The Climate Action Index: A Subnational Assessment Framework for Policy, Impact and Climate Finance Utilization

Climate change remains one of the most critical challenges of our time, and developing economies like Nigeria face heightened risks due to their dependence on carbon-intensive growth. Over the past decade, while Nigeria’s GDP grew by 6.4% between 2011 and 2021, the country also witnessed a staggering 14.7% surge in greenhouse gas emissions. This divergence clearly illustrates the urgent need for policies that decouple economic progress from environmental harm. Looking ahead, projections estimate that Nigeria’s GDP will reach around $1.35 trillion in purchasing power parity (PPP) terms by 2025. As the nation strides toward this ambitious goal, it becomes imperative to adopt a structured, data-driven approach to climate governance. Despite the commitments set out in the Climate Change Act (Federal Republic of Nigeria, 2021) and Nigeria’s Nationally Determined Contributions (NDCs), there remains a significant gap between policy ambitions and on-the-ground implementation. Current measures often lack robust mechanisms for subnational tracking, evaluation, and accountability. To address these challenges, the Climate Action Index (CAI) has been developed as a transformative tool. The CAI translates broad climate goals into actionable, state-specific performance metrics, providing an integrated framework to assess climate governance effectiveness, financial efficiency, and environmental outcomes across Nigeria’s 36 states and the Federal Capital Territory (FCT). Its design centers on three key pillars: Policy Alignment (40%)—Evaluates how well state-level policies, legislative frameworks, and institutional capacities align with Nigeria’s NDC targets and international climate commitments. This includes the presence of climate action plans, emissions regulations, and enforcement mechanisms. Spending Efficiency (30%)—Assesses the effectiveness of climate-related budget allocations, tracking fiscal spending on renewable energy, adaptation, and mitigation projects. This ensures that climate finance is strategically deployed to maximize impact. Outcome and Targeted Impact Transparency (30%)—Measures real-world progress in emissions reduction, resilience-building efforts, and socio-economic benefits. It incorporates a targeted impact sub-metric to evaluate how well climate interventions align with state-specific vulnerabilities and priorities. The CAI’s robustness comes from its integration of diverse data from high-resolution satellite imagery and economic