Climate Change, Livelihood Transformation, and Adaptive Governance in the Sahel Fringe of North West Nigeria: A Complex Systems Analysis

The interaction between climate change drivers, livelihood transformation processes, and governance responses in Nigeria's Sahel fringe constitutes a complex adaptive system exhibiting emergent properties, feedback dynamics, and threshold behaviours that linear policy analysis fails to capture. This doctoral research applies complex systems theory and analysis to the challenge of adaptive governance for climate change in the Sahel fringe of North West Nigeria, covering Sokoto, Zamfara, and Katsina states. An extended mixed methods design combines agent-based modelling of household livelihood decision-making under climate variability, long-term socio-ecological panel data analysis drawing on 25 years of household survey and environmental monitoring records, and 18-month qualitative institutional ethnography across three governance levels. The agent-based model captures interactions between 4,200 virtual households with heterogeneous assets, climate scenario inputs derived from CMIP6 downscaled projections, and governance intervention scenarios. System dynamics analysis identifies three potential bifurcation points in the coupled social-ecological system at which governance interventions can prevent transition to undesirable system states. Qualitative institutional analysis examines how governance actors interpret and respond to non-linear system dynamics, finding systematic cognitive biases toward linear projections that underestimate threshold risks. The study makes original theoretical contributions by extending Ostrom's institutional analysis and development framework to incorporate explicit non-linearity and tipping point dynamics, and demonstrates the tractability of agent-based modelling in a Nigerian governance context. Operational contributions include a governance decision support tool validated through co-production workshops with Sokoto State environmental planning officials. Keywords: complex systems, climate adaptation, adaptive governance, Sahel, agent-based modelling.