Potential impacts of stratospheric aerosol injection on crop yields and related economic outcomes in Africa

[Geoengineering News]

https://iopscience.iop.org/article/10.1088/2752-5295/ae4921

Authors: Rhoda Fiyinfoluwa Ayedun, Babatunde J Abiodun and Lili Xia

23 February 2026 

Abstract

Climate change poses a significant threat to crop production and food security in Africa, primarily by increasing dry areas across many regions. Stratospheric Aerosol Injection (SAI) could emerge as a potential cost-effective strategy to mitigate temperature-related impacts globally, yet its implications for African agriculture remain underexplored. This study evaluates the effects of climate change and SAI on crop yields and economic outcomes across Africa. We assessed maize, sorghum, and millet yields under present and future climates, with and without SAI intervention aimed at limiting warming to 1.5°C under the SSP2-4.5 scenario, using the process-based Decision Support System for Agrotechnology Transfer Cropping System Model (DSSAT-CSM). SAI effectively reduces temperature increases continent-wide but alters precipitation patterns unevenly. During the growing season, it is projected to offset rainfall declines in some parts of West Africa while intensifying reductions in Southern, East, and Central Africa. Under SSP2-4.5, maize and millet yields are projected to decline across most regions relative to the present-day levels. Sorghum shows mixed responses, with gains in parts of West and East Africa and losses elsewhere, particularly in the Sahel, Botswana, and South Africa. Compared with SSP2-4.5, SAI mitigates yield losses for maize and millet, though not entirely. For sorghum, it reduces losses where yield loss is greater than 10%. Despite reduced rainfall, SAI improves overall crop performance with the lowest improvement occurring in Southern Africa. Economically, all regions are projected to incur losses from declining yields under SSP2-4.5. SAI offers partial relief, especially in West Africa, where losses are offset by approximately 73 million USD, nearly double the continental average of 39 million USD. At the national level, SAI provides the greatest relief from agriculture-related economic losses simulated under SSP2-4.5 in Nigeria, Mali, Benin, Niger, and Ghana. These findings underscore the potential of SAI to reduce climate-induced agricultural and economic risks in Africa, while highlighting regional disparities in its effectiveness. However, SAI is not a substitute for reduction of emissions or investments in adaptive capacity.

Source: IOP Science