Modelling Non-Linear Climate Tipping Points and Agricultural System Transitions in Northern Nigeria Under High-Emissions Scenarios

Agricultural systems in northern Nigeria's North West and North East geopolitical zones may be approaching non-linear tipping points under high-emissions climate trajectories where incremental adaptations become insufficient and transformative system transitions are required, yet the thresholds, spatial differentiation, and transformation pathways for such tipping points remain theoretically underdeveloped and empirically uncharacterised for Nigerian contexts. This study theorises and models non-linear climate tipping points for agricultural systems in northern Nigeria using an integrated socio-ecological systems modelling framework under SSP3-7.0 and SSP5-8.5 emissions scenarios. The theoretical contribution builds on resilience theory's panarchy framework and non-linear systems dynamics to conceptualise agricultural system tipping points as regime shifts between stable states triggered by climate threshold crossings interacting with social-ecological feedbacks. Empirical modelling combines CMIP6 ensemble climate projections downscaled to 10-kilometre resolution with crop simulation modelling (DSSAT model suite), agent-based modelling of farming household adaptive behaviour, and dynamic vegetation modelling for the grassland-cropland interface. The modelling framework is parameterised using household survey data from 800 farming households across Kano, Katsina, Yobe, and Borno States. Sensitivity analysis quantifies threshold climate values at which simulated agricultural system outputs transition non-linearly from viable to collapsed states. Results identify three distinct tipping point thresholds for northern Nigerian agricultural systems: rainfall seasonality shift exceeding 15 days delay in monsoon onset, growing season temperature increase exceeding 2.8 degrees Celsius above baseline, and land degradation threshold interactions amplifying climate sensitivity. The study provides the first operational tipping point analysis for agricultural systems in northern Nigeria and makes original contributions to climate impact modelling methodology. Keywords: climate tipping points, agricultural systems, northern Nigeria, high-emissions scenarios, resilience theory.