Local drying climate magnified by urbanization in West Africa

Urbanization often increases surface runoff and land surface temperature due to loss of land cover. However, the effect of urbanization on local atmospheric humidity remains understudied despite the disastrous effects it can have on human health and water-food-energy-ecosystem nexus. Here, we examined changes in atmospheric humidity in the West Africa (WA) region between 1985 and 2018. There was an increase in vapour pressure and decrease in atmospheric humidity in urban areas suggesting intensified urban drying island (UDI) effects. Rapid urban expansion has aggravated UDI effect in recent years, particularly during the hot, wet summer but mild during the cold, and dry winter. In future climate, the impacts of the UDI effect in the region may be enormous considering the increasing rate of urbanization in the region. To achieve a sustainable future, city planners and policymakers should consider the UDI effect by promoting developments that increase green land cover. Overall, this study provides a detailed understanding of the urban ecosystem's environmental change, which is helpful for local climate change adaptation and mitigation.