Evolvement of Precautionary Principle in Environmental Law---Dialogue between Law and Science

2019 Fiscal Year Final Research Report

• Project/Area Number: 16K03448
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: New fields of law
• Research Institution: Waseda University
• Principal Investigator: OTSUKA Tadashi 早稲田大学, 法学学術院, 教授 (90143346)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Keywords: 予防原則 / 科学的不確実性 / 公害 / 環境リスク / 原子力損害 / 差止 / 環境損害 / 因果関係

Outline of Final Research Achievements

This　research firstly analyzed the application of Precautionary Principle. Regarding the environmental risk, I reached the conclusion that the three stages should be separated. 1)No consistent understanding of the observed facts exists; 2) Almost consistent understanding of the observed facts emerges: 3) Consistent understanding of both the observed facts and causation exists. Only at the third stage, we can discuss the uncertainty as a probability or range of quantified values. Regarding the causation for environmental risk, I adopt the opinion that that causation is a “factual condition”.
Secondly, regarding nuclear power plants, in injunction litigations, I reached the conclusion that judges should consider how to cope with the case where scientific uncertainty exists such as earthquakes and volcano eruptions. In State redress litigations, I reached the conclusion that the scientific uncertainty is dealt with in the determination of the “fault” and Hand formula can be used.

Free Research Field

新領域法学

Academic Significance and Societal Importance of the Research Achievements

様々な化学物質に対する予防原則の適用について、科学者と法律家が加わって判断基準を構築し、また、過去の公害に関してどの時点で何をすべきであったかの判断を示したこと。原発事故の損害賠償については、国はどの段階で何をすべきであったかを（行為時の）過失の判断の中で検討したことに意義がある。また、自主避難者への賠償の判断基準を示した点。原発差止に関しては、科学的不確実性のある事象に対して裁判所がどう判断すべきかを示した点。環境損害については、先進的な外国法を紹介し、わが国が進むべき途を示した点。
環境リスクに関する因果関係を、要件事実において事実と捉えるべきとの議論を展開し、理由付けを示した点。