Abstract:
As the global imperative to transition toward net-zero economies intensifies, competition for critical minerals has escalated, drawing attention to the largely untapped resources of the deep seabed. Under the United Nations Convention on the Law of the Sea (UNCLOS), the deep seabed and its resources are designated the "common heritage of mankind". However, the International Seabed Authority's (ISA) regulatory framework for exploitation remains underdeveloped, thereby creating significant potential for conflict within international law between parties with competing interests. In particular, an underexamined issue has been the interface of international investment law with deep seabed mining. This paper examines the intersection of international investment law and the UNCLOS regime in this context, highlighting the potential legal challenges arising from deep seabed mining projects in regions such as the Clarion-Clipperton Zone - as illustrated by Nauru's sponsorship of The Metals Company. In doing so, it demonstrates that the prevailing investment law regime risks creating premature limits on a state's authority to regulate based on environmental concerns, threatening the environmental stewardship objectives central to the UNCLOS regime. It focuses specifically on three issues: the threshold question of whether deep seabed mining qualifies as a protected investment; the asymmetry between UNCLOS obligations and the dispute settlement access available to sponsoring states and investors respectively; and the implications of this asymmetry for sponsoring state regulatory authority and environmental governance. By identifying a fundamental misalignment between investment law's emphasis on regulatory stability and UNCLOS's requirements for adaptive environmental management, the paper demonstrates that current international legal frameworks are inadequately designed to govern commercial activities in areas designated as the common heritage of mankind. In doing so, it points to the urgent need for legal and institutional reform before commercialization of the deep seabed forecloses the opportunity to achieve it.
