There is an abundance of reports and articles on the extent of future bioenergy usage. Decision-makers might turn to bioenergy projections in hopes of making informed decisions for policies or investments. This report aims to highlight irregularities and differences regarding calculations and results in 15 global bioenergy projection studies for the year 2050, and to find underlying connections by applying a metaanalysis with a methodological focus. Statistical distributions were made for the projected global bioenergy potentials. A growth rate study based on the projected global bioenergy potentials was made and used as a simple “reality check”. Regarding Sweden and the EU, it was investigated whether decisions has been made based on estimated bioenergy potentials. The final aim was to make recommendations for bioenergy decision-makers and policy-makers. There are many statistical distributions fitting the projections for 2050. The distribution functions showed that with a 95 % confidence level, the bioenergy projections in 2050 is 151.3 EJ. The interquartile range of all studies included in this report for primary bioenergy in the year 2050 was shown to be 120-400 EJ, with minimum value of 30 EJ and maximum of 1600 EJ. A mere third of the projection values were in the vicinity of a linear or exponential trendline based on historical values. The historical annual average growth rate for bioenergy from 1971 to 2011 was found to be 1.9 percent. A higher growth rate is required to achieve the larger quantities that are projected in most studies, the most extreme rate was 7.6 percent, which is far above the average. The EU has adopted a biomass action plan partly based on bioenergy projections by the European Energy Agency in 2006. National and international energy projection reports influence Swedish politics, albeit not directly in propositions. The difference between individual reports and articles projected bioenergy level in 2050 is significant. It is recommended to read more than one. Most forecasting models and estimates will likely perform poorly numerically, so it is recommended to look for underlying factors, connected longterm trends, or behavioral consequences.

Includes bibliographical references (leaves 15-16). / Caption title. / Research supported by a Vinton Hayes fellowship.

För att kunna sänka utsläppen av växthusgaserna med 20 procent till år 2020 och med 80 procent till 2050 har de båda länderna (Storbritannien och Sverige) valt att använda sig av olika strategier. Storbritannien har valt en rättsligt bindande lag, The Climate Change Act medan Sverige valt att använda sig av ett av riksdagens miljömål, Begränsad klimatpåverkan, och då med inriktning mot klimatförändringarna. Genom att länderna valt att hantera klimatfrågan med olika strategier, skapas det skillnader och likheter mellan dessa länder. För att kunna synliggöra dessa har en dokumentstudie genomförts. Länderna har även jämförts enligt en komparativ metod och med hjälp av typologier inom dessa fyra kategorier: energimix, klimatpolitiska målsättningar, klimatpolitiska styrmedel och klimatpolitisk ansvarsfördelning. Resultatet belyser de politiska styrningsskillnaderna mellan länderna och deras  klimatpolitiska likheter. Länderna skiljer sig åt politiskt. Storbritannien har delat upp sina åtgärder och styrmedel mellan departementen, medan Sveriges klimatarbete till största del sker i kommunerna. Både Storbritannien och Sverige använder sig av ekonomiska styrmedel och då genom både skatt och olika bidrag. Båda länderna ser detta som ett effektivt sätt att minska klimatpåverkan. Även administrativa styrmedel som regleringar och gränsvärden används i båda länderna. Eftersom de politiska systemen skiljer sig åt mellan de två valda länderna är det svårt att förklara skillnaderna mellan länderna. Min genomgång av det empiriska materialet indikerar dock att Storbritannien har en mer detaljerad väg att gå för att nå de uppsatta klimatmålen.

De internationella klimatförhandlingarna handlar om att hitta lösningar för att stabilisera halten av växthusgaser i atmosfären och att uppnå tvågradersmålet. För att uppnå målet finns olika utsläppsmål att sträva mot. Ett är ett utsläppstak där varje land inte får släppa ut mer än 2 ton CO2-ekv/capita per år för att tvågradersmålet ska uppnås. Ett annat utsläppsmål är att minska de nationella utsläppen med en viss procentsats. EU:s del i minskningen ligger på 80-95 % till 2050. Som en del av arbetet mot målet presenterade EU i mars 2011 en färdplan för ett utsläppsnålt samhälle. Där presenteras åtgärder för fem olika sektorer samt hur stora utsläppsminskningarna beräknas kunna vara för varje sektor. Energisektorn är den sektor som beräknas minska mest och väntas nästintill nå en nollnivå. Även bostads- och servicesektorn väntas minska sina utsläpp kraftigt. Jordbrukssektorn är den sektor som beräknas minska minst. I färdplanen uppmanas varje medlemsland att ta fram en nationell färdplan till 2050. Det här examensarbetet syftar till att analysera ett antal av de nationella färdplanerna för att bl.a. ta reda på vilka förutsättningar och möjligheter som har en betydande påverkan. Resultatet visar att alla länderna antagit samma mål som EU, nämligen 80 %. Om alla länderna minskar med 80 % till 2050 är det bara Slovenien som når gränsen på 2 ton CO2-ekv/capita. Alla andra länder ligger över gränsen. Vägen till minskade utsläpp är framförallt utsläppsnåla energitekniker, energieffektiviseringar och en ökad användning av el eftersom den har potential att bli emissionsfri. Vindkraft är den teknik som många av de studerade länderna väljer att satsa på, främst till havs då utrymmet på land är begränsat. Kärnkraft är en energikälla som det råder delade meningar om. En del länder anser att det är en bra koldioxidsnål energikälla som gynnar klimatet medan andra länder menar att den är för osäker både ekonomiskt och säkerhetsmässigt. CCS (carbon capture and storage) tas upp av alla de studerade länderna som en möjlig åtgärd för att minska utsläppen. För att minska användningen av fossila bränslen i transportsektorn är det framförallt biodrivmedel och el som ska användas. Slutsatser som kan dras av arbetet är att CCS med de rätta förutsättningarna kommer att finnas i större skala 2050 än idag. Elbilar kommer att spela en stor roll i transportsektorn. Kärnkraft och förnybara alternativ är tekniker som kommer att spela en stor roll i energisystemet 2050. För att nå tvågradersmålet krävs internationella överenskommelser som också minskar risken för koldioxidläckage. / The international climate negotiations are to find solutions to stabilize concentrations of greenhouse gases in the atmosphere and to achieve the two degree target. To achieve this goal there are various emission targets to aim for. One is a ceiling in which each country must not emit more than two tons CO2-ekv/capita per year for two degree target to be achieved. Another emission target is to reduce national emissions by a certain percentage. EU's part in the reduction is 80-95 % by 2050. As a step towards the target in March 2011 the European Union launched a roadmap to a low carbon economy. It sets out measures for five different sectors and the size of the emission reductions estimated for each sector. The energy sector is the sector that is expected to decrease most, and is expected to almost reach a zero level. Also housing and service is expected to reduce their emissions significantly. The agricultural sector is the sector that is expected to decrease the least. The roadmap urges each member country to develop a national roadmap for 2050. This examination work aims to analyze a number of national roadmaps to find out what resources and opportunities that have a significant impact on the roadmap. The results show that all the countries have adopted the same target as the EU, namely 80%. If all countries reduce by 80% by 2050, only Slovenia will reach the limit of two tons CO2-ekv/capita, all other countries are above the limit. The ways to reduce emissions are primarily low-carbon energy technologies, energy efficiency and increased use of electricity because it has the potential to be emission-free. Wind power is the technology that many of the countries are choosing to invest in, mainly at sea when the space on land is limited. Nuclear power is an energy source where the opinion is split in two. Some countries consider it a good low-carbon energy source and favorable climate, while others argue that it is uncertain in both economy and safety. CCS (carbon capture and storage) is taken up by all the countries studied as a possible measure to reduce emissions. To reduce use of fossil fuels in the transport sector, it is primarily biofuels and electricity to be used. Conclusions to be drawn from this work are that CCS with the right conditions will be on a larger scale in 2050 than today. Electric cars play a big role in the transport sector. Nuclear power and renewable alternatives are techniques that will play a major role in the energy 2050. To reach the two-degree target requires international agreements that also reduce the risk of carbon leakage.

Afin de limiter les impacts du changement climatique sur la planète, les experts du Groupe Intergouvernemental d’experts sur l’Evolution du Climat (GIEC) préconisent une division par deux des émissions mondiales de gaz à effet de serre à l’horizon 2050. Cet objectif impose une division par quatre (i.e. facteur 4) des émissions de gaz à effet de serre des pays industrialisés comme la France. Le secteur des transports peut-il se plier à cette exigence ?A l’aide du modèle TILT (Transport Issues in the Long Term), centré sur les relations macroéconomiques entre croissance économique, technologies, mobilité et émissions de CO2, cette thèse recherche les conditions à réunir pour que soit atteint, en France, le « facteur 4 ». Si les progrès techniques annoncés par les ingénieurs sont au rendez-vous, nous pouvons atteindre un facteur 2. L’autre moitié du chemin doit donc être réalisée par une modification des comportements des individus et des entreprises. Trois familles de scénarios sont proposées pour en illustrer le contenu de ces évolutions. / In France an objective of dividing greenhouse gas emissions by four, from the 1990 level, by 2050 has been set. Are these ambitions out of our reach? What will the price to pay for this objective be?We have built a long-term backcasting transport demand model (TILT, Transport Issues in the Long Term). This model is centered on defined behavior types -in which the speed-GDP elasticity plays a key role- in order to determine demand estimations. This model lets us understand past tendencies -the coupling between growth and personal and freight mobility and adapt behavioral hypothesis -linked to the evolution of public policies- in order to show how a 75% reduction objective can be attained.The main results are an estimation of CO2 emissions for the transport sector taking into account technical progress and demand. These results are presented as three scenario families named: Pegasus, Chronos and Hestia. Each family corresponds to a growing degree of constraint on mobility.It is possible to divide greenhouse gas emissions in the transport sector by four. Technical progress is able to lead to more than half of these reductions. The interest of these scenarios is to show that there exist different paths –through organizational change- to getting the other half of the reductions.

A pesquisa por novos materiais e processos que possam garantir aeronaves mais leves e operacionalmente mais viáveis, tem-se dado praticamente em todos os componentes de uma aeronave, com consequência direta no menor consumo de combustível e benefícios para o fabricante, operadores e a população em geral com aplicação do conceito de \'aeronave verde\'. Nestes quesitos, materiais/processos, destacam-se as ligas de alumínio (2xxx e 7xxx) e a solda por fricção mistura (FSW- Friction Stir Welding) por sua relação custo/benefício. A soldagem por fricção de elementos estruturais aeronáuticos formados de materiais dissimilares que possuem propriedades mecânicas distintas é de grande interesse para a indústria aeronáutica, devido aos ganhos de peso e de custo de operação que esse tipo de junção pode gerar. Sendo assim foram avaliadas as principais propriedades mecânicas de interesse e correlacionar com a microestrutura de ligas dissimilares e similares soldadas pelo processo de FSW e a inteiração destas com os meios ambiente, criogênico e corrosivo aos quais, aeronaves podem ser sujeitas durante os voos. Para tal desenvolvimento a solda dissimilar foi realizada com as ligas de alumínio-lítio 2050-T84 e alumínio 7050-T7451, enquanto que a solda similar foi realizada com a liga de alumínio-lítio 2198-T851. Foram feitas análises de ciclo térmico durante a soldagem e ambas juntas foram classificadas como solda quente, que prevê intensa variação microestrutural e afetam as propriedades mecânicas de dureza, a tenacidade fadiga e corrosão fadiga. A caracterização microestrutural realizada pela técnica de EBSD evidenciou alta quantidade de CAA que resultou na redução da dureza e aumento da tenacidade à fratura na região de contato entre a peça de trabalho e o ombro da ferramenta. De contra partida, a taxa de propagação de trinca por fadiga aumentou ligeiramente no meio salino. / The research for new materials and processes that produce light materials and operationally viable, has occurred in almost all the components of an aircraft, with a direct consequence in the lower fuel consumption and benefits for the manufacturing, operators and the population in application of the concept of \'green aircraft\'. In these questions, materials/processes, the most important are aluminum alloys (2xxx and 7xxx) and friction stir welding for their cost/benefit ratio. Friction stir welding of aeronautical structural elements made of dissimilar materials with distinct mechanical properties is of great interest to the aeronautical industry due to the weight and operating costs that this type of joint can result. Thus, the main mechanical properties of interest and correlate with the microstructure of dissimilar and similar alloys welded by the FSW and their interaction with the ambient, cryogenic and corrosive environments to which aircraft may be subject during flight. To development, the dissimilar weld performed with the lithium-aluminum alloys 2050-T84 and aluminum 7050-T7451, while the similar solder performed with the lithium-aluminum alloy 2198-T851. Thermal cycle analyzes were done during welding and both joints were classified as hot welding, which provides intense microstructural variation and affect the mechanical properties of hardness, fatigue toughness and fatigue corrosion. The microstructural characterization performed by the EBSD technique evidenced a high amount of CAA that resulted in low hardness and high fracture toughness in the region of contact between the workpiece and the tool shoulder. On the other hand, the rate of crack propagation by fatigue increased slightly in the saline atmosphere.

A pesquisa por novos materiais e processos que possam garantir aeronaves mais leves e operacionalmente mais viáveis, tem-se dado praticamente em todos os componentes de uma aeronave, com consequência direta no menor consumo de combustível e benefícios para o fabricante, operadores e a população em geral com aplicação do conceito de \'aeronave verde\'. Nestes quesitos, materiais/processos, destacam-se as ligas de alumínio (2xxx e 7xxx) e a solda por fricção mistura (FSW- Friction Stir Welding) por sua relação custo/benefício. A soldagem por fricção de elementos estruturais aeronáuticos formados de materiais dissimilares que possuem propriedades mecânicas distintas é de grande interesse para a indústria aeronáutica, devido aos ganhos de peso e de custo de operação que esse tipo de junção pode gerar. Sendo assim foram avaliadas as principais propriedades mecânicas de interesse e correlacionar com a microestrutura de ligas dissimilares e similares soldadas pelo processo de FSW e a inteiração destas com os meios ambiente, criogênico e corrosivo aos quais, aeronaves podem ser sujeitas durante os voos. Para tal desenvolvimento a solda dissimilar foi realizada com as ligas de alumínio-lítio 2050-T84 e alumínio 7050-T7451, enquanto que a solda similar foi realizada com a liga de alumínio-lítio 2198-T851. Foram feitas análises de ciclo térmico durante a soldagem e ambas juntas foram classificadas como solda quente, que prevê intensa variação microestrutural e afetam as propriedades mecânicas de dureza, a tenacidade fadiga e corrosão fadiga. A caracterização microestrutural realizada pela técnica de EBSD evidenciou alta quantidade de CAA que resultou na redução da dureza e aumento da tenacidade à fratura na região de contato entre a peça de trabalho e o ombro da ferramenta. De contra partida, a taxa de propagação de trinca por fadiga aumentou ligeiramente no meio salino. / The research for new materials and processes that produce light materials and operationally viable, has occurred in almost all the components of an aircraft, with a direct consequence in the lower fuel consumption and benefits for the manufacturing, operators and the population in application of the concept of \'green aircraft\'. In these questions, materials/processes, the most important are aluminum alloys (2xxx and 7xxx) and friction stir welding for their cost/benefit ratio. Friction stir welding of aeronautical structural elements made of dissimilar materials with distinct mechanical properties is of great interest to the aeronautical industry due to the weight and operating costs that this type of joint can result. Thus, the main mechanical properties of interest and correlate with the microstructure of dissimilar and similar alloys welded by the FSW and their interaction with the ambient, cryogenic and corrosive environments to which aircraft may be subject during flight. To development, the dissimilar weld performed with the lithium-aluminum alloys 2050-T84 and aluminum 7050-T7451, while the similar solder performed with the lithium-aluminum alloy 2198-T851. Thermal cycle analyzes were done during welding and both joints were classified as hot welding, which provides intense microstructural variation and affect the mechanical properties of hardness, fatigue toughness and fatigue corrosion. The microstructural characterization performed by the EBSD technique evidenced a high amount of CAA that resulted in low hardness and high fracture toughness in the region of contact between the workpiece and the tool shoulder. On the other hand, the rate of crack propagation by fatigue increased slightly in the saline atmosphere.

Afin de limiter les impacts du changement climatique sur la planète, les experts du Groupe Intergouvernemental d'experts sur l'Evolution du Climat (GIEC) préconisent une division par deux des émissions mondiales de gaz à effet de serre à l'horizon 2050. Cet objectif impose une division par quatre (i.e. facteur 4) des émissions de gaz à effet de serre des pays industrialisés comme la France. Le secteur des transports peut-il se plier à cette exigence ? A l'aide du modèle TILT (Transport Issues in the Long Term), centré sur les relations macroéconomiques entre croissance économique, technologies, mobilité et émissions de CO2, cette thèse recherche les conditions à réunir pour que soit atteint, en France, le « facteur 4 ». Si les progrès techniques annoncés par les ingénieurs sont au rendez-vous, nous pouvons atteindre un facteur 2. L'autre moitié du chemin doit donc être réalisée par une modification des comportements des individus et des entreprises. Trois familles de scénarios sont proposées pour en illustrer le contenu de ces évolutions.

At the UN Climate Change Conference in Cancun in 2010, all the industrialised countries committed to producing long-term national strategies to achieve low levels of greenhouse gas emissions. The aim was to meet the goal of reducing emissions by 80-95 per cent by 2050, in line with the two-degrees-goal. In February 2011, the European Commission presented a communication on a roadmap for the EU for moving to a competitive low-carbon economy in 2050. Sweden has actively supported the conclusions within the EU that countries should draw up their own roadmaps, but Sweden has not yet produced a national roadmap to 2050. This thesis examines why the Swedish government has not yet agreed on a low-carbon development strategy to 2050 in line with the agreement at the climate conference in Cancun 2010 and the directives from the European Commission. The purpose of this study is to examine why the investigation on a Swedish roadmap 2050 produced by the Swedish Environmental Protection Agency, never reached the political decision agenda, in the Swedish parliament. The objective of the study is achieved by applying the Multiple Streams Model, a theory on policy processes and agenda setting, on the case of the Swedish roadmap 2050. The study concludes that (1) the level of political consensus is too low, especially in terms of the basic assumptions that underlie the roadmap; and (2) the document produced by the Swedish Environmental Protection Agency was too weak to become a bill.

The Great East Japan earthquake and the resulting tsunami struck Japan east coast on March 11th 2011. All nuclear power plants on the east coast were automatically shut down, and several thermal plants were damaged: Japan was left with only 19% of its nuclear capacity available (i.e. 9 GW). The Fukushima-Daiichi nuclear power plant underwent major incidents, with a fusion of the nuclear core and radioactivity leakage, the most important nuclear accident since Chernobyl. During the summer 2011, the Japanese government undertook emergency measures to offset the expected 20% capacity shortage in Tokyo and Tohoku areas. On the supply side, capacity was recovered by restarting and restoring fossil-fuelled power generation, and importing power from neighboring areas. On the demand side, stringent demand restriction measures led to a summer peak demand 10 GW lower in the Tokyo area and 3.1 GW lower in the Tohoku area, compared to 2010. In early 2012, only 2 reactors were still in operation, after further nuclear shutdowns. Market-driven electricity conservation reforms and subsidy-driven supply capacity additions aim to avoid emergency measures in the summer 2012 similar to those of summer 2011, and offset the expected 9% power deficit in the country. For the longer term, Japan government has launched various initiatives to review the 2010 Basic Energy Plan, which envisaged a nuclear expansion. In this study, a model was developed to assess the economic and environmental impacts of three contrasted scenarios, reflecting different options for Japan’s electricity mix by 2050. The results show that a nuclear phase-out would induce additional costs of the order of €850bn to the power system over the period 2010-50, compared to the Basic Energy Plan, while also preventing Japan to reach its CO2 emissions’ reduction targets by 2050. A sensitivity analysis shows that a reduced renewables development would lower the cost of the power system, but put aside climate change mitigation and energy security of supply. On the other hand, a reduced electricity demand through energy efficiency measures would have a positive impact on both CO2 emissions and the security of supply. / <p>-</p> / -