How green technology innovation affects carbon emission efficiency: evidence from developed countries proposing carbon neutrality targets

With the introduction of national carbon neutrality targets, carbon emission reduction actions in developed countries have become a hot topic as part of the international community's drive to take action to mitigate climate change. Carbon emission efficiency is an important indicator that can be used to measure progress toward carbon emission reduction targets. The relationship between green technology innovation and carbon emission efficiency has not been adequately studied, and the transmission mechanism is not yet clear. Based on the above research gaps, taking 32 developed countries that have proposed carbon neutral targets as research samples, this paper used spatial econometric models to explore the impact of green technology innovation on carbon emission efficiency and adopted spatial mediation model and spatial moderation model to analyze the transmission effects of economic development, urbanization, and financial development on environment-related green technology and carbon emission efficiency. This paper aimed to provide a policy basis for developed countries to mitigate carbon emissions and achieve carbon neutrality goals as soon as possible. The following results were obtained: (1) Luxembourg, Norway, and Switzerland were found to be efficient in terms of carbon emissions, while most developed countries were in an inefficient state. (2) Environment-related green technology innovation significantly improved carbon emission efficiency. (3) Economic development and urbanization had a mediating role on green technology innovation and carbon emission efficiency. In other words, green technology innovation could have an indirect impact on carbon emission efficiency by influencing economic development and urbanization. (4) Financial development could positively moderate the sensitivity of carbon emission efficiency to green technology innovation. Improving the level of green technology innovation is one way to improve carbon emission efficiency, and the mediating effect of economic development and urbanization can be used as a focus point to improve carbon emission efficiency. The pressure of carbon emission reduction can be moderated by finance development. The results of this study provide theoretical support that will assist developed countries in achieving their carbon neutrality targets.