An Exploratory Protocol for Sustainability-Oriented Cross-Index Assessment of National Climate Policy Effectiveness

Many national climate policies coexist with a persistent gap between stated temperature goals and observed emissions trends, creating a demand for transparent and comparable tools to evaluate policy effectiveness. However, widely used climate-policy ratings differ in scope, indicator design, time coverage, and scoring scales, often producing inconsistent country assessments and complicating evidence-based decision-making. This paper proposes an integrated protocol for cross-index assessment of national climate-policy effectiveness. We combine a comparative analysis and a SWOT analysis of four representative approaches - the Climate Change Performance Index (CCPI), Climate Action Tracker (CAT), the Climate Laws, Institutions and Measures Index (CLIMI), and the Climate Policy Measure Index (CPMI) - with a pilot inter-index consistency test using correlation analysis for a small country sample. The pilot indicates strong alignment among broad, composite approaches (CCPI, CAT, CLIMI), while an instrument-focused metric (CPMI, centered on carbon-pricing and fiscal signals) shows weaker consistency with outcome- and gov-ernance-oriented ratings. Building on these insights, we compile an integrated indicator set that links outcomes (GHG levels and trends), structural drivers (energy mix, efficiency), policy in-struments (pricing, regulation, subsidies), governance capacity (legal and institutional strength), and enabling conditions (finance, public engagement, international cooperation). The proposed protocol is intended as a decision-support framework to reconcile discrepancies across existing indices and to structure multidimensional evaluations; limitations of the pilot analysis motivate a larger-sample validation and harmonization of index time frames in future work.