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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.

Climate change projections for Central America: A regional climate model study

Karmalkar, Ambarish 01 January 2010 (has links)
Central America has been identified as one of the regions in the world where potential climate change impacts on the environment can be pronounced and is considered a climate change ‘hot-spot’. The Intergovernmental Panel on Climate Change Fourth Assessment Report indicates that the region around the western Caribbean and Central America is one where a majority of the climate model simulations indicate rather large changes in temperature and precipitation. This region, however, is one with considerable topographic relief, which implies the existence of large gradients in many critical climate variables. The interactions between the complex topography of Central America and the neighboring oceans give rise to numerous climate zones, horizontally and vertically. Consequently, the region has high biodiversity, it harbors high-value ecosystems and it is important to provide more realistic scenarios to assist in adaptation and mitigation work in the region. In this study, I aim to understand climate change in Central America at spatial scales relevant for impacts assessment.^ A regional climate model PRECIS was employed to carry out two experiments: the baseline (present-day) run and the scenario run, both performed at 25-km horizontal resolution. The thorough examination of the model performance showed model’s success in capturing the spatial and temporal variability of the key climate variables and its strength in simulating topographically-induced regional climate features. The projected increase in temperature, a large decrease in precipitation in most of Central America, and corresponding hydrological changes under the A2 scenario may have serious negative consequences on water resources, agricultural activities and the ecosystem dynamics in the region. ^

Barriers and enablers to the adoption of practices to improve crop production and reduce vulnerability to climate risks in the semi-arid Omusati Region,Namibia

Chappel, Angela 11 February 2019 (has links)
Namibia is almost entirely semi-arid or arid. With evaporation rates being higher than precipitation rates, farming conditions are extremely adverse. This is exacerbated by the impacts of climate change, namely increased temperature, decreased rainfall and higher rainfall variability, all of which are projected to worsen in the future. More than half of the population is reliant on rain-fed subsistence agriculture for their source of food but these challenging conditions mean that there is widespread food insecurity across the subsistence farming community in Namibia. This leads to a state of vulnerability and dependence on government support in the form of social grants, food aid and remittances from family members in urban areas. The locus for this study is three villages: Omaenene, Okathitukeengombe and Oshihau, in the north-central Omusati region of Namibia. This research investigated local perceptions of climate change vulnerability, farming practices used in other regions that could reduce this vulnerability and finally barriers and enablers to the uptake of new farming practices. These objectives were answered through the use of a systematic literature review and interviews with the local community. Findings revealed that the local population is already experiencing a hotter and drier climate, which has decreased their yield output. Many farmers are concerned about future climatic changes while some are comforted by support from the government or God. In both of these cases, the farmers are vulnerable because they are not currently adapting or planning to adapt to climate change. Although a majority of the farmers claimed that they are willing to try new farming practices, they are inhibited by: limited access to new information, mistrust of new farming practices as well as insufficient labour and resources. Three adaptive farming practices – planting pits, bunds and composting – aimed predominantly at water harvesting, soil conservation and increasing soil quality were selected by the researcher, from a systematic literature review, as appropriate for the village sites. Some of the social and institutional enablers that could be enhanced to promote the uptake of these practices are: i) support from local authorities and possibly enlisting the help of religious and traditional leaders (including building trust within these networks), ii) enhancing information access predominantly through the radio, iii) explaining the severity of climate change and the value of adaptation practices, iv) establishing self-help labour groups and v) the creation of demonstrations sites. In the face of irreversible climate change, this research aims to contribute to empowering local people to adapt their farming practices to the harmful experienced and predicted impacts of climate change and climate variability.

South Africa's climate change response policy design and implementation at local level: a case of Vhembe District, Limpopo Province, South Africa

Mulaudzi, Gundo 05 1900 (has links)
MENVSC (Geography) / See the attached abstract below

Characterising the role of climate change in perpetuating Zimbabwean farmers' health risks from exposure to endocrine disrupting pesticides

Zinyemba, Cliff 06 November 2020 (has links)
Climate change and endocrine disrupting chemicals are currently amongst key drivers for a range of non-communicable diseases and adverse human health conditions. Pesticides constitute an important source of endocrine disrupting chemicals. A growing public health concern is the potential relationship between climate change and adaptive increases in agricultural pesticide use. Effectively, with increases in pesticide use, there may be increased potential for elevated pesticide exposures and, thus, increased endocrine disrupting health risks. The aim of this thesis was to assess whether climate change is a key risk perpetuating factor for endocrine disrupting health risks due to increased agricultural pesticide uses and exposures. The study was conducted in Zimbabwe with farmers in the cotton farming district of Rushinga. Three research methods: 1) interviews with farmers, 2) quantitative structure-activity relationship modelling and, 3) stakeholder interviews with government cotton agronomists working in Rushinga district who acted as key informants. Qualitative in-depth interviews were conducted with 50 active smallholder farmers who had grown cotton for a minimum of 30 years. The interviews gathered farmers' perceptions and observations regarding climate change, changes in pest types, pest populations, pesticide use patterns, pesticide handling practices, and adaptive practices, amongst others. Quantitative structure-activity relationship modelling was, further, applied in identifying key risk pesticides of concern. Amitraz, endosulfan, fenvalerate and lambda-cyhalothrin were determined as having a high likelihood of acting as endocrine disruptors, as validated by literature highlighting the four pesticides' hormone-related cognitive, physiological and reproductive adverse health effects. Findings indicated that a number of farmers' adaptative practices were found to be incremental and, potentially, maladaptive, thereby enhancing pesticide use and exposure. This was indicative of climate change's potential for perpetuating pesticide-related endocrine disrupting health risks. Opportunities exist, however, for farmers to reduce pesticide use, and, thus, potential endocrine disrupting health risks through certain autonomous transformational adaptive practices, such as crop switching and cotton acreage reduction. Assistance to farmers by the government and development agencies, for enhancing opportunities for transformational adaptation is therefore recommended. Furthermore, there is need, at policy level, for phasing out pesticides with endocrine disrupting properties. There is, furthermore, a clear need for enhancing farmers' access to, and comprehension of, pesticide risk information through various innovative means, including research translation to reduce exposure risks.

Environmental Performance of Multinationals: A Comparative Study Based On Climate Change Strategy

Narayanan, Santhosh 30 June 2014 (has links)
In the context of distinctive international business phenomena of global environmental concern i.e., climate change, this dissertation addresses two research questions. Does multinational enterprise (MNE) orientation (global- or regional-orientation) have an influence on the carbon performance of the multinational? Is there any significant home country effect that drives carbon performance? Stakeholders are increasingly watching the green performance of the firms and investors are looking for information of how firms deal with externalities such as carbon emission. Environmental capabilities are increasingly becoming the core competence of a multinational enterprise. This also enables the MNE to be an active entity and play a key role in global environmental governance. Defining carbon performance as the capability of firms to integrate climate change strategy into the overall strategy, this dissertation used resource-based view and institutional theory as the theoretical framework along with the concept of regionalization of firms. We argue that differences in integrating strategy to reduce carbon emission (carbon performance) are related to MNE orientation and home country effect. Using a sample of 324 firm-years drawn from the carbon disclosure project reports 2011, 2012, and 2013, we analyzed the data running a logistic regression. We found that global-oriented MNEs had better carbon performance compared with regional-oriented MNEs (p This result was against the hypothesized relationship. One of the reasons for this result could be projected good image by the firms in environmentally non-sensitive industries because of cost advantage. Lower environmental institutional distance between home and host country of a firm increased the likelihood of its carbon performance regardless of its orientation as global or regional (p

Urban climate adaptation as a process of organisational decision making

Taylor, Anna January 2017 (has links)
In a world that is increasingly urbanised, cities are recognised as critical sites for tackling problems of climate change, both by reducing greenhouse gas emissions and addressing the impacts of changing climate conditions. Unlike climate change mitigation, adaptation does not have one clear, commonly agreed collective goal. Governing and making decisions on climate adaptation in cities entails contestation over knowledge, values and preferences. Currently, the two dominant conceptualisations of adaptation are as cycles or pathways. Do these models adequately theorise what can be empirically observed in cities as to how climate adaptation is undertaken? Most research on urban climate adaptation emanates from the Global North, where political, scientific, economic and administrative systems are well established and well resourced. There is a dearth of empirical research from cities of the Global South contributing to the development of urban climate adaptation theory. This thesis contributes to addressing this gap in two ways. Firstly, by drawing on both conceptual and methodological resources from the field of organisational studies, notably the streams and rounds models of decision making, organisational ethnography and processual case research. Secondly, by conducting empirical case study research on three processes of city scale climate adaptation in Cape Town, South Africa, a growing city facing many development challenges where the local government began addressing climate adaptation over ten years ago. The three adaptation processes studied are: the preparation and adoption of city-wide sectoral climate adaptation plans; the creation of a City Development Strategy with climate resilience as a core goal; and the inclusion of climate change projections into stormwater masterplans. Data were gathered through interviews, participant observation, focus groups and document review, through embedded research within a formal knowledge co-production partnership between the University of Cape Town and the City of Cape Town government. Processual analysis and applied thematic analysis were used to test models of adaptation and decision making against data from the three case studies. The findings suggest that both the cycles and pathways models of climate adaptation inadequately represent the contested and contingent nature of decision making that prevail within the governance systems of cities such as Cape Town. Based on ethnographic knowledge of how Cape Town's local government undertakes climate adaptation, it is argued that the rounds model of decision making provides conceptual tools to better understand and represent how the process of climate adaptation in cities is undertaken; tools that can be used to enhance the pathways model. The study concludes that progress in adapting cities to a changing climate is currently constrained by both the problems and potential solutions or interventions being too technical for most politicians to deal with and prioritize and too political for most technical and administrative officials to design and implement. It calls for urban climate adaptation to be understood as distributed across a multitude of actors pursuing concurrent, discontinuous processes, and thereby focus needs to be on fostering collaboration and coordination, rather than fixating on single actors, policies, plans or projects.

Sensitivity of a global climate model to the urban land unit

Bogart, Tianna A. 06 December 2013 (has links)
<p> With more than half of the world's population living in urban areas, it is important that the relationships between the urban environment and climate are better understood. The current research aims to continue the effort in assessing and understanding the urban environment through the use of a global climate model (GCM). Given the relative newness of the presence of an urban land type and model in a GCM, there are many more facets of the urban-climate relationship to be investigated. By comparing thirty-year ensembles of CAM4 coupled with CLM4 both with (U) and without (U<sub>n</sub>) the inclusion of the urban land type, the sensitivity of the atmospheric model to urban land cover is assessed. As expected, largest differences tend to be in the Northern Hemisphere due to the location of most of the globe's densest and expansive cities. Significant differences in the basic climate variables of temperature and precipitation are present at annual, seasonal, and monthly scales in some regions. Seasonality to the urban influence also exists with the transition months of Spring and Fall having the largest difference in temperatures. Of the eleven regions defined by Oleson (2012), three were most impacted by the presence of urban land cover in the model&mdash;Europe, Central Asia, and East Asia. </p><p> Since urban attributes can vary greatly within one world continent, the sensitivity of regional climates to the urban type parameters is also explored. By setting all urban land cover to only one urban density type, the importance of city composition on climate, even within the same city, is highlighted. While preserving the distinct urban regional characteristics and the geographical distribution of urbanized areas, the model is run with homogeneous urban types: high density and tall building district. As with the default urban and excluded urban runs, a strong seasonality to the differences between the solo-high-density simulation and default urban (U<sub>HD</sub> &ndash; U) and solo-tall-building-district-density simulation and default urban (U<sub>TBD</sub> &ndash; U) exists. Overall, the transition and winter months are most sensitive to changes in urban density type.</p>

Consequences of altered precipitation, warming, and clipping for plant productivity, biodiversity, and grazing resources at three northern temperate grassland sites

White, Shannon R Unknown Date
No description available.

Pond hockey dads and climate change : how Canadian fathers feel about the threat of losing the game they love

Gordon, James 04 May 2012 (has links)
This text/video thesis investigates how Canadian fathers feel about the threat of losing pond hockey, a revered game they love, to climate change. It responds to the David Suzuki Foundation’s (DSF) assertion that under a global ‘business as usual’ rate of producing greenhouse gases, the skating season of the world’s largest ‘rink’--the Rideau Canal--would shrink from a nine week historical average to just one week by century’s end (DSF, 2009a). Seven outdoor-hockey-loving fathers were interviewed, which revealed their willingness to share feelings of concern, sadness, fear, uncertainty, and need for action to mitigate against and adapt to the ill-effects of climate change on this game, and more serious social situations. Despite concerns it was revealed they took few substantial actions against climate change, which they recognized might affect themselves, their children, communities, and future generations. Conversation, at times nostalgic, helped make these issues more salient.

Sedimentary Processes and Environmental Signals from Paired High Arctic Lakes

Cockburn, JACLYN 04 September 2008 (has links)
Suspended sediment delivery dynamics in two watersheds at Cape Bounty, Melville Island, Nunavut, Canada were studied to characterize the hydroclimate conditions in which laminated sediments formed. Process work over three years determined snow-water equivalence was the primary factor that controlled sediment yield in both catchments. Cool springs (2003, 2004) enhanced runoff potential and intensity because channelized meltwater was delayed as it tunneled through the snowpack and reached the river channel (sediment supply) within 1-2 days. In warm springs (2005), meltwater channelized on the snowpack and did not immediately reach the river bed (7-10 days). Sediment transport was reduced because flow competence was lower and sediment supplies limited. Sediment deposition in the West Lake depended on surface runoff intensity. Short-lived, intense episodes of turbid inflow generated underflow activity which delivered the majority of seasonal sediment. In 2005, runoff was less intense and few underflows were detected compared to the cooler, underflow dominated 2004 runoff season. As well, grain-size analysis of trapped sediment indicated that deposition rates and maximum grain-size were decoupled, indicative of varied sediment supplies and delivery within the fluvial system. These decoupled conditions have important implications for paleohydrological interpretations from downstream sedimentary records. Two similar 600-year varve records were constructed from the lakes at Cape Bounty. Although these series were highly correlated throughout, time-dependent correlation analysis identified divergence in the early 19th century. Because the varve records were from adjacent watersheds and subject to the same hydroclimatic conditions, the divergence suggests watershed-level changes, such as increased local active layer detachments. The varve record from West Lake was highly correlated with lagged autumn snowfall and spring temperature. Similar relationships between these variables and East Lake were not as strong or significant. Long-term climatic interpretations should be carefully assessed. A single record from either of these lakes might lead to autumn snowfall and/or spring-melt intensity reconstructions, given the process work and weather record correlations. The recent divergence reveals potential changes likely to occur as warming increases variability within the Arctic System. Multidisciplinary monitoring and observations should continue in order to quantify future variability and evaluate the impact on these systems. / Thesis (Ph.D, Geography) -- Queen's University, 2008-09-02 12:11:53.483

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