Promoting interdisciplinary research and transdisciplinary expertise for realizing sustainable society

Sustainability is an important concept for society, economics, and the environment, and sustainability science is launching and becoming a distinct scientific field. In sustainability science, an emphasis is put on the importance of integrating diverse disciplines and promoting transdisciplinary expertise. But how to bridge the existing gaps among disciplines and sectors. In this contribution, we illustrate the concept of network of networks as a boundary spanning motif. At first, we consider the interdisciplinary characteristics of sustainability science, and discuss the key issues to integrate disciplines. By analyzing the structure of sustainability science, we found that papers focusing on common problems, tools, frameworks, and social and political aspects bridge multiple disciplines. Therefore, these researches have a potential to integrate them. Then, we discuss the necessity of transdisciplinary expertise, and show initiatives conducted in Japan.