The ocean’s importance for climate and biodiversity has become more recognized, at the same time that competition and geopolitical tensions are on the rise. In this perspective, SEI researchers explore two conflicting ocean-related trends that will shape 2026.
This perspective explores one of the major trends discussed during SEI’s trendspotting webinar, Currents 2026.
The ocean was once the last frontier, a blank blue void on formal maps. Today, the ocean is a contested geopolitical, ecological, economic and digital space. It is increasingly governed, monitored and industrialized. It soaks up carbon and stores climate-changing heat and is home to the most biodiversity on the planet.
Two conflicting trends will shape the ocean in 2026: the growing recognition of the ocean as essential for moderating the climate and protecting biodiversity, and the expanding geopolitical tensions unfolding at sea.
The year began with some rare good news. On 17 January 2026, the High Seas Treaty officially entered into force after two decades of negotiations. Also known as the Agreement on the Conservation and Sustainable Use of Marine Biological Diversity of Areas Beyond National Jurisdiction or the BBNJ Agreement, this global framework aims to conserve biodiversity in international waters.
The High Seas Treaty is important since it covers the two-thirds of the world’s ocean that lies outside national jurisdictions, representing over 90% of Earth’s habitat by volume. For the first time, a multilateral mechanism now exists to designate and manage marine protected areas (MPAs) on the high seas, a significant step forward given that less than 10% of the ocean is currently under any form of protection.
The High Seas Treaty complements the Kunming–Montreal Global Biodiversity Framework, adopted in 2022 under the Convention on Biological Diversity (CBD): under the framework, countries agree to protect at least 30% of land, inland waters and the ocean by 2030. Together, the High Seas Treaty and the Biodiversity Framework reflect a growing global realization: the ocean is not an empty void, but a living system that requires active, collective stewardship. Increasingly, this is seen as one of the most promising routes to action on biodiversity and climate.
“The ocean opportunity gap” is becoming a new key phrase for untapped marine solutions that could accelerate progress towards biodiversity and climate goals. It is estimated that ocean-related climate measures that are ready for implementation may be able to deliver up to 35% of annual greenhouse gas emission cuts needed by 2050.
Until now, these solutions have remained largely unknown and underutilized, but that seems about to change. Last November, an Ocean Task Force was launched at the climate meeting UNFCCC COP30 to speed up the integration of ocean actions in countries’ national climate plans, including their nationally determined contributions (NDCs) under the Paris Agreement. The attempts will be accelerated ahead of COP31 and a pre-COP conference to be held in the Pacific, a region often considered a leader in ambitious ocean-focused climate mitigation. Similarly, the World Economic Forum–driven 30×30 Ocean Action Plan pushes for clear roadmaps towards conserving 30% of the ocean, ahead of the CBD COP17, to meet in Armenia in October.
The most recent review of countries’ NDCs shows that 78% now refer to the ocean, a 39% rise compared to the previous iteration. Another study shows that countries increasingly seek to integrate NDCs, biodiversity plans and ocean plans. This is not surprising given that many measures could benefit both biodiversity and climate goals. Examples include improved marine spatial planning, changes in regulations and subsidies related to fishing, investments in renewable energy and the establishment of marine protected areas. The Ocean Task Force specifically highlights the role of coastal resilience, including integrated coastal management, coral reef protection and mangrove restoration.
Countries and communities exploring these solutions are increasingly trying to learn from each other. SEI is working with partners in the Caribbean to test new approaches to coral reef and mangrove restoration. This includes locally led living labs in Colombia, Dominican Republic and Cuba to understand not only technical solutions, but how these can contribute to communities and livelihoods.
Another important shift in how we view the ocean relates to infrastructure. Marine spaces are increasingly turning into built seascapes, shaped by offshore wind farms, subsea cables, pipelines, aquaculture systems and digital monitoring devices. Modern society relies on such structures to deliver renewable energy, global connectivity and environmental information, and they are multiplying rapidly.
This infrastructure buildup marks a fundamental break from the past. Where maritime law once imagined the high seas as an open, largely ungoverned space, the modern ocean is increasingly crowded and industrialized. The seabed, once of limited strategic interest, now hosts thousands of kilometres of telecommunications cables that carry roughly 95% of international digital and financial traffic. Offshore renewable energy zones are expanding quickly as countries race to decarbonize. The potential acceleration of deep-sea mining further complicates matters.
This transformation raises new governance questions. How can regulators balance ecological protection with expanding commercial uses? How should marine spatial planning adapt to growing competition for space? Built seascapes create risks for marine wildlife, but they also bring new habitats, data and funding opportunities for conservation.
Sustainable Ocean Plans, called for by the Ocean Panel for all coastal states by 2030, could help provide answers to these questions. Effective governance will depend on co-designed solutions, a central focus of SEI’s research across multiple regions. In addition to the living labs in the Caribbean, SEI’s Living Lab East (Mistra C2B2) in the Baltic brings together municipalities, authorities, industry and civil society to co-develop multifunctional planning pathways that address trade-offs between offshore energy, fisheries, biodiversity and security considerations.
Not all actors, however, seek cooperation in maritime spaces. In recent years, sabotage, hybrid operations and cyber-attacks targeting marine infrastructure have increased. Finding the responsible actors is often difficult. Many technologies that are shaping built seascapes (autonomous drones, sensors and subsea robotics) have dual civilian–military uses, making it hard for states to respond or deter hostile actions. Countries are continuously trying to strengthen the protection of critical infrastructure.
Geopolitical tensions extend to maritime boundaries as well, particularly in regions such as the South China Sea, eastern Mediterranean, parts of the Caribbean, and the Arctic. Disputes may reflect territorial claims linked to military strategies but also access to natural resources such as fisheries, energy sources, minerals or seafaring routes.
Climate change adds further complexity. Sea-level rise can shift baselines used for maritime delimitation, raising concerns in low-lying island states. In the Polar regions, accelerated ice melt can make new seafaring routes and resources become more accessible. This can aggravate existing geopolitical tensions in the Arctic and increasingly also in the Antarctic.
Together, these developments reveal a powerful tension shaping ocean governance in 2026.
On the one hand, unprecedented recognition of the ocean as a global system essential for climate regulation, biodiversity and human well-being brings hope for constructive action. The High Seas Treaty, new conservation campaigns, and integrated climate–biodiversity approaches all reflect this momentum.
On the other hand, the geopolitical landscape continues to fracture. The very space that could catalyse global collaboration is also becoming a zone of rivalry, vulnerability and mistrust. Marine infrastructures are growing more valuable and more exposed. Maritime borders remain contested. Hybrid threats are harder to detect and deter.
Given this context, major new global ocean agreements beyond the High Seas Treaty are unlikely in the near term. Instead, progress may emerge through regional and issue-specific arrangements, where cooperation is more feasible. The European Union’s Ocean Pact reflects such a shift; expected to be further solidified during 2026, the pact could provide a more strategic, integrated and geopolitically informed approach to ocean governance that recognizes both ecological limits and strategic realities.
The ocean now embodies a striking paradox: it is simultaneously a catalyst for global sustainability and a theatre of intensifying geopolitical rivalry. These trajectories do not unfold in isolation; they frequently overlap in both space and time. In many regions, the same waters targeted for conservation, climate action and renewable energy expansion are also sites of strategic competition over resources, boundaries and critical infrastructure. Managing this convergence will be one of the central challenges shaping ocean politics in 2026 and beyond.
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Past event / Join us for the fifth SEI Currents – our webinar exploring the forces that will shape the year ahead.
