- Healthy oceans are vital for our economies. Stopping marine degradation would protect industries like fishing and tourism, while also helping to combat climate change. The ECB Blog discusses the action that needs to be taken and why these challenges matter to central banks.
By Andrej Ceglar, Irene Heemskerk and John Hutchinson
Oceans cover over 70 percent of the Earth’s surface. Yet their importance for our economies, and indeed for life on this planet as we know it, remains vastly underappreciated.
The ocean economy, which includes fisheries, tourism and coastal industries, is estimated to account for up to 5 percent of global services and products. Oceans provide essential value to society, to planetary health and to biodiversity. And, as perhaps one of their most vital functions in the face of the current climate crisis – they extract heat and carbon dioxide from the atmosphere which helps mitigate global heating.
But overexploitation, global warming, pollution and habitat degradation put these benefits at risk. As environmental pressures intensify, disruptions to food supply, transport and coastal protection can become more frequent and persistent.
This blog post offers an overview of why healthy oceans are so important, why this matters for central banks and what actions need to be taken.
Oceans: An engine of the economy and a source of livelihoods and food
Over the past 25 years, the ocean economy has doubled in size to about €2.3 trillion, with most growth originating in Asia and the Pacific.
Shipping carries about 80 percent of international trade by volume. Overall, the ocean economy has outpaced global growth in recent decades.
In the European Union (EU), ocean-related businesses generate about €251 billion in gross value added (GVA). They account for about 1.7 percent of total EU GVA and about 2.4 percent of total employment. Offshore renewable energy is a prominent example of this as one of the fastest-growing sectors in the EU. Marine biotechnology – although still small in terms of market size – is projected to grow as innovations in marine-derived foods, pharmaceuticals and materials accelerate.
But these economic benefits are at risk.
Overfishing and habitat destruction have depleted many fish stocks. Furthermore, ongoing ocean warming is contributing to pronounced declines in marine life. The International Union for Conservation of Nature estimates that 10 percent of marine species are at risk of extinction. In the EU, around 40 percent of assessed fish populations are not in good or sustainable status.
Oceans play a pivotal role in mitigating climate change
So far, we have focused on the direct benefits that are at risk if we continue to degrade ocean ecosystems. However, there are the potentially much larger indirect effects.
Oceans are among the planet’s most powerful defences against climate change. Since the Industrial Revolution, they have absorbed roughly one-third of all human carbon dioxide emissions and over 90 percent of the excess heat trapped by greenhouse gases.
Oceans help to moderate regional climates and reduce the intensity of temperature extremes, but these physical abilities to mitigate are limited.
Climate change is rapidly heating our planet’s oceans.
The past decade has seen record-high seawater temperatures that reached unprecedented levels in 2024. Ocean heating impairs carbon dioxide uptake, raises sea levels through thermal expansion and alters ocean-atmosphere interactions in ways that can intensify some extreme weather events.
Notably, higher ocean surface temperatures are already linked to more intense hurricanes, typhoons and heavy rainfall events. Marine heatwaves are becoming more frequent, decimating sensitive ecosystems like coral reefs and kelp forests.
Since 2023, exceptionally high ocean temperatures have exposed around 80 percent of the world’s coral reefs to bleaching-level heat stress – the largest global bleaching event on record. This widespread degradation weakens the ability of coral reefs to protect coastlines from waves and storm surges, which increases risks to coastal communities and infrastructure.
At the same time, ocean acidification has gone beyond safe limits, increasingly endangering marine ecosystems. As oceans absorb more carbon dioxide, they become more acidic, endangering marine life and the ecosystem services on which humanity depends. Cold-water corals, tropical coral reefs, and Arctic marine life are especially at risk.
If these trends continue, oceans could ultimately invert from a carbon sink to a carbon source.
2024 was the hottest year ever recorded for global oceans, accelerating rising sea levels through thermal expansion and melting of glaciers and polar ice. Global mean sea level has climbed about 21 centimetres since 1900, and the rate of rise is speeding up.
Since 2000, glacier melt and ice sheet loss in Greenland and Antarctica have become the dominant contributors to increasing sea levels. The rise, about 1.7 mm per year last century, has more than doubled to over 3.7 mm per year. Scientists warn that if ice sheet disintegration accelerates, extreme scenarios of over two metres of sea level rise by 2100 cannot be ruled out, and that the average rise today is already higher than expected.
Every increment of sea rise amplifies coastal flood risks and erosion, threatening low-lying cities, ports, and even whole island nations such as Tuvalu. Some coastal communities – for example, in Panama, the Solomon Islands, the United States and France – are already planning to relocate.
The potential impact of these developments is massive: 65 percent of the global economy is located within 100 kilometres of the coast, and 12 of the world’s 15 megacities are located along coastal areas. Without adaptation, rising seas could cost the EU alone up to €500 billion worth of services in the coastal regions per year by 2080.
Why this matters for central banks
Oceans are relevant to price stability, and this will likely become more pronounced as marine ecosystems deteriorate.
Pressures on marine and ocean ecosystems affect key economic activities. These include fisheries, aquaculture, tourism and maritime transport, reducing output and employment, which may increase the risk of price volatility for food and traded goods.
The degradation of coastal ecosystems also weakens natural protection against storms and flooding, threatening people, damaging infrastructure, and risking fiscal and financial stability. As the capacity of oceans to regulate climate and weather diminishes, climate-related disturbances will tend to increase.
These effects will likely increase economic losses, raising macroeconomic uncertainty and potentially making it more difficult to keep prices stable. If oceans lose their ability to absorb carbon dioxide, reducing carbon emissions will require costly investment such as carbon sequestration technology.
Evidence suggests that when we overlook global temperature dynamics, which includes ocean surface temperatures, we underestimate climate-related economic damages by five to six times. By increasing uncertainty around the timing, magnitude and persistence of shocks, ocean degradation complicates macroeconomic forecasting and the conduct of monetary policy.
With this in mind, more granular data on economic and financial exposures in coastal and ocean-dependent sectors are crucial to the work of central banks.
What needs to be done
In October 2025, a major “planetary health check” report warned that more than three-quarters of Earth’s life-support systems, including the oceans, are now in the “danger zone”.
Central banks are not climate policymakers, and we cannot prevent ocean degradation. However, we can, and must, observe and research the economic and financial consequences. And we must integrate ocean-related risks into macroeconomic models, scenario analyses and stress-testing frameworks.
Effectively protecting the ocean’s economic and ecological functions will require a much wider collective action, though. At a global level, we must cut greenhouse gas emissions and scale up nature-based, infrastructural adaptation. We must also adapt and catalyse finance for marine and coastal conservation and embed ocean sustainability into economic decision-making.
Each degree of warming increases sea levels and jeopardises livelihoods, with knock-on economic effects and financial losses.
On a positive note, the commitments announced in June 2025 at the UN Oceans conference suggest that the global community is beginning to respond. Governments and investors pledged significant financing. This includes €1 billion from the European Commission for ocean science and conservation, and €8.7 billion for ocean economy sustainability from philanthropists, private investors and public banks. It also includes €3 billion from the European Investment Bank and the Asian Development Bank to fight marine plastic pollution.
Additionally, in 2025, the UN High Seas Treaty reached the required 60-country ratification milestone and entered into force on 17 January 2026.
This landmark agreement, which took two decades to materialise, will enable the creation of marine protected areas on the high seas. The goal is to safeguard 30 percent of international waters through marine protection areas, activity restrictions, and environmental impact assessments. Currently, only about 1 percent of the high seas are protected. The Treaty’s entry into force marks a historic step toward conserving marine biodiversity in areas that have long been unregulated.
Protecting our oceans is not just an environmental goal – it is an economic necessity and a precondition for long-term resilience.
