This book is an outcome of an international symposium: Sustainability -Can We Design the Future of Human Life and the Environment? which was held as a satellite event of the "Love the Earth"-Expo 2005 (Aichi, Japan). Each chapter is based on the lecture given by the following eminent researchers: Yoshinori Ishii, Hans-Peter Durr, Yoshinori Yasuda, Minoru Kawada, Yasunobu Iwasaka, Werner Rothengatter, Hisae Nakanishi, Yang Dongyuan, Lee Schipper, Itsuo Kodama, and Yoshitsugu Hayashi.In the Part I titled "A Sustainable Relationship between Nature and Humans", we discuss what will become of fossil fuels and petroleum, and what kind of indicators should be used to monitor the energy expended by human society. We then discuss environmental impacts caused by different civilizations and values on Nature and ethics, based on the perspective of environmental archaeology and on the discussions by Kunio Yanagita, the father of Japanese folklore study.The Part II is titled and shows "International Conflict Concerning Environmental Damage and Its Causes". The Asian dust (Kosa) is a typical example of transboundary conflicts between nations. Another example can be found in the EU's attempt to put in place a common motorway toll system across EU countries having different geographical and economic conditions. Finally, Part III covers the opinions and further debates on sustainable future earth based on the lectures in Parts I and II.We hope that great insights in this book will come across to readers, and be of help in steering the world towards a sustainable society in harmony with biosystems on earth.