Global climatic processes which control the interannual variability of summer rainfall over South Africa are studied. Monthly and seasonal rainfall variations are analysed with respect to fluctuations in sea surface temperature (SST), outgoing longwave radiation (OLR) and tropospheric winds. OLR is used as a proxy for convective intensity and for the identification of areas of sympathy and opposition to convection over South Africa. Wind data (and derived parameters) are employed to explore large- scale tropical dynamical structures. Plausible explanations are offered for the observed associations. A change in sign of the correlation structure from the October/November rainfall regime to the December through March regime is indicative of a shift from downstream advective processes (Atlantic side) to a teleconnection-type of behaviour (Indian Ocean side). Rainfall variations during the late summer months show significant (and negative) links with SST fluctuations within the equatorial/tropical Pacific and Indian Ocean areas and are consistent with results obtained in analyses with respect to OLR fluctuations. December OLR in the Western Equatorial Indian Ocean is associated with a large portion of the variance in late summer rainfall, and points to a possible relation with the evolution of the Indian monsoon. The positive association implies that reduced cloudiness off the eastern coast of equatorial Africa in the spring precedes above normal mid- and late- summer rainfall over South Africa. Vertical mass overturnings are investigated through the velocity potential and derived parameters (the Zonal Circulation and Meridional Circulation Indices). The results suggest that the vertical tropospheric cells are among the important associated components which modulate climate across southern Africa, and that broad scale flows have an impact upon regional circulation cells. Evaluation of the vertical circulations with respect to wet and dry composites reveals that the Walker-type cell which connects a branch over the Indian Ocean gradually forms after November and reaches peak development in February. A slight increase of SST in the Central Equatorial Indian Ocean (CEI) modifies the Walker cell anomaly leading to below normal summer rainfall over South Africa. Additional thermodynamic inputs in the CEI region are conducive to deeper convection, hence elevated outflow signatures are observed in the velocity potential and related fields. It is conjectured that the teleconnections between South Africa, the CEI and the remote Pacific Ocean regulate the depth of moisture influx and convergence over South Africa. Based on the results of this study, it is believed that empirical models could be designed for long-range prediction of summer rainfall anomalies over the central interior of South Africa.

In an attempt to determine why trees and grasses are able to coexist in savannas, Walter (1971) first proposed the root niche separation model for savannas which suggests that trees and grasses have differential access to water due to spatial differences in their rooting profiles. Subsequent studies in various savannas around the world have found that this is often not the case. In the central region of the Kruger National Park February & Higgins (2010) found that trees and grasses root at the same depths within the soil profile. In this study I determine whether the existence of fine roots in the soil profile necessarily indicates root activity. I also aim to determine the effect of increased water and nitrogen availability on root activity of trees and grasses. Pits of 20 x 20 em were dug to a depth of 40 em in plots that were either irrigated with the equivalent of 30 ml of rainfall per month or left without irrigation. This study was performed at the end of the rainfall season. I found that trees and grasses root at the same depths under moist and dry edaphic conditions as well as in plots with increased nitrogen. Tree roots are however, significantly more active than grass roots in non-irrigated plots. Temporal separation in root activity therefore seems to be a factor that allows for the coexistence of trees and grasses in savanna ecosystems.

Quiet Flows the River explores the lives of the people living in the coastal area of Bangladesh. Affected by the consequences of climate change, they continue to adapt and struggle each day to survive in their homelands.

This thesis investigates the governance of two global challenges in terms of policy learning and collective action. The COVID-19 pandemic and anthropogenic climate change pose critical challenges to human well-being as much as they depend on collective responses to contain them. The comparative analysis of governance structures in climate change and the COVID-19 pandemic shows similarities and differences. A significant difference is the timing and pace of the responses: while international organisations and governments took drastic measures in response to the spread of the coronavirus, global and national responses for climate change have been comparatively slow. However, similarities emerge in the nature of the responses to these two global challenges: individual behavioural change is necessary to manage the challenges, which rarely occur without political guidance and public policy. The thesis combines the concepts of collective action and policy learning in a conceptual framework for the comparative analysis of global governance between the COVID-19 pandemic and climate change. The success of the rapid and large-scale coordinated response to the COVID-19 disease outbreak has indicated that these conceptual notions are required for global governance and that they can be harnessed on a large-scale to address a GPG or commons problem. Therefore, in order to more effectively address the GPG problem of climate change, these conceptual notions of global governance need to be harnessed not only between international organisations and governments but between governments and non-state actors. The shared policy challenges of both crises, therefore, highlight the importance of good policy design and the coordination of actors. The lessons identified can be broadly applied to the global commons problem of climate change and can help policy makers identify where enhanced policy learning and collective action is required. In particular this should be applied to coordinate policy learning and collective action from municipal to global levels and enhance the participation of the global public for long-term climate policy.

Climate change is a threat to food security. A substantial body of research supports this conclusion for climate change threats to plants with agricultural value, as well as wild-harvested food from animals, such as fish. However, much less is known about climate change threats to wild-harvested food plants despite these species meeting important dietary needs for a large number of households in developing countries, especially when crops fail or during other times of hardship. My study was the first to look at climate change risk to a broad group of wild edible plants and focussed on the wild food plants (WFPs) of southern Africa. The aims of my study were to determine where WFPs occur in southern Africa; whether these WFPs will be threatened by climate change; and how climate change risk for WFPs intersects with climate change risk to staple crops. Species distribution models were used to obtain the historical geographic range of 1190 WFP species and to make projections of range change for 2070 under both low (Representative Concentration Pathway (RCP) 2.6) and high (RCP 8.5) greenhouse gas emissions scenarios. I also mapped percentage change between historical and future yields for maize and sorghum to identify regions where both crops and WFPs, or just one of these are at risk from climate change. WFP species richness in southern Africa generally increases from west to east across the region, with the Eastern Cape, Kwazulu-Natal and Mpumalanga provinces of South Africa having the highest WFP species richness. It is projected that for RCP 2.6, 40% of WFP species will experience a decrease in range extent within southern Africa, increasing to 66% of WFP species for RCP 8.5. For RCP 2.6, the loss of suitable climatic conditions is projected to decrease local WFP species richness most in the north-eastern parts of southern Africa, while increases in WFP species richness are projected in the south and east of South Africa. For RCP 8.5, decreases of more than 200 species are projected for multiple regions in north-eastern South Africa, and local WFP species losses of more than 50% are projected for most of Botswana. Despite these decreases, WFPs could still play an important role in food security during times of low agricultural yield as a result of changing climate conditions, especially in low-income, rural communities that are reliant on smallholder farming. For instance, in parts of the Eastern Cape province of South Africa and northern Namibia, WFP species richness is projected to increase while maize and sorghum yield are projected to decrease. People may be more able to rely on WFPs as a nutritional safety net in these regions into the future. This safety net, however, may be lost in large regions of South Africa's North West and Free State provinces, on the north-eastern border between South Africa and Botswana, as well as parts of northern Namibia, where declines in both crop yield and WFP species richness are projected. This research could prove valuable for climate change adaptation planning, especially in more vulnerable rural regions of southern Africa. Furthermore, by integrating traditional knowledge of WFPs into food security risk assessments and response options, it could provide a more inclusive range of food supply options people can use in order to mitigate risk. However, in order to ensure future food security, more research is needed on WFP uses, nutritional value, responses to climate change, and suitability for cultivation. Still, by looking beyond the farm level and conventional crops to the exceptional diversity of WFPs people obtain from their environment, my research has made a first step towards understanding the linkages between WFPs, agriculture, food security, and climate change.

Thesis advisor: Philip E. Strahan / The dissertation consists of two essays on corporate finance, banking, and political economy. The first chapter studies how partisan-driven views about climate change affect institutional investors’ investment in assets that are exposed to climate risk. The second chapter examines how unexpected political chaos can affect politically active companies in a negative way. In “Climate Change, the Partisan Divide, and Exposure to Climate Risk”, I study how partisan-driven beliefs about climate change affect the distribution of climate risk across mortgage lenders. Using wildfires to capture climate exposure, I find that Republican-leaning lenders are more likely to approve mortgage applications in high wildfire risk areas than Democratic-leaning lenders. This difference in approval rates is only evident among second-lien and jumbo mortgage applications, highlighting how securitization affects risk-taking incentives. Lastly, Republican-leaning lenders originate more climate-exposed second-lien and jumbo loans and thus hold more wildfire risk. The findings suggest that dispersion over climate change beliefs affects how institutional investors hold climate risks, potentially affecting financial stability. In “Downsides of Corporate Political Spending: Evidence from Mass Shootings”, I study the negative impacts of corporate political spending on firm outcomes. Using data from 20 years of mass shootings, I find that when mass shootings take place, companies that primarily donate to pro-gun-rights politicians experience negative stock price reactions and worse operating performance. The negative impacts on companies’ bottom line are stronger when incidents are deadlier. The decline in operating performance reverses within a couple of years. The findings are not driven by firms contributing to Republican politicians. Similarly, using Summary of Deposits data from FDIC, I find that banks primarily donating to pro-gun-rights politicians also experience higher deposit outflows around mass shootings. After incidents, firms significantly reduce corporate political donations to pro-gun-rights politicians. Overall, my findings highlight negative impacts on companies resulting from their political spending being disapproved by stakeholders. / Thesis (PhD) — Boston College, 2022. / Submitted to: Boston College. Carroll School of Management. / Discipline: Finance.

This study investigated the spatial variability of soil moisture as well as changes within the soil profile of different land use types in the Suid Bokkeveld, situated to the south-west of the Nothern Cape, South Africa. This area has been experiencing harsh weather conditions that affect local agricultural production and multiple livelihood activities. The primary aim of the research was to analyse the influence of land use adopted in response to weather and climate change by studying the effects of soil moisture variations in the area. The study found that, together with depth and soil particle size, different types of land use contribute to soil moisture variations. Out of the five types of land uses that were investigated, rooibos cultivated farms had the highest soil moisture variability. The second highest variability was found in grazing cultivated farms and the lowest in natural and grazing never cultivated land, respectively. The results confirm that the shift from rooibos tea and wheat cultivation to grazing has contributed to a reduction in soil moisture variations. The grazing cultivated and fallow system could therefore be an effective land use types to ensure water and soil conservation, reduce land degradation and adapt to weather and climate change. The significance of this study lies in it being one of the first explorations into soil moisture in this area. Other forcing factors will need to include building a comprehensive and integrated understanding of soil moisture variability based on multiple influencing factors.

Climate change is an increasingly urgent problem. How it is communicated and represented are of interest to those seeking to understand action or inaction on the issue. There is increasing interest on how it is being communicated visually. This research speaks to the growing body of literature on the visual communication of climate change in order to contribute to the wider critical literature addressing the role of images in the communication of climate change. It does so by considering a neglected site of climate change imagery: the Intergovernmental Panel on Climate Change's (IPCC) report covers. The IPCC's report covers from the first ones in 1990, to the latest ones of 2014, are investigated in this quantitative and qualitative case study where the subject matter, both literal and symbolic of this (hitherto unexamined) body of images, is interrogated. This dissertation sought to identify and investigate what, exactly, the IPCC is using to visually represent and communicate climate change outside the realm of its scientific graphs and diagrams. It sought to compare these findings with the larger lexicon of climate change imagery and look at how the IPCC negotiates the communicational and representational problems inherent in the visual communication of climate change. The question ultimately asked was whether the IPCC's cover images are effective representations of climate change. What was found was that the IPCC images departed significantly from standard climate imagery. The conclusions drawn from the initial content and thematic analysis was that the IPCC images are frequently too banal, bland and decontextualized to be effective representations or communicators of climate change but do offer some potentially effective avenues overlooked in other representations.

It already seems preposterous to be able to sufficiently meet global food demand of the expected nine billion people by 2050 while at the same time maintain our emissions levels below 2ᵒC by the end of the century. This is more so for a continent such as Africa where much of this population is expected to arise from considering the fact that the continent is ranked to have the highest proportion of food insecure population. In order to overcome this challenge, we will need a total revolution of our agricultural production systems to systems that not only focus on increasing food production but also build our resilience to climate change. An example of one such practice is System of Rice Intensification (SRI) which is acclaimed to increase rice production while at the same time reducing the pressure on scarce water resources, minimizing agricultural greenhouse gases emissions and improving the farmers' households' adaptive capacity to climate change impacts by increasing their income. However, despite the success attributed to SRI, its uptake across Sub Saharan Africa is arguably low. This is puzzling considering the high proportion of food insecurity in the region and the region's susceptibility to damage from increased severity and frequency of climate extreme events such as droughts and floods due to its geographical positioning and the limited adaptive capacity of its people. In this work, the researcher sought to understand the barriers and enablers to the adoption of the System of Rice intensification in Mwea irrigation scheme (MIS) in Kenya. The findings show that most barriers to the uptake of SRI in MIS occur during the dissemination of SRI. Further critical barriers to the uptake of SRI in MIS were identified as follows: lack of formal SRI training, high costs of rice production, failure to involve key stakeholder institutions such as SACCOs while marketing SRI and farmer's age. Moreover, the study also depicted that most barriers to SRI adoption were intertwined, thus focusing on a single barrier would be myopic. Furthermore, enablers to the uptake of SRI in MIS are tied to the benefits of SRI pre-empted by lead farmers. This correlation implies that the benefits of SRI are key motivators for SRI adoption. Other enablers include training. However, informal training on SRI through social networks which play a crucial role at disseminating climate adaptation activities amongst small scale farmers, is marked with a lot of inconsistencies which makes it a barrier for SRI uptake. In this regard, we advise that SRI trainers clearly highlight the activities involved in SRI and their resultant benefits during initial SRI information dissemination.

Protected areas should be reviewed under expected future climate conditions so that conservation and expansion strategies can be developed appropriately. An assessment of the vulnerability of protected areas to climate change is a necessary step in developing such strategies. Indeed, a vulnerability assessment is an important step in developing adaptation strategies for conservation. This is important as substantial climate change has already been experienced at a park level in South Africa. The aim of this study was to develop a method for assessing the relative vulnerability of protected areas to climate change and to apply this to South Africa’s 19 national parks. The method includes identifying and quantifying potential impacts of climate change on each focal protected area, carried out by developing and/or using projections for species, ecosystems, infrastructure, tourism and neighbouring communities. Potential impacts were combined with measures of each park’s adaptive capacity to develop an overall park vulnerability score. This study has taken vulnerability assessment at a protected area level further than has been attempted before by assessing not only the biophysical but also the socioeconomic impacts of climate change on a protected area, quantifying the potential changes (potential impacts) and developing a relative index. The results indicate that climate change has the potential to contribute significantly to the threats faced by South Africa’s national parks. Apart from a potentially devastating impact on species and ecosystems, the effects on tourism demand, community relations and infrastructure are of concern. Not surprisingly, the most vulnerable parks are largely coastal, where tourist infrastructure is at risk of both flooding and sea-level rise, and there are higher population densities. Furthermore, coastal ecosystems are expected to transform significantly which will have consequences for range-restricted species. Management strategies need to take heed of the magnitude of potential impacts identified in this study and work towards developing adaptation pathways.