Doctoral thesis

The Impact of Climate Extremes on Dryland Ecosystems and Societies in Sub-Saharan Africa

Imprimatur date2023
Defense date2023

Over the past sixty years, land productivity in Africa has steadily declined, primarily due to climatic constraints that limit its full potential. With three-quarters of Africa's landmass being drylands spread across 46 out of 54 countries, the region is highly sensitive to climate and environmental challenges. This has led to severe and recurring climate extreme events, disproportionately affecting the livelihoods of the population, especially the poor. However, limited research and evidence exist on the magnitude of climate change outcomes and their impact on ecosystems, agriculture, and food production, as well as the response of individual households to these extreme events. The principle objective of this PhD thesis was to enhance our understanding of the impact of climate extremes on dryland ecosystems and society in sub-Saharan Africa (SSA), comprehensively examining various levels of impact. To achieve this, several methods were applied. First, by conducting a systematic scoping review at the continental scale, we compiled existing knowledge and identified gaps regarding trends and impacts of droughts in SSA. Next, an investigation was done on the influence of natural volcanic forcing and internal climate variability on one of the most extreme droughts that occurred during the 20th century in SSA; this analysis of the climatic impacts following the Mount Pinatubo eruption in 1991 also included identification of implications of this to geoengineering solutions of global warming. We then assessed the spatio-temporal characteristics of droughts in Tanzania, with a specific focus on examining their distribution and patterns over time. Lastly, by utilizing household panel survey data in Tanzania, I estimated the influence of climate extreme shocks on the decision of households among agro-pastoral communities to cope with droughts and heat and how market accessibility would facilitate.

The key findings of this study were: 1) extreme climate events such as droughts and heatwaves are intensifying over SSA and there is a demand for more empirical research on the continent especially to the underrepresented blocks such as central Africa, 2) stratospheric volcanic induced aerosols exacerbate droughts in SSA, implicating extreme caution for geoengineering solutions, 3) droughts have been significantly increasing in Tanzania over the past 61 years and the dry seasons are becoming drier while crop growing seasons have been impacted severely. This poses a major challenge to rain-fed agricultural schemes. Finally, 4) decisions of rural households to adapt to climate extremes rely on market accessibility as food consumption becomes constrained. All these findings have policy implication that, specificity will always remain to inform the details and therefore caution should be exercised in devising and implementing solutions to the climate crisis at any level, including solar radiation management to reduce warming.

  • Climate Extremes
  • Dryland
  • Ecosystems
  • Societies
  • Sub Saharan Africa
Citation (ISO format)
KITASHO, Neema Maburre. The Impact of Climate Extremes on Dryland Ecosystems and Societies in Sub-Saharan Africa. 2023. doi: 10.13097/archive-ouverte/unige:174046
Main files (1)
accessLevelPrivateaccessLevelPublic 01/01/2026
Secondary files (1)

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Creation01/03/2024 9:48:16 AM
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