Climate change will limit the potential for intensification in Senegal

Abstract Climate change poses an increasing threat to food security in sub-Saharan Africa. This study assesses the impact of climate change on millet yields and investigates how it may limit the potential for agricultural intensification. The STICS crop model, driven by a high-resolution, bias-corrected ensemble of CMIP6 climate projections based on the SSP5-8.5 scenario, was used to simulate millet yields under various nitrogen input scenarios in Senegal. Climate projections indicate an average +3°C regional temperature increase by 2056–2085, alongside significant uncertainty in future rainfall patterns. Depending on the level of intensification, yield losses range from 19% to 32%. Although intensification could theoretically increase yields by a factor of 4.8, this potential is reduced to an average of 2.9 under future climate conditions and is virtually eliminated in some climate models. This reduction is primarily driven by rainfall projections where rainfall deficits strongly affect “intensified” yields. Thermal factors are also important for future yield, especially heat stress which inhibit grain filling in millet. To our knowledge, these findings are amongst the first to highlight how future climate uncertainty could significantly reduce the effectiveness of nitrogen-based intensification for millet in Senegal. They emphasise the urgent need to design adaptation pathways specifically tailored to smallholder systems. These pathways should include improved soil and water management, climate-resilient cultivars, and risk-adjusted fertiliser strategies. This will help to safeguard productivity while promoting sustainable intensification.