World’s oceans dying: Can UN summit in Nice reverse tide?

More than half of marine species risk extinction by 2100.

As coral reefs bleach, fish stocks collapse, and sea temperatures break records, world leaders are heading to the French Riviera — not for leisure, but for one of the most urgent diplomatic gatherings of the year.

From June 9 to 13, the coastal city of Nice will host the Third United Nations Ocean Conference (UNOC3), a high-level summit co-chaired by France and Costa Rica. Its mission: to confront a deepening ocean emergency that scientists warn is nearing a point of no return.

“The ocean is facing an unprecedented crisis due to climate change, plastic pollution, ecosystem loss, and the overuse of marine resources,” Li Junhua, a senior UN official serving as Secretary-General of the event, told UN News.

“We hope the conference will inspire unprecedented ambition, innovative partnerships, and maybe a healthy competition,” he said, highlighting the need for international cooperation to avoid irreversible damage.

The pressure is on. UNOC3 is bringing together world leaders, scientists, activists, and business executives to tackle the growing crisis in the world’s oceans. The goal: to spark a wave of voluntary pledges, forge new partnerships, and — if organizers succeed — inject a much-needed dose of accountability into the fight against marine degradation.

The week-long talks will culminate in the adoption of a political declaration and the unveiling of the Nice Ocean Action Plan — an effort to match the scale of the crisis and accelerate action to conserve and sustainably use the ocean.

Warming seas, bleaching reefs
The crisis isn’t a distant threat: it’s happening now. In April, global sea surface temperatures hit their second-highest levels ever for that month, according to the European Union’s Copernicus Climate Change Service. Meanwhile, the most extensive coral bleaching event in recorded history is underway — sweeping across the Caribbean, the Indian Ocean, and parts of the Pacific. More than a single event, it’s a planetary unraveling.

Coral reefs, which sustain a quarter of all marine species and underpin billions in tourism and fisheries, are vanishing before our eyes. Their collapse could unleash cascading effects on biodiversity, food security, and climate resilience.

And the damage runs deeper still. The ocean continues to absorb more than 90 per cent of excess heat from greenhouse gas emissions — a worldwide service that may be nearing its limits. “Challenges like plastic pollution, overfishing, biodiversity loss, ocean acidification, and warming are all linked to climate change,” Mr. Li warned.

Turning versus tipping points
Still, there have been notable breakthroughs. In 2022, the World Trade Organization struck a far-reaching deal to phase out harmful subsidies that fuel overfishing, offering a rare glimmer of multilateral resolve. The following year, after decades of deadlock, nations adopted the High Seas Treaty, known by the shorthand BBNJ, to safeguard marine life in international waters. That long-awaited agreement is now poised to enter into force at the Nice summit.

But policy alone cannot reverse an ecosystem in free fall. “The global response is insufficient,” Li Junhua cautioned.

Progress, in other words, depends not only on political will but on the resources to match it.

An estimated 60 per cent of the world's marine ecosystems have been degraded or are being used unsustainably.

A lifeline starved of funds
Despite its vital role in regulating life on Earth — producing half of our oxygen and buffering against climate extremes — the ocean remains chronically underfunded. Sustainable Development Goal 14, on ‘Life Below Water’, receives the least resources of the 17 global UN goals Member States agreed to meet by 2030.

The estimated cost to protect and restore marine ecosystems over the next five years is $175 billion annually. “But less than $10 billion was allocated between 2015 and 2019,” Mr. Li noted, signalling the need to move ocean funding from trickle to torrent.

That ambition is at the heart of what the Conference aims to deliver.

The Nice Ocean Action Plan
The theme of UNOC3, Accelerating action and mobilizing all actors to conserve and sustainably use the ocean, reflects a shift from declarations to delivery.

Over five days, participants will grapple with the big questions: how to stem illegal fishing, reduce plastic pollution, and scale sustainable blue economies. Hundreds of new pledges are expected to build on the more than 2,000 voluntary commitments made since the first ocean summit in 2017.

The Nice Ocean Action Plan is set to align with the Kunming-Montreal Global Biodiversity Framework, a 2022 agreement calling for the protection of at least 30 per cent of marine and terrestrial ecosystems by 2030.

Alongside new pledges, the plan will include a formal declaration, which Mr. Li described as a “concise” and “action-oriented” political document.

“The draft political declaration, led by Australia and Cabo Verde, focuses on ocean conservation and sustainable ocean-based economies and includes concrete measures for accelerating action,” the UN official teased.

The rapid loss of biodiversity threatens the livelihood of 3 billion people, including coastal communities.

Crisis by the numbers — and what Nice hopes to deliver
• Up to 12 million metric tons of plastic enter the ocean every year — the equivalent of a garbage truck every minute. At Nice, delegates hope to advance a global agreement to tackle plastic pollution at its source.

• Over 60 per cent of marine ecosystems are degraded or unsustainably used. The summit aims to bolster efforts toward protecting 30 per cent of the ocean by 2030 and to launch a roadmap for decarbonizing maritime transport.

• Global fish stocks within safe biological limits have plunged from 90 per cent in the 1970s to just 62 per cent in 2021. Nice hopes to pave the way for a new international agreement on sustainable fisheries.

• More than 3 billion people depend on marine biodiversity for their livelihoods. In response, the summit seeks to boost financing for blue economies and elevate community-led solutions.

In small developing island states, the ocean is not just an economic engine, it’s a lifeline.

From Paris to Nice
The timing of the summit is intentional. A decade after the landmark Paris Agreement set targets for limiting global warming, UNOC3 is pushing to place the ocean at the centre of climate action — not as an afterthought, but as a frontline battlefield.

“UNOC 3 addresses the interconnected crisis facing our oceans,” noted Mr. Li.

The summit also aims to be inclusive, highlighting voices often sidelined in global forums, such as women, Indigenous people, fisherfolk, and coastal communities. “These groups are the first to suffer the impacts of climate change and ocean degradation,” Mr. Li emphasized. “But they are also leaders and problem solvers, so they must be empowered.”

A pivotal moment
Nice isn’t just a scenic backdrop — it’s part of the story. The Mediterranean is warming 20 per cent faster than the global average, making it a so-called climate “hot spot.” For many, the location only sharpens the stakes.

Whether the conference generates real momentum or simply more declarations will depend on what countries, companies, and communities bring to the table.

As delegates descend on the sun-drenched coast of Nice, the sea laps gently at the shores. But the question rising with the tide is anything but gentle: can the world still turn this around?