This chapter identifies an evolving trend in the ICJ’s engagement with science, which has started with the marginalization of scientific evidence, continued with making superficial evidentiary assessments, but ultimately demonstrated an increasing willingness to engage with science. As to framing techniques, mandating the parties’ negotiations in science-intensive questions, the prevalence of finding procedural breaches as well as decoupling the notion of ’risk’ from substantive, scientific criteria will be discussed. In terms of fact-finding, the chapter addresses evolving procedures for taking expert evidence, and applicable standards of proof. The causal analysis evidences the Court’s struggle with establishing the requisite proof in cases of uncertain causation. As to the standard and extent of review, the study examines the reasonableness test, and defends the majority's solution in the Whaling in the Antarctic case based on insights from Science and Technology Studies.

This chapter provides a comprehensive classification of the adjudicatory techniques identified in previous analytical chapters. As no unified approach manifests in the adjudicatory landscape with respect to handling scientific knowledge, the chapter discerns two parallel trends in the scientific engagement of major international fora. Certain practices impede or even preclude the intrusion of science into adjudicatory assessment and thereby downplay the role of science in the judicial inquiry; while others aim to incorporate scientific knowledge in the judicial analysis. The chapter provides a typology of judicial techniques that serve either to downplay science or to integrate it in the judicial analysis in terms of the framing of disputes, the process of fact-finding, the causal inquiry, and the standard of review. The comparative analysis also includes references to quasi-adjudicatory solutions of the UN Compensation Commission, and the US – Marshall Islands Nuclear Claims Tribunal. It also addresses good practices from domestic climate change litigation case law and US toxic tort jurisprudence to provide good practices of conducting a science-intensive judicial inquiry.

This chapter first identifies five entry points for science in environmental investment disputes. It continues with analysing framing techniques of both litigants and arbitrators that aim to strategically manage the science-intensity of the legal inquiry. The chapter discusses varied scientific fact-finding methods of investment tribunals. Despite that party-submitted evidence dominates investment arbitration, on rare occasions panels appoint independent experts. As to causal inquiry, the chapter discusses that open causal assessments remain a rarity in arbitral practice, though science-based causal nexus increasingly gains relevance in environmental disputes. As to the standard of review, arbitral tribunals are generally deferential towards the scientific claims of host states. Yet they design different standards to review the scientific basis of host states' risk regulatory measures, for instance, some focus on the transparency of the regulatory process, while others rely on regulatory trends of other states. This chapter concludes with analysing and comparing the various standards of review applied in science-intensive investment arbitral proceedings.