Abstract
A revolution in the energy sector is crucial for achieving environmental sustainability since almost three-fourth of global carbon dioxide emissions is generated from the energy sector. It is believed that combustion of unclean energy resources is the major contributor to the multifaceted environmental adversities experienced across the globe. Thus, the development of clean energy technologies, to elevate their shares in the global energy mix, is deemed necessary to reinstate environmental well-being worldwide. Against this background, this study aims to explore the symmetric and asymmetric impacts of public research and development investments for nuclear and renewable energy development and economic growth on carbon dioxide emissions in the context of Japan over the 1974-2017 period. As opposed to the conventional approaches, this study contributes to the literature by specifically scrutinizing the environmental effects associated with public investments in clean energy development projects; whereas the majority of the preceding studies have either considered the environmental impacts associated with the overall research and development investments in the energy sector or that made by firms in general. However, evaluating the effects of such investments for clean energy development is more appropriate for policy-making purposes. The results from both the symmetric and asymmetric analyses reveal that higher public investments in clean energy research and development-oriented projects help to curb carbon dioxide emissions in Japan. Besides, such investments for nuclear energy development are evidenced to be relatively more effective in facilitating the nation's carbon emission-abating agenda. In contrast, economic growth in Japan is evidenced to trigger higher carbon dioxide emissions. In line with these key findings, this study offers several policy-level suggestions in respect of undergoing clean energy transition and achieving environmental sustainability in Japan.