Climate change, cocoa migrations and deforestation in West Africa: What does the past tell us about the future?

Cocoa farming has been a major driver of deforestation in West Africa, notably in Côte d'Ivoire, the world's leading cocoa producer. Cocoa has been a "pioneer crop" that was grown after forest clearing, and instead of replanting aging plantations, farmers usually migrated to the forest frontiers to establish a new cocoa farm. During the second half of the twentieth century, the cocoa frontier moved from the drier east to the wetter southwest of the country, fueled by massive immigration of prospective cocoa farmers from the savanna. It has been argued that the climate gradient was a major driver of these east-west migrations and that cocoa farmers, by replacing forest with farm land over vast areas, contributed to the further drying of the climate in a positive feedback cycle. If this were the case, then a hotter and drier future climate would likely continue to push cocoa farmers into the wetter southwest of the sub-continent, with the last forest reserves of southwestern Côte d'Ivoire and Liberia as the only remaining destinations. Based on an analysis of long-term rainfall measurements in major cocoa growing areas of Côte d'Ivoire and interviews with cocoa farmers about their history and motives of migration, we argue that climate and drought have been supporting factors, but not usually the main drivers of cocoa migrations, which were mostly a response to the perceived availability of forest land for planting. We also show that the observed decrease in rainfall in the cocoa regions during the 1970s and 1980s was not primarily a response to local deforestation related to cocoa farming, although deforestation may have caused microclimatic changes. Climate extremes like the 1982/3 drought have also triggered adaptations of farming practices like replanting and crop diversification. To prevent cocoa farming from continuing to act as a driver of deforestation in a hotter climate, governments and supply chain actors should discourage forest frontier dynamics and shoul