The Ocean: A Key Player in Climate Protection

Since the beginning of industrialization, the ocean has absorbed over 90 percent of the excess heat from the atmosphere and bound around 30 percent of human-made carbon emissions. Without this buffering effect, global warming would be far more severe. But the ocean also has a limit: it is warming, acidifying, and losing oxygen. The consequences are devastating — coral reefs are dying, sea ice is melting, and species are migrating to cooler regions or disappearing entirely.

Polar bears on melting ground

Polar bears depend on pack ice, which is rapidly disappearing. The Arctic is warming more than twice as fast as the global average. In recent winters, temperatures in the central Arctic were up to 6 °C above the long-term mean. By 2050, the Arctic could be ice-free in summer. This will affect not only polar bears but the entire climate system, as melting ice reduces the Earth’s ability to reflect sunlight and accelerates global warming.

Instead of addressing the root causes of these developments, political and economic attention is increasingly turning toward technological fixes.

Risky technologies as substitutes for proven measures?

The most effective way to stabilise the climate is a drastic reduction in greenhouse-gas emissions. This is scientifically undisputed and technically feasible. Yet, rather than implementing structural changes in the energy, transport, and economic systems, some actors are placing their hopes in technological interventions in the climate system — such as marine geoengineering.

These include cloud brightening over the ocean or adding substances to seawater to artificially bind carbon. The ecological consequences of such interventions remain poorly understood and pose significant risks to marine ecosystems. They mislead by suggesting simple answers to a complex problem and divert attention from proven solutions. OceanCare is warning against such experiments and advocates for long-term, effective, and ecologically sound measures.

Future-proof strategies instead of incalculable risks

OceanCare aims to preserve the ocean as a powerful ally in climate protection. One key focus is stopping fossil-fuel projects, especially in sensitive marine regions where oil and gas activities threaten ecosystems both directly and indirectly. There are already positive result that we can point to: Spain and Portugal, under pressure from civil-society organizations, have banned new fossil exploration in their territorial waters.

Other human activities also undermine the climate functions of the ocean. OceanCare advocates for an international ban on deep-sea mining, as interventions in these little-known ecosystems could destroy natural carbon stores in seabed sediments and worsen the climate crisis.

Another area for action is global shipping. A moderate reduction in vessel speed by ten per cent could not only significantly cut emissions but also reduce underwater noise — thereby easing the overall stress on the marine environment.

Protecting and restoring marine habitats is essential for climate protection. Ecosystems such as coastal seagrass meadows store large amounts of carbon, support nutrient cycles, and purify water. By reducing pollution and conserving or regenerating vulnerable habitats, these natural carbon sinks can be strengthened for the long term.

Protecting the ocean is protecting the climate

Through its Because Our Planet is Blue campaign, OceanCare is raising awareness of the ocean’s vital role in climate protection. Most recently, over 114,000 signatures from civil society were collected and handed over to the UN Special Envoy for the Ocean at the UN Ocean Conference (UNOC) in Nice in June 2025. These voices represent a growing global movement calling for binding protection of marine ecosystems — a powerful contribution to tackling the climate crisis.