Includes bibliographical references / Drought is one of the natural hazards that threaten the economy of many nations, especially in Southern Africa, where many socio-economic activities depend on rain-fed agriculture. This study evaluates the capability of Regional Climate Models (RCMs) in simulating the Southern African droughts. It uses the Standardized Precipitation-Evapotranspiration Index (SPEI, computed using rainfall and temperature data) to identify 3-month droughts over Southern Africa, and compares the observed and simulated drought patterns. The observation data are from the Climate Research Unit (CRU), while the simulation data are from 10 RCMs (ARPEGE, CCLM, HIRHAM, RACMO, REMO, PRECIS, RegCM3, RCA, WRF, and CRCM) that participated in the Regional Climate Downscaling Experiment (CORDEX) project. The study also categorizes drought patterns over Southern Africa, examines the persistence and transition of these patterns, and investigates the roles of atmospheric teleconnections on the drought patterns. The results show that the drought patterns can occur in any season, but they have preference for seasons. Some droughts patterns may persist up to three seasons, while others are transient. Only about 20% of the droughts patterns are induced solely by El Niño Southern Oscillation (ENSO), other drought patterns are caused by complex interactions among the atmospheric teleconnections. The study also reveals that the Southern Africa drought pattern is generally shifting from a wet condition to a dry condition, and that the shifting can only be captured with a drought monitoring index that accounts for temperature influence on drought. Only few CORDEX RCMs simulate the Southern African droughts as observed. In this regard, the ARPEGE model shows the best simulation. The best performance may be because the stretching capability of ARPEGE helps the model to eliminate boundary condition problems, which are present in other RCMs. In ARPEGE simulations, the stretching capability would allow a better interaction between large and small scale features, and may lead to a better representation of the rain producing systems in Southern Africa. The results of the study may be applied to improve monitoring and prediction of regionally-extensive drought over Southern Africa, and to reduce the socio-economic impacts of drought in the region.

In response to the protracted and ineffective international action on the climate change crisis, this study critically considers the potential of building-integrated agriculture (BIA) as retrofitting strategy to improve the climate change adaptation (CCA) capacity of buildings in South African inland cities. Based on a pragmatism paradigm, the study uses a mixed method research design, to evaluate current BIA farms and their efficacy as CCA retrofitting strategies to improve the thermal performance of the local built environment. The exploratory research is structured in three phases. During the first phase the unused and underutilised spaces of Hatfield, a rapidly changing neighbourhood in Tshwane, South Africa, are mapped and defined in terms of their latent climate change adaptation capability. Secondly, the spatial and technological characteristics of the current BIA industry is surveyed through a series of interviews and observational studies. As the final research phase, a specific BIA farm type, passively controlled non-integrated rooftop greenhouses, is assessed in terms of its reciprocal thermal impact on the built environment. As outcome, the research findings reveal a land-use form that can contribute to the climate change adaptation response strategies of South African cities on a spatial level. Unfortunately, the design resolution and technological realisation, specifically the prevalent form currently implemented in Johannesburg and Tshwane, adversely affect both farmers and building occupants during overheated periods. As a result, the study advocates developing and testing contextually appropriate technological solutions in the BIA industry. The study advances the climate change discourse by assessing the performance of BIA farms as constituent entities in networks of small-scaled climate change adaptation projects in resource constrained urban environments. / Thesis (PhD)--University of Pretoria, 2020. / Architecture / PhD / Unrestricted

Marine ecosystems are already threatened by the effects of climate change through increases in ocean temperatures and pCO2 levels due to increasing atmospheric CO2. Marine fish living close to their thermal maximum have been shown to be especially vulnerable to temperatures exceeding that threshold, and even relatively small increases in elevated pCO2 levels have led to behavioral impairments with amplified predation risks. These ongoing threats highlight the need for further understanding of how these changes will impact fish and if any potential for adaptation or acclimation exists. The coral reef fish, Acanthochromis polyacanthus, has been well studied in response to singular environmental changes both through its phenotype and molecular expression profiles within and across generations. However, key questions regarding transgenerational heritability and molecular responses to multiple environmental changes have not been addressed. To further understand A. polyacanthus I examined the mechanisms behind heritability of behavioral tolerance to elevated pCO2 in an attempt to determine the maternal and paternal contributions to this phenotype. There was a strong impact of parental phenotype on the expression profiles of their offspring regardless of environmental exposure. Offspring from both parental pairs expressed mechanisms involved in tolerance to ocean acidification suggesting this phenotype is reliant on input from both parents. Creation of a new proteomic resource, a SWATH spectral library, delivered a closer examination of the link between phenotypic and expression changes. Analysis on different constructed libraries led to the use of an organism whole library combined with study specific data to analyze proteomic changes in A. polyacanthus under the combined environmental changes of ocean acidification and warming. With direct comparisons to transcriptomic changes in the same individuals I identified an additive effect of elevated pCO2 and temperature associated with decreases in growth and development. However, a strong role of parental identity on the expression profiles of offspring reinforced the high genetic variability of this species. This thesis provides novel insights into the heritability of phenotypic traits and the molecular responses to combined stressors in A. polyacanthus, as well as presenting a new resource for proteomic studies in this fish and other non-model species.

>Magister Scientiae - MSc / The need to improve groundwater security remains critical especially in urban areas where demand for groundwater as an alternative source of water supply increases. Declining trends in availability of surface water because of climate change effects further exacerbates problems of water supply shortage to meet the increasing demand for water, hence the need for groundwater sources. The use of hydrogeophysics data and derivative analysis in understanding aquifer dynamics remains limited and poorly understood therefore, the study argues that when hydrogeophysics data and derivative analysis are not used in aquifer characterization, it results in models that are not solution-based and cannot guide groundwater management. The study was aimed at providing improved understanding on characterization of aquifer dynamics for solution-based modelling while addressing the importance of integrating hydrogeophysics data and derivative analysis in amplifying the heterogeneities that exist in aquifer system.

Research on the different ways in which climate change and adaptation (CCA) is communicated and taught has been growing in popularity over the last few decades. Researchers in communication science have found that the way in which information is presented and transferred is important in influencing people's perceptions and attitudes towards particular topics and issues. With this in mind, the lack of interest or realization of the severity of climate change at many levels of governance may be indicative that climate change, the subsequent negative impacts thereof and the need to implement adaptive and mitigative strategies - is not being effectively communicated to these audiences. This research explores the effect of CCA training-courses on participant knowledge, perceptions and attitudes towards CCA and related issues. It also highlights training methods and elements of course design which participants identified as enabling factors in enabling their understanding of CCA. The data collection used a mix methods approach, and focused around two training-courses. Participants (n=37) were mid-career professionals, many of whom engage in decision-making and policy development activities in different levels and sectors of government. Quantitative data was collected using scaled pre-and-post training tests. Qualitative data was collected through 14 semi-structured interviews, process observations, and anonymous feedback slips. A majority of participants (68%), showed an increase in knowledge scores after attending training. Similarly, 62% of participants responded more positively to questions relating to CCA in the post-training test compared to their pre-test responses. This research did not find a strong correlation between changes in knowledge, and changes in perceptions and attitudes; however, there were positive changes in all three variables. Participants discussed six methods of teaching and training which enabled their understanding of CCA and related issues; namely, PowerPointTM presentations, group work, practical exercises, games and role-play. Learnings from studying the training-courses highlight the importance of collaborative learning, diversity in participant groups, active engagement of participants with various mixed training methods and careful framing of content such that it inspires a sense of confidence rather than hopelessness. The effective communication and transfer of CCA information to professionals that are engaged in decision-making and policy development is key to increasing adaptive capacity, and subsequently adaptation at scale. It is therefore critical that CCA communication and capacity building efforts, such as training-courses, are designed such that they optimize participant learning and understanding.

>Magister Scientiae - MSc / With current climate change, growing population, and rapid industrialization of developing countries, water is increasingly becoming a scare resource. Within a power plant, processes that consume most water are demineralized water production (boiler make-up), heat rejection (cooling) and emission control (wet flue gas desulfurization). Eskom’s fleet of existing coal-fired power plants are not equipped with SO2 abatement technologies and therefore retrofitting of the plants will be required to meet the compliance levels for SO2 emissions.

Climate change is causing increases in the frequency, severity, and extent of fires in the boreal forest, which in turn is expected to change historical cycles of permafrost response and recovery to disturbance. A review of recent literature (forming part of this thesis) shows that there are disparities in current knowledge of post-fire permafrost response. First, the majority of studies on permafrost-fire interactions have been conducted in Alaska, leaving regional gaps for the boreal forest across Canada. Second, there are limited direct measurements of certain variables which affect post-fire permafrost dynamics. These include snow depth, burn severity, and soil moisture, as well as ground ice content and quantified subsidence and thermokarst development. Third, the majority of post-fire permafrost studies address near-surface impacts, neglecting permafrost conditions at depth. Finally, there is a lack of long-term information and regional investigations over a broad range of environmental conditions, particularly how permafrost responds across a variety of ground ice contents. This thesis addresses these knowledge gaps through in-situ measurements and analysis of permafrost conditions following fires occurring over the last half century and in particular in 2014 and 2015, along a 650 km latitudinal transect spanning the discontinuous zones, from isolated patches (57.8°N) to extensive discontinuous permafrost (63.1°N), in northwest Canada. A variety of monitoring techniques were used to evaluate permafrost change, including ground and air temperature measurements, direct current electrical resistivity tomography (ERT) surveys, measurements of frost table depth, snow depth, organic layer thickness, burn severity, and ground subsidence. Samples of frozen and unfrozen soil were collected by coring or pit digging, and laboratory analyses conducted to establish soil characteristics. Laboratory experiments were also performed to establish a relationship between resistivity and temperature, and to generate a threshold between frozen and unfrozen soil that could assist in the interpretation of ERT surveys. A total of 68 sites along the Mackenzie Highway in northern Alberta and southern Northwest Territories (NWT) were examined to evaluate permafrost change due to climate warming and forest fire since an initial survey in 1962. The transect extends through the isolated patches and sporadic discontinuous permafrost zones, including 11 sites which burned at various times between 1971 and 2012. Overall, there has been significant permafrost degradation, especially at sites with thin organic layers and coarse-grained soils. This occurred preferentially at the southern end of the transect, where nearly 2°C of climate warming has occurred, such that even undisturbed sites experienced degradation. However, permafrost has persisted at about half of the sites where black spruce (Picea mariana) canopies with organic layers generally >40 cm thick overlie fine-grained sediments. Permafrost even persisted at the majority of burned sites, but greater frost table depths were observed at those which were burned in 2012. A second transect was established to examine permafrost change following the abnormally severe fire year of 2014 (and more limited fires in 2015) that affected sites across a wide range of conditions in the southern NWT. Eleven monitoring sites were established in the sporadic and extensive discontinuous zones between 2015 and 2016, and annual field surveys were conducted through to 2019, including the first repeat ERT surveys conducted following fire. Permafrost change occurred at all sites, including unburned ones, indicating the ongoing impacts of climate change in the region. Snow-depth days, maximum snow depth, and the nival offset were all greater at burned sites. Permafrost change was more pronounced at burned sites, with greater relative decreases in average apparent resistivity and increases in frost table depths and ground temperatures, particularly at sites with low gravimetric moisture content, coarse soil textures, and organic layers <40 cm thick. These changes are pronounced in the near surface (<5 m depth), with deeper permafrost appearing relatively unaffected within the 5-year post-fire time-frame. The field observations indicate that permafrost can still persist following fire at a significant percentage of locations in the discontinuous zone. However, slow degradation is occurring at both burned and unburned sites due to the warming climate, and particularly at dry sites with coarse-grained soils and thin organic layers. Post-fire permafrost change is evident at sites which burned in the last 10 years, but over the long-term, frozen ground appears resilient to fire, with characteristics like active layer thickness returning to pre-fire levels. Similarly, cold permafrost on the taiga shield is resilient to fire, even with thin residual organic layers. At high ice-content sites, however, where ground subsidence and thermokarst develop, water inundation and permafrost thaw can occur, particularly in areas which have been severely burned. This thesis underlines, therefore, the importance of monitoring and modelling a variety of landscape types to establish post-fire permafrost impacts and temperature trajectory, and more specifically the effects of heterogeneity of drainage conditions, substrate, and organic layer thicknesses on the fate of permafrost in the boreal forest.

We live in a constantly changing world, where recent human-induced changes and climate change affect virtually every component of the Earth's surface and systems. Coastal ecosystems are particularly at risk, as one of the most utilised and urbanised of natural systems worldwide, as well as being at risk from sea level rise. This will degrade or even destroy many feeding and breeding sites. Those species colonising new habitats in an attempt to escape rising sea level and climate change related threats, will be competing for space with the growing human population and urbanisation. Although 97 of 346 seabird species (28%) are globally threatened, 57 (17%) have increasing populations, including 17 gulls (Larinae). The Kelp Gull Larus dominicanus is a cosmopolitan species with an increasing population worldwide. Kelp Gulls in southern Africa L. d. vetula are one of 15 seabird species that breed in the region, and one of only five breeding seabirds listed as Least Concern in the region. Three Kelp Gull breeding colonies in Plettenberg Bay, Western Cape, were surveyed to provide an updated count for this area. A combination of direct counts and the trial use of an unmanned aerial vehicle (UAV),were used as methods of counting nests. The direct monitoring of nests allowed for the effect of different microhabitats on the breeding performance of Kelp Gulls to be investigated, which has implications for their ability to adapt to future habitat changes. The importance of anthropogenic food items in the diet of Kelp Gulls breeding in Plettenberg Bay was explored through the use of regurgitated pellets of indigestible matter, and chick regurgitations, and how this is reflected in the time spent in various areas as shown by GPS loggers and point counts in urban areas. Another aspect of the urban adaptation of Kelp Gulls is the incorporation of anthropogenic debris in their nests, which was examined at eight breeding colonies throughout the Western Cape.

Many studies have projected a future warming over Southern Africa without including the influence of on - going vegetation changes in the region. This study investigates how the vegetation changes may alter the projected warming. For the study, two regional climate models (RegCM and WRF) were applied to simulate the present day (1970 - 2005) and the future (2030 - 2065; IPCC RCP 4.5) climate, with and without vegetation change. The study considers two scenarios of vegetation change: the first accounts for the potential impacts of natural bush encroachment and commercial forestation in the eastern part of South Africa, while the second accounts for the expansion of grass cover along the western region of the Grassland Biome in South Africa. The result s of this study agree with that of previous studies in that elevated greenhouse emissions will induce warming over Southern Africa in the future , but further indicate that the ongoing vegetation change s may considerably alter the magnitude of the warming. Forestation may enhance the warming over the forested area and induce cooling elsewhere. It may also produce wet conditions locally and induce dry conditions over other area within the region. In contrast, the expansion of grass cover may reduce the projected warming over the grass covered area and induce warming elsewhere. It may also induce dry conditions locally and produce wet conditions over other areas in the sub-continent. Both vegetation change scenarios ( i.e. forestation and expansion of grass cover ) alter the projected future climate changes through their influence s on local surface albedo ; while forestation decreases the surface albedo, the expansion of grass cover increase s it . However, the changes in rainfall and temperature from the vegetation changes could enhance the frequency drought over some areas and reduce it over other areas with in Southern Africa. This study, therefore, suggests that the vegetation changes may produce unexpected impacts on future climate. It also suggests that before using vegetation changes to mitigate climate change in Southern Africa, the biogeochemical benefits (i.e. carbon sequestration) should be carefully weighed against biogeophysical effects (i.e. changes in albedo).

Due to climate change, fisher households who depend on fishing for their livelihood are faced with a number of challenges that include low productivity. There is now an acknowledgement internationally that fishers cannot depend on hunting fish when all other food producing sectors have adapted. How economic and feasible is it for fishers to consider aquaculture in the face of climate change? This dissertation investigates the economic viability of aquaculture as a climate change adaptation option in rural fisher communities of Zimbabwe. The southern lowveld district of Mwenezi was used as a case study in the economic evaluation of pond culture and cage culture as a climate change adaptation strategy from a baseline position. Data was obtained from secondary sources which include the private sector involved in aquaculture, civil society organisations and the fishers practising aquaculture in both Mwenezi and another district, Kariba. The cost benefit analysis method of economic evaluation was used to assess the economic viability of pond and cage culture forms of aquaculture. The net present value, internal rate of return and benefit cost ratio were used as the decision criteria. Two scenarios were considered depending on the type of funding for the initial investment - scenario one was built on donor funding support while scenario two relied on a bank loan with interest for financing. A sensitivity analysis was also performed to determine the extent to which different factors affect the economic viability of both pond and cage culture. Both pond and cage culture were found to be economically viable as climate change adaptation options in fisher communities of Zimbabwe. Cage culture was found to have a higher net present value under both scenarios when compared to pond culture. However, under scenario two, pond culture was found to have a higher internal rate of return and benefit cost ratio. The inconsistencies were due to the variations in the scale of upfront investments between pond and cage culture where the latter requires a higher initial investment. Key factors that affect the viability of aquaculture as an adaptation strategy in Zimbabwe include the market price of fish, the cost of fish feeds and the price of fingerlings. While these factors are primarily economic, there are other factors which may affect the viability such as the increasing frequency of natural disasters.