COP30: What about the ocean?

24 Nov 2025

3 minute read

With the conclusion of the COP30 climate conference last week, we look at the role the ocean played in negotiations, the commitments made, and the action we still need to see.

The Conference of the Parties (COP) to the United Nations Framework Convention on Climate Change is the world’s annual climate summit. UK representatives Prime Minister Keir Starmer and Nature Minister Mary Creagh attended this year’s gathering, COP30, which took place from 10–21 November in Belém, Brazil. There, they joined leaders, scientists and activists from across the globe to accelerate action against climate change and highlight the urgency of the challenge ahead.

The ocean’s role at COP30

One of the key actions taken for the ocean is the introduction of a roadmap for scaling up ocean-based climate solutions: the Blue Package. Guided by the Ocean Breakthroughs targets for marine conservation, aquatic food, energy, shipping and tourism, it aims to turn ambition into action.

The conference also featured the Ocean Pavilion: a dedicated hub designed to spotlight the ocean’s role in climate negotiations. It hosted lectures, panel discussions and events on marine issues, bringing together leading scientists, policymakers, financiers, and civil society groups.

Yet, with the Amazon rainforest as the backdrop, deforestation dominated the agenda, leaving ocean-based climate action struggling to gain the attention it deserves.

Our unsung climate hero

While forests often take centre stage, the ocean is quietly doing the heavy lifting in the fight against climate change:

The ocean captures and stores around 30% of the carbon emissions and has absorbed 90% of the warming which has taken place in recent years.
Seagrass alone absorbs and stores 35 times more CO2 than rainforests.
Mangroves store more carbon per area than nearly any other habitat on Earth.
Deep water sands and muds are the biggest store of carbon in the UK environment – with up to £1 billion worth of carbon storage in the deep sea.

Credit: Laura McConnell

At the same time, a warming climate poses a huge threat to the ocean’s ability to continue in its role as the planet’s climate regulator. Rising sea levels, coral bleaching, ocean acidification, and species migration are already signs that the ocean’s ability to regulate climate is weakening.

What’s at stake?

In just the last decade, the ocean has warmed by 0.2°C. This is enough to push ecosystems toward dangerous tipping points.

What progress has been made

Encouragingly, we’re seeing greater emphasis and recognition of the ocean’s role in climate policy:

The High Seas Treaty – a landmark agreement that strengthens protections for international waters – has now reached the 60 ratifications needed to come into force from January 2026. At COP30, the Treaty was celebrated and awarded Prince William’s Earthshot Prize, highlighting its global importance.
National climate plans (NDCs) often overlook the ocean, but the tide is turning. Through initiatives like the Blue NDC Challenge, more countries are including the ocean in their climate commitments. This year, 78% of member countries reference the ocean in their NDCs – a 39% increase compared to earlier submissions.

ratifications of the High Seas Treaty

78%

member countries that reference the ocean in their national climate plans

What do governments still need to do?

Despite progress, much remains unfinished:

Blue finance is lagging. Less than 1% of global climate finance supports ocean-based solutions, making Sustainable Development Goal 14 (Life Below Water) the least funded of all.
Small Island Developing States remain on the frontline of climate change. Programmes like Blue Belt and Darwin Plus offer vital lifelines for communities in the UK Overseas Territories and represent global best practice. Yet, to meet the scale and urgency of the crisis, these initiatives must be expanded and replicated worldwide.
The economy vs. nature narrative needs to be challenged. Our economies depend on healthy seas. Protecting nature isn’t a cost – it’s smart economic policy. For example, expanding circular economy initiatives and scaling up regenerative aquaculture worldwide will reduce pollution and strengthen ocean resilience.

Ultimately, bold ocean action can become humanity’s greatest strength against climate change. COP30 showed that, while much remains to be done, governments across the world are beginning to rise to the challenge – placing the ocean at the heart of climate action.

Let's join together as the voice of our ocean