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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
211

The establishment of the long-term rainfall trends in the annual rainfall patterns in the Jonkershoek Valley, Western Cape, South Africa

Moses, Godfrey January 2008 (has links)
Magister Scientiae - MSc / The overall aim of this project was to establish whether there is a long-term decline of rainfall collected in rainfall gauges within the Jonkershoek Valley that have the longest and best quality records. / South Africa
212

Climate change scenario simulations over Eritrea by using a fine resolution limited area climate model : temperature and moisture sensitivity

Beraki, Asmerom Fissehatsion 10 February 2006 (has links)
The climate of the eastern section of the Sahelian latitude, especially over the Eritrean subdomain, is often associated with long drought episodes from which the atmospheric mechanisms are poorly understood. In an effort to improve our knowledge of weather and climate systems over this region, the PRECIS Regional Climate Model (RCM) from the United Kingdom (UK) was obtained and implemented. Such a climate model that is based upon the physical laws of nature has the ability to simulate regional-scale atmospheric patterns, and therefore, may significantly contribute to our understanding of local atmospheric processes. In this dissertation the assessment of past regional climate trends from both observations and model simulations, and the simulation of scenarios for possible future climate change were regarded as important. To investigate this, the PRECIS RCM was first nested over the Eritrean domain into the “atmosphere only” HadAM3H global General Circulation Model (GCM) and forced at its lateral boundaries by a 30-year present-day (1961-1990) integration of the same global model. Secondly, the PRECIS RCM was constrained at its lateral boundary by the “fully coupled” HadCM3 GCM (for Sea Surface Temperatures (SSTs) and sea-ice) and its improved atmospheric component (HadAM3H GCM). The latter simulations provided boundary conditions for the A2 and B2 future emission scenarios (Special Report on Emission Scenarios (SRES)) to simulate a 20-year (2070-2090) projection of future climate. These experiments allowed for verification of both spatial and temporal present-day climate simulations, as well as possible future climate trends as simulated by the PRECIS RCM over the Eritrean domain, with specific emphasis on temperature and moisture related variables. The study indicates that PRECIS RCM climate simulations are mostly in harmony with observed spatial patterns. This skill may be attributed to the full representation of the climatic system (land surface, sea, ice, atmosphere and atmospheric chemistry such as sulphur and greenhouse gasses) in the model configuration. However, when comparing PRECIS RCM results with the much coarser resolution (2.5ox2.5o) National Centre for Environmental Prediction (NCEP) reanalysis data, obvious differences do occur. These differences are not necessarily the result of poor model performance, but may be attributed to more detailed simulations over the finer RCM grid (0.44o x 0.44o). Future climate scenario simulation with the PRECIS RCM over Eritrea produce increased surface temperature in both the A2 and B2 SRES scenario integrations, relative to the present climatology. This temperature increase also appears in the driving GCM (HadCM3) as well as in other GCM results from the Inter Governmental Panel for Climate Change (IPCC) initiative. There are, however, mixed signals in rainfall projections. According to PRECIS RCM results, rainfall is expected to increase in most of the Eritrean region. Copyright 2005, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. Please cite as follows: Beraki, A F 2005, Climate change scenario simulations over Eritrea by using a fine resolution limited area climate model : temperature and moisture sensitivity , MSc dissertation, University of Pretoria, Pretoria, viewed yymmdd < http://upetd.up.ac.za/thesis/available/etd-02102006-152327 / > / Dissertation (MSc)--University of Pretoria, 2007. / Geography, Geoinformatics and Meteorology / Unrestricted
213

Climate change, collective action, and state compliance : obstacles on the road to Copenhagen

Shankland, Michael 11 1900 (has links)
Climate change is a type of prisoner’s dilemma. Reductions in greenhouse gas (GHG) emissions are a public good and are costly to provide. Consequently, nation-states generally have done little to curb their emissions. Countries could be encouraged to reduce their emissions if the international community of states were to sanction, or the world were to shame, states that did not act. However, financial and technological aid is more likely to induce states to impose tougher restrictions on GHG emissions. In order for Copenhagen to precipitate major action on climate change the treaty must either compel countries to fulfill their obligations or assist states in transitioning their economies away from fossil fuels toward alternative energy sources. If the treaty fails to do both of these things then we can only hope that the largest producers of greenhouse gases either take steps to reduce their emissions voluntarily or are forced to take action in response to domestic pressure from their citizens and/or sub-national governments. Otherwise, we will have no choice but to adapt to an increasingly warmer planet and the consequences thereof. / Arts, Faculty of / Political Science, Department of / Graduate
214

The Response of Cladoceran Communities to the Climatic Changes of the Late Holocene Southwestern Québec

Cooper, Emily January 2015 (has links)
This thesis focuses on a chronological analysis of the cladoceran communities from a sediment core of a small oligotrophic lake in southwestern Québec, Canada over the past 1250 years. The sediments of the lake were varved, which allowed for accurate dating. A previously published pollen study of the lake provided a record of the paleoclimatic and landscape changes in the region. The core was then used to infer how changes in temperature and landscape changes impacted the taxonomic composition of the cladoceran community through time. Cladoceran diversity was high throughout most of the Medieval Warm Period and into the Little Ice Age and decreased during the modern period in response to increased temperatures and anthropogenic impacts. Daphnia and plant-associated species greatly decreased in the past 100 years. This shift, combined with increased temperatures and changes in the landscape opened up a niche for the colonization by the smaller Bosmina longirostris. The modern communities are unlike most of what was observed throughout the past millennium.
215

Urban Vulnerability: Bridging Systems and People-Centred Approaches in Dawei, Tanintharyi Region, Myanmar

Martin, Taylor January 2016 (has links)
This research discusses urban vulnerability to environmental change in Dawei, Myanmar through the analysis of the exposure and sensitivity of urban systems. The scope of this research attempts to encompass the complexity of multi-scalar relationships between the exposure and sensitivity of urban systems and wider supporting ecological systems to climatic and non-climatic shocks and stresses. Moreover, this research aims to bridge systems and people-centred approaches by considering the existing sensitivity of vulnerable populations living in Dawei through the use of two case studies. Specifically, an urban livelihoods approach was used to consider the entitlements, priorities, and capacities of households to cope with shocks and stress given existing challenges. The analysis of findings have been presented according to nested scales, beginning with the macro-level in the consideration of the exposure of urban socio-ecological systems; the meso-level through the analysis of the differential exposure and sensitivity of two communities living in Dawei in light of access to urban infrastructure and services; and lastly, the micro-level through the analysis of household sensitivity through the application of a livelihoods approach.
216

A history and test of planetary weather forecasting

Scofield, Bruce 01 January 2010 (has links)
A unique methodology for forecasting weather based on geocentric planetary alignments originated in ancient Mesopotamia. The method, called astrometeorology, was further developed by Greek, Arab, and Renaissance scientists including Ptolemy, Al-Kindi, Tycho Brahe and Joannes Kepler. A major 17th century effort to test the method in a Baconian fashion was made by John Goad. Building on the ideas of Kepler and Goad, I test an isolated component of the method, specifically a correlation between geocentric Sun-Saturn alignments and cold temperatures, using modern daily temperature data from New England, Central England, Prague and other locations. My hypothesis states there is a correlation, shown in daily temperature records, between cooling trends in specific regions and the geocentric alignments of the Sun and the planet Saturn. The hypothesis is supported by a number of tests that show lower temperatures on days when Sun-Saturn alignments occur, especially when near the equinoxes. The astronomy of this positioning suggests that tidal forces on the atmosphere may be part of a mechanism that would explain the apparent effect. The abandonment of planetary weather forecasting by the intellectual elite in 16th and 17th century Europe is next organized as a history and discussion. In the final section, applications of the methodology to climate cycles is explored, particularly in regard to a 1536-year recurring cycle of outer planets and a cycle of similar length found in climate records. In addition, an account of biological processes that are structured around astronomical cycles is presented.
217

Implementing community renewables: institutional work in South Africa's renewable energy procurement programme

Wlokas, Holle Linnea January 2017 (has links)
In 2014, for the first time in its history, South Africa fed the national electricity grid with electricity generated through utility-scale renewable energy projects. The Renewable Energy Independent Power Producer Procurement Programme (REIPPPP) is the policy instrument driving this change. The process requires bidding private energy companies to commit resources in alleviation of local socio-economic needs. This thesis analyses the question how the institutions evolve in the implementation of community benefit requirements. The theoretical frameworks of institutional work and logics helps to analyse this new organizational field and interaction of various actors in government, industries and communities. An action research approach grounds this research empirically and aims to create the opportunity for actors to reflect on their actions and engagement in the community benefit implementation process. The research asks how are government, companies and communities shape institutions in the implementation of the community benefit requirements in South Africa's REIPPPP? The study first analyses the procurement requirements for community benefit and ownership, then, secondly, reviews the first 64 approved project bids for suggestions made in response to these requirements. A third research step involves fieldwork in 13 wind and solar projects across the country, the fieldwork consisting of interviews with project stakeholders about their experiences. The research negotiates access to an emerging and competitive, but also enquiring industry, one that has shared with the researcher important insights into its evolving community engagement and its development practices and considerations. The findings reveal that, in the implementation of South Africa's community renewables, government and companies dominate institutional work efforts in the stages of policy formulation and project development. But communities, the least informed and capacitated actor among the three, face the results and they have particular ways of responding, including corrective and disruptive ways. Reflective spaces are dominated by industry and strategically exclude communities from both asserting their experiences as well as from the opportunity to participate in creating collective understanding and agreeable processes that would foster the long-term relationship between company and community. This is a shortcoming that requires urgent attention to ensure positive institutional work and developmental impact.
218

Impact of climate change and irrigation development on hydropower supply in the Zambezi River Basin, and implications for power sector development in the Southern African Power Pool

Spalding-Fecher, Dennis Randall January 2018 (has links)
This thesis investigates the hypothesis that the combination of future changes in climate and development (primarily irrigation) in the Zambezi River Basin (ZRB) threatens the technical and economic viability of existing and planned hydropower plants, and in turn the expansion plans and costs of the regional power system for Southern African countries. This hypothesis is evaluated using the following three questions to structure the analysis. ● How could future climate and irrigation expansion in the Zambezi River Basin affect hydropower generation potential? ● How could development in Southern Africa affect power demand, and how might this demand be met? ● How could the changes in water availability for hydropower (i.e. due to climate change and development) affect regional electricity expansion plans, generation costs and greenhouse gas emissions? The methodological tool used to address the first research question is the Water Evaluation and Planning (WEAP) scenario modelling system, developed by Stockholm Environment Institute. WEAP is a combined hydrological and water allocation model that is widely used internationally. The modelling demonstrates that the change in future climate is the overwhelming driver of future production at almost all hydropower plants in the ZRB over the study period of 2010-2070. The difference in mean generation under wetting and drying climates (i.e. difference between the values under wet and dry scenarios) is 12-16% for individual existing plants. This difference is as much as 30% for individual new plants, with all plants other than Batoka showing variation in mean annual generation of more than 13%. The impact of irrigation, on the other hand, is mainly an issue for plants downstream from Kariba, and even then the magnitude is typically less than a third of the impact of the alternative climates. The water modelling results therefore do not vary significantly across alternative development futures, because the accelerated irrigation development is still not large enough to dramatically impact hydropower. The second research question is analysed using Stockholm Environment Institute's Long- Range Energy Alternatives Planning (LEAP) model to trace the impacts of socio-economic development on electricity supply and demand. The analysis combines a simulation of current utility plans with a least cost optimisation to meet the remainder of supply needed over the long term. The analysis shows that the underlying socio-economic drivers of demand lead to both a dramatic increase in total electricity demand and a shift across sectors and countries within the region. Total electricity demand for the Southern African Power Pool (SAPP) region increases by 8-14 times over period from 2010 to 2070, with the combined demand from the rapidly growing countries of Democratic Republic of Congo (DRC), Mozambique and Zambia becoming larger than South African demand by 2070. At the sectoral level, the share of total demand from the extractive and manufacturing sectors increases from 59% in 2010 to 70% in 2070 under the most optimistic development scenario, based on a compound annual growth rate of consumption in excess of 5%. Activity level growth is the main driver of demand growth. Comparison with other studies in the region show that the mid-term demand estimates (e.g. 2025-2030) in this study are generally within the range of other research, with somewhat higher demand estimates from the most optimistic development scenario. Total electricity supply required over the longer term is met through the addition of 400-1400 GW of new capacity, or 8-20 times the current capacity of the region. More strikingly, the power mix shifts from almost 80% coal-fired power to 24-44% coal by 2070, with the balance being supplied mainly by solar, wind, hydropower and nuclear generation. The regional shift is no less dramatic, with South Africa's share of total generation declining from 84% to only a third, based on the higher growth rates in countries such as DRC, Mozambique and Zambia. The third research question is the most important in terms of the original contribution of this PhD thesis. Applying the WEAP and LEAP tools to an integrated multi-country system is a methodological advance pioneered in this thesis, showing that the integrated methodology can provide information to address not only the immediate questions about generation choices under an uncertain future climate, but also system costs and GHG emissions. The analysis shows that the reduction in hydropower generation under a drying climate leads to a shift in both capacity expansion choices and the operation of the regional power system, while the increases in hydropower output under a wetting climate are smaller. In other words, the "downside" of future climate changes is larger than the potential "upside". At an aggregate level, the increases in generation costs are a small share of total generation costs (i.e. less than 1% over the full study period compared to the baseline climate). However, the impact on generation costs for hydro-dependent countries such as Mozambique, Zambia and Zimbabwe is considerably larger, and these countries also gain more under a wetting climate. Finally, because some hydropower could be displaced by coal, regional GHG emissions could increase by more than 6 MtCO2 per year in the medium term, or the equivalent of a large coalfired power station. This research has important policy implications for the water and electricity sector in the region. The potential transformation of the electricity supply sector would require a fundamental shift in resource use, grid management and infrastructure development in the region. The shift in the resource base for electricity generation will pose challenges for grid integration and balancing supply and demand across countries and load centres. Historically, the development of transmission capacity, and the resulting trade in electricity, has been constrained by the political and economic realities of the region. There are signs that the politics could be shifting, however, for political, economic and environmental reasons. In addition, the relatively low consumption of water in the Zambezi River Basin in the past meant that explicit trade-offs across sectors and across countries posed less of a challenge for the basin overall. This is very likely to change in the future, as increased demand from all sectors, and major potential changes in climate will require more explicit agreements across both countries and user groups on how best to utilise a limited resource. This research demonstrates the tools that could be used to integrate both climate change and upstream development demands into the feasibility studies before investment decisions are made. The research also illustrates the first steps toward integrating climate change and upstream development considerations into national and regional electricity planning. The electricity and water sectors are important contributors to the development of the Southern Africa, and hydropower in the ZRB lies at the intersection of these fields. Climate change, however, has the potential to add increased stress on these sectors, both directly and indirectly, and yet is not being considered in many individual hydropower power investments, or in national or regional electricity planning. The integrated scenario analysis approach in this thesis demonstrates how the impacts of climate change, as well as increased irrigation demand for water, could be assessed not only for specific hydropower plants and for the entire sector power sector. Preparing for this possible range of future climates can increase the resilience of the sector and reduce the risk of stranded assets in the power sector.
219

Fear and serenity in a changing climate: emotional reactions to climate exacerbated commons dilemmas

Sugrue, Peter M. 13 January 2021 (has links)
The climate change mitigation targets to maintain a relatively stable climate may not be met. Even if targets are met, substantial climate change could occur. In a changing climate, how can social science facilitate composed decision making? One way is through studying emotional reactions to a changing climate. Therefore, this thesis examined how engagement with climate catastrophe scenarios influenced various emotions. Relative to other conditions, “negative” emotions (e.g., fear) were predicted to increase in scenarios related to climate change, and “positive” emotions (e.g., serenity) were predicted to decrease in the same scenarios. Participants engaged with one of five conditions, four of which reflected environmental effects (e.g., local harmful effect from climate change). Before and after condition engagement, participants took a questionnaire of specific emotions. Conditions that described environmental harm were associated with large decreases in “positive” emotions (e.g., serenity) compared to other primes. However, they were not consistently associated with “negative” emotions (e.g., fear). Conversely, qualitative responses frequently mentioned increases in feelings of “fear” or “sadness”; however, decreases in emotions like “calmness” were rarely mentioned. Error played some role in emotional measurement. Nonetheless, psychological research about climate change may include a blind spot: focusing on emotions that are provoked by climate change while ignoring emotions that are depleted by it. A decrease in a “positive” emotion (e.g., calmness) may be conceptually distinct from an increase in an assumed “negative” counterpart (e.g., fear). What are the implications of this distinction? Does avoidance of climate change stem from fear of the subject, or more from its perception as a “buzzkill”? Overall, research of emotional reactions to climate change could facilitate engagement, mitigative behavior, contingency planning, and a more composed transition in a changing climate. / Graduate
220

Invasive architecture: Post-preservationist design for shifting ecologies & fragile landscapes

January 2017 (has links)
In the next century, the world’s ecosystems are going to change dramatically. Within the Mississippi Delta, shrinking swamps, degraded wetlands, and invasive species of current day southern Louisiana will only continue to evolve. Plant distribution and range, weather patterns and storm frequencies, and uncontrollable growth of weeds are expected to have a huge impact on our environment. Weeds, any non-planned plant, are expected to grow more fiercely with rising levels of pollution, a warmer climate, and higher CO2 levels. Some consider weeds as being at the heart of environmental ruination; they must must be eradicated and they must be destroyed. Arguably, human impact plays a more significant role concerning the integrity of the environment. These are constructed and now changing ideas surrounding nature. In many cases, weeds and invasive species are detrimental. But these plants are also perfectly acclimated to their surroundings, offering the opportunities of phytoremediation, erosion control, storm water control, and even habitat creation with no use of resources and at no monetary cost. The Louisiana landscape has been irrevocably changed through geographical and climatic processes as well as human intervention. Its permanent transformation is expected with not only its shifting ecology but rising sea levels, erosion, and saltwater intrusion. Complete submersion is imminent in the next few centuries. Like the act of keeping New Orleans dry, there is tension between releasing human control over larger environmental systems and saving what we know and understand. Rather than working against nature, an architecture of awareness and acknowledgement of present circumstances and an anxious future can be established. This thesis seeks to investigate the evolving landscape of the future Louisiana coast through the design of a mutually beneficial system that is conscious of both the destruction and benefits of invasive plants. How can the existing and expected landscape occupants be productive and useful? How can the elements that make southern Louisiana so special be adapted for our changing ecologies? And what is the role of architecture in an evolving landscape on the brink of collapse? This thesis hopes to illuminate the ways in which something (sometimes seemingly) destructive can be positive, productive, and conscious. Considering shifting ecologies, how can architecture merge with the new landscapes and adapt to our present preservation needs now and environmental concerns in the future? / 0 / SPK / specialcollections@tulane.edu

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