1. Introduction
In West Africa, many smallholder farmers deal with low and unpredictable crop yields and incomes, as well as chronic food insecurity. These challenges are particularly acute in the dry lands, where land degradation, depleted soil fertility, water stress, current climate variability, and high costs of fertilizers contribute to low crop yields (Zougmoré et al., 2014). Moreover, annual cycles of rainfall are strongly determined by the position of the inter-tropical convergence zone, making the climate of the region one of the most erratic in the world and predictions of future changes in climate, especially rainfall, highly uncertain (Traore et al., 2013).
Despite contrasting scenarios of climate change for this region, all models expect an increase of climate variability (Cooper et al., 2008; Jalloh et al., 2013). Consequently, climate change will pose huge challenges to food security (Waongo et al., 2015) and particularly to child nutrition and health (Johnson and Brown, 2014). African farmers have consistently been exposed to high variability in their production environment, and therefore already use a broad spectrum of coping strategies including the selection of drought tolerant varieties or crops, traditional water harvesting techniques (e.g. zai), the diversification of income sources by combining cropping with livestock
earing, and off-farm activities (Abdulai and CroleRess, 2001; Dostie et al., 2002; Thomas et al., 2007; Thornton et al., 2007). These coping strategies may not be sufficient to face the expected increase in climatic variability of unknown magnitude, which will likely result in novel solutions (Andrieu et al., 2015). Therefore, coping strategies in a perspective of transformational adaptation need to be considered. Rippke et al. (2016) concluded that in some areas in the Sahel production of nine of the major crops will become unviable by 2050, with the most affected crops being maize and bananas. Areas in northern Ghana, northern Benin, and northeastern Ivory Coast will become unsuitable for growing bananas without technical and socio-economic transformation, as will large swathes of Mali, Senegal, and Burkina Faso for growing
maize.
