Climate change has increasingly shifted courts into a central role in environmental governance, driving a rapid growth of climate-related litigation across diverse legal regimes. This study examines the evolving role of judicial activism in climate policy enforcement and doctrinal innovation through a comparison-based methodology across ten jurisdictions between 2015 and 2024. The methodology integrates doctrinal legal analysis with a multidimensional judicial analytics model, combining case selection indicators, reasoning intensity measures, judicial influence metrics, doctrinal expansion tensors, and temporal efficiency assessments. The study systematically examines how courts interpret and expand environmental rights, enable transnational jurisprudence, and influence the implementation of policies through court judgments. The findings indicate that in countries with strong institutional infrastructure, such as Germany, the Netherlands and France, judicial mandates are more closely aligned with policy enactments. By contrast, in newer legal systems like Pakistan and Colombia, courts display greater creativity in reasoning despite structural limitations. The reliance on scientific evidence, rights-based claims, and intergenerational justice principles enhances judicial legitimacy and strengthens the adaptability of the process. Differences in enforcement timelines and institutional readiness further demonstrate that the existence of sophisticated doctrinal reasoning alone does not guarantee effective outcomes without supportive legal and administrative frameworks. Overall, the research contributes to the literature by providing a comparative, model-based evaluation of how courts reinterpret environmental law and act as catalysts for legal change in addressing global environmental challenges.