Based on the concept of a "Sustainable Development" confirmed at the United Nations Conference on Environment and Development (Rio Summit) in 1992, institutions and policies related to environment / climate change have been evolved significantly. A lot of global environmental treaties have been developed, and the global environmental regime has been also evolved. The development of environment / climate change institutions and policies, especially environmentally law, have been progressed in both developed and developing countries.
Since the Rio Summit, Japan has reviewed the environmental law (ex. enactment of the Basic Environmental Law) and expanding (ex. enactment of the Basic Law for Establishing the Recycling-based Society). By taking advantage of the experience of overcoming serious pollution, Japan has pledged supports for developing countries in the international community, and JICA has conducted a lot of environmental cooperation projects with mainly ASEAN countries. Through these efforts, it is reported that such activities have led to the development of environmental institutions and policies in each country.
However, by the environmental reports in each country and project reports, it is reported that there are still many challenging issues for improving environmental quality and implementing policies for environment / climate change despite progress of institutional policies. The legal system would have significant problem from the viewpoint of the legitimacy of law, unless the government enforces it in accordance with its legal framework. In addition, more advanced environmental regimes such as marine plastic litter issue, Circular Economy, and a decarbonized society have been formulated. Each country should address these issues.
Given these circumstance, this study tries to conduct case analysis of each country's efforts and identify difficulties for implementing environmental / climate change policies. And, this study will develop and show the policy implication, touching on systems and policy issues in developed countries.