Há décadas a comunidade científica vem alertando sobre as mudanças climáticas e a necessidade de reduzir as emissões gases de efeito estufa. Sobre dois pilares fundamentais têm se sustentado a narrativa e as ações para enfrentar a crise ecológica global (a) na desmaterialização da economia usando tecnologias e processos cada mais eficientes (b) na descarbonização da economia usando fontes renováveis. Não obstante, os resultados gerais deste trabalho não encontraram evidência empírica de desmaterialização ou descarbonização da economia mundial. Partindo deste resultado em escala global, aprofundou-se a análise empírica ao nível individual de todas as economias do planeta. Os resultados encontrados indicam que em 4 economias com elevada renda e desenvolvimento tecnológico tem havido descasamento forte (strong decoupling) do uso de energia e das emissões de CO2. Porém, este resultado contrasta com evidências compiladas que apontam que o determinante principal deste descasamento está associado a um processo de desindustrialização destas economias e, concomitantemente, uma acelerada importação de mercadorias produzidas pelas indústrias da Ásia, especialmente a chinesa (energizada a carvão). Portanto, a julgar pela dominância fóssil passada e ainda vigente, não se vislumbra um cenário no curto e médio prazos, de ruptura abrupta entre crescimento econômico futuro e o uso de energia majoritariamente produzida com fósseis. O que está em curso é a gestação de uma futura transição energética alimentada pela introdução de fontes renováveis na matriz energética mundial nos últimos anos, mas com limitações socioeconômicas importantes que são descritas neste trabalho. É mostrado que América Latina pode ter um papel crucial nesta transição, com a industrialização e sinergia regional entre seus recursos naturais (tanto renováveis como não renováveis), sendo as reservas de lítio para produção de baterias um recurso estratégico para impulsionar a mobilidade elétrica. Além da importância socioambiental e política dos padrões analisados neste trabalho, é mostrada também a relevância teórica destes, pois permitem aprofundar o questionamento da representação ortodoxa das relações entre Economia e Natureza. / For decades the scientific community has been warning about climate change and the need to reduce greenhouse gas emissions. On two fundamental pillars have been supported the narrative and the actions to face the global ecological crisis (a) \'dematerialization\' of the economy using more efficient technologies and processes (b) decarbonization of the economy using renewable sources. Nevertheless, the overall results of this work did not find empirical evidence of dematerialization (strong decoupling) or decarbonization of the global economy. Starting from this result on a global scale, the empirical analysis was deepened including all the economies of the planet. Our findings are that in 4 high income and technological advanced economies are signs of strong decoupling between both energy use and CO2 emissions. However, these results contrasts with evidence in favor of a decoupling process associated with the deindustrialization of these economies. Simultaneously, the flux of imports produced by Asian industries, especially by coal-fired Chinese industries is increasing. Thus, judging by past and still prevailing fossil dominance, there is no indication of a short-medium term scenario with abrupt rupture between future economic growth and the use of energy (mostly produced with fossils). Currently, there is a global energy transition brewing, pushed by the efforts to insert renewable sources in the world energy matrix. However, important socioeconomic limitations described in this work remains. Latin America may be a crucial actor in the global energy transition, promoting the industrialization and synergy between natural resources (both renewable and non-renewable); being lithium reserves for the production of electric batteries one of the strategic resources to put forward the option of electric mobility. Besides the socioenvironmental and political importance of the results presented here, it was also highlight the theoretical relevance of these, since they allow to deepen in the debate about the orthodox representation of the relations between Economy and Nature.

Includes bibliographical references (p. 165-188)

Orientadores: Marcelo Pereira da Cunha, Joaquim Eugênio Abel Seabra / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-24T19:54:08Z (GMT). No. of bitstreams: 1 Canto_SimoneTatianedo_M.pdf: 1446988 bytes, checksum: 3c884c3df852de562463eee9e45e87b2 (MD5) Previous issue date: 2014 / Resumo: Este trabalho tem como objetivo avaliar os indicadores de energia e emissões de gases de efeito estufa (GEE) na cadeia produtiva da gasolina e do óleo diesel mineral no Brasil, com uso do modelo de insumo-produto monetário e híbrido, de modo a realizar, também, uma comparação entre os seus resultados. O ano base utilizado foi de 2009, ano mais recente possível de estimar a matriz de insumo-produto a partir dos dados divulgados pelo Instituto Brasileiro de Geografia e Estatística (IBGE). Os modelos (monetário e híbrido) contêm 25 setores e 114 produtos; a técnica permite que sejam computados todos os efeitos diretos e indiretos envolvidos na cadeia produtiva dos setores avaliados. A base de dados usada consistiu, basicamente, nas tabelas de recursos e usos do IBGE (relativas ao ano de 2009), bem como na matriz consolidada relativa aos setores e produtos energéticos (também de 2009) do Balanço Energético Nacional (BEN), divulgado pela Empresa de Pesquisa Energética (EPE). Os resultados obtidos com os dois modelos foram muito próximos, tanto para a gasolina quanto para o óleo diesel; em geral, os efeitos indiretos capturados no modelo híbrido foram um pouco maiores dado o maior encadeamento entre os setores energéticos quando as transações setorias entre estas atividades são computadas em unidades físicas. Com o uso do modelo híbrido, os principais resultados obtidos são de 1,201 ktep e 1,202 ktep de energia incorporados em cada 1 ktep de gasolina e óleo diesel, respectivamente; com relação às emissões de GEE, os indicadores encontrados são de 75,32 gCO2eq/MJ para a gasolina e 86,91 gCO2eq/MJ para o óleo diesel / Abstract: The goal of this study is to evaluate energy and GHG emissions indicators for gasoline and diesel oil in Brazil; the methodology chosen was the Input-Output (IO) Analysis. For this purpose, an economic IO model and a hybrid IO model were made to provide a comparison between them. The analysis considers 2009 as base year, because this is the most recent year which is possible to estimate the Brazilian input-output matrix from official data when the project started. Both models (economic and hybrid) have 25 sectors and 114 commodities; the approach allows all direct and indirect effects through production chain to be estimated. The main data collected and used to build the models were the use and make matrices (provided by The Brazilian Institute of Geography and Statistics ¿ IBGE) and the consolidated matrix with energy flows for primary and secondary energy sources (provided by The Brazilian Energy Research Company ¿ EPE). The results obtained with both models are very similar, considering gasoline as well as diesel oil; in general, the indirect effects captured by the hybrid model are a little bit higher due to the stronger linkage among the energy sectors when the transactions through these activities are accounted in physic (energy) units. From hybrid model, the main results are 1,201 toe and 1,202 toe embodied energy for 1 toe of gasoline and diesel oil, respectively; with respect to GHG emissions, the indicators are 75.32 gCO2eq/MJ to gasoline and 86.91 gCO2eq/MJ to diesel oil / Mestrado / Planejamento de Sistemas Energeticos / Mestra em Planejamento de Sistemas Energéticos

The thesis is dedicated to the Russian view on energy security. Its aim is to evaluate how successful is Russian energy policy in sustaining energy and economy security in longterm perspective, and how well it deals with current and future potential problems of energy sector. The topic became of interest due to recent oil price drop, which led Russian economy to crisis and gave rise to discussion on its dependency on fossil fuel exports. First chapter is dedicated to definition of energy security of Russia as an exporting country. Next chapter is dedicated to SWOT analysis of current state of energy sector and defines its strengths, weaknesses, opportunities and threats. Last chapter evaluates how successful is Russian energy policy in relation to defined energy security and performed SWOT analysis.

This master's thesis aims to assess energy dependency on primary energy sources of the three main economic actors in the contemporary world scene that includes the European Union, the United States and China. Energy geopolitics gets a new face nowadays, turns upside down and the centers of world economy must face all these changes. Disparity in availability of energy sources and consumption, new drilling and manufacturing technologies, methods of extractions, new players and adopted energy policies as well as limited domestic supplies have a significant impact on the structure of the energy mix and energy (un)self-sufficiency. In the first part, the author deals with engineering and deployment of observed energy sources as well as the definition of energy dependency respectively energy security. In the next chapters, the author focuses especially on three economic centers while analyzing the nature, characteristics and trend of their production and consumption of energy as well as energy raw materials flow to these countries respectively to integrations. At the end, the author obtains by these analyses an image of energy dependency or vulnerability of these economies.

Climate change threatens global food security by increasing extreme-weather shocks and reducing the productivity of major global crops. While recent research has highlighted the risk of rising extreme heat, comparatively little is known about how the intensity distribution of rainfall, and rainfall’s interactions with heat, influence global crops. Further, as the broader climate transition gains momentum, the industrial activities needed to mitigate and adapt to climate change will emit CO₂. These emissions remain unquantified and largely ignored in research and policy, and thus present an under-assessed risk to crops and society at large.This thesis advances the understanding of present and future agricultural risks from two aspects of hydroclimatic complexity: hourly rainfall intensity and temperature-moisture (T-M) couplings. Both aspects are expected to shift under climate change, with highly uncertain crop impacts. It further simulates the adaptation and mitigation emissions embedded in the broader climate transition, illuminating a previously under-appreciated benefit of enhance climate ambition. Climate warming is expected to intensify rainfall, decreasing the frequency of drizzle while boosting heavy and extreme events. I show that surprisingly heavy rainfall is optimal for US maize and soy yields, with yield loss due to drizzle and very extreme downpours. As a result, the future concentration of rainfall into fewer, heavier hourly events will benefit crop yields 2-3%, partly offsetting larger damages from warming. T-M couplings arising from land-air interactions and atmospheric circulation may shift under 21st Century warming, altering the likelihood of concurrent heat and drought extremes, with uncertain risks to crops. I demonstrate that maize and soy grown in regions with strong T-M couplings historically suffered enhanced crop sensitivity to heat. These couplings will strengthen over most of global croplands this century, worsening the impact of warming on crops by 5% globally, with large regional variations. The energetic demands of the broader climate transition – such as steel for wind turbines, and concrete for coastal barriers – will initially be satisfied by fossil fuels. I show that simulated mitigation and adaptation will emit 185GtCO₂ by 2100 under a transition path consistent with current policies (~2.7°C warming by 2100), equivalent to half the remaining carbon budget for 1.5°C. However, these emissions can be reduced by 90% under a 1.5°C transition path, a previously unidentified co-benefit of enhanced climate ambition.

In an emerging energy landscape that increasingly discourages the use of traditional fossil fuels, there remain applications for which the continued use of high energy density liquid fuels is required, such as aviation and other uses where space and weight are critical design factors, or long term energy storage where cost and long term availability are required. To achieve this while transitioning to green sources of energy requires the design of next-generation combustion engines that can burn alternative fuels such as bio-derived or synthetic fuels; this process will be heavily dependent on design tools such as computational fluid dynamics packages, underpinned by accurate chemical kinetic models for the fuels in question. These kinetic models often contain thermodynamic information about hundreds of unique chemical species and thousands of chemical reactions forming an interconnected network between species governing their rates of production and destruction. Historically, generation of such high-fidelity kinetic models has required decades of research---too long for the engines that will require advanced fuels. Development of a kinetic model that is predictive of certain quantities of interest (ignition delay times, flame speeds, etc) can broadly be broken into four distinct stages: 1) initial ``crude'' model generation, 2) experimental design, 3) experiments and ab-initio theory calculations, and 4) kinetic model optimization. Advances in data-enabled science and ever-increasing computing power have offered pathways towards eventually automating this process. This work aims to introduce a collection of tools and building blocks that will assist in the overall aim of automatic kinetic model development, and in doing so fill important gaps in the current capabilities available in the literature. In particular, the work here touches on aspects of all four of the stages in the model development process described above. With regard to 1), while there are tools available in the literature for automatic generation of kinetic models for an increasingly large library of fuels, these models remain subject to the constraints imposed by current chemical kinetic model structures and combustion codes. Here, automatic screening procedures are introduced that investigate the impact on kinetic model prediction errors due to two distinct issues related to pressure-dependent chemistry: the lack of a new class of chemical reaction type in current chemical kinetic models, and effects due to how species-specific energy transfer parameters are represented in pressure-dependent stabilization reactions within kinetic models. With regard to 2) and 3), a Bayesian optimal experimental design algorithm is paired with computer-controllable perfectly-stirred reactor experiments with unique capability to both explore a combinatorically complex experiment parameter space (including flowing up to ten unique gas mixtures simultaneously) and measure dozens of chemical species using rapid, on-line diagnostics. This setup allows for key reaction pathways to be carefully "sensitized'' with the addition of trace quantities of key chemical species, a capability that has not been used elsewhere in literature. Generally speaking, other experimental design algorithms in literature have not explored experimental design spaces that are radically different from those used by experienced researchers in their manual experimental design processes, and the complexity of the mixtures explored by most traditional combustion experiments is limited to two or three different chemical species at most. The sensitization of key reaction pathways unlocks the ability to perform truly transformational parameter inferences with minimal amounts of experimental data. With regard to joining step 3) to 4) in the above process, semi-automated post-processing codes allow for rapid optimizations to be performed for a prior kinetic model on the basis of experiments chosen by our experimental design algorithm. Critically, a combination of the experimental design algorithm developed here and the jet-stirred reactor experiments described was tested on the kinetic model for N₂O decomposition, which has uncertainties for key reaction rates that have persisted for decades (indeed, researchers suggest kinetic rate constants for N₂O+O=N₂+O₂ that differ by at least four orders of magnitude!). Optimizations using the Multi-Scale Informatics (MSI) tool developed by our research group were run on the basis of experimental data obtained in the aforementioned experiments, and used to gain insights about the rate constant for a key reaction in N₂O decomposition chemistry, N₂O+O=N₂+O₂ , serving as a proof-of-concept for key portions of what will form the backbone of an automatic kinetic model development pipeline.

The road freight transport industry is facing radical changes that have the potential to fundamentally change the industry and pressure actors to embrace sustainability throughout their operations and implement technology in the broadest sense. The road transport industry is permeated by the use of fossil fuels and accounts for a significant part of the total CO2 emissions in the world. The entire industry is facing a fossil-free transition to reach the global environmental initiatives that countries have undertaken. At the same time as the industry is phasing out fossil fuels and using more sustainable fuels, the literature has a coherent view that transported goods are expected to increase significantly, and the imprint of the COVID-19 pandemic is increasingly affecting the industry with shortages of drivers and more vulnerable supply chains. This study has aimed to identify changes that affect the road freight transport industry in the short term (0-5 years) and the long term (5-20 years) with a focus on Europe. Furthermore, the study has applied the results of the study to a framework of future scenarios that previous research has contributed with, in collaboration with over 50 industry experts from the transport industry, to evaluate the impact of the changes concerning the expected futures that the research has resulted in. The study has applied literature search, a document study, and interviews with actors from the industry to collect relevant data and has resulted in most of the identified changes that the road transport industry is expected to be affected by in the short and long term.  The changes have been divided into three levels: ecosystem, business, and technology. The macro factors that affect the industry are increased regionalization and urbanization, increased customer requirements and consumption, and extensive introduction of laws and regulations concerning environmental impact and technology. Furthermore, the business changes are increased operational costs, the establishment of partnerships and alliances, circularity, and lack of staff. The technical factors consist of AI, IoT, and new more sustainable fuels. The primary effects include increased local production of goods that contribute to shorter transport distances but more transport, fossil-free transport with mainly electricity and hydrogen as fuel and thus new establishments of electricity and hydrogen infrastructure, many global initiatives to achieve sustainability, extensive application of technologies to streamline supply chains as well as more comprehensive rules and requirements regarding new unexplored technologies. Furthermore, future scenarios have been applied to evaluate the possible impact on the industry, which is visualized in figure 14. Suggestions for further research in the field are changes in the industry that take place but which this work has not addressed as it is not perceived as having significant effects on the road transport industry, such as increased deliveries of fresh goods, 3D printing, multimodal transport, and an older population and thus increased shipments of medical devices. / Vägtransportbranschen står inför radikala förändringar med potential att förändra industrin fundamentalt och pressar aktörerna till att anamma hållbarhet genomgående i sina operationer och implementera teknologi i vid bemärkelse. Vägtransportbranschen genomsyras av användning av fossila bränslen och står för en väsentlig del av de totala CO2 utsläppen i världen. Hela industrin står inför en fossilfri omställning för att nå upp till de globala initiativen som länder åtagit sig att genomföra i ett försök att bromsa den negativa klimatpåverkan som utsläpp leder till. Samtidigt som branschen ska fasa ut fossila bränslen och använda hållbarare drivmedel påstår litteraturen att transporterat gods ökar markant och COVID-19 pandemins avtryck påverkar i allt större utsträckning med brist på chaufförer och sårbarare försörjningskedjor. Denna studie har syftat till att identifiera förändringar som påverkar vägtransportindustrin på kort sikt (0–5 år) samt på lång sikt (5–20 år) med fokus på Europa. Vidare har studien tillämpat resultaten på ett ramverk av framtida scenarion som tidigare forskning bidragit med i samarbete med över 50 industriexperter för att utvärdera förändringarnas påverkan med avseende på de möjliga framtiderna som forskningen resulterat i. Studien har tillämpat litteratursökning, dokumentstudie samt intervjuer med aktörer från vägtransportindustrin i syfte att samla relevant data och har resulterat i flertalet identifierade förändringar som vägtransportbranschen förväntas påverkas av på kort och lång sikt.  Förändringarna har uppdelats i tre nivåer; ekosystemets, affärsmässiga samt tekniska. De makrofaktorer som påverkar industrin är ökad regionalisering och urbanisering, ökade kundkrav och konsumtion samt införande av lagar och regler. Vidare är de affärsmässiga förändringarna etableringar av partnerskap och allianser, cirkularitet och brist på personal. De tekniska faktorerna består av AI, IoT och nya hållbarare drivmedel. De primära effekterna innefattar ökad lokal tillverkning av varor som bidrar till kortare transportsträckor men fler transporter, fossilfria transporter med främst elektricitet och vätgas som drivmedel och därmed nyetableringar av el- och vätgasinfrastruktur, många globala initiativ för att uppnå hållbarhet, omfattande tillämpning av teknologier för att effektivisera försörjningskedjorna samt mer omfattande regler och krav gällande nya outforskade teknologier. Vidare så har framtida scenarios tillämpats för att utvärdera möjlig påverkan på industrin, detta är visualiserat i figur 14. Förslag på fortsatt forskning inom området är förändringar i industrin som sker men som detta arbete inte behandlat då det inte uppfattats som att de ger väsentliga effekter på vägtransportbranschen, exempelvis ökade leveranser av färska varor, 3D-printing, multimodala transporter samt en äldre befolkning och därmed ökade transporter av medicinska hjälpmedel.

Thesis Ph.D. ((Applied Mathematics)) -- University of Limpopo, 2022 / The world is under threat from the devastating effects of the continued depletion of the Ozone layer. Increased global warming is causing catastrophic ecological damage and imbalance due to accelerated melting of glaciers, rampant runaway veld res, widespread floods and other extreme events. The delegates to the Cop26 Climate Change Summit were reminded that the continued burning of fossil fuels is releasing carbon into the atmosphere at an unprecedented pace and scale and that the world is already in trouble. Complete substitution of fossil fuels with clean energy sources is the only solution through which the world can be saved from the deleterious effects of global warming. However, total dependence on renewable energy sources can only be possible through novel technology that enables efficient energy utilization and conservation. For instance, the evolution of advanced techniques in manufacturing processes has led to the reduction in the size of various industrial and engineering designs that consume reduced amounts of energy. Efficient energy utilization in thermo-fluid flow systems can be achieved through entropy generation minimization. Entropy is a thermodynamic quantity that represents the unavailability of a system's thermal energy for conversion into mechanical work. In this study, thermodynamic analysis of reactive variable properties third-grade fluid flow in channels with varied geometries and subjected to different physical effects was investigated with the second law of thermodynamics as the area of focus. Entropy generation and inherent irreversibility analysis were the main focus of the study where the sensitivities of these quantities to the embedded parameters were numerically and graphically described and analysed. The semi-analytic Adomian decomposition method, the semi-implicit fi nite difference scheme and the spectral quasilinearisation method were employed to solve the nonlinear differential equations modelling the flow systems. The results reveal that the effects of the parameters on flow velocity, fluid temperature, entropy generation and inherent irreversibility cannot be neglected. In particular, conditions for entropy generation minimization were successfully established and documented. / University of Limpopo

Through the historic usage of fossil fuel, climate impacts have been severe and threaten to disrupt global economies and biological diversity. Hydrogen has emerged as a technology which can enable the productionand storage of renewable energy with no carbon emissions. However, energy transitions are complex as the sector is characterized by lock-in and path dependency due to co-evolution with infrastructure, policy and geography. The purpose of this study is to explore how hydrogen energy can overcome the lock-in and path dependency of fossil fuels. To achieve this, a qualitative single-case study of Sweden was conducted. The theoretical foundation consists of the Multi-Level Perspective and lock-in. The results indicate that in order for hydrogen technology to become large-scale and overcome lock-in, four criteria need to be fulfilled; hydrogen technology needs to be more cost-efficient, investments in infrastructure for hydrogen is required, a market needs to be established for the production of hydrogen and governments/institutions need to support hydrogen through regulation and investments. / Under decennier av fossil användning har klimatpåverkan blivit mer allvarlig och hotar att negativt påverka globala ekonomier och den biologiska mångfalden. Vätgas har framkommit som en teknik som möjliggör produktion och lagring av förnybar energi utan koldioxidutsläpp. Övergångar till nya energilösningar är dock svåra eftersom sektorn kännetecknas av “lock-in” och “path dependency”på grund av samutveckling med infrastruktur, politik och geografi. Syftet med denna studie är att undersöka hur vätgas kan övervinna “lock-in” och “path dependency” av fossila bränslen. För att uppnå detta genomfördes en kvalitativ fallstudie av Sverige. Den teoretiska grunden för studien består av Multi-Level Perspective och lock-in. Resultaten visar att fyra kriterier måste uppfyllas för att vätgas ska gå från en nisch innovation till att vara en del av dagens sociotekniska system. Vätgas måste bli mer kostnadseffektiv, investeringar i infrastruktur för vätgas krävs, en marknad måste skapas för produktion av vätgas och regeringar/institutioner behöver stödja vätgas genom föreskrifter.