Browsing by Subject "Climate Change"

Now showing 1 - 20 of 43
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    Aloe Pillansii on Cornell's Kop : are population changes a result of intrinsic life history patterns or climate change?
    (2004) Duncan, John A; Hoffmann, Timm
    Aloe pillansii populations in the biodiversity hotspot of the Succulent Karoo in Southern Africa are thought to be under threat of extinction. This study investigated the population at the type locality; Cornell's Kop in the Richtersveld, South Africa. It has been suggested that theft, animal damage and more recently climate change have caused a decline in the population by over 50% in the last decade, however very little is known about this rare species. Repeat photography and surveys were used to analyse life history patterns and dynamics of the population and thus establish what the potential threats to this keystone species actually are. Repeat photography indicates that there have been high rates of adult mortality over the last fifty years (1.8% of the population dies annually), which results in an average predicted lifespan of 39 years for the remaining adult population on Cornell's Kop. However, a recent survey reported that over 40% of the population recorded were seedlings, which weren't found in a 1995 survey, which is indicative of a recent recruitment pulse on Cornell's Kop and that conditions on the hill are still habitable for A. pillansii. Growth analyses suggest that A. pillansii has an average annual growth rate of 20 mm.yr⁻¹, which in tum means that 8 m individuals may be up to 453 years old. This long-lived strategy would require A. pillansii to only recruit infrequently, during periods of high rainfall, in order to sustain a viable population, which is consistent with findings on other large desert succulents. Seedling ages were estimated from their heights and it was found that 50% of the seedlings appear to have germinated five to ten years ago; this is consistent with rainfall records from the area which indicate that rainfall was consistently above the annual average for this same period. The findings indicate that although the adult A. pillansii population is declining, the presence of 30 seedlings suggest that the population is entering a recruitment phase after just coming out of a lengthy senescent phase. Although A. pillansii 's extensive lifespan makes it a potentially useful indicator species of climate change, the evidence presented in this study does not suggest that climate change has affected the dynamics of this population.
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    An analysis of the state of green business in the South African retail sector
    (2013) Christelis, Theodora Anita
    'Green' business is claimed by some South African retailers even though they lack well-founded and integrated sustainable, social, and environmental commitments. This is because no standards of greening exist for retail in South Africa. The purpose of this study is to explore, 'What constitutes green retail in the South African supermarket sector?' This required investigation into the sustainability of the companies' green business processes, social component of sustainability, and the existing state of the green retail sector. The five dominant supermarkets were selected to answer a questionnaire based on different environmental variables and principles. Interviewee responses were supplemented with publicly available company reports and these were then critiqued by allocating a level of commitment to sustainability of companies' green business processes, social considerations of sustainability, and establishing the current state of the green retail sector. Results show that within business processes, sustainable procurement is becoming increasingly accounted for through eco-labels and enterprise development programs. Distribution processes assist in verifying green claims and production. Various international and local sustainability programs are used to validate green efforts in the lack of national standards. Best practice frameworks are being utilised in the absence of local green standards and where limited, some are creating their own innovative solutions. Sustainability is a core focus at an executive level to some to ensure full integration of sustainability. Retailers may not necessarily pursue trends, but they have similar pressures that are often variably addressed. Although retailers' attempts to green their operations may not be standardised, the retail industry in South African has almost privatised sustainability and socio-economic development as they have superseded legislation to contribute to society and transform communities. It is an opportunity for retailers to take responsibility for their operations and in doing so create innovative solutions that address South Africa's environmental and social issues, in spite of the lack of green standards and governmental regulation, and in doing so become leadership companies that are accountable to their consumer base.
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    An analysis of vegetation pattern and its relationship to NDVI data in the Namaqualand area, South Africa
    (2003) Fox, Sarah-Jane Caroline; Hoffmann, Timm; Hoare, David
    The Namaqualand area in the North Western Cape, South Africa is unique in comparison to other similar semi-arid areas of the world. It has a high biodiversity and endemism and is consequently an area of interest for a growing number of conservation initiatives. Climate plays an important role in influencing the phenology and growth of the vegetation in the area. Remote sensing techniques were used to reveal the vegetation patterns in the greater Namaqualand area and to relate them to climatic variables. To do this we used the normalised difference vegetation index (NDVI) to relate biomass to altitude, rainfall and vegetation type. Each vegetation type in the area had a unique temporal signature and the climatic variables influencing the summer rainfall and winter rainfall vegetation types differed significantly from each other. Mean annual NDVI was significantly correlated to precipitation and potential evapotranspiration (PET) (r = 0.60, -0.63 respectively). A multiple regression model explained 52% of the variance when Mean Annual NDVI was related to climatic variables. Mean NDVI in August (the month of maximum NDVI in most of Namaqualand) was significantly related to PET and the current plus two previous months of precipitation (r = -0.72 and 0.74 respectively). A multiple regression model for mean NDVI in August and climatic variables explained almost 58% of the variance. The results suggest that NDVI can be used successfully as a measure of growth and phenology in the Namaqualand area and that NDVI could be used in climate models, drought prediction, desertification predictions and a number of other applications in the future.
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    Antarctic climate change: extreme events disrupt plastic phenotypic response in Adélie penguins
    (Public Library of Science, 2014) Lescroël, Amélie; Ballard, Grant; Grémillet, David; Authier, Matthieu; Ainley, David G
    In the context of predicted alteration of sea ice cover and increased frequency of extreme events, it is especially timely to investigate plasticity within Antarctic species responding to a key environmental aspect of their ecology: sea ice variability. Using 13 years of longitudinal data, we investigated the effect of sea ice concentration (SIC) on the foraging efficiency of Adélie penguins ( Pygoscelis adeliae ) breeding in the Ross Sea. A 'natural experiment' brought by the exceptional presence of giant icebergs during 5 consecutive years provided unprecedented habitat variation for testing the effects of extreme events on the relationship between SIC and foraging efficiency in this sea-ice dependent species. Significant levels of phenotypic plasticity were evident in response to changes in SIC in normal environmental conditions. Maximum foraging efficiency occurred at relatively low SIC, peaking at 6.1% and decreasing with higher SIC. The 'natural experiment' uncoupled efficiency levels from SIC variations. Our study suggests that lower summer SIC than currently observed would benefit the foraging performance of Adélie penguins in their southernmost breeding area. Importantly, it also provides evidence that extreme climatic events can disrupt response plasticity in a wild seabird population. This questions the predictive power of relationships built on past observations, when not only the average climatic conditions are changing but the frequency of extreme climatic anomalies is also on the rise.
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    Assessing the representation of teleconnective drivers of rainfall over Eastern Africa in global and regional climate models and projected future changes
    (2017) Endris, Hussen Seid; Hewitson, Bruce; Lennard, Chris
    Climate variability is an important characteristic of regional climate, and a subject to significant control from teleconnections. An extended diagnosis of the capacity of climate models to represent remote controls of regional climate (teleconnections) is vital for assessing model-based predictions of climate variability, understanding uncertainty in climate projections and model development. An important driver of climate variability for Africa is the sea surface temperature (SST) - rainfall teleconnection, such as the El Ni˜no/Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD). In this study, an assessment of the teleconnection between tropical SSTs and Eastern African rainfall in global and regional climate models is presented, with particular attention paid to the propagation of large-scale teleconnection signals (as represented by model reanalyses and Coupled Global Climate models (CGCMs)) into the domain of the Regional Climate Models (RCMs). The teleconnection-rainfall relationship with the Eastern Africa region is assessed in two rainfall seasons (June-July-August-September and October-November- December) under present and future periods. Evaluation runs (RCMs driven by reanalysis datasets) and historical simulations (RCMs driven by CGCMs) are assessed to quantify the ability of the models to capture the teleconnection relationship. The future analysis is performed for two Representative Concentration Pathway scenarios (RCP4.5 and RCP8.5) to assess future change in this relationship as a result of global warming. Using ERA-interim reanalysis as perfect boundary conditions, the RCMs adequately simulate the spatial and temporal distribution of rainfall in comparison with observations, although the model performance varies locally and seasonally within the region. Furthermore, the RCMs correctly capture the magnitude and spatial extent regional-scale seasonal rainfall anomalies associated with large-scale oceanic modes (ENSO and IOD). When the lateral boundary conditions are provided by CGCMs, RCMs barely capture the regional teleconnection patterns associated with large-scale modes, and mostly depend on the selection of the driving CGCM. Comparison of the CGCM-driven RCM simulations with the reanalysis-driven RCM simulations revealed that most of the errors in teleconnection found in the RCM simulations are inherited from the host CGCMs. The ERA-Interim driven downscaled results show better agreement with observed spatial teleconnection patterns than the CGCM driven downscaled results. Analysis of the CGCMs and corresponding downscaled results showed that in most cases both the CGCM and the corresponding downscaled simulations had similar teleconnection patterns, but in some cases the RCM results diverge to those of the driving CGCM results. It has been demonstrated that similarities in SST-rainfall teleconnection patterns between the RCM simulations and respective driving CGCM simulations are noted over the equatorial and southern part of the region during OND season, where the rainfall is primarily controlled by large-scale (synoptic-scale) features, with the RCMs maintaining the overall regional patterns from the forcing models. Di↵erences in RCM simulations from corresponding driving simulations are noted mainly over northern part of the domain during JJAS, which is most likely related to mesoscale processes that are not resolved by CGCMs. Looking at the model projections of the future, although the spatial pattern of teleconnections between ENSO/IOD and rainfall still persist, important changes in the strength of the teleconnection have been found. During JJAS, ENSO is an important driver of rainfall variability in the northern parts of the region where dry anomalies are associated with El Ni˜no and wetter anomalies with La Ni˜na. Both regional and global ensemble projections show higher rainfall during La Ni˜na and lower rainfall during El Ni˜no over the northern part of the region compared to the present period. During OND, the teleconnection between ENSO/IOD and rainfall is projected to strengthen (weaken) over Eastern horn of Africa (southern parts of the region) compared to the present period. This implies heavy seasonal rains associated with positive phases of ENSO and IOD will increase in future across the Eastern horn of Africa. The change OND rainfall teleconnections are stronger and also more consistent between the models and scenarios as compared to the change in JJAS teleconnections. These findings have an important implication for the water and agricultural managers and policies in the region to tackle the anticipated droughts and floods associated anthropogenic climate change. Finally, the analysis demonstrated that the largest source of uncertainty in the regional climate model simulations in the context of teleconnective forcing of rainfall over Eastern Africa is the choice of CGCM used to force the RCMs, reinforcing the understanding that the use of a single GCM to downscale climate predictions/projections and using the downscaled product for assessment of climate change projections is insufficient. Simulations from multiple RCMs nested in more than one GCM, as is undertaken in the Coordinated Regional Downscaling Experiment (CORDEX), are needed to characterize the uncertainty and provide estimates of likely ranges of future regional climate changes.
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    Attribution of the risk of extreme flood events to climate change in the context of changing land use and cover: case study of the shire river basin flood of 2015
    (2019) Likoya, Emmanuel; Wolski, Piotr
    The 2015 flood event in the Shire River basin was characterised by Malawi Government’s Department of Disaster Management (DoDMA) as the worst on record. It led to the damage in property worth millions of dollars with recovery still ongoing 3 years later. Over 150 fatalities were confirmed at the time with hundreds of others missing. The extent of the damage of the disaster was perhaps underlined by the swift adoption of the disaster management policy which was still in draft format then and the adoption of the climate change management policy a year later. In the aftermath of the disaster, as with most extreme weather events elsewhere around the world, questions were asked as to whether climate change might have had a hand in the occurrence of such an event and whether, going into a warmer climate, events of that nature of extremity will be the new normal. By using the risk-based event attribution methodology based on dedicated attribution experiments with a global climate model, and focusing on one of the sub-catchments of the Shire River basin, this study explored whether climate change from anthropogenic sources might have influenced the likelihood of such an event occurring. However, given the nature of hydrological events and the land use history of the basin, land use and cover change is another potential flood risk factor which, if overlooked, might affect conclusions with regards to the contribution of external factors to the risk of flooding. To account for both climate change and land use and land change, four sets of rainfallrunoff simulations were run using the Hydrologiska Byrans Vattenbalans-avdelning (HBV) hydrological model which has the ability to simulate the impact of land use and climate change on rainfall-runoff relationships. Each set was a combination of a climate scenario-either “factual” or “counter-factual”- and land use and cover change scenario-either factual (historical) or counterfactual (current). The climate scenarios were based on simulated rainfall and temperature from the HadAM3p model run in two modes-the “factual” and “counter-factual”- simulating the climate with atmospheric conditions closely resembling the atmosphere at the time of occurrence of the event and the climate as it would have been without human emissions of greenhouse gases. The proportion of the risk was calculated to determine how the risk of experiencing a flood of the January-April 2015 magnitude (for 1-day, 10- day, and 30-day maximum flows) changes with climate change only, land use and cover change only, as well as both climate change and land use and cover change. The results demonstrated that the probability of exceeding the 1-day maximum flow of the 2015 magnitude was lower in the factual (current) climate than in the counter-factual. However, changes in land use modify the flood risk such that, when land use change was accounted for, the extent of the reduction in the risk was lower. On the other hand, exceedance probabilities for 10-day and 30-day maximum flows were higher in the factual (current) climate. This was further heightened by changes in land use and cover. The study also established that observational uncertainties typical of the region may influence event attribution results to some extent. The results, which are based on a single attribution method and a single global climate model, do not span the method-model uncertainty range. As a consequence, the results are limited and do not constitute a fully defensible attribution statement.
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    Climate change adaptation measures in agriculture : a case of conservation agriculture for small-scale farmers in Kalomo District of Zambia
    (2015) Somanje, Albert Novas; Crespo , Olivier
    In most of the developing countries, small scale farmers (SSFs) are usually the primary agricultural producers of staple crop. Furthermore, they highly depend on rainfall for their rain-fed agricultural production. SSFs have limited capacity to adapt to extreme climate variability, thus rendering them to be among the most vulnerable to climate change. Some recent studies show that agricultural production and productivity is being negatively impacted by climate change and variability in most parts of Southern Africa. This is likely to continue for decades into the future, unless corrective or adaptation measures are implemented to reduce the impact on agriculture. Conservation Agriculture (CA) is one of the climate change and weather variability adaptation measures being promoted for SSFs in Kalomo District of Zambia. CA is not only being promoted to improve production and productivity for food security for the majority rural population, but also as an adaptation measure for sustainable agricultural production. The present study analysed the CA practices being promoted in Kalomo district of southern Zambia and the associated challenges in the management and implementation, as well as, how best these challenges can be addressed. Semi-structured interviews and literature review were used as methodologies of data collection for the study. The findings of the study indicate that among the three principles of CA, minimum tillage is mostly practiced compared to crop rotation and retention of crop residue. Within minimum tillage, ripping was found to be practiced on a larger scale compared to making basins. The major challenges include planning and human resource development, financial resource and policy constraints and cultural barriers to adoption of CA.
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    Climate change and small-scale fishing in South Africa: a community scale social vulnerability assessment for the southern Cape handline fishery
    (2022) Andra, Kayla; Jarre, Astrid; Karenyi, Natasha
    Climate change is majorly affecting the quality and quantity of marine organisms, as well as people's livelihoods. Coastal communities, small-scale fishers, and fishing-reliant individuals are especially vulnerable to climate change impacts (and other stressors) that alter the state and availability of ocean resources. Therefore, implementing integrated management approaches (such as the Ecosystem Approach to Fisheries (EAF)) is crucial to address these vulnerabilities. This study concerns the vulnerability to the impacts of climate change of fishers who act as crew members in the southern Cape commercial handline fishery. The southern Cape is a rural, peri-urban, and urban region characterised by agriculture, fishing, tourism, and retirement services as major economic activities. Aside from their documented social, governance, and economic stressors, small-scale fishers in the southern Cape also face biophysical stress (i.e., changes in wind, rainfall, and sea state). The Global learning for understanding local solutions (GULLS) survey instrument and a social vulnerability framework were created to assess vulnerability and its comprising concepts (sensitivity, exposure, and adaptive capacity) for coastal communities experiencing notable climate change. This study presents the first quantitative analysis of the data collected in the southern Cape in 2014-15. Univariate and multivariate analyses were performed to answer four key questions to investigate whether social vulnerability (as well as sensitivity, exposure, and adaptive capacity) differed among the communities, how variable vulnerability is within the communities, what drives the differences among the communities and to gain insight on the implications for issues of scales. The fishing communities differed significantly in their overall social vulnerability scores. Sensitivity and exposure were similar between the fishing communities. Sensitivity was the main driver of vulnerability for all fishers due to their attachment to fishing as an occupation, low self-sufficiency, and attachment to their communities. There was no significant difference in the dispersion (homogeneity) of the fishers' responses within the communities. The results also corroborate previous qualitative research, showing that variations between the communities are driven by adaptive capacity. The “component” scale (the second scale of the four-scale GULLS framework) yielded the most beneficial results and is recommended for future analyses. In addition, recommendations are made for future surveys to address uneven weighting, fundamental system changes (such as COVID-19), and questions irrelevant to the southern Cape small-scale fishers. Overall, with these recommendations, an improved survey offers a quicker methodology that can easily be communicated with various decision-makers and paves the way for consistent temporal comparisons that stimulate a long-term understanding of vulnerability. Most importantly, these recommendations and methods can contribute to the Ecosystem Approach to Fisheries (EAF) implementation in the southern Cape and the sustainability of this marine social-ecological system.
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    Conceptualising and quantifying the nonlinear, chaotic climate: implications for climate model experimental design
    (2015) Conradie, Willem Stefaan; Abiodun, Babatunde Joseph; Daron, Joseph D; Hauser, Tristan P
    Uncertainty in climate system initial conditions (ICs) is known to limit the predictability of future atmospheric states. On weather time scales (i.e. hours to days), the separation between two atmospheric model trajectories, initially "indistinguishable" (compared to unavoidable uncertainties) from one another, diverges exponentially-on-average over time, so that the "memory" of model ICs is eventually lost. In other words, there is a theoretical limit in the lead time for skilful weather forecasts. However, the influence of perturbations to climate system model ICs - particularly in more slowly evolving climate system components (e.g., the oceans and ice sheets) - on the evolution of model "climates" on longer time scales is less well understood. Hence, in order to better understand the role of IC uncertainty in climate predictability, particularly in the context of climate change, it is necessary to develop approaches for investigating and quantifying - at various spatial and temporal scales - the nature of the influence of ICs on the evolution of climate system trajectories. To this end, this study explores different conceptualisations and competing definitions of climate and the climate system, focussing on the role of ICs. The influence of ICs on climate quantifications, using probability distributions, is subsequently investigated in a climate model experiments using a low-resolution version of the Community Climate System Model version 4 (CCSM4). The model experiment consists of 11 different 50-member ensemble simulations with constant forcing, and three 50-member ensemble simulations under a climate change scenario with transient forcing. By analysing the output at global and regional scales, at least three distinct levels of IC influence are detected: (a) microscopic influence; (b) interannual-scale influence; and (c) intercentennial-scale influence. Distinct patterns of interannual-scale IC influence appear to be attributable to aperiodic and quasi-periodic variability in the model. It is found that, over some spatial domains, significant (p < 0.01) differences in atmospheric variable "climatologies", taken from 60-year distributions of model trajectories, occur due to IC differences of a similar order to round-off error. In addition, climate distributions constructed using different approaches are found to differ significantly. There is some evidence that ensemble distributions of multidecadal temperature response to transient forcing conditions can be influenced by ICs. The implications for quantifying and conceptualising climate are considered in the context of the experimental results. It is concluded that IC ensemble experiments can play a valuable role in better understanding climate variability and change, as well as allowing for superior quantification of model climates.
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    Contesting transdisciplinary climate knowledge: a decolonial perspective on the FRACTAL project in Windhoek, Namibia
    (2019) Pelaez, Avila Julia Peláez; Scott, Diane; McClure, Alice
    Recent trends in sustainability research have particularly propagated transdisciplinary approaches in knowledge production. These new modes of knowledge production seek to deconstruct universalist principles and epistemic authorities from positivist research approaches. The potential of replicating existing power dynamics into these transdisciplinary spaces has, however, not sufficiently been critically questioned yet. This study proposes that transformative change in development of African cities requires a deconstruction of these power dynamics, that current transdisciplinary sustainability research is not yet sufficiently engaging in. To examine the power dynamics, the study applied a decolonial lens in its analysis. In a novel approach to contesting climate knowledge, the study sought to deconstruct the foundational concepts that are operationalised in the transdisciplinary knowledge generation. The analysis focused on tracing assumptions to identify imaginaries, that construct the geopolitical space and condition knowledge politics within a transdisciplinary research programme in Windhoek, Namibia. It further sought to reveal the mechanisms in the programmatic research design that condition epistemic authorities and subjectivities in the collaborative processes. Power dynamics were traceable through imaginaries as well as the evidencing of epistemic authority. Two overarching imaginaries could be traced, which are based in the construction and engagement of the geopolitical space in Windhoek: the imaginary of the social impact and desirable future and the imaginary of the sciencepolicy interface. Both imaginaries were underpinned by the vision of transformation, whose operationalisation revealed to be instrumental in determining the actual transformational potential in contrast to the envisioned one. The analysis indicated the concept of transformation to be an inhibiting factor due to uncontested power dynamics that were replicated in the transdisciplinary space. Epistemic authority was especially evident in connection with the climate information that was generated to inform the knowledge co-production. A contestation of authoritative knowledge was evident with regards to contextualising the information for present and future climates in Windhoek. However, the scientific climate information itself was not questioned for its authority. The conceptual design of the stakeholder engagement revealed to be the main mechanism that created subjectivity. The study concluded with an exploratory section, an ‘epistemic disobedience’, which engages the principle of Walking With that is used by the indigenous activist movement of the Zapatistas in Mexico to create a vision of a new world. Walking With is used to reconstruct a vision of a decolonial approach to generating climate knowledge in an African urban space. This exploration further exemplifies a dimension of decolonial criticism, which is the importance of going beyond deconstruction towards fostering decolonial thinking.
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    The distribution and population structure of Aloe pillansii in South Africa, in relation to climate and elevation
    (2004) Bolus, Cosman; Hoffmann, Timm
    South Africa comprises almost 10% of known plant species and also has the only arid zone "hotspot" defined worldwide, namely the succulent Karoo. Anthropogenic climate change predictions for South Africa suggest rapid climate change in the next 50 years will have adverse effects on its vegetation biomes. This study shows how the aborescent succulent, Aloe pillansii, has a limited distribution due significantly to environmental and climatic variables and therefore it is potentially at risk given anthropogenic climate change predictions. The total South African A. pillansii population investigated is made up of 1202 individuals and is found in the Richtersveld, which is part of the Succulent Karoo. The A. pillansii individuals were sampled in terms of their height and geographical position and then defined into subpopulations by a distance of 2 kms of separation. The sub-populations were then evaluated in terms of their respective environmental and climatic variables acquired from a CCWR database for South Africa using Arc View 3.2. The sub-population size class distributions were also constructed so that population dynamics and recruitment could be investigated. The results show how the A. pillansii sub-populations are limited to a specific environmental and climatic range. The sub-populations group along similar environmental and climatic variables with the healthiest sub-populations found at lower elevation, higher temperatures and higher Potential Evapo-Transpiration. The climatic range of A. pillansii is also evident from the range of its environmental and climatic variables and the associated unhealthy sub-populations that lie on the extremes of this range. Recruitment was found to correlate strongly with the environmental and climatic variables, % winter rainfall and elevation, suggesting it is moisture limited. The evidence found in this study of A. pillansii 's specific environmental and climatic distribution may have negative implications for its future survival and conservation especially with present indications of anthropogenic climate change.
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    Does the availability of shade limit use of water troughs by desert birds?
    (2015) Abdu, Salamatu; Cunningham, Susan J; Ryan, Peter G; McKechnie, Andrew E
    Climate change poses a major threat to living organisms, with maximum temperatures expected to continue to rise over the next few decades. Hot desert environments are particularly at risk because they experience high environmental temperatures, scarce vegetation, low productivity and unpredictable water sources. Endotherms such as birds face the challenge of maintaining a stable body temperature while avoiding dehydration. This study was carried out in the southern Kalahari, in South Africa's Northern Cape, where about 50% of bird species (36 species) depend on free-standing drinking water. Livestock farms within this area provide artificial water points, which benefit birds as well as livestock. This study determined the role of shade and cover in the use of these artificial water points by birds. An experiment was conducted at six waterholes using the Before-After, Control-Impact (BACI) design. After an initial baseline was established, three waterholes were shaded while the other three were left unshaded. Camera traps were used to record the pattern and intensity of water use by bird species at different times of the day and at varying air temperatures. A total of 36 bird species drank at the water holes, but data analysis was confined to the ten most abundant species. Of the ten, six species responded to the presence of shade/cover, with four species reacting positively (Cape Glossy Starling Lamprotornis nitens , Red - headed Finch Amadina erythrocephala , Black - throated Canary Serinus atrogularis , and Laughing Dove Spilopelia senegalensis ), four showing no significant change in drinking patterns, and two showing a decrease in visitor numbers when the site was shaded (Cape Turtle - Dove Streptopelia capicola, Namaqua Dove Oena capensis). This suggests that providing shade at waterholes is not a universal solution to the problem of increasing heat stress experienced by birds coming to drink. Certain species such as the Laughing Doves and Cape Turtle-Doves avoided waterholes during the warmest time of the day while the Namaqua Doves were frequent visitors at this time. However, the Laughing Dove took advantage of the shade provided at midday (warmest temperatures) as their numbers increased. The Red-headed Finch and Black-throated Canary also increased at water holes with temperature irrespective of the time of day. These patterns imply that the provision of shade modifies the behavior of some bird species in response to predation risk or heat stress. These species utilized shade at different times of day and with varying intensities as temperatures rose.
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    Economic impacts of climate change in South Africa: A preliminary assessment of unmitigated damage costs
    (2002-02) Turpie, J; Winkler, H; Spalding-Fecher, R; Midgley, G
    This study aimed to provide a preliminary desktop estimate of the economic impacts of climate change in South Africa, based on the findings of the Vulnerability and Adaptation Study for the South African Country Study on Climate Change (1999). Damages are those predicted for 2050 and are valued in year 2000 rands, unless otherwise stated. Predicted impacts from this study include changes in terrestrial and marine ecosystems which will have profound impacts on agriculture, forestry, rangelands and fisheries, as well as on biodiversity. In addition, changes n hydrology may have immense consequences in terms of human health by increasing suitable habitat for waterborne diseases, as well as affecting water supply and the maintenance of ecosystem functioning. Prediction of the economic impacts of climate change is particularly difficult because of the global scale of the impacts and the long time horizon involved. Such studies have mostly been carried out in developed countries, and often only concentrate on market impacts such as agriculture. Impacts are typically divided into market and non-market impacts, with ecosystem and health damages relegated to the latter category, but this study recognises that all impacts have their basis in changes to natural systems, and that all types of impacts have both market and non-market components.
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    Electricity supply options, sustainable development and climate change priorities: case studies for South Africa
    (Magnum Custom Publishing, 2007) Winkler, Harald; Mwakasonda, Stanford; Garg, Amit; Halsnaes, Kirsten; Mukheibir, Pierre
    This report summarizes the results of the Projecting future energy demand: Balancing development, energy and climate priorities in large developing economies project that has been managed by the UNEP Risø Centre on behalf of UNEP DTIE. The project, sponsored by UNEP, is a partnership between the UNEP Risø Centre and centers of excellence in South Africa, China, India and Brazil. The focus of this report is on the energy sector policies that mainstream climate interests within development choices. The country study results for future energy and environment projections that are included in this report are backed by intensive economy-energy-environment modeling by the Energy Research Centre at the University of Cape Town, South Africa, wherein general scenario analysis of the energy sector explores some policies in more depth. The report argues that starting from development objectives is critical to mitigation efforts in developing countries. Instead of defining local benefits as ancillary to mitigation, reductions of GHG emissions should be seen as the co-benefits of policies that drive local sustainable development. A development-focused approach seems more likely to be implemented than the imposition of GHG targets by the international community—especially as South Africa has adopted development targets such as the Millennium Development Goals and promoted the Johannesburg Plan of Action.
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    Environmental changes and regime shift analysis in the southern Benguela using output from earth system models
    (2025) Wilcox, Maxine; Ortega-Cisneros, Kelly; Shannon, Lynne
    The accelerating pace of anthropogenic carbon emissions has triggered profound changes in Earth's climate, affecting marine ecosystems and fisheries globally. This study focuses on the southern Benguela, an integral region of the southern African Eastern Boundary Upwelling System (EBUS), investigating the potential impacts of climate change on this biologically productive region. Utilising data from the latest Coupled Model Intercomparison Project 6 (CMIP6), this research explores the implications of future extreme events, such as marine heatwaves, hypoxia, and acidification, on the southern Benguela ecosystem. Output from two earth system models (ESMs): the Geophysical Fluid Dynamics Laboratory (GFDL) and the Institut Pierre Simon Laplace (IPSL) was integrated with shared socioeconomic pathways (SSPs) to simulate environmental changes over time under historical scenarios (1970 – 2014), as well as low fossil fuel emission scenarios (SSP1-2.6) and high fossil fuel emission scenarios (SSP5-8.5). Trends in sea temperature, pH, chlorophyll-a concentration, integrated primary production, and oxygen concentration were plotted over the three different scenarios on the west and south coasts of the southern Benguela, over three depth levels. In addition, these time series were analysed using the sequential t-test algorithm for regime shift detection (STARS), in an attempt to detect any abrupt, long-term shifts. Projections under SSP1-2.6 tended to follow their historical trajectories, and displayed gradual changes over time. Under SSP5-8.5, however, future projections showed considerable temperature increases, conflicting trends in chlorophyll-a concentrations and integrated primary production, and concerning declines in pH and oxygen concentrations. Regime shifts were detected on both coasts for both ESMs, and tended to coincide temporally with extreme events observed in the environmental trends. In future scenarios on the west coast, clusters of regime shifts tended to be detected shortly after extreme events. Through a comparison of historical observations and hindcasts, the study also evaluated the reliability of the two ESMs, and it was found that GFDL generally exhibited better agreement with historical observations. The kind of ESM model-to-historic observation evaluations as carried out in this study play a crucial role in enhancing models' consistency and ought to be prioritised in the progression of CMIP7. Ultimately, this study contributes novel insights into the environmental dynamics of the southern Benguela. This research serves as a foundation for understanding future changes that may impact the region, providing valuable information for decision-makers, policymakers, and resource managers. In the face of climate change, these findings emphasise the need for adaptive and sustainable fisheries management strategies to ensure the conservation of the southern Benguela ecosystem and the millions of livelihoods it sustains.
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    An exploration of South Africa's wind climate using station records and reanalysis data
    (2016) Argent, Brendan; Hewitson, Bruce; Lennard, Christopher James; Hahmann, Andrea
    Sparse information about the wind climate of South Africa behooves an exploration of the drivers of surface wind speed, especially in the context of wind resource assessment. This work quantifies the coupling between the synoptic circulation states and station-scale flows to develop a process-based regionalisation of wind regimes over the country .A thorough inspection of available South African Weather Service (SAWS) wind records is conducted and a quality control procedure is applied. The procedure reveals a large proportion of the data are missing and existing data contain numerous errors such that only107 of the original 960 stations passed the quality control criteria. However, data from these107 stations only overlap temporally 2% of the time, which makes the data inappropriate fora regionalisation procedure. To ameliorate this, a method for incorporating bias-corrected time series data from a reanalysis data set is developed. Data from the 0.3◦ resolution hourly Climate Forecast System Reanalysis (CFSR) be-tween 1989-2010 is selected to improve the temporal coverage of the station data. The raw CFSR data overestimates wind speeds and underestimates the temporal variability and long-term trends. A bias correction method based on the wind speed and direction, time of day and month of the year is developed which successfully removes the mean error on wind speed and direction and improves the correlation with station records. This is achieved without disrupting spatial correlation patterns. Corrected and extended wind time series from each station site are used for the regionalisation. The regionalisation uses a self-organising map (SOM) to define the archetypal synoptic circulation patterns in the reanalysis data set and the influence of these on the local wind climate is quantified. 12 representative atmospheric states are defined by the SOM that are consistent with the existing literature and capture the major synoptic circulation states. A hierarchical clustering is then used to define wind climate regions based on the coupling between these circulation states and the extended station data. Six relatively cohesive spatial wind-climate groupings are identified that are physically consistent with the driving synoptic environment and are characteristic in terms of terrain and response to synoptic drivers. This process-based regionalisation facilitates a future assessment of potential changes in the wind climate of South Africa as a result of a warming world.
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    Exploring the adoption rationales and effects of off-grid renewable energy access for African youth: a case study from Tanzania
    (University of Cape Town, 2020) Rabenold, Colton; Sowman, Merle; Simpson, Nicholas
    In addition to being one of the poorest countries in Africa, Tanzania is considered the 13th most vulnerable nation in the world to climate change and climate variability. Currently over 63% of Tanzanians have no access to the national power grid. Instead they rely on biomass and kerosene lamps to provide energy in their homes. In addition, rural youth in Tanzania have limited occupational pursuits other than subsistence farming (both formal and informal). Utilizing a case study approach, this research qualitatively explores the effects of energy access in the form of solar PV for those seeking to secure this public good at a household-level. Face-to-face interviews conducted in the coastal region of Tanzania concentrated on understanding rationales for adopting off-grid energy (adoption rationales), particularly respondent's 'Awareness', 'Motivation' and selected 'Pathways' (the AMP Framework). High rates of rural poverty highlight systemic lack of energy access in Tanzania. In contrast, livelihood transformations through solar PV were observed in the case to couple with energy access. Indicators of improvement in living standards were observed to have cascading influence on other adopters which, in turn, encouraged further uptake. This innovative adoption lead to decreased pressure on the surrounding ecosystems, but environmental factors did not influence initial adoption rationales. Reflecting on the findings, the author develops a framework for better understanding of the role private actors take in transitions from to off-grid energy access in Africa. Reflecting on the case observations, particularly how respondents sought shape the flow of events independent, and sometimes in spite of, the State, the framework extends current understandings of nodes of change in rural communities and provides a more extensive exploration of behavioural theories (the AMP Framework and Diffusion Theory). Novel connections are made conceptually with emerging nodes of change and decision-making theories of change to provide fresh extension of these approaches to understanding poverty arrangements in Africa and what researchers and decision makers might need to consider for targeted interventions towards universal energy access on the continent. The thesis concludes with a range of principles for energy access in Africa distilled from the observations and framework developed. They include environmental principles of sustainable resource management and socioecological balance, social principles of equality and participation, and economic principles of access and stability.
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    Exploring the effects of climate change communication and training efforts: lessons from training-courses aimed at mid-career professionals
    (2017) Van Wyk, Claire; Ziervogel, Gina; Pasquini, Lorena
    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.
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    Framed: COP17 on South African television
    (2013) Meiring, Rouxnette; Glenn, Ian
    The media have a critical role to play in informing and changing public opinion on climate change, "the defining human development issue of our generation" (United Nations Development Programme for Human Development Report, 2008, 1). Developing countries are most likely to suffer the worst effects of climate change, yet few studies exist on climate change communication in the media in developing countries and in particular in Africa. Studies on climate change communication in the media focus mostly on the print media and on developed countries, yet in Africa, more people consume their news through television or radio. So far, no study has examined television news reports of a United Nations Conference of the Parties in Africa. This study examines the way four South African television news stations (three public and one private) framed climate change news over six weeks: two weeks before, during and after the 17th United Nations Conferences of the Parties in Durban (COP17) South Africa, 2011/11/07 – 2012/01/07. Coding words were used to identify climate change stories in the main newscasts on SABC 1, 2, 3 and e.tv each day. These were transcribed and in the cases of SABC1 and 2 broadcasts translated from three indigenous languages (Afrikaans, isiXhosa and isiZulu) into English. A quantitative, descriptive statistical analysis looked at the occurrence of four primary frames in these climate change stories, using binary coding questions to identify each frame. The results in the binary coding sheets were analysed by using spreadsheets. The coding questions were also used to identify and explore secondary and additional frames, which were then illustrated in graphs. Differences in framing between public and private television were also illustrated in graphs (for example local versus foreign stories, time devoted to stories, depth of stories and occurrence of climate change stories with a human angle). Secondly, a qualitative inductive analysis of text and visual material looked at links between frames (for example the link between extreme weather conditions and human action using cause and impact visuals, as well as the link between news image and source – the framing of the politician, the activist and the scientist.) This section also looked at emotionally anchoring images of hope and guilt and the role of banners, posters and maps in climate change stories on television. Though other studies claim that coverage of the summit was "almost invisible" (Finlay 2012, 16) this study shows very high coverage on especially SABC 1 (isiXhosa and isiZulu). The following hypotheses were confirmed: the political/economic frame will dominate on all stations during COP17 but the ecological frame will be highest on at least some stations in the weeks after COP17. The ethics frame will be dominated by the secondary "Inequality/Justice" frame while the "Religion" frame will be of minimal importance. When activists set the agenda, the motivational frame will hardly feature. Climate change scepticism will receive little attention on South African television. Local (South African and African) stories will be more prominent on public television than on private television.
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    Future changes in extreme rainfall events and African easterly waves over West Africa
    (2016) Egbebiyi, Temitope Samuel; Abiodun, Babatunde Joseph
    This study examines the relationship between African Easterly Waves (AEWs) and extreme rainfall events over West Africa, and investigates how climate change could alter this relationship in the future. Satellite observations, reanalysis data, and regional climate model (RCA4) simulations (forced with eight global climate simulations) were analysed for the study. The study used the 95th percentile of daily rainfall as a threshold to identify extreme rainfall events, and applied spectral analysis to extract 3-5 days and 6-9 days AEWs from 700hPa meridional wind component over West Africa. The capability of RCA4 to reproduce the rainfall climatology, extreme rainfall events, the characteristics of AEWs and the contribution of AEWs to extreme rainfall events over the region during the past climate (1971-2005) was examined and quantified using statistical analysis. The future changes (2031-2065) in these parameters were projected for the RCP4.5 and RCP8.5 climate-change scenarios. The results of the study show that RCA4 gives a realistic simulation of the West African climate, including the annual rainfall pattern, the structure of AEWs, and the characteristics of the African Easterly Jet that feeds AEWs. The bias in the simulated threshold of extreme rainfall is within the uncertainty of the observed values. The model also captures the link between the structure of AEWs and the rainfall pattern over West Africa, and shows that the percentage contribution of AEWs to extreme rainfall events over the region ranges from 20 to 60%, as depicted by reanalysis data. For the RCP4.5 and RCP8.5 scenarios, the RCA4 ensemble mean projects a future increase in annual rainfall and in the frequency and intensity of extreme rainfall events over the sub-continent, but the increase is generally higher for the RCP8.5 scenario. It also projects a decrease in the frequency of rain days, no changes in the structure of the AEWs, and an increase in the variance of the waves. However, the simulations from the ensemble mean shows no substantial changes in the contribution of AEWs to the extreme rainfall events, suggesting that the increase in the frequency and intensity of the extreme rainfall events may not be attributable to the changes in AEWs. The study's application is in understanding and mitigating the future impact of climate extremes over West Africa.