In today's society, technological innovation progresses daily, but it also brings to light ethical and social challenges. Against this backdrop, the importance of Responsible Research and Innovation (RRI), which considers Ethical, Legal and Social Issues (ELSI) at universities, is increasing. The purpose of this series is to share our knowledge on various engineering-related technologies and their social impacts, and to deepen public understanding. In other words, we will explore the ELSI/RRI of future technologies from multiple perspectives. We also aim to provide viewers with new perspectives through the insights and dialogue of researchers at the forefront of future technologies. Volume 2 of the series is titled "Energy and Environment." Facing the major challenge of climate change, how should we build a sustainable society for the future? Four leading professors from different fields will tackle this question without a single answer. Please enjoy this discussion that intentionally offers no definitive conclusions.