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Global warming and climate change have been identified as strategic issues for South Africa, which as a developing country is more vulnerable to climate change and have less capacity to deal with the impact. This research investigates the contribution of the South African cement industry to greenhouse gas emission and how the Clean Development Mechanism can be used towards sustainable development and climate change mitigation measures. A review of the South African cement industry was done through documentary research. The research was directed in consultation with a network of industry experts. Data from various sources was interpolated to quantify greenhouse gas contributions. The results from a qualitative analysis of the registered cement-sector Clean Development Mechanism project portfolio were used to identify opportunities for using the mechanism in climate change mitigation initiatives. The cement industry contributes less than two percent of greenhouse gas emissions in South Africa. As this is not significant, greenhouse gas emission reduction projects and sustainable development are driven mostly by public concerns, corporate responsibility and rising cost of fossil fuels. Opportunities for Clean Development Mechanism projects lie in waste utilisation as alternative fuel and raw materials and in improved energy-efficiency by retrofitting appropriate technology. The main constraints are the lack of capacity to initiate and implement projects, restrictive legislation for project approval and transaction costs. / Dissertation (MBA)--University of Pretoria, 2010. / Gordon Institute of Business Science (GIBS) / unrestricted

Clouds play an important role in the earth's energy budget, and changes in their properties can remarkably impact the amount of warming in response to greenhouse gas increases. In this study, we applied the Coupled Feedback Response Analysis Method (CFRAM) to estimate the contributions of cloud property changes to the magnitude of the annual mean-surface temperature response in a transient simulation where CO2 increases at rate 1% yr-1 , using the NCAR Community Climate System Model, version 4 (CCSM4). To examine closely the contributions of changes in cloud properties to the annual mean-surface temperature, the full-cloud level is divided into three levels in terms of the cloud-top pressure (CTP). This study found that the annual and global mean-surface temperature response is a warming of (+0.175 oK) due to the net cloud feedback that comes mainly from the positive SW cloud feedback. The medium (400 < CTP < 700 mb) clouds changes are the dominant contributors (+0.175 oK) to the surface warming due to their magnificent positive SW cloud feedback (+0.33 oK). High (CTP < 400 mb) clouds changes cause a weak negative contribution (-0.0218 oK) to the surface warming because of the close cancellation between their large negative SW and large positive LW high-cloud feedbacks. Low (CTP > 700 mb) cloud changes are the least contributors to SW and LW cloud feedbacks (positive SW and negative LW); however, they still contribute positively (+0.0217 oK) to the net cloud feedback with an absolute magnitude that is almost equal to the contribution of the high-cloud changes. Furthermore, this study found that the annual mean-surface temperature increases in the Polar Regions (60o-90o in both hemispheres) are due to the positive LW cloud feedback from the changes in the three cloud levels, mostly due to positive LW medium-cloud feedback. However, the annual mean surface warming for the region covered between (60o S-60o N) is due to the positive SW low- and medium-cloud feedbacks. / A Thesis submitted to the Department of Earth, Ocean, and Atmospheric Science in partial fulfillment of the requirements for the degree of Master of Science. / Fall Semester, 2014. / November 13, 2014. / CFRAM, Climate Change, Cloud Effect, Cloud Feedback, Cloud Properties, surface warming / Includes bibliographical references. / Ming Cai, Professor Directing Thesis; Guosheng Liu, Committee Member; Zhaohua Wu, Committee Member.

Climate feedback mechanisms are known to substantially affect the surface temperature response to an external forcing. This study aims to advance our physical and quantitative understanding of forcing and feedback contributions to the surface temperature response to an external forcing. The dissertation begins with a comprehensive overview of the climate feedback concept and the frameworks used to interpret the effects of forcing and feedbacks on surface temperature. The climate feedback-response analysis method (CFRAM), a relatively new climate feedback framework whose advantages over the traditional climate feedback analysis framework are delineated, is then used to study the seasonal surface temperature response to a doubling of CO2 in a global warming simulation of the NCAR CCSM4. This allows us for the first time to explain the major features of the seasonal warming structure quantitatively. Polar regions, for example, experience the largest warming and the greatest seasonal variation, with maximum warming in fall/winter and minimum warming in summer. In summer, the large cancelations between the shortwave and longwave cloud feedbacks and between the surface albedo feedback warming and the cooling from the ocean heat storage/dynamics feedback lead to a warming minimum. In polar winter, surface albedo and shortwave cloud feedbacks are nearly absent due to a lack of insolation. However, the ocean heat storage feedback relays the polar warming due to the surface albedo feedback from summer to winter, and the longwave cloud feedback warms the polar surface. Therefore, the seasonal variations in the cloud feedback, surface albedo feedback, and ocean heat storage/dynamics feedback, directly caused by the strong annual cycle of insolation, contribute primarily to the large seasonal variation of polar warming. Furthermore, the CO2 forcing, and water vapor and atmospheric dynamics feedbacks add to the maximum polar warming in fall/winter. The CFRAM allows for a process-based decomposition of the temperature response into individual contributions by the forcing and non-temperature feedbacks, which implicitly include the thermal-radiative coupling (i.e., temperature feedback) effects between the surface and atmosphere. To uncover this hidden effect in the CFRAM, this study develops and introduces a method known as the surface feedback-response analysis method (SFRAM) to isolate the temperature feedback effects on surface temperature, allowing for a physical and quantitative understanding of the temperature feedback effects. The temperature feedback effect is found to be the most important contributor to the surface temperature change, accounting for nearly 76% of the global mean surface warming. From the CFRAM perspective, the temperature feedback effect is just the indirect effects of the forcing and non-temperature feedbacks. The SFRAM analysis, in conjunction with the CFRAM results, indicates that in general the indirect effects of the forcing and non-temperature feedbacks on the surface temperature change are larger than the direct effects; thus demonstrating the influence and strength of the temperature feedback effect in the CFRAM results. By isolating the temperature feedback loop, an understanding of why the indirect effects are generally larger than direct effects is achieved. The SFRAM also serves as a bridge to the traditional TOA feedback analysis. A comparison of the SFRAM results with those of the traditional TOA feedback analysis indicates the largest disparity in interpretation is given for the lapse-rate feedback, which is shown to just stem from a misinterpretation of the temperature feedback effects on surface temperature. A better and more intuitive explanation is achieved through the surface perspective of the SFRAM than the TOA perspective of the traditional feedback analysis. A reconciliation of the surface and TOA perspectives is achieved once the temperature feedback effects are included with the effects of the forcing and non-temperature feedbacks, as in the CFRAM analysis. / A Dissertation submitted to the Department of Earth, Ocean, and Atmospheric Science in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Fall Semester, 2014. / October 28, 2014. / carbon dioxide, climate feedbacks, global warming, surface temperature, temperature feedback / Includes bibliographical references. / Ming Cai, Professor Directing Dissertation; Xiaoming Wang, University Representative; Robert G. Ellingson, Committee Member; Philip Sura, Committee Member; Zhaohua Wu, Committee Member.

This dissertation includes a series of studies that present innovative methodologies to improve tornado risk and vulnerability assessments. Limitations of the historical tornado dataset are well known and relate to inconsistencies in data collection procedures, rating assessments, updates in technology, and public awareness. The limitations make it difficult to accurately evaluate tornado risk and vulnerability. Thus, the research presented in this dissertation aims to 1) improve tornado risk assessments using the historical dataset by accounting for known non-meteorological factors and 2) enhance tornado vulnerability assessments by utilizing a new dataset containing more precise damage survey data. This work includes three individual studies, two focused on risk and one on vulnerability, using different geographic scales. Tornado occurrence rates computed from the available reports are biased low relative to the unknown true rates. A method to estimate the annual statewide probability of getting hit by a tornado improves this low bias by using the average report density as a function of distance from nearest city center. The method is demonstrated on Kansas and then applied to 15 other tornado-prone states from Nebraska to Tennessee over the period 1950--2011. The adjusted rates are significantly higher than the raw rates and thus, the return periods are less than previously thought (closer to 1000 years). The expected annual number of people exposed to tornadoes has also increased for every state. The evaluation of tornado occurrences is improved using a statistical model that produces a smoothed regional-scale climatology. The model is applied to data aggregated at the county level, including annual population, annual tornado counts, and an index of terrain roughness. The model has a term to capture the smoothed frequency relative to the state average and is used to examine additional hypotheses concerning relationships of tornado activity with terrain roughness and County Warning Area. Tornado reports are found to increase by 13\% for a two-fold increase in population across Kansas after accounting for improvements in rating procedures. The pattern of spatially correlated errors also shows Kansas tornado activity to be consistent with the dryline climatology. The model is significantly improved by adding terrain roughness, which has a negative relationship with tornado activity and its flexibility is demonstrated by fitting it to data from Illinois, Mississippi, South Dakota, and Ohio. Advancements in technology have improved the collection of tornado damage survey data which can be used to enhance vulnerability assessments. The National Weather Service (NWS) Damage Assessment Toolkit (DAT) contains the most extensive GIS-based damage survey data available to the public which provides more precise damage path areas. These data are used with socioeconomic data in two statistical models. The models are developed to determine which factors are significant predictors of the incidence and magnitude of casualties while accounting for maximum EF Scale rating, total path area, and population density at the storm level. Percent unemployment is a significant predictor and produces the best model for the incidence of at least one tornado casualty. Although percent elderly generates the best model for predicting the magnitude of casualties, it is only marginally significant and its relationship is negative. The Southeast has the highest averages of the sensitivity factors considering all of the tornado events. These results highlight the need for heightened tornado awareness and preparedness as our exposure to these events increases due to our population continuing to expand. As demonstrated in this work, these methods can be used to enhance regional/local tornado forecasts, insurance risk estimates, public policy, urban planning, and emergency management and mitigation with the detection of spatiotemporal patterns in tornado activity (due to variations in climate) and vulnerability (due to changes in population demographics and urban sprawl). They can be employed to examine other geographic locations on multiple scales. They can also be adapted to study the patterns and relationships of other spatial and temporal phenomena. / A Dissertation submitted to the Department of Geography in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Spring Semester 2016. / April 8, 2016. / Climatology, Risk, Statistics, Tornadoes, Vulnerability / Includes bibliographical references. / James Elsner, Professor Directing Dissertation; Robert Hart, University Representative; Christopher Uejio, Committee Member; Stephanie Pau, Committee Member; Lorilee Medders, Committee Member.

This dissertation seeks to understand physical processes in submerged and dry caves in Florida. First, for submerged caves, we prove the possibility of an upward saline water intrusion due to the Venturi effect occurring in a submerged cave's restrictions, i.e. narrow connections between two otherwise large tunnels. A model is developed to obtain an analytical solution for estimating the saltwater discharge through caves into freshwater aquifers. Additionally, Florida springs are examined, and the saltwater discharges due to the Venturi effect are calculated to be between 0.02 to 0.23 m3/s, which is significant especially for the springs with a mean annual freshwater discharge of less than 10 m3/s. Second, in an effort to develop a deeper understanding of dry caves, the microclimate of the so-called Dragon's Tooth Cave is examined. The ventilation patterns are analyzed by using in-situ measurements of temperature, CO2, and Radon-222. Estimated cave air renewal times vary from 2.4 days at the Entrance room to 6.6 days at the Dragon's Belly room. Next, a theoretical model is developed that uses outside temperatures to predict ventilation rates. Combined with simple first-order CO2 and Radon-222 mass balances, the model predicts net CO2 and Radon-222 concentrations in the cave, and shows an excellent agreement with the measurements. / A Dissertation submitted to the Geophysical Fluid Dynamics Institute in partial fulfillment of the Doctor of Philosophy. / Fall Semester 2016. / November 8, 2016. / Dry Caves, Karst, Submerged Caves, Ventilation / Includes bibliographical references. / Nicholas Moore, Professor Co-Directing Dissertation; Ming Ye, Professor Co-Directing Dissertation; Christopher Tam, University Representative; Markus Huettel, Committee Member.

In 2015, Pope Francis published his second encyclical entitled Laudato Si’: On Care for Our Common Home. The encyclical’s primary purpose was to address the widespread inequality, poverty and injustice that threatens to worsen as we begin to see the effects of global climate change. Pope Francis’s entreaties to care for the earth as our home, and for the those left vulnerable due to environmental crises, can be connected to a tradition of hospitality that has a long history in Christian theology. My research aims to answer the questions: What would an ethic of environmental hospitality look like? And is the rhetoric of hospitality useful when coming up with solutions to the ecological and cultural crises arising as a result of global climate change? In answer to the first question, there is some scholarship in environmental ethics that comes very close to advocating for hospitality when dealing with issues of biodiversity and habitat loss, climate refugees, resource scarcity, and other future ramifications of global warming. A recontextualization of God as host, nature as a home, and humanity as guest differs from the stewardship model of environmental ethics in that the misuse of nature is no longer simply a form of mismanagement, it is now an act of inhospitality, a breach of an ancient and fundamental relational bond, that of host and guest. Beyond rhetoric, hospitality can function as a practical avenue for action and change in humanity’s treatment of each other and of nature, moving toward systems that value care, restoration, and generosity. My hope is that this research adds definition and shape to the discourse of environmental hospitality. / A Thesis submitted to the Department of Religion in partial fulfillment of the requirements for the degree of Master of Arts. / Summer Semester 2018. / June 28, 2018. / Christianity, Climate Change, Environmentalism, Ethics, Hospitality / Includes bibliographical references. / Aline Kalbian, Professor Directing Thesis; Martin Kavka, Committee Member; Michael McVicar, Committee Member.

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Thesis submitted in fulfilment of the academic requirements for the degree of Doctor of Philosophy School of Geography, Archaeology and Environmental Studies University of the Witwatersrand, Johannesburg October 2015 / The eastern Lesotho highlands observe climate patterns distinct from adjacent lower altitude regions, representing a niche environment with unique biodiversity, comprising well-adapted but restricted biomes. With a heavy reliance on subsistence agriculture, Lesotho faces risks to both the economy and individual livelihoods, should current rates of climate change persist or intensify. Furthermore, eastern Lesotho serves as southern Africa’s primary water catchment, with precipitation exceeding evaporation. Any changes in the climate and hydrological systems, as are likely under climate change scenarios, would compromise biomes, livelihoods, and water security both locally and regionally. Climate change research in eastern Lesotho, is thus of particular value, yet meteorological data are sparse and the palaeoenvironmental history remains poorly resolved. This research presents the first multi-proxy Holocene palaeoenvironmental and palaeoclimatic reconstruction for eastern Lesotho. This reconstruction is developed from the results from pollen, diatom and sediment analyses, extracted from sediment cores obtained from two peat bogs at Sani Valley (~2,800 m.asl) and Mafadi Wetland (~3,390 m.asl), and from an exposed gully-sidewall profile at Sekhokong (~2,950 m.asl), approximately 1km south of the Sani Valley site. The reconstructions are temporally constrained by AMS radiocarbon dates obtained for all three sites. Mafadi Wetland demonstrates marked differences to the lower altitude sites, including slower sedimentation rates, a decrease in pollen and diatom taxa diversity, and an increase in the relative abundance of ice-tolerant diatom taxa. The microtopography of the three sites influences the rates of sedimentation, sediment properties, pollen composition, and distinct palaeoenvironmental and palaeoclimatic reconstructions for each site. The Sekhokong record commences in the late Pleistocene, with a wet period from ~13,180-10,850 cal. yr BP, interrupted by a dry period from ~13,080-12,830 cal. yr BP. From ~10,550-6,420 cal. yr BP, the Sekhokong record indicates a drier climate with a slow transition to warmer, wetter conditions. The Mafadi Wetland record commences with cold, wet conditions from ~8,140-7,580 cal. yr BP, followed by a warmer, drier period from ~7,520-6,680 cal. yr BP. Thereafter, greater microclimatic differences are apparent. For Sekhokong, warmer, dry conditions are inferred for ~6,420-6,000 cal. yr BP, followed by cold, wet conditions from ~6,000-5,450 cal. yr BP. Warmer, dry conditions commence earlier at Mafadi Wetland, from ~6,160-5,700 cal. yr BP, coinciding with the initiation of a longer wet period at Sani Valley, from ~6,200-4,900 cal. yr BP. At Sekhokong, a dry, warmer period follows from ~5,450-3,700 cal. yr BP. At Sani Valley, drier conditions are evident from ~4,770-4,470 cal. yr BP, followed by a cold, wet period from ~4,460-2,260 cal. yr BP. For Mafadi Wetland, these cold, wet conditions endure longer, from ~5,600-1,100 cal. yr BP. This overlaps with similarly cool, wet conditions at Sekhokong, from ~3,650- 1,200 cal. yr BP. By contrast, dry conditions are evident at Sani Valley, from ~2,260-1,350 cal. yr BP. For all three sites, ~1,000 cal. yr BP to present is characterised by progressive drying, with discrete wet events. Pronounced cold events are detected at ~12,660 cal. yr BP, ~8,400-8,000 cal. yr BP and ~150 cal. yr BP. The results of this study indicate similarities with records from adjacent studies in western Lesotho and South Africa, although with notable variability in the timing of events. The palaeoenvironmental reconstructions for eastern Lesotho, and their comparison with existing studies, provide valuable information to improve the understanding of southern African Holocene climates, and to facilitate the development of high resolution, accurate climate models for the eastern Lesotho region.