This study examines the impact of technological change (environmental patents), human capital, and income on carbon (CO₂) emissions in Germany, France, and the Netherlands, three EU member countries, over the period 1974–2019. The study applies the Fourier-ADL approach and various time series estimators to test the Environmental Kuznets Curve (EKC) hypothesis. The results show that the EKC hypothesis is valid for all three countries, and human capital contributes to carbon reduction. Environmental patents contribute to CO₂ mitigation in Germany but not in France and the Netherlands. The study suggests that France and the Netherlands should invest more in environmental patents to benefit from their CO₂ reduction effects, while Germany can continue relying on environmental patents to achieve its carbon neutrality goals. The study contributes to the literature by examining the influence of environmental patents on CO₂ emissions using Fourier-based methods and focusing on leading EU countries.This study examines the impact of technological change (environmental patents), human capital, and income on carbon (CO₂) emissions in Germany, France, and the Netherlands, three EU member countries, over the period 1974–2019. The study applies the Fourier-ADL approach and various time series estimators to test the Environmental Kuznets Curve (EKC) hypothesis. The results show that the EKC hypothesis is valid for all three countries, and human capital contributes to carbon reduction. Environmental patents contribute to CO₂ mitigation in Germany but not in France and the Netherlands. The study suggests that France and the Netherlands should invest more in environmental patents to benefit from their CO₂ reduction effects, while Germany can continue relying on environmental patents to achieve its carbon neutrality goals. The study contributes to the literature by examining the influence of environmental patents on CO₂ emissions using Fourier-based methods and focusing on leading EU countries.