An Original Investigation of the Health Consequences of Climate Change for Nigerian Communities: A Systematic Evidence Synthesis and Theoretical Model

Climate change is increasingly recognised as a fundamental threat to population health in sub-Saharan Africa, and Nigeria's vulnerability to climate-related health risks including extreme heat, flooding, drought-linked food insecurity, and vector range expansion requires a systematic evidence synthesis and original theoretical modelling to guide community health adaptation planning. This study conducted an original investigation into the health consequences of climate change for Nigerian communities through systematic evidence synthesis and theoretical model development. A systematic review methodology was employed, searching eleven databases for publications on climate change and human health in Nigeria from 2015 to 2024. Sixty-three eligible publications were included in a narrative and thematic synthesis organised by health outcome category: heat-related illness, vector-borne disease, waterborne disease, food security and malnutrition, mental health, and displacement-related health. Primary fieldwork supplemented the review through structured community vulnerability assessments in eight communities across four geopolitical zones selected to represent diverse climate risk profiles: flood-prone Niger Delta communities, drought-affected Sahel communities, extreme heat-affected urban communities, and highland communities facing altered disease vector distributions. The original Nigerian Climate-Health Vulnerability Framework developed through synthesis and fieldwork proposes four theoretical dimensions: biophysical exposure pathways, community sensitivity factors (including poverty, housing quality, and healthcare access), adaptive capacity determinants (including health system resilience, livelihood diversification, and social capital), and health system response adequacy. Expert validation by 22 climate health, environmental epidemiology, and community medicine scholars confirmed the framework's theoretical originality and policy relevance for Nigerian health adaptation planning.

Keywords: climate change, health consequences, Nigeria, systematic review, climate-health vulnerability framework