환경소송에서의 인과관계 법리에 관한 고찰 ― 인과관계 법리의 발전과정과 적용 국면에 대한 분석을 중심으로 ―

In environmental litigation, the Supreme Court of Korea has not merely applied the general principles of causation under tort law. But it has also adopted the so-called Theory of Probability and the so-called New Theory of Probability to alleviate the plaintiff's burden of proof. Furthermore, the legislature enacted the Act on Liability for Environmental Damage and Relief Thereof, explicitly stipulating the presumption of causation as an independent provision. This regulation should be understood as a measure to further ease the plaintiff’s burden of proof compared to the aforementioned theories, and the recent Supreme Court’s ruling aligns with this interpretation. In other words, the causation doctrine in Korean environmental litigation has progressively evolved toward reducing the plaintiff’s burden of proof. Accordingly, it is critical that the likelihood of success in litigation depends on which causation theory is applied to cases. However, the boundary of applicability remains somewhat unclear. Therefore, it is necessary to clarify the specific arena in which each causation theory is applied. To conclude, there are no particular restrictions on applying the general causation principles under tort law. The Theory of Probability and the New Theory of Probability are specifically limited to “litigations for damages caused by pollution”. Furthermore, this study preliminarily clarifies the meaning of “pollution” based on the Pollution Prevention Act, the Framework Act on Environmental Policy, and the inherent characteristics of pollution that make it difficult for plaintiffs to prove causation. Meanwhile, under the Act on Liability for Environmental Damage and Relief Thereof, the presumption of causation applies when “a facility has contributed to the cause of environmental damage”. While the definitions of “facility” and “environmental damage” in this context are relatively unambiguous, further amendments to the Act or its Enforcement Decree may be necessary for improvement. This study aims to clarify the contexts in which different causation theories apply in environmental litigation, thereby contributing to a more systematic regulatory framework for such cases.