From words to deeds: unpacking the configurations for effective dual carbon policy based on a three-dimensional analytical framework in China

Climate policy effectiveness research increasingly focuses on understanding how policies translate into outcomes across diverse contexts, recognizing that implementation mechanisms are as crucial as policy design itself. Analyzing 88 national and 493 provincial policy documents from China (2020–2023), we identify the dual carbon policy: what works, what makes it effective, and what causes it to fail. We establish an Objectives-Tools-Effectiveness framework and apply improved Policy Modelling Consistency (PMC) indexing and fuzzy set Qualitative Comparative Analysis (fsQCA) to identify effective implementation pathways. Three key findings emerge. First, China’s policy tools exhibit structural imbalances, including over-reliance on environmental regulations, supply-demand mismatches, and inadequate coverage in green finance and carbon sinks. Second, a significant design-implementation gap exists; while 93.1% of provinces achieve high-quality PMC, only 55% attain effective implementation performance. Third, we observe asymmetric patterns: successful configurations demonstrate favourable substitution (economic resources and social participation serve as alternatives), whereas failed pathways exhibit deficiency cascade (multiple weaknesses reinforce each other: Ningxia’s vague goals, weak enforcement and coal dependence produced worse outcomes than any single deficiency), whereas failed pathways exhibit an inverse barrel effect, where multiple deficiencies reinforce each other rather than creating opportunities for compensation, and policy planning clarity emerge as a core variable across all effective pathways. These findings reveal that policy effectiveness depends on coordinated alignment between design and implementation elements rather than design quality alone, a lesson critical for the 195 parties to the Paris Agreement as they enhance the ambition of their Nationally Determined Contributions (NDCs) under the UNFCCC, highlighting the necessity of aligning policy design with implementation capacity in NDC scaling. The study advocates differentiated governance strategies tailored to regional contexts, offering evidence-based frameworks to optimize climate policy implementation by systematically understanding both success and failure mechanisms. Prioritize implementation monitoring over design refinement: Tracking cross-departmental coordination and actual outcomes matters more than perfecting policy documents.Establish minimum thresholds across multiple dimensions: Partial strengths cannot compensate for critical weaknesses; simultaneous attention to planning, capacity, and engagement prevents deficiency cascades.Treat planning clarity as non-substitutable: Clear targets, timelines, and accountability assignments form the essential foundation enabling other elements to function.Adopt regionally differentiated strategies: Resource-constrained regions should leverage social participation; economically advanced regions can prioritize market instruments and technology Prioritize implementation monitoring over design refinement: Tracking cross-departmental coordination and actual outcomes matters more than perfecting policy documents. Establish minimum thresholds across multiple dimensions: Partial strengths cannot compensate for critical weaknesses; simultaneous attention to planning, capacity, and engagement prevents deficiency cascades. Treat planning clarity as non-substitutable: Clear targets, timelines, and accountability assignments form the essential foundation enabling other elements to function. Adopt regionally differentiated strategies: Resource-constrained regions should leverage social participation; economically advanced regions can prioritize market instruments and technology