IntroductionClimate change poses fundamental threats to food security and health systems, with children under five experiencing disproportionate nutritional vulnerability. Nigeria’s high climate sensitivity and severe child undernutrition burden create a critical nexus requiring policy attention. This study aims to systematically analyze pathways through which climate change worsens child undernutrition in Nigeria and critically evaluates the National Climate Change Policy’s responsiveness to these documented impacts.MethodsA systematic review of literature published between 2019 and 2024 was conducted following PRISMA guidelines, searching multiple databases (PubMed, ScienceDirect, The Lancet, Google Scholar) and organizational websites.ResultsFrom 1,084 found records, 27 studies met inclusion criteria after rigorous screening. Our critical policy analysis reveals that while Nigeria’s National Climate Change Policy (2021–2030) acknowledges child vulnerability and references a reported stunting prevalence of 43.6%, it does not operationalize this recognition. The policy lacks specific goals, measurable indicators, or targeted interventions to reduce child stunting and wasting. A critical disconnect exists between the documented climate-nutrition pathways and Nigeria’s policy response.DiscussionTo protect vulnerable children, there is a need for integration of explicit nutrition security goals, strengthened intersectoral collaborations among the Federal Ministries of Health, Agriculture and Food Security, Environment, Finance and the Economy, and Women Affairs, alongside international partners such as UNICEF, WHO, and the World Food Programme, and implementing climate-sensitive and sustainable interventions that address inequities and gender disparities.Systematic review registrationPROSPERO (International Prospective Register of Systematic Reviews). CRD420261330377, https://www.crd.york.ac.uk/PROSPERO/view/CRD420261330377.