Transport Productivity, Hydrogen Innovation, and Environmental Sustainability: Evidence From High‐Income Economies in Achieving SDG Targets

ABSTRACT Environmental sustainability has become a major policy challenge for high‐income economies, particularly as expanding transport systems increase energy demand and ecological pressure. This raises concerns about the compatibility of economic efficiency with the Sustainable Development Goals (SDGs). Against this backdrop, the present study investigates the impacts of transport productive capacities (TPC) and hydrogen and fuel cell R&D (HFR&D) on environmental sustainability in six high‐income SCAN‐DK economies from 2004 to 2024. To provide a comprehensive assessment, the study uses ecological footprint (EF) and load capacity factor (LCF) as complementary sustainability indicators and applies second‐generation panel econometric techniques, including Westerlund–Edgerton cointegration, and the Augmented Mean Group (AMG) estimator. The empirical results reveal a clear dual dynamic. TPC improves transport efficiency and economic connectivity but significantly increases ecological pressure by raising EF and reducing LCF, indicating that productivity gains alone may undermine sustainability through Rebound Effects. In contrast, HFR&D significantly lowers EF and improves LCF, demonstrating that hydrogen‐related technological innovation mitigates transport‐induced environmental degradation and strengthens ecological resilience. These findings suggest that transport infrastructure expansion should be integrated with hydrogen‐based clean energy transitions. Policymakers should therefore prioritize hydrogen innovation and green transport strategies to balance economic efficiency with long‐term progress toward SDG‐7, SDG‐9, and SDG‐13.