in SK uranium deposits, life cycle GHG emissions intensity for uranium from SK is among the lowest in the world. Further, the life cycle GHG emission intensity estimate from uranium mining-milling in SK is a small (approximately 10%) contributor to the life cycle GHG emissions intensity from the nuclear fuel cycle for light water reactors overall, amounting to approximately 1.2 g CO2e/kWh electricity (0.6 g CO2e/kWh electricity calculated using the regional hydroelectric power source).

Conventional fossil fuels are widely used, however there are growing concerns about the security of their supply, volatility in their prices and the environmental impacts of their extraction and use. The objective of this research is to investigate the potential for replacing conventional fuels in various applications, focusing on the Alberta oil sands industry. Such investigations require systems-level approaches able to handle multiple criteria, uncertainty, and the views of multiple stakeholders. To address this need, the following are developed: life cycle assessment (LCA) and life cycle costing models of polygeneration systems; a life cycle-based framework for multi-sectoral resource use decisions; and a method combining LCA and real options analyses to yield environmental and financial insights into projects. These tools are applied to options for utilizing oil sands outputs, both the petroleum resource (bitumen) and by-products of its processing (e.g., asphaltenes, coke), within the oil sands industry and across other sectors. For oil sands on-site use, multiple fuels are assessed for the polygeneration of electricity, steam and hydrogen, in terms of life cycle environmental and financial impacts; asphaltenes gasification with carbon capture and storage (CCS) is the most promising option, able to reduce greenhouse gas (GHG) emissions to 25% of those of current natural gas-based systems. Coke management options are assessed with the life cycle-based framework; the most promising options are identified as: Electricity generation in China through integrated gasification combined cycle; and, hydrogen production in Alberta, either for sale or use by the oil sands industry. Without CCS, these options have amortized project values ranging from $21 to $160/t coke. The application of the combined LCA and real options analyses method finds that uncertainty in natural gas and potential carbon prices over time significantly impacts decisions on coke management; the formulated decision tree identifies increases of 29% and 11% in the financial and GHG emissions performance, respectively, of the overall coke management project compared to pursuing the decision identified by the life cycle-based framework. While promising options for replacing conventional fossil fuels are identified through systems-level analyses, there are trade-offs to be made among the financial, risk and environmental criteria.