3. Electronic Theses and Dissertations (ETDs) - All submissions
Permanent URI for this communityhttps://wiredspace.wits.ac.za/handle/10539/45
Browse
8 results
Search Results
Item Phenological advance in the South African Namaqualand Daisy Bloom over the past decades(2024) Snyman, Pascal LudwigClimate change is driving changes in environmental suitability, competitive dynamics and phenological cycles of plants and animals. Through the analysis of the timing of phenological events the impact of climate change on plant and animal species can be measured and assessed effectively. In this study the impact of climate change on the timing of bloom of Namaqualand daisies is explored. Although the Namaqualand is described as a desolate and arid region during the summer months, the region is transformed into a wonderland of colours during the springtime flowering. Using documentary sources including newspaper archives from The Rand daily Mail, Volksblad and Die Burger as well as social media records from Flickr and iNaturalist, a phenological dataset spanning 1935-2018, including first flowering, full bloom and end of bloom dates for the Namaqualand daisies was compiled. First flowering and full bloom phenology of the Namaqualand daisies are advancing significantly at rates of 2.6d.decade-1 and 2.1d.decade-1. Climatic data, collectively spanning 1959-2018, from seven Namaqualand weather stations were individually correlated to the three flowering datasets. Calculations reveal that temperatures are increasing significantly in Namaqualand. The overall increase in temperature, from 1959-2018, for all seven assessed weather stations in Namaqualand is calculated at 1.18°C. Although no significant changes in precipitation were calculated, five out of the seven weather stations demonstrate slight decreases in precipitation over time ranging between 0.05-9.32mm from 1959-2018. The timing and amount of precipitation in the Namaqualand region is highly variable over time. For the periods spanned by both climate and phenology data, the relationships between the two were explored. Increasing temperatures are driving the calculated advances of the daisy flowering dates at statistically significant rates of change ranging from 0.01-0.11d.°C-1. The main climate drivers of Namaqualand daisy flowering phenology are winter and spring temperatures, the onset of the winter rainy season during April and May, and total winter precipitation. The rates of advance and climate drivers are broadly consistent with global phenological meta-analyses and records for the Southern Hemisphere. The advances in the timing of Namaqualand daisy flowering will have a significant impact on the tourism sector in the region, as flower viewing tours need to be prearranged months in advance.Item Habitat selection by a threatened lizard, the sungazer (Smaug giganteus): implications for conservation(2024) Stanton-Jones, WadeClimate change and habitat transformation are some of the primary threats that reptiles face as a consequence of persisting in their selected habitats. Some species, such as habitat specialists, may be particularly vulnerable to these threats given their restricted geographic ranges, strict habitat requirements, and limited dispersal abilities. Knowledge of the factors that drive habitat and microhabitat selection by a species, the impact that habitat transformation may have on that species, and how the species is expected to respond to climate change is necessary for informing conservation management strategies. Smaug giganteus (the sungazer) is a threatened (Vulnerable), habitat specialist lizard that is endemic to the Highveld grasslands of South Africa. Unfortunately, suitable habitat exists in a landscape where anthropogenic activities (e.g., agriculture and mining) are prevalent, and a major threat that sungazers face is habitat transformation and fragmentation. Sungazers are unique within their family (Cordylidae) in that they rely on self-constructed burrows in specific microhabitats within the grassland matrix as long-term, often permanent, shelter and refuge sites. Because of this, aspects of their life history, and the current threats that they face, sungazers may be particularly vulnerable to the combined effects of climate change and habitat transformation. The primary aim of this thesis was to assess the consequences of habitat selection and use by sungazers by investigating the potential impact of climate change on habitat suitability for the species, the fine-scale impacts of habitat transformation, and to identify the microhabitat requirements by sungazers such that recommendations for future conservation management of the species could be made. The potential impact of climate change on habitat suitability for sungazers was assessed by projecting their current ecological niche envelope into the future, under different climate change scenarios. The models predicted that sungazers may experience minor range contractions under the moderate case scenario, but vulnerability to climate change increased under the worst-case scenario. At the broadscale level, the models predicted that sungazers would shift their geographic range to the southwest. However, given the species life history traits, limited dispersal capacity, and the fragmented habitat in which subpopulations exist, climate tracking is unlikely, and sungazers may be more vulnerable to the effects of climate change than predicted by niche models. An assessment of the demographics and dynamics of four sungazer subpopulations existing at sites with different habitat conditions revealed that the impact of habitat transformation on sungazers may be more devasting than what was previously reported. In this study, the sungazer subpopulations existing in habitats transformed by mining activities, and severe overgrazing have declined by more than 50% over a 16-year period. This assessment at the subpopulation level (colony level) suggests that the current size of the sungazer population is probably an overestimate. A comparison between the microhabitat characteristics surrounding sungazer burrows and random sites in the landscape revealed that sungazers use microhabitats comprised of low vegetation cover and short grasses in which to construct their burrows. Burrow construction in these microhabitats generally occurs on northerly facing slopes. When constructing their burrows, sungazers tend to orientate burrow entrances in the same direction as the aspect of the slope but northerly directions are preferred. This thesis provides the first insights into the potential effects that climate change may have on sungazers in the future and highlights the severity of impact that habitat transformation has on sungazers at fine spatial scales. The findings not only justify the importance of conservation management for sungazers but provide critical information to assist with future conservation protocols.Item Exploring extreme rainfall events in KwaZulu-Natal over the period 1989-2019(2024) Ntleko, Thabisile Phiwengomusa ZibusisozonkeChanges in weather and climate extremes have been observed across the globe. These include an increase in the frequency, magnitude, and severity of extreme events, have been attributed mainly to climate change due to increased anthropogenic activity since pre-industrial times. Although these weather and extreme events have increased and intensified globally on average, some spatial and temporal variations of trends are evident at regional scales. This study was conducted to explore the incidence and trends of extreme rainfall events over KwaZulu-Natal for the period 1989-2019. Rainfall data was sourced from the South African Weather Service for 11 stations distributed across the province. Extreme climate events (ECEs) were identified by calculating subsets of the World Meteorological Organisation (WMO) Expert Team on Climate Change Detection Indices (ETCCDI) and WMO Expert on Sector-Specific Climate Indices (ET-SCI) for each of the 30 years of interest. Thereafter, trends in these extreme climate events were calculated using linear regression. The results reveal marked spatial and temporal differences in both the occurrence of the ECEs and their trends. The incidence of ECEs depict a seasonal pattern, where majority of events occur during the summer rainfall months. However, over the coastal regions ECE’s occur throughout the year and exhibit more frequent and intense events compared to overland regions. The trend analysis detected a majority of decreasing trends in the frequency, intensity and duration of extreme rainfall events for the period of study, with only 10 of the 77 calculated trends being statistically significant. The spatial distribution of trends was heterogeneous for most parts of the province apart for the KwaZulu-Natal Midlands, which consistently observed decreasing trends for all calculated indices.Item Perspectives on climate change and energy security in South Africa: a study of Eskom(2024) Rasimphi, Khuliso JamesGlobal changes in climatic conditions have both direct and indirect implications on various energy sources and systems, particularly in terms of energy generation vis-à-vis security for sustainable social-economic development. This study examined the relationship between climate change and energy security in South Africa, focusing on energy production, accessibility, and affordability as key determinants. The investigation also explored measures to minimise Eskom’s carbon footprint and opportunities for transitioning the energy sector to cleaner energy sources. A mixed research method, including structured questionnaire surveys, semi-structured interviews, observations, and existing records, was used for data collection. The data was mainly analysed by use of the Microsoft Excel package to generate statistical correlations and relationships to draw the key conclusions contained in this paper. Eskom coal power plants’ ten-year (2010 to 2020) carbon footprint was found to be constantly above 200 million per year. The power utility’s ten-year CO2e trend was primarily influenced by production activities. This is because all Eskom’s coal power plants (except for Medupi) do not have CO2e abatement technology, and the available technologies in the market are too expensive. The study also found that Waterberg (LP) and Nkangala (MP) regions, where most coal power plants are located, have been receiving inconsistent and insufficient rainfall from 2010 to 2021; and projections are suggesting a further decline in precipitation distribution and incline in average temperatures in these regions. Despite all these glaring climate change implications, the current study found that water consumption (2020 to 2021 trend) at coal power plants remained high even in periods wherein energy availability factor had dropped, and therefore indicative of thermal inefficiency. The study also found that South Africa’s slow approach in building a climate change resilient and adaptive energy system was caused by a slow and ineffective implementation of IRP. Thus, South Africa must embark on a decisive transition programme to cleaner energy sources mix as a critical and urgent measure to decarbonize and enhance the energy sector’s resilience against climate change effects, and ensure energy availability, reliability and affordability. The study concludes that Eskom coal power plants should focus their efforts on resolving maintenance problems, operational inefficiencies, and developing adaptation strategies to decarbonize and build resilience against climate change vulnerabilities such as irregular precipitation and high temperature, while ensuring energy security. The energy policy and IRP should be adaptive and continuously informed by regional research to determine the most suitable energy sources for specific regions to ensure an effective transition to cleaner energy systems.Item The nature of climate change communication in South Africa: its past, political and socio-economic undertones(2024) Sithole, EnochThe United Nation’s Intergovernmental Panel on Climate Change (IPCC) has noted that the observed and projected impacts and risks generated by climate hazards, exposure and vulnerability have increased with impacts attributable to climate change. The increase in climate extremes has led to some irreversible impacts as natural and human systems are pushed beyond their ability to adapt. Climate change has altered terrestrial, freshwater and ocean ecosystems at a global scale, with multiple impacts observable at regional and local scales, where changes in the ecosystem structure, species, geographic ranges, and timing of seasonal life cycles is apparent. Climate change is having diverse and adverse impacts on human systems throughout the world, affecting water security, food production, health, livelihoods, settlements, and infrastructure. According to the IPCC, it is “unequivocal” that human influence is warming the atmosphere, land, and oceans. The world climate body adds that humans are exacerbating climate change through the burning of fossil fuels and other activities. Faced with the global warming challenge, humanity has no choice but to engage in measures to mitigate and adapt to the resulting climate change. Climate change communication has been identified as one of the measures that will need to be applied in addressing climate change. This is so because for action against climate change to succeed, society will need to be mobilised to change behaviour and implement other measures. Climate change communication is the awareness, education, and mobilisation tool thereof. This PhD thesis investigates climate change communication in South Africa over the past century (since 1902) through an analysis of climate change-related news articles in three newspapers – the Rand Daily Mail, Mail & Guardian, and Business Day. The idea is to establish how key stakeholders – the government, the business sector, the scientific community, non-governmental organisations (NGOs) and the media – have communicated on climate change, and whether their communication on the subject has been underpinned by political and socio-economic considerations. Results show that while the scientific community has been communicating on ‘climate change’ from about 1935, when the first article on the subject was published by the Rand Daily Mail, other stakeholders such as the government, the business sector, and NGOs, only started communicating on climate change in the 1990s. Government and business sector communication has been underpinned by financial and economic undertones. Climate change communication scholarship in South Africa has been limited v compared to that elsewhere globally, especially in western countries. This thesis argues that South Africa will need to massively improve its climate change communication, as such communication plays a fundamental role to ensure a seamless transition from coal and other fossil fuels to a low carbon economy.Item South Africa - exploring the 2016 planned carbon emissions tax(2015-02-27) Edelstein, AliciaAt the 2009 Copenhagen climate-change talks South Africa proposed a reduction in greenhouse gas emissions by 34% in 2020 and 42% in 2025. This report is intended to research and conclude upon whether South Africa can practically implement a carbon emissions tax in order to reduce the amount of carbon dioxide and other greenhouse gases emitted, as well as on whether the introduction of a carbon emissions tax would be an appropriate way in which to address the climate change problem and South Africa’s contribution thereto. The research undertaken is necessary as South Africa is a relatively large emitter of carbon dioxide and other greenhouse gases thereby contributing to the global problem of climate change which is caused by these emissions and if South Africa wants to honour its proposed reduction, a measure is needed in order to ensure South Africa reduces its harmful greenhouse gas emissions, of which the levying of a carbon emissions tax is researched as such a measure. The research, a detailed literature that identified potential areas of concern or negative impact on the economy and the identified ‘issues’ were when used in a correspondence survey to test the perception of professionals with a knowledge of the proposed carbon tax. The conclusion reached was that a carbon emissions tax cannot be successfully implemented at this time due to the prevailing economic conditions in South Africa as well as the potential resulting negative effects on the country’s low-income population and on South Africa’s international competitiveness. It is recommended that the possibility of implementing a carbon emissions tax should be re-evaluated at a future stage once the country’s economy is more developed.Item Climate change-related human security threats to border integrity and safeguarding for South Africa(2014-07-11) Vorster, Magriet;Climate change is a very current and contentious issue that has received a lot of attention during the past two decades because of its global influence and impact. Climate change affects the entire globe and the impact is mostly continental and regional and is not limited along state borders. Whether a person or group believe in the existence of global warming or not, the scientific evidence leaves no doubt that the climate is changing (Mazo, 2010: 9). Climate change influence the environment people live in and have a direct impact on all aspects of their daily lives. In a globalized world almost all problems cross borders, and environmental issues have long been recognized as among the most international and the most transnational of all (Parsons, 2009: 5). Climate change acts as a “threat multiplier” by exacerbating existing vulnerabilities, and must be analysed in relation to the adaptive capacity of those affected (individuals, communities and states), taking account of the wider political, socio-economic and demographic context (ACCES, 2011: 9). Although climate change has a global impact, the African continent is likely to be more severely affected than other regions of the globe and it will have a profound negative impact on all facets of human security. Long-term shifts in the climate seem likely to catalyse conflict by creating or exacerbating food, water and energy scarcities, triggering population movements, and placing larger groups of people in competition for more and more limited resources. Increased climate variability, including the greater frequency of extreme weather events, will also complicate access to resources, thereby exacerbating conditions that are conducive to promoting conflict. Southern Africa is described as a predominantly semi-arid region with high intra- seasonal and inter-annual rainfall variability, with extreme events such as droughts and floods occurring frequently. In Southern Africa, there has been an increase in inter-annual variability of rainfall over the past 40 years, with more intense and widespread droughts. Floods and droughts in Southern Africa are gradually increasing in number and frequency as well and already the entire region is considered a climate change "hotspot". As can be seen from the findings of the various chapters, climate change has a very complex predicted impact on all the dimensions of human security and a few major key issues in this regard came to light. These issues include urbanisation, migration, environmental degradation and biodiversity loss, water scarcity, spread of diseases, slow onset climate change, economic decline and poverty, criminality and conflict. The most profound issues that will have an impact on South African border integrity and safeguarding include urbanisation, migration, environmental degradation and biodiversity loss, water scarcity, spread of diseases, economic decline and poverty, criminality and conflict. Migration can be singularly highlighted as it has the potential to amplify and exacerbate all of the abovementioned issues. States have national security strategies and policies in order to guide policy and legislation to adequately protect the state from threats and to determine national security priorities. Border safeguarding is an important aspect of state security and strategy, policy and legislation, informed by the national security strategy and policy, constantly have to evolve and adapt to changes in the threat pattern affecting states. The border safeguarding environment of any state is very complex and faced with multiple external and international threats. Climate change-related human security threats will further amplify and complicate these threats as the impact of climate change becomes more pronounced in the southern African region. In order for South Africa to successfully address these threats in the border safeguarding environment it is important that a sound National Security Strategy and Policy provide focus and priorities for all government departments involved. This is a very complex field with multiple factors and only the key issues are highlighted and discussed in this paper.Item Living with multiple, complex risks of commercial sugarcane farming in KwaZulu-Natal : the role of climate change?(2009-04-14T12:32:20Z) Massey, Ruth ThokozileThe aim of this research is to examine the contextual environment in which farmers operate so as to improve our understanding of the factors shaping vulnerability to climate risk. A key focus is on the livelihoods of sugarcane farmers, using a case study of small-, medium-scale (emerging) and large-scale sugarcane farmers in the KwaZulu-Natal Midlands area of Eston and its surrounds. A social vulnerability assessment was undertaken under the Sustainable Livelihoods Framework (SLF) to test the hypothesis that climate risk is considered a major contributing factor to the vulnerability of commercial farmers in KwaZulu-Natal and needs to be effectively managed. This involved an investigation into the multiple stresses (both external and internal, on-farm and off-farm, climatic and non climatic) acting on the system. It is clear that climate change risk and variability is a major, but not the sole contributing factor to the vulnerability of commercial farmers in this part of KwaZulu-Natal. Climate change does need to be effectively managed but it will be best done in conjunction with the management of the other multiple and interacting threats and stresses identified in this study. Climate change and vulnerability, as well as the other multiple stresses, are acting on an already vulnerable system, exacerbating and compounding present risks. This research also explored a number of coping and response strategies that commercial farmers have adopted in response to the threats and stresses and investigated particularly, what elements enhance or restrict these strategies (both on-farm and off-farm). These strategies posses potential as possible future adaptation options. It was found that the issues of access to livelihood assets (social, financial, natural/environmental, physical, human, knowledge assets and capital under the SLF) are key to the adaptive capacity and the adaptation strategies that farmers employ. Institutions (both formal and informal) play a pivotal role in this access to livelihood assets both enabling and restricting access. In conclusion, this work determined that a focus on only one element, such as climate change, will not significantly reduce the vulnerability of commercial farmers. There is an interactive, dynamic and multifaceted network present with a number of factors acting within and from outside the system. Political, biophysical, social and economic factors interact and combine to compound vulnerability, requiring more integrative and multiple response strategies.