Abstract
Summary The need to assess major infrastructure performance under a changing climate is widely recognized yet rarely practiced, particularly in rapidly growing African economies. Here, we consider high-stakes investments across the water, energy, and food sectors for two major river basins in a climate transition zone in Africa. We integrate detailed interpretation of observed and modeled climate-system behavior with hydrological modeling and decision-relevant performance metrics. For the Rufiji River in Tanzania, projected risks for the mid-21st century are similar to those of the present day, but for the Lake Malawi-Shire River, future risk exceeds that experienced during the 20th century. In both basins a repeat of an early-20th century multi-year drought would challenge the viability of proposed infrastructure. A long view, which emphasizes past and future changes in variability, set within a broader context of climate-information interpretation and decision making, is crucial for screening the risk to infrastructure.
Highlights
In sub-Saharan Africa (SSA), exposure and vulnerability to climate risk is high across crucial economic sectors.[1,2,3,4,5] Recent extreme drought and flooding events demonstrate the scale of disruption.[6,7,8] The 2015–2016 drought across southern Africa highlighted the cascading nature of impacts involving food insecurity, power cuts, and drinking water shortages,[6] disproportionally affecting small and medium-sized enterprises.[7]
Characterizing historical rainfall variability Rainfall over southern East Africa (sEA) is primarily controlled by the African rain belt, which is intensely active from December to March and predisposed to north-south fluctuations,[29] driving high interannual rainfall variability with a standard deviation (SD) of ~200 mm around a crop production-critical level in both basins (Figures 2A and 3)
Rainfall variability over our study basins substantially reflects the control of ENSO23–25 and the IOD22 (Figure 3) occurring both independently[26] and through complex interactions.[48,49]
Summary
In sub-Saharan Africa (SSA), exposure and vulnerability to climate risk is high across crucial economic sectors.[1,2,3,4,5] Recent extreme drought and flooding events demonstrate the scale of disruption.[6,7,8] The 2015–2016 drought across southern Africa highlighted the cascading nature of impacts involving food insecurity, power cuts, and drinking water shortages,[6] disproportionally affecting small and medium-sized enterprises.[7]. Despite awareness of climate impacts on development,[8,16] climate variability and future change have received limited attention in investment decisions[17] and practical coordination on adaptation remains superficial and sectoral,[18] despite guidelines appearing.[19,20] Most investments in large hydropower plants are still made under the assumption that rainfall or river flow patterns will resemble historical patterns, which are often poorly characterized. This poses severe risks to performance.[21] the vast majority of studies on future projections focus on changes in mean climate. Information on past and possible future changes in variability is typically neglected in climate risk assessments.[22]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
