The 2025 UN Ocean Conference: Turning the Tide on Ocean Governance

Our ocean is changing at a rate that is unsustainable and unprecedented, and the impacts are being felt the world over. It’s the consequence of a triple planetary crisis — the interconnected environmental challenges of climate change, pollution, and biodiversity loss.

The UN Ocean Conference is uniting global voices to mobilize collective action around these pressing issues and how they affect the ocean, people, and the planet. Ahead of the Conference in Nice, France, I sat down with our climate and ocean experts for an in-depth conversation on the latest science and policy developments.

Kristyn Gillis, Simon Walmsley, and Kerrlene Wills on the UN Foundation’s Climate and Environment team joined Jessie Turner, Executive Director of the International Alliance to Combat Ocean Acidification (OA Alliance) to discuss the urgency of catalyzing action around Sustainable Development Goal 14: conserve and sustainably use the ocean, seas and marine resources for sustainable development.

The conversation has been edited for clarity and length.

The Ocean and Climate Change

Megan: The triple planetary crisis refers to the interrelated challenges of climate change, pollution, and biodiversity loss. But what does it really mean?

Simon: Oceans cover 71% of the planet. They are the biggest climate regulator in the world. We often hear that forests are the lungs of the Earth, but actually, it’s the ocean. Phytoplankton in the ocean produce more oxygen than all forests combined.

Jessie: To build on what Simon is saying, in its role as climate regulator, the ocean has absorbed 90% of all excess heat produced by the burning of fossil fuels, and it has absorbed 30% of all carbon emissions.

That has major consequences for our ocean. It makes the ocean warmer, more acidified, and less full of oxygen. Collectively, this slows currents, changes the way carbon cycles through the ocean, and generally makes the ocean less hospitable for marine species and ecosystems.

When you add in other stressors like pollution from land, wastewater, stormwater, and coastal development, that creates a lot of extra pressure on marine ecosystems and species that are already struggling in the context of climate change. And that’s really what we’re talking about when we say that climate change and pollution lead to accelerated biodiversity loss in our ocean.

Kerrlene: As it gets harder for ocean life to survive in warmer seas, people whose lives and livelihoods depend on the ocean feel the impact — we’re seeing that happen more and more every year.

And small island developing states, which are extremely dependent on the ocean, are seeing some of the most severe impacts — from stronger hurricanes in the Caribbean to sea level rise and coastal erosion in the Pacific that is causing islands to essentially disappear.

Kristyn: In the science community, we call these “cascading impacts” because you end up with bigger problems than you anticipated. In these cases, we could see die-offs of entire species which would cascade through the ecosystem. If we don’t have enough fish, then people won’t have enough food or be able to earn the same income. If the ocean is unhealthy, it can’t absorb the same amount of heat or carbon, exacerbating climate change.

When you take all of these challenges together, you realize that they can’t be solved in silos. If you really want to protect the ocean and protect the people who depend on it — which is everyone — you have to consider that almost every decision we make impacts the ocean and find ways to mitigate harms and elevate solutions.

Simon: Exactly. Because there aren’t just cumulative harms; there are also cumulative wins.

Megan: Let’s unpack that, what kind of cumulative wins? And how can the UN Ocean Conference help us confront these interconnected challenges?

Jessie: There are three things that I want to see prioritized at the Ocean Conference: advancing policy and good governance for our ocean; accelerating useful and applicable science for the best management choices; and increasing calls from civil society and government to reduce our impacts on the ocean, including reducing greenhouse gas emissions. To me, that’s the UN Ocean Conference trifecta.

Kristyn: Can I add implementation? I would make that the fourth pillar. Implementation is really, really important because there’s all this talk about commitments that are made, but what happens next? How do we actually achieve those goals? It comes down to implementation, which involves finance and money. Because you can’t really do anything unless you have money.

Simon: I would add to that capacity building, which is about sharing resources. It’s about a just and equitable transition. It’s about leaving no one behind.

Back to the point I made about cumulative wins, I’ll give an example. An antifouling system is something that goes on the bottom of a ship’s hull that gets rid of what settles on it and makes the ship go faster because it has less drag. There are more environmentally friendly hull treatments available that not only prevent the transportation of alien species but also reduce pollution that accelerates ocean acidification and create less friction which helps with energy efficiency.

This is a cumulative win because if you have a smooth hull, then you’re also helping reduce climate change and greenhouse gas emissions. Environmentally friendly hull treatments shouldn’t be available just to the large shipping companies that can afford them. This is where capacity building, sharing resources, and technology transfer come in, because we need to make sure this kind of hull treatment reaches everyone who can benefit.

Advancing Ocean Governance

Megan: Most of the ocean is outside the jurisdiction of any one nation. How are countries working together to protect the ocean and advance ocean governance?

Simon: The high seas are everything beyond 200 nautical miles of a sovereign state, which makes up 64% of the world’s oceans. They’re not owned by any one country, but are known as the common heritage of humankind. They are regulated internationally by various bodies, but so far those bodies haven’t come together to specifically protect biodiversity in the high seas. It’s so incredibly important to protect these areas — to not only protect species and habitats but also the interconnections that provide breeding, foraging grounds, and migratory pathways.

For example, if you don’t manage high seas fisheries, it can impact local fishing. Take tuna, which as a highly migratory species spends significant amounts of time in the high seas but is also caught for food by subsistence communities. If you don’t manage tuna stocks in the high seas, there will be massive impacts on the primary protein available to local communities.

Jessie: Governments can no longer afford to overlook acidification in mainstream policy agendas. It’s an essential part of the ocean-climate nexus that threatens healthy marine ecosystems, fisheries, and aquaculture on which blue economies and citizens’ well-being depend.

That’s why the OA Alliance, alongside our 145 members across 25 countries, is committed to building collective momentum and securing an important place for acidification and climate change on this year’s multilateral agenda

Kerrlene: Multilateral policies are setting the tone for environmental sustainability and mitigating climate impacts on the ocean. We have some strong agreements out there that need to be ratified: the Biodiversity Beyond National Jurisdiction (BBNJ) Agreement, also known as the High Seas Treaty; the World Trade Organization (WTO) Agreement on Fisheries Subsidies; and the International Maritime Organization (IMO) Net-Zero Framework, which is up for formal adoption this October.

The first thing I’ll say about the importance of these agreements is that each one unlocks finance.

The WTO Fisheries Subsidies Agreement has a financial component to support countries fighting illegal, unreported, and unregulated fishing. The BBNJ agreement unlocks finance for countries to establish marine protected areas and do a lot more research. And then the IMO agreement unlocks finance to support developing countries, particularly small island developing states and least developed countries, in transitioning to a greener future for international shipping.

The next step: ratify, ratify, ratify!

The 2025 UN Ocean Conference

Megan: Why should we pay attention to the UN Ocean Conference?

Jessie: We are only five years away from the Sustainable Development Goals’ 2030 deadline. We are at a mission critical point, with a short runway remaining to make serious progress on the policy, science, and investment side of the SDGs.

SDG 14, Life Below Water, lists seven targets. The UN Ocean Conferences have been an important part of keeping governments, industry, civil society, and scientists accountable for making progress on these different targets.

Kerrlene: I completely agree, Jessie. We need a space to hold people accountable for the commitments that they’ve made and ensure that we have a stock-take of where things are. And I think in the context of the ocean, it brings a very fragmented space together to have a discussion. If you didn’t have the Conference and this formal UN process, how else are you having a conversation that brings all the different UN institutions and bodies together — from WTO to UNCTAD [the United Nations Conference on Trade and Development], the IMO, and IPCC [the Intergovernmental Panel on Climate Change] — to talk about what they’re doing in this space. It decreases the fragmentation of the work.

Simon: It’s an opportunity for innovation because you’re bringing all these different players together in this fragmented context that Kerrlene highlighted. Necessity is the mother of invention. And a great thing about the UN Ocean Conference is it highlights the necessity and brings the invention together.

Kristyn: The Conference also presents an opportunity to include individuals, Indigenous communities, and subnational governments that aren’t normally in these conversations. Unlike some closed-door processes, more people will be able to join the conversation and be a part of the solutions at the UN Ocean Conference. So I think the inclusion aspect is vitally important.