The dynamics of livestock systems in sub-Saharan West Africa on the 2040 horizon will be determined more by current and expected societal changes than by climate change. Climate change is expected to result in increases in the concentration of carbon dioxide in the air, in temperatures in the warmer seasons, and in rainfall mainly due to more frequent and intense heavy storms. These increases are expected to favour crop production, but also runoff, soil erosion and flooding. The rapid and persistent increase in rural population density despite dramatic urbanisation is expected to fuel further expansion of cultivated lands and the reduction and fragmentation of rangelands, hampering pastoral mobility. This is likely to reduce the activity of seasonally mobile pastoral livestock farming, but also that of sedentary livestock farming deprived of rangelands and a source of competitively priced young animals. A policy that would advocate the end of seasonal regional transhumance in favour of ranching and stabling, would precipitate the decline of pastoral livestock and increase their fragility in the face of climatic and security risks. This change would require an investment that is beyond the reach of livestock breeders, who would be reduced to working for private investors or agro-industrial companies. The only policy that could sustainably support livestock systems in their diversity and complementarity would be resolute public investment by States and Regional Economic Communities (RECs) in the transformation and modernisation of pastoral mobility. Access to pastoral resources and regional and local herd mobility should be secured by reaffirming the community or public status of water points and rangelands in hyper-arid zones, but also of non-cultivable land in wetter zones, as well as negotiated access rights to cultivated land after harvest. Frameworks for local and regional consultation should be established, and contractual agreements between pastoralists, agro-pastoralists and farmers should be facilitated. It is necessary to complete, rehabilitate and manage the hydraulic and veterinary infrastructures, the livestock passage corridors, the land reserved for grazing, the lodgings or enclosures for the livestock, with a view to creating a network of infrastructures adapted to the available forage resources, established in consultation with the livestock breeders' associations and the local authorities. A national and international commitment should overcome the civil insecurity that is rampant in many pastoral regions, along with significant investments in education, health, roads and telecommunications infrastructure that would ensure security and the adaptation of pastoral livestock farming to societal changes.