Within the contexts of the global warming crisis facing the world, climate change mitigation strategies must be developed with a deep understanding of the science behind the impact of climate change and adaptations that must be made. This book discusses the mitigation strategy of climate change from the perspective of Japan and adopts a comprehensive view on climate change science, taking into consideration the recent international discussions on the subject, including those of the United Nations Framework Convention on Climate Change and the Intergovernmental Panel on Climate Change. Furthermore, this book discusses energy and environment strategies in Japan, particularly after the Fukushima Daiichi nuclear power accident, underpinning Japan's historical lack of natural resource and the resulting difficulties it faces in keeping up with the demand for energy. Finally, this book provides the quantitative model to assess scenarios for climate mitigation and their associated costs and economic impacts for the formulation of a national strategy for an effective and sustainable set of climate change mitigation measures.