Some implications of terrestrial ecosystems response to climate change for adaptation in Nigeria's wooded savannah

Knowledge of non-linear and variable climate risks generated by the interaction between climate and terrestrial ecosystems at local spatial scales is important for place-based and context specific adaptation. In this study we generated 24 risk factors from 9 climate risk determinants based on the trend in present and future climate, water footprints associated with climate–ecogeographic interactions, climate–land cover relations and socio-demographic profiles. The description of aggregate climate risk was compared across community clusters, local government areas, and 3 broad zones in the wooded savannah of Nigeria. The results suggest rainfall, which is increasing at about 0.6 mm/decade under the present climate will decline by about 4 mm/decade under future climate. Future maximum temperature is projected to increase by about 0.02 °C/decade, a rate that is lower than the present 0.06 °C/decade. Rainfall was found to be the most important determinant of ecosystem changes and propagation of natural resource systems and the livelihoods they support. Climate risks vary spatio-temporally across zones, local government areas and community clusters with strong orientation to water (rainfall) footprint. The likelihood of the geographic shifting of risks such as loss of arable lands and human migration from moisture deficit areas to more favorable areas due to the changing water footprint is high.

► We assess climate risk based on 24 risk factors extracted from 9 climate risk determinants.
► The pattern of risk is non-linear and strongly orientated towards the water footprint.
► The changing water footprint would result in changing spatial distribution of climate risks.
► Crop water efficiency is a necessary adaptation option for future small-holder farmer.