How International Climate Law knows?The emerging epistemic architecture in the climate regime and its links to the international biodiversity regime

The years 2024 and 2025 marked a turning point for international climate law and its relationship with knowledge. A series of landmark decisions (the ICJ, Inter-American CtHR, ITLOS, and ECtHR) have reshaped not only substantive climate obligations but also a deeper, often overlooked question: how does international climate law know? By tracing these developments, this proposal aims to achieve two goals: argue that international climate law operates as a regulatory epistemic system; and, subsequently interrogate what are the contacting points of that legal epistemic system with the biodiversity protection.

As starting point, across these fora, states advanced a traditional doctrinal argument: the scope of their climate obligations must be determined within the four corners of treaty text, sovereignty considerations, and legal reasoning alone. All four tribunals rejected this view: climate science and socio-ecological risk considerations are integral components of legal interpretation. This conceptual move mirrored the proceedings themselves where a pluralised evidentiary practice was considered inviting experts, communities, and scientific bodies to share a procedural space. These practices signal an emerging epistemic architecture for the climate regime, reflecting what counts as valid climate knowledge, whose knowledge must be heard, and what methodological qualities evidence must meet to shape legal meaning.

Taken together, these rulings reveal a redesign of climate law’s epistemologies. First, they clarify that states (and increasingly private actors) have a duty to know: a positive, iterative, dynamic, participatory, and horizontal obligation to generate, access, assess, and share climate-relevant information. Second, they illuminate the interdependence between human rights and climate epistemics, particularly through the right to science, due diligence duties, and participatory epistemic rights.

This epistemic shift might have direct implications for biodiversity governance: (1) the tribunals’ reasoning relied heavily on biodiversity instruments (e.g. CBD and UNCLOS) revealing a bidirectional flow of epistemic standards between the biodiversity and climate regimes; (2) This raises the question regarding to the extent to which climate-law epistemic standards can be transferred into biodiversity regulation; and (3) the possibility that epistemic participation (now recognised as a human right) could migrate into biodiversity law as a normative requirement.