Climate Change Vulnerability and Adaptation Pathway Analysis for the Nigerian Horticultural Sector: An Integrated Assessment

Nigeria's horticultural sector faces multidimensional climate change threats including shifting rainfall seasonality, increased temperature extremes, elevated CO2 concentration effects, and heightened pest and disease pressure. A comprehensive integrated assessment of sector-wide vulnerability and viable adaptation pathways has not previously been developed for Nigerian horticulture. This dissertation constructs an integrated vulnerability and adaptation assessment framework for the Nigerian horticultural sector, combining biophysical crop modeling, socioeconomic household vulnerability analysis, and participatory stakeholder scenario planning. The DSSAT crop modeling platform was calibrated and applied for key horticultural crops across representative sites in all six geopolitical zones under RCP 4.5 and RCP 8.5 climate scenarios to 2060. Vulnerability mapping integrated biophysical exposure, smallholder farmer sensitivity metrics, and adaptive capacity indices. Expert stakeholder workshops were conducted in all six zones to generate and evaluate adaptation pathways. Results project mean horticultural yield declines of 15 to 32 percent by 2060 under RCP 8.5 across crops and zones, with North East and North West zones most severely affected. Adaptation pathway analysis identifies crop diversification, precision irrigation, and heat-tolerant variety deployment as the most cost-effective strategies. The study provides Nigeria's first geopolitically comprehensive horticultural climate vulnerability and adaptation assessment, establishing a knowledge base for national agricultural climate policy. Keywords: climate change vulnerability, adaptation pathways, Nigerian horticulture, crop modeling, integrated assessment