Climate risk adaptation by smallholder farmers: the roles of trees and agroforestry

•The potential of agroforestry as an adaptation strategy is now being recognized.•Its biophysical and socio-economic benefits are well understood at the farm-level.•On a broader scale, the environmental services it provides should also be considered.•This will help promote its status as a viable and effective system to address impacts of climate change.•Research, policy and dissemination efforts are needed for its promotion and widespread adoption.