## 3 Results and Discussion
### Region-Specific Climate Extremes and Threats to Environmental Stability
#### 3.2.4 Africa  
To understand the spatial and temporal variability of heatwave phenomena in the Southern African region, [PERSON] et al. (2013) identified heatwaves using three different approaches. From their study, heatwaves were reported to be a major concern to societies as they can negatively impact human health, the economy, and natural ecosystems. More specifically, heatwaves as a climate extreme can increase the risk of human mortality and morbidity, particularly among vulnerable people, food insecurity due to crop failure, more predisposition to wildfires, and significant economic loss.  
Region-specific climate extremes, with evidence from a global panel of regions, were explored by [PERSON] et al. (2013) in terms of their impact on economic production. They made an investigation based on a dataset containing the subnational economic output and Gross Regional Product (GRP) for more than 1500 regions in 77 countries, which allowed for estimating the historic climate impact at varying timescales. It was found that temperature affects productivity levels significantly and can also influence biodiversity and ecosystem health, induce habitat degradation, increase the proliferation of diseases, and contribute to drought and water stress, forest fires, and ocean warming. From an economic standpoint, an increase to about 3.5 \({}^{\circ}\)C by the end of the century can reduce global productivity output by 7-14% in 2100, which will be more detrimental to tropical and poor regions.  
[PERSON] et al. [98] investigated some elements of climate extremes using a standardised evapotranspiration index and future projections of rainfall and temperature in some wet parts of southwest Ethiopia. It was found in the research that Ethiopia is one of the most predisposed and vulnerable countries to climate extremes, and there is a need for a thorough understanding of these climate extremes at short and long timescales to aid the minimisation of the potential impacts of these extremes. The extreme climatic events experienced in the wettest part of southwestern Ethiopia were extreme drought, extreme wet, severe drought, and severe wet during the study period. They attributed extreme drought to increased evapotranspiration caused by excess heat and global warming. At the same time, drought threatens environmental stability because it affects the ecosystem by reducing water availability and increasing biodiversity loss, vegetation stress, and the depletion of soil health.  
Climate change is a global phenomenon; it has various manifestations, such as signals and other changes, and this was explored in the Sahel catchment of Burkina Faso [99]. Extreme climate indices, changes in the climate, and spatiotemporal variations were investigated in the Dano catchment in Burkina Faso using historical data from 1981 to 2010 and projected data for 2020 to 2049. It was found that the catchment would experience a reduction in the mean annual rainfall and warming of about 25.5% and 25.6% for increases of 1.35 \({}^{\circ}\)C and 1.55 \({}^{\circ}\)C, respectively. A reduction in rainfall significantly affects environmental stability and can result in soil degradation and desertification, water scarcity for the biodiversity in the environment, reduced agricultural productivity, and a number of other effects.