Africa faces significant food security challenges, particularly concerning rice, a staple crop whose demand has quadrupled between 1990 and 2018. This surge is driven by population growth and dietary changes. Despite yield improvements, production lags behind demand, leading to increasing import dependency, primarily from Southeast Asia and India. This dependence renders Africa vulnerable to external supply and price shocks, as seen during the 2008 food crisis. While self-sufficiency policies might seem appealing, their effectiveness in improving food security is uncertain, given the high spatiotemporal variability in rice yields and constraints on intensification. The combination of import dependency, yield variability, and widespread undernourishment necessitates a thorough analysis of the future impacts of climate and socio-economic changes on Africa's rice supply. This study focuses on rice due to its escalating importance in Africa's food system.

Existing studies on the impact of climate change on African rice yields present varying results. Some studies project yield changes ranging from -24% to +18% by 2070, emphasizing the need for heat-resistant cultivars. Others predict limited yield losses (<5%), highlighting the potential offsetting effect of CO2 fertilization. Regional studies show varying impacts, with significant yield losses projected for some areas, potentially mitigated by new cultivars. However, research on the indirect effects of climate change in exporting regions on Africa's rice availability remains limited. Furthermore, the impact of climate-driven year-to-year yield variability on African rice systems is not well understood, despite projections of increased variability in other regions. Existing studies using the Shared Socioeconomic Pathway (SSP) framework often lack regional specificity or fail to consider yield variability and consumer responses, hindering effective policymaking.

This study employs an ex ante assessment of rice availability and stability in Africa using a modeling sequence that combines the Global Biosphere Management Model (GLOBIOM) and the Environmental Policy Integrated Climate Model (EPIC-IIASA). The analysis uses an envelope of socio-economic and climatic pathways to assess the integrated impacts of gradual climate change, year-to-year variations, and socio-economic development on rice availability. The model considers five distinct GCMs under two forcing pathways (SSP126 and SSP370) and three SSPs (SSP1, SSP2, and SSP3) representing different levels of socio-economic challenges. The study incorporates both gradual climatic effects and year-to-year anomalies. Annual EPIC-IIASA yield projections are converted to decadal GLOBIOM resolution using 30-year average values. Temporal variations in rice availability are analyzed using percentile frameworks, considering both yield anomalies and trends within the 2035-2065 time window. The model accounts for land allocation, management shifts, and changes in crop demand due to population, GDP, trade facilitation, and dietary preferences, but it does not explicitly model cross-price effects between crops.

The study's key findings show that socio-economic development, driven by population effects, is the primary determinant of changes in African rice availability, outweighing the influence of climatic pathways. Socio-economic development dictates both rice production and consumption levels. While climate change can reduce rice productivity in certain regions, this effect is often offset by increased imports and expanded production areas. Gradual climate change has a more limited impact than indicated by some previous studies. Climate change is not predicted to significantly increase the magnitude of rice yield shocks in most African regions. However, regions heavily reliant on rainfed production and those with high self-sufficiency remain vulnerable to local yield shocks. Import-dependent regions, in contrast, show greater sensitivity to yield shocks occurring in major exporting regions like Southeast Asia (SEA). The magnitude of consumer response to climatic anomalies in SEA varies across SSPs, with lower responses observed under SSP1 (Sustainability), which assumes fewer trade barriers. Local yield variations impact consumption in both lower and upper tails of the distribution, whereas external (SEA) effects mainly affect the lower tail, suggesting that only negative effects of yield variations spill over through trade.

The findings underscore the importance of socio-economic factors in shaping rice availability in Africa. While climate change poses regional challenges, its impact on overall rice availability and stability is less pronounced than socio-economic drivers. The limited impact of climate change on yield variability, contrary to findings in other regions and for other crops, suggests potential opportunities for mitigation in African rice production. However, the vulnerability of rainfed regions and import-dependent regions to local and external shocks, respectively, remains a concern. The study's observation that reducing trade barriers under SSP1 lowers the magnitude of import-driven consumption shocks highlights the importance of trade policies in enhancing rice security. The model's limitations regarding cross-price effects and extreme weather events suggest avenues for future research.

This study highlights the crucial role of socio-economic development and trade policies in ensuring rice availability and stability in Africa. While climate change poses regional challenges, its overall impact is less significant than socio-economic factors. Agricultural productivity growth, reduced trade barriers, and strategies to manage local yield variability, such as shifting to irrigation systems, are crucial for enhancing rice security. Future research should refine the model to better capture cross-price effects, extreme weather impacts, and spatial population dynamics.

The study's model does not account for cross-price effects between crops, which could influence land allocation and consumption patterns. The model also has limitations in capturing the full range of responses to extreme weather events such as severe droughts. The lack of explicit modeling of within-country migration could also influence the accuracy of projected consumption responses. Furthermore, the study focuses on long-term projections, potentially overlooking short-term fluctuations and crises.