In Tokyo this March, a global group of leading policymakers, scientists and advocates met at the annual World Ocean Summit to collaboratively forge the urgent solutions required to restore a resilient ocean.

For decades, the ocean has silently absorbed humanity’s excesses, acting as the world’s most potent climate buffer.

The ocean is arguably the most significant tool in our arsenal to combat climate change and the loss of nature. It regulates global temperatures, absorbs vast quantities of heat and carbon dioxide, and sustains marine ecosystems that feed billions. A report from the High-level Panel for a Sustainable Ocean Economy estimates that the ocean has the potential to provide up to 35% of the emissions reduction needed to meet the Paris target of 1.5C.

Already, the ocean has soaked up around 90% of excess heat associated with greenhouse gases since 1970. The Southern Ocean alone absorbs an estimated 12% of human-generated carbon dioxide emissions annually. That’s more than the volume emitted by private cars globally.

Hot on the heels of the warmest year on record in 2024, the Earth has just experienced its hottest-ever January. Likewise, the ocean is reaching record heights. According to the World Meteorological Association, sea surface temperatures were above average last year and hit the second-highest rate on record this January.

Scientists now harbour grave concerns that a warmer ocean may lose its capacity to absorb heat. Reaching this tipping point could have catastrophic consequences: climate change could accelerate beyond current predictions, amplifying extreme weather, intensifying droughts and further destabilising the ecosystems that humans depend on.

We stand watch over an ocean that may be tipping into crisis. It is a triple crisis—of climate change impacts, biodiversity loss and pollution, exacerbated by growing economic activities in the ocean and urbanisation and industrialisation along coasts. It is a crisis where each component connects with and influences the other—climate impacts exacerbate nature loss, pollution undermines ecosystem health and so on.

This ocean crisis is systemic. It eats at the very heart of the ocean’s resilience, at its regulating functions and its vital role in stabilising earth systems as a whole. It is a crisis that could well undermine our own health and economic well-being. A healthy ocean, and indeed healthy nature, are the very foundations of our economy. It is a crisis that demands a commensurate system-level response, and a change in our behaviour towards, and relationship with, the ocean.

Yet, despite its pivotal role in regulating the Earth’s systems, the ocean remains an afterthought in global negotiations. While it has slowly made its way on to the COP agenda, its prominence is far from where it needs to be.

In June, as the world’s governments come together at the United Nations Ocean Conference, we have a crucial opportunity to shift decisively from ambition to political action.

There is an abundance of ideas, but they are meaningless as long as political will is insufficient or absent. This is our urgent task—if our present efforts and initiatives to stabilise the ocean as a system are failing, then what? And what does this mean for the possibility of—and transition to—a more sustainable, balanced and equitable relationship with the ocean?

The ongoing shocks and disruptions from the second Trump administration to the global political and economic order, to progress on climate change, the environment and the ocean, and to axed or suspended funding from public and private sources in the US threaten to derail the precious momentum for change that has been building.

Nevertheless, with a sense of cautious optimism, we must explore and celebrate the many initiatives, big and small, top-down and bottom-up, to restore and regenerate ocean health, implement ocean solutions to climate change, transition sectors and industries to lower carbon emissions and nature-positive practices, assess new materials for plastics, and offer paths to scaling financing for ocean resilience—in short, the opportunities presented by the sustainable use of the ocean.

Let 2025 be not just another footnote in the slow decline of ocean health but the wake-up call that prompts us to arrest it.