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Assessing Seychelles' vulnerability and adaptation to a historical landslide disaster through archival researchSomers, Rabia January 2017 (has links)
A research report submitted to the Faculty of Science, University of the
Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the
degree of Master of Science.
5 June 2017 in Johannesburg / Global climate change and its related actual and potential impacts to society has
called for studies that look to the past to better understand historical climate
trends and how they may inform future climate trends. Specific in this area of
research is environmental histories, wherein information on historical climate
events and disasters are retrieved from historical documentary sources, i.e.
archives, in order to study the potential causes and effects of these occurrences,
as well as levels of vulnerability and resilience through the analysis of coping and
adaptation strategies of societies. / MT 2017
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Marine biofouling organisms respond to multiple stressors in a changing climateHou, Huiyi, 侯慧仪 January 2013 (has links)
The marine environment is likely to experience profound climate change in the coming 100 years and beyond. Ocean acidification (OA) is one of the climate change issues attracting the attention of researchers all over the world. The decreasing pH of the oceans might threaten marine biofouling organisms. However, climate change is not only involved with ocean acidification (OA) but the change of other environmental variables, such as temperature and salinity. These environmental factors act as multiple stressors and synergistically affect shell-forming biofoulers, in which, the calcium carbonate skeleton structure plays an important role of protection. Previous studies regarding the response of marine biofoulers to the environmental stressors were generally summarized in this article. Then a calcifying biofouling tube worm, Hydroides elegans, were reared from larval stage to early juvenile stage under control and treatment conditions to examine the combined effects of temperature (24, 30°C), pH (8.1, 7.7) and salinity (34, 27ppt). Juvenile growth and chemical composition (Mg/Ca and Sr/Ca) of their calcareous tubes were tested and used as assessment of effects of the three environmental stressors. The experiment revealed that H. elegans was robust to the environmental change because juvenile development positively responded to temperature and the interaction between temperature and salinity. Other combinations did not exert significant effect. The results suggest the need of further study of proteomics and transcriptomics to reveal the mechanisms of calcification as well as long-term studies to examine the energy costs of adaptation. In addition, the non-significant chemical composition (Mg/Ca and Sr/Ca) of the tube of this organism suggest a need of further exploration of the same animal but not only focus on three factors but the seawater chemical composition as well. / published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management
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Climatic change and Chinese population growth dynamics over the last millenniumLee, Fung, 李峰 January 2007 (has links)
published_or_final_version / abstract / Geography / Doctoral / Doctor of Philosophy
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Assessing species' vulnerability to climate changeFoden, Wendy Bernardina 06 May 2015 (has links)
A thesis submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy. Johannesburg, 2014. / Climate change (CC) is expected to have profound impacts on biodiversity, but predicting these remains a major scientific challenge. Current approaches to quantifying such impacts focus largely on measuring exposure to CC, ignoring the biological traits that may significantly increase or reduce species’ vulnerability. In addition, their input requirements restrict use to wide-spread and better-studied species, creating taxonomic and geographic biases in global CC vulnerability estimates.
To address this, I developed a framework which draws on both biological traits and exposure modelling to assess three dimensions of CC, namely exposure, sensitivity and adaptive capacity. In the first fully-representative study of entire taxonomic groups, my collaborators and I applied this framework to each of the world’s birds, amphibians and corals (16,857 species). Results identify the Amazon as an area of high concentration of CC vulnerable birds and amphibians, and the central Indo-west Pacific (Coral Triangle) for corals. Comparisons with species’ IUCN Red List threat statuses reveal species and regions both of new and greatest overall priority for conservation globally.
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Towards a multi-proxy holocene palaeoenvironmental and palaeoclimatic reconstruction for Eastern LesothoFitchett, Jennifer Myfanwy 20 January 2016 (has links)
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.
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Stakeholder driven research in a hydroclimatic contextHartmann, Holly Chris. January 2001 (has links)
Stakeholder driven research has been advocated to link hydroclimatic research with the needs and capabilities of groups affected by climatic variability and related governmental policies. A stakeholder driven research agenda was designed, focusing on hydroclimatic forecasts and their assessment, within the context of an interdisciplinary integrated assessment of the vulnerability of diverse stakeholders to climate variability in the U.S. Southwest. Water management, ranching, and wildland fire management stakeholders were solicited for their input. Their perspectives about hydroclimatic variability and opportunities for using hydroclimatic forecasts differed widely. Many individuals were uninformed or had mistaken impressions about seasonal hydroclimatic forecasts, but understood practical differences between forecasts for "normal" conditions and "nonforecasts" having total uncertainty. Uncertainty about the accuracy of forecasts precludes their more effective use, as does difficulty in distinguishing between "good" and "bad" information. A survey of hydroclimatic forecasting confirmed stakeholder perceptions and identified improvements in hydrologic predictability that could be rapidly incorporated into current operations. Users faced a complex and evolving mix of forecasts available from many sources, but few corresponding interpretive materials or reviews of past performance. Contrasts between the state of meteorologic and hydrologic forecasting were notable, especially in the former's greater operational flexibility and more rapid incorporation of new observations and research products. The research agenda uses predictions as the linkage between stakeholders and scientific advances in observations (e.g., snow conditions) or process understanding. The agenda focuses on two areas: (1) incremental improvement of seasonal water supply forecasts, and (2) improvement of stakeholder perceptions of forecasts through ongoing forecast assessments. A forecast evaluation framework was developed that provides consistency in assessing different forecast products, in ways that that allow individuals to access results at the level they are capable of understanding, while offering opportunity for shifting to more sophisticated criteria. Using the framework, seasonal temperature and precipitation outlooks issued by the National Weather Service were evaluated, considering regions, lead times, seasons, and criteria relevant to different stakeholders. Evaluations that reflect specific user perspectives provide different assessments of forecast performance. Frequently updated, targeted forecast evaluations should be available to potential users.
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Influence of climate change and variability on Coffea arabica in the East African highlandsCraparo, Alessandro January 2017 (has links)
A thesis submitted in fulfilment of the requirements for the degree of
Doctor of Philosophy (Agroclimatology) at the University of Witwatersrand, 2017. / Plant development is inherently linked to meteorological variability. The phenology, distribution and production of crops and wild relatives has already altered in response to climate change. Recent years have produced the warmest mean annual global temperatures since 1880, with 2016 setting the highest record thus far. Such profound changes have sparked investigations into the impact of temperature and rainfall on crop development, particularly those with profound economic importance such as coffee (C. arabica). The crop is a fundamental source of income for smallholder farming communities and governments throughout the tropical highlands. However, the impact of climate change on C. arabica has yet to be quantified using empirical data in East Africa, leaving uncertainty in the cultivable future of the crop. Therefore, the objective of this thesis is to investigate the influence of climate change and variability on C. arabica yields and phenology in East Africa.
Using a spatio-temporal approach, trends and relationships between coffee performance and meteorological variables were analysed at different scales and time periods ranging from the macroclimatic national scale (49 year), to the meso- and microclimatic farm level (3 year) scale, and finally to the microclimatic canopy and leaf level (hourly) scales. Data from all three climatic continua reveal for the first time that temperatures, and particularly rapidly advancing night time temperatures, are having a substantial negative impact on C. arabica yields. Forecasting models based on these biophysical relationships indicate that by the year 2050, smallholder farmers would on average harvest approximately 50% of the yield they are achieving today. Warming night time temperatures are also responsible for advancing ripening and harvest phenology. As a result, bean filling and development time is reduced, thereby potentially resulting in lower quality coffee. Trends in precipitation do not appear to have any substantial impact on C. arabica yields or harvest phenology, however, it is proposed that rainfall would act synergistically with temperatures to influence plant development and other phenological phases such as flowering. Finally, thermography is introduced as a novel complementary technique to rapidly analyse the suitability of different agroecological systems on coffee physiology at the leaf level. High temporal resolution (hourly) data, illustrate the success of the method in variable meteorological and environmental conditions. The findings contribute to advancing the protocol for use at the canopy and plantation level on coffee, so that appropriate microenvironment designs and adaptation mechanisms be put in place to accommodate climatic change.
Avoiding increments in night time temperatures is key to maintaining or improving yields and fruiting development. Farming at higher altitudes and novel agroforestry systems may assist in achieving lower night time temperatures. Importantly, data reveal that careful analysis of various cropping systems, particularly at lower altitudes, is critical for providing suitable microenvironments for the crop. / XL2017
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Tourism and climate change risks : opportunities and constraints in South AfricaReddy, Melissa 06 March 2012 (has links)
M.Sc., Faculty of Science, University of the Witwatersrand, 2011 / Global climate change, often referred to as „global warming‟ is possibly one of the most serious environmental challenges facing the world this century (DEAT, 2004; IPCC, 2007). There have been several studies (e.g. Viner and Agnew, 1999; Higham and Hall, 2005; IPCC, 2007; Midgley et al., 2008) on the potential impacts of climate change on the tourism sector and the likely effects are shown to be extremely wide ranging and may have far-reaching consequences for the tourism sector in many regions and areas of the world.
From a review of the literature it was evident that there was limited literature on the response to climate change by the tourism industry in terms of mitigation, adaptation and long- term strategic planning to manage future anticipated climate change impacts. Given this background, this research explores the tourism industry with regard to game and nature reserves in South Africa and probes the perceptions of climate change amongst park managers and tourism operators to understand their awareness regarding the projected impacts of climate change. Mitigation and adaptation strategies that were in place or being developed in the management of the game and nature reserves are identified and examined. Challenges that were experienced by the tourism managers/operators in promoting effective mitigation and adaptation strategies in the nature based tourism sector in South Africa are highlighted and discussed and recommendations are provided.
Purposeful sampling was employed in the research and the stakeholders were identified according to their important roles in the South African Tourism Industry with regard to game and nature reserve management. These included the Department of Environmental Affairs and Tourism, South African National Parks (SANParks), South African National Botanical Institute (SANBI) and the Provincial Park Managers which comprises the Eastern Cape Parks, Gauteng Department of Agriculture and Rural Development (GDARD), Ezemvelo KZN Wildlife, Limpopo Tourism and Parks Board, Mpumalanga Parks Board, North West Parks and Tourism Board and Cape Nature. The research data was collected using open-ended questionnaires and interviews with the stakeholders.
Results of this research showed that there was a basic understanding of climate change and its associated impacts on tourism consistent with what is being established in the scientific literature. Despite this awareness among relevant stakeholders, there was however not much formal long-term strategic planning or mitigation and adaptation plans in place to manage or „manage‟ the suggested projected impacts of climate change on the tourism industry. The research results also highlighted many challenges experienced by the nature- based tourism sector.
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Climate Change Adaptation Planning for Cultural and Natural Resource Resilience: a Look at Planning for Climate Change in Two Native Nations in the Pacific Northwest U.S.MacKendrick, Katharine 09 1900 (has links)
xii, 172 p. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number. / The literature indicates that for indigenous peoples the environmental impacts of
climate change and some proposed solutions threaten lifeways, subsistence, economic
ventures, future growth, cultural survivability, rights, land ownership, and access to
resources. However, limited understanding and awareness of the vulnerability and
capacity of American Indian and Alaska Native tribes and of climate change impacts at
the local level affect climate policymaking, planning, and equity. Case studies with the
Coquille and Hoopa Valley Indian tribes in the Pacific Northwest U.S. explore the key
considerations in planning for climate change adaptation, particularly for cultural and natural resource resilience. Document analysis and semi-structured interviews offer
insight on the risks the tribes face and the role of traditional and local knowledge and
experience in planning for climate change adaptation. Conclusions offer information
useful in planning for climate impacts, local-level climate adaptation research, and
climate policy development at the local to global levels. / Committee in Charge:
Dr. Michael Hibbard, Chair;
Dr. Cassandra Moseley;
Kathy Lynn
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Climate change risk communication and asset adaptation of indigenous farmers in the Delta State of NigeriaEbhuoma, Eromose Ehije January 2017 (has links)
A thesis submitted to the Faculty of Science, School of Geography and Environmental Studies, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy. Johannesburg, October, 2017. / The purpose of this study was to examine how subsistence farmers in the Delta State of Nigeria employed their asset portfolios i.e. human, financial, social, natural and physical capitals to build their adaptive capacity and resilience to climate variability and change. The study was also interested in understanding the extent to which climate change risk communication facilitated the protection and adaptation of subsistence farmer’s assets in the face of extreme weather warnings.
Primary data were obtained using the Participatory Climate Change Adaptation Appraisal (PCCAA), which comprises both the asset vulnerability analytical and the asset-based adaptation operational frameworks. The systems thinking approach, together with the asset vulnerability analytical framework were also used as an operational vulnerability framework to highlight the myriad factors undermining the rural poor from maximising their asset portfolios during food production. Focus group discussions and semi-structured interviews facilitated the use of the PCCAA tools.
Meteorological data reinforced subsistence farmer’s perception (62%) that there has been an increase in temperature within the last decade, which have adversely affected on groundnut production. The farmers (92%) also listed heavy rainfall event and flooding as a climatic variable that impede their ability to produce cassava throughout the year. This is because their farmlands, which are generally low-lying, are always inundated for approximately four months every year. Nonetheless, the farmers still engaged in cassava production annually by adopting a strategy indigenously referred to as elelame (follow-water-go).
It is important to mention that in spite of the rapidly changing climate, the subsistence farmers did not rely on Seasonal Climate Forecast (SCF) in order to determine the appropriate time to grow their food. Instead, they relied on their Indigenous Knowledge
Systems (IKS) not limited to cloud observations, croaking of frogs and peculiar sounds made by the swamp chickens. However, the farmers acknowledged that their IKS have not been as reliable as it has always been in the past decades. Nonetheless, the farmers underlined being misled by an inaccurate scientific forecast in 2013 and, a lack of trust in the source of the forecast are some of the reasons they continue to rely primarily on IKS.
With climate change expected to continue occurring at unprecedented levels in Nigeria, it is crucial to build subsistence farmers trust in SCF while simultaneously not undermining the value of their IKS. This is because there is growing consensus that if subsistence farmers continue to rely on IKS alone, the key assets that play a huge role in food production will likely be eroded. This will adversely hamper households’ ability to continue obtaining the livelihood they aggressively pursue. Thus, a useful starting point will be to generate a “unified” forecast whereby SCF compensates for the limitations of farmer’s IKS. However, for the unified forecast to make meaningful contributions to the ways in which farmers produce their food and protect their assets in anticipation of an extreme weather forecast, it must be communicated through the various mediums that the farmers rely upon to receive vital pieces of information.
Keywords: Indigenous knowledge systems, seasonal climate forecast, climate change risk communication, Delta State, Nigeria. / LG2018
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