The year of 2022 will celebrate the 40th anniversary since the United Nations Convention on the Law of the Sea (UNCLOS) was opened for signature on 10 December 1982 in Montego Bay (Jamaica). Forty years have passed, and major changes in the world have created new challenges; in particular, the sea level rise has made urgent the debate regarding its implications on international law, and this essay argues that the convention still plays the role of the constitution for the oceans and the seas as a vital basis of their legal order.

In 2020, Reflections on the Making of the Modern Law of the Sea was published, and it could be considered as a final contribution from one of the titans, and one of the most important architects of UNCLOS, Satya N. Nandan (1936–2020). Nandan and co-author Kristine E. Dalaker vividly recreate the historical landmark Third United Nations Conference on the Law of the Sea (1973–1982). The Conference marked a cornerstone of the codification of the international law of the sea. This book enables the reader to better understand why this Conference extended to almost one decade of negotiations, and how the negotiators overcame various obstacles and difficulties.

The Conference was notable not only for the enormity of its task, but also for its innovations in treaty making. Nandan emphasizes the importance of innovative approaches, such as creativity, and neutrality, in multilateral negotiations. UNCLOS was the result of great contributions, both collective and individual, and of influential experts’ initiatives, like those from Jens Evensen, Tommy Koh, Elliot Richardson, and the “Nandan approach”. The Convention established certainty in place of the chaos and uncertainty created by the proliferation of unilateral claims before the convening of the conference, and it provides for an equitable relationship among States in their use of the oceans based on their respective geographical characteristics, economic circumstances, political imperatives, and global responsibilities. The Convention serves as a legal framework for cooperation and for peaceful settlement of disputes relating to its interpretation and application.

Geographical Change and the Law of the Sea by Kate Purcell aims to analyze the implications of geographical change by rising sea levels and other weather events for maritime jurisdiction under the law of the sea. In this context, scholars have focused attention on the implications of erosion, inundation, loss of habitability, and, in 1990, David Caron suggested the “ambulatory thesis”. Accordingly, maritime baselines and zonal limits measured from them as a general rule are ambulatory, “moveable”, dynamic, and they shift due to the coastline changes. Therefore, a coastal State could adjust, redraw, or relocate them. More ambitiously, the proponents of the ambulatory thesis proposed reforms such as the amendment of UNCLOS, the negotiation of a new treaty, or the development of a new customary rule through State practice.

In her book, Purcell first highlights the “symbolic” and “functional” roles of geography in law relating to maritime jurisdiction and to maritime limits and boundaries. She agrees that this perspective is consistent with the desire of establishing and ensuring a stable legal order and stability for the oceans and the seas, as provided in the UNCLOS. However, in different parts of her book Purcell concludes that there is no basis in the existing law for the view that States are required to adjust established maritime limits in response to geographical change. She criticizes the arguments advocated by David Caron and his supporters, in that they are not well founded in treaty law or customs. By examining the practice in the United States, the Netherlands, Finland, and Australia she shows that there is no general State practice by which countries updated or revised established maritime limits or baselines in the event of geographical change.

These two books have different styles and approaches. The first is based on a historical perspective and the second is focused on the novel development of geographical change due to rising sea levels or climate change, and their possible impact on the modern international law of the sea. Nevertheless, it is interestingly noted that the authors flag the importance of UNCLOS in ensuring order and stability against chaos and uncertainty at sea. Indeed, the Convention is “the law that rules the waves today”, and to support humanity's connection to the sea.

The world has changed dramatically in the four decades since the signing of UNCLOS. New technological developments and emerging natural phenomenon, including climate change and the sea level rise, had not been anticipated by States negotiating UNCLOS. The sea level rise has now become a global threat and is increasing alarmingly, challenging different areas of international law such as those related to statehood and protection of persons. Taking into consideration the possible legal effects of sea level rise on the questions of the law of the sea, the United Nations International Law Commission in 2019 included the topic of “Sea-level rise in relation to international law” in its long-term agenda and is looking ahead in order to develop appropriate legal solutions.