908 resultados para Hydrology and Climate Change II


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This article deals with climate change from a linguistic perspective. Climate change is an extremely complex issue that has exercised the minds of experts and policy makers with renewed urgency in recent years. It has prompted an explosion of writing in the media, on the internet and in the domain of popular science and literature, as well as a proliferation of new compounds around the word ‘carbon’ as a hub, such as ‘carbon indulgence’, a new compound that will be studied in this article. Through a linguistic analysis of lexical and discourse formations around such ‘carbon compounds’ we aim to contribute to a broader understanding of the meaning of climate change. Lexical carbon compounds are used here as indicators for observing how human symbolic cultures change and adapt in response to environmental threats and how symbolic innovation and transmission occurs.

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The higher education system has a critical role to play in educating environmentally aware and participant citizens about global climate change. Yet, few studies have focused on higher education students’ knowledge and attitudes about this issue. This study aims to contribute to a comprehensive understanding of views and attitudes about climate change issues, across the postgraduate student population in three universities—the on Campus University of Porto and University of Coimbra, and the distance learning Universidade Aberta, Portugal. We surveyed university students and graduates from three master programs in environmental sciences targeting their knowledge, attitudes and behaviour on climate change issues, and their views of the role that their master degree had on it. A majority of the respondents believed that climate change is factual, and is largely human-induced; and a majority expressed concerns about climate change. Still, the surveyed students hold some misconceptions about basic causes and consequences of climate change. Further research is necessary to comprehend the university postgraduate students’ population, so that curricula programs can be adapted to grant consensus on scientific knowledge about climate change, and an active engagement of the graduate citizens, as part of the solution for climate change problems.

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This paper addresses a potential role that tariffs and tariff policy can play in encouraging countries to take part in a multilateral effort to mitigate climate change. It begins by assessing whether increasing tariffs on products from energy intensive or polluting industries amounts to a violation of WTO rules and whether protectionism in this case can be differentiated from genuine environmental concerns. It then argues that while lowering tariffs for environmental goods can serve as a carrot to promote dissemination of cleaner technologies, tariff deconsolidation is a legitimate stick to encourage polluting countries to move towards an international climate agreement. The paper further explores this view by undertaking a partialequilibrium simulation analysis to examine the impact of a unilateral unit increase in tariffs on the imports of the most carbon-intensive products from countries not committed to climate polices. Our results suggest that the committed importing countries would have to raise their tariffs only slightly to effect a significant decline in the imports of these products from the non-committed countries. For instance, a unit increase in the simple average applied tariffs on the imports of these carbon-intensive products in 2005 from our sample of non-committed exporting countries would reduce the imports of these products by an average 32.6% in Australia, 178% in Canada, 195% in the EU, 271% in Japan and 62% in the US, therebysuggesting the effectiveness of such a measure in pushing countries towards a global climate policy.

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A Cimeira europeia de Dezembro 2013 deu à União Europeia um mandato para uma nova estratégia de segurança. As alterações climáticas têm desempenhado um papel cada vez mais importante nos debates sobre segurança europeia. A União tem sido uma das organizações a melhor identificar as alterações climáticas como um “multiplicador de ameaça” e a desenvolver todo um conjunto de iniciativas políticas, destinadas a relacionar fatores aliados às alterações climáticas com as políticas externas e de segurança. A UE tem pressionado para um ambicioso acordo internacional sobre clima até 2015 pelo que importa considerar a relação entre duas agendas: a da política externa e da segurança. O autor examina problemas resultantes da fragmentação de responsabilidades entre vários atores institucionais europeus aos quais falta um enfoque sobre questões climáticas. O artigo explora ainda a relação entre alterações climáticas e políticas de emigração da UE; a relação entre clima, segurança energética e política de defesa e a dimensão geoeconómica das respostas políticas da União. Conclui com uma reflexão sobre se o fenómeno das alterações climáticas terá um efeito positivo sobre a cooperação europeia, em particular no domínio da gestão de crises com origem climática ou se ao invés incentivará os Estados a uma postura de isolamento.

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The starting point for this study was the consideration of future climate change scenarios and their uncertainties. The paper presents the global projections from the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (AR5) and compares them with regional scenarios (downscaling) developed by the Brazilian National Institute for Space Research (Instituto Nacional de Pesquisas Espaciais - INPE), with a focus on two main IPCC scenarios (RCP4.5 and RCP8.5) and two main global models (MIROC and Hadley Centre) for the periods 2011-2040 and 2041-2070. It aims to identify the main trends in terms of changes in temperature and precipitation for the North and Northeast regions of Brazil (more specifically, in the Amazon, semi-arid and cerrado biomes).

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Earth climate has changed significantly in the last century and the different models indicate that it will continue to change over the next decades, even if the emission of greenhouse gases stop immediately. These changes have impact on different plant populations, as well as in the actual distribution of several species. As plants, in general, have a smaller capacity of dispersion compared with the animals it is likely that they will suffer the impacts of the climate change more intensively.

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Summary: Climate change has a potential to impact rainfall, temperature and air humidity, which have relation to plant evapotranspiration and crop water requirement. The purpose of this research is to assess climate change impacts on irrigation water demand, based on future scenarios derived from the PRECIS (Providing Regional Climates for Impacts Studies), using boundary conditions of the HadCM3 submitted to a dynamic downscaling nested to the Hadley Centre regional circulation model HadRM3P. Monthly time series for average temperature and rainfall were generated for 1961-90 (baseline) and the future (2040). The reference evapotranspiration was estimated using monthly average temperature. Projected climate change impact on irrigation water demand demonstrated to be a result of evapotranspiration and rainfall trend. Impacts were mapped over the target region by using geostatistical methods. An increase of the average crop water needs was estimated to be 18.7% and 22.2% higher for 2040 A2 and B2 scenarios, respectively. Objective ? To analyze the climate change impacts on irrigation water requirements, using downscaling techniques of a climate change model, at the river basin scale. Method: The study area was delimited between 4º39?30? and 5º40?00? South and 37º35?30? and 38º27?00? West. The crop pattern in the target area was characterized, regarding type of irrigated crops, respective areas and cropping schedules, as well as the area and type of irrigation systems adopted. The PRECIS (Providing Regional Climates for Impacts Studies) system (Jones et al., 2004) was used for generating climate predictions for the target area, using the boundary conditions of the Hadley Centre model HadCM3 (Johns et al., 2003). The considered time scale of interest for climate change impacts evaluation was the year of 2040, representing the period of 2025 to 2055. The output data from the climate model was interpolated, considering latitude/longitude, by applying ordinary kriging tools available at a Geographic Information System, in order to produce thematic maps.

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Soils are the largest sinks of carbon in terrestrial ecosystems. Soil organic carbon is important for ecosystem balance as it supplies plants with nutrients, maintains soil structure, and helps control the exchange of CO2 with the atmosphere. The processes in which wood carbon is stabilized and destabilized in forest soils is still not understood completely. This study attempts to measure early wood decomposition by different fungal communities (inoculation with pure colonies of brown or white rot, or the original microbial community) under various interacting treatments: wood quality (wood from +CO2, +CO2+O3, or ambient atmosphere Aspen-FACE treatments from Rhinelander, WI), temperature (ambient or warmed), soil texture (loamy or sandy textured soil), and wood location (plot surface or buried 15cm below surface). Control plots with no wood chips added were also monitored throughout the study. By using isotopically-labelled wood chips from the Aspen-FACE experiment, we are able to track wood-derived carbon losses as soil CO2 efflux and as leached dissolved organic carbon (DOC). We analyzed soil water for chemical characteristics such as, total phenolics, SUVA254, humification, and molecular size. Wood chip samples were also analyzed for their proportion of lignin:carbohydrates using FTIR analysis at three time intervals throughout 12 months of decomposition. After two years of measurements, the average total soil CO2 efflux rates were significantly different depending on wood location, temperature, and wood quality. The wood-derived portion soil CO2 efflux also varied significantly by wood location, temperature, and wood quality. The average total DOC and the wood-derived portion of DOC differed between inoculation treatments, wood location, and temperature. Soil water chemical characteristics varied significantly by inoculation treatments, temperature, and wood quality. After 12 months of decomposition the proportion of lignin:carbohydrates varied significantly by inoculation treatment, with white rot having the only average proportional decrease in lignin:carbohydrates. Both soil CO2 efflux and DOC losses indicate that wood location is important. Carbon losses were greater from surface wood chips compared with buried wood chips, implying the importance of buried wood for total ecosystem carbon stabilization. Treatments associated with climate change also had an effect on the level of decomposition. DOC losses, soil water characteristics, and FTIR data demonstrate the importance of fungal community on the degree of decomposition and the resulting byproducts found throughout the soil.

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The Mara River Basin (MRB) is endowed with pristine biodiversity, socio-cultural heritage and natural resources. The purpose of my study is to develop and apply an integrated water resource allocation framework for the MRB based on the hydrological processes, water demand and economic factors. The basin was partitioned into twelve sub-basins and the rainfall runoff processes was modeled using the Soil and Water Assessment Tool (SWAT) after satisfactory Nash-Sutcliff efficiency of 0.68 for calibration and 0.43 for validation at Mara Mines station. The impact and uncertainty of climate change on the hydrology of the MRB was assessed using SWAT and three scenarios of statistically downscaled outputs from twenty Global Circulation Models. Results predicted the wet season getting more wet and the dry season getting drier, with a general increasing trend of annual rainfall through 2050. Three blocks of water demand (environmental, normal and flood) were estimated from consumptive water use by human, wildlife, livestock, tourism, irrigation and industry. Water demand projections suggest human consumption is expected to surpass irrigation as the highest water demand sector by 2030. Monthly volume of water was estimated in three blocks of current minimum reliability, reserve (>95%), normal (80–95%) and flood (40%) for more than 5 months in a year. The assessment of water price and marginal productivity showed that current water use hardly responds to a change in price or productivity of water. Finally, a water allocation model was developed and applied to investigate the optimum monthly allocation among sectors and sub-basins by maximizing the use value and hydrological reliability of water. Model results demonstrated that the status on reserve and normal volumes can be improved to ‘low’ or ‘moderate’ by updating the existing reliability to meet prevailing demand. Flow volumes and rates for four scenarios of reliability were presented. Results showed that the water allocation framework can be used as comprehensive tool in the management of MRB, and possibly be extended similar watersheds.

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The reduction of Greenhouse Gases (GHG) plays a central role in the environmental policies considered by countries for implementation not only at its own level but also at supranational levels. This thesis is dedicated to investigate some aspects of two of the most relevant climate change policies. The first part is dedicated to emission permit markets and the second part to optimal carbon taxes. On emission permit markets we explore the strategic behavior of oligopolistic firms operating in polluting industrial sectors that are regulated by cap and trade systems. Our aim is to identify how market power influences the main results obtained under perfect competition assumptions and to understand how actions taken in one market affects the outcome of the other related market. A partial equilibrium model is developed for this purpose with specific abatement cost functions. In Chapter 2 we use the model to explain some of the most relevant literature results. In Chapter 3 the model is used to analyze different oligopolistic structures in the product market under the assumption of competitive permits market. There are two significant findings. Firstly, under the assumption of a Stackelberg oligopoly, firms have no incentives for lobbying in order to manipulate permit prices up, as they have under Cournot competition...

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Sea level rise and other effects of climate change on oceans and coasts around the world are major reasons to halt the emissions of greenhouse gases to the maximum extent. But historical emissions and sea level rise have already begun so steps to adapt to a world where shorelines, coastal populations, and economies could be dramatically altered are now essential. This presents significant economic challenges in four areas. (1) Large expenditures for adaptation steps may be required but the extent of sea level rise and thus the expenditures are unknowable at this point. Traditional methods for comparing benefits and costs are severely limited, but decisions must still be made. (2) It is not clear where the funding for adaptation will come from, which is a barrier to even starting planning. (3) The extent of economic vulnerability has been illustrated with assessments of risks to current properties, but these likely significantly understate the risks that lie in the future. (4) Market-based solutions to reducing climate change are now generally accepted, but their role in adaptation is less clear. Reviewing the literature addressing each of these points, this paper suggests specific strategies for dealing with uncertainty in assessing the economics of adaptation options, reviews the wide range of options for funding coastal adaption, identifies a number of serious deficiencies in current economic vulnerability studies, and suggests how market based approaches might be used in shaping adaptation strategies. The paper concludes by identifying a research agenda for the economics of coastal adaptation that, if completed, could significantly increase the likelihood of economically efficient coastal adaptation.

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Nous avons utilisé la télédétection pour examiner comment l’abondance du caribou migrateur pouvait influencer la quantité de ressources alimentaires, et comment ces changements pouvaient affecter la dynamique de population et les patrons d’utilisation de l’espace des caribous. Nous avons évalué les relations entre le caribou et ses ressources alimentaires pour l’aire de mise bas et l’aire d’estivage du troupeau Rivière-George (TRG) du nord du Québec et du Labrador (Canada) entre 1991 et 2011. Nous avons modélisé les relations entre la productivité primaire et des variables climatiques, nous permettant d’isoler les effets d’autres facteurs, comme la pression de broutement des caribous. Nous avons trouvé une relation négative entre la densité de caribous et la productivité primaire à grande échelle, suggérant que la pression de broutement par les caribous pouvait réduire l’abondance des ressources alimentaires et contribuer à la dégradation de l’habitat. Une forte tendance au réchauffement durant la période d’étude, couplée avec un déclin de la taille de population du TRG, a cependant entrainé une productivité primaire plus élevée. Cette hausse de la productivité primaire pourrait représenter un rétablissement de la végétation suite à la réduction de la pression de broutement et/ou un effet du réchauffement climatique.

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The metapopulation paradigm is central in ecology and conservation biology to understand the dynamics of spatially-structured populations in fragmented landscapes. Metapopulations are often studied using simulation modelling, and there is an increasing demand of user-friendly software tools to simulate metapopulation responses to environmental change. Here we describe the MetaLandSim R package, mwhich integrates ideas from metapopulation and graph theories to simulate the dynamics of real and virtual metapopulations. The package offers tools to (i) estimate metapopulation parameters from empirical data, (ii) to predict variation in patch occupancy over time in static and dynamic landscapes, either real or virtual, and (iii) to quantify the patterns and speed of metapopulation expansion into empty landscapes. MetaLandSim thus provides detailed information on metapopulation processes, which can be easily combined with land use and climate change scenarios to predict metapopulation dynamics and range expansion for a variety of taxa and ecological systems.

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Climate change projections point to increasing air temperature and reduced precipitation in southern Portugal, which would affect farming systems. This study aims to assess the impacts of climate change on irrigated agriculture in southern Portugal. These impacts were assessed by combining climate model data with a soil water balance model and a numerical model for the design of irrigation systems. Meteorological data from two weather stations were used along with three climate models (HadRM3P, HIRHAMh and HIRHAMhh; 2071–2100). The crop rotations studied included sugar beet–maize–tomato–wheat and sunflower–wheat–barley. Two adaptation measures were considered: (i) maintaining the current crop varieties; (ii) using new crop varieties. The results from the considered climate change scenarios indicated that the impacts of climate change on irrigation requirements depend on the adopted adaptation measures. On average, the seasonal irrigation requirements increased by 13–70% when new crop varieties were used and by −13 to 7% when the current crop varieties were maintained. The impacts of climate change on irrigation system design were considerable, with the design flow rate increasing by 5–24%.