Sustaining life on Earth

The ocean sustains all life on Earth. Yet it’s facing a multidimensional crisis driven by overfishing, pollution (especially plastics, sewage, and industrial/agricultural runoff), habitat loss, invasive species, and climate change. 

No matter where we live, the ocean is essential to our lives. It supplies 50% of the oxygen we breathe and is home to fish and other species that provide food and income for more than three billion people. Its coral reefs and oyster beds shelter marine life and protect our shores by absorbing wave energy and storm surges.

On the edges of the ocean, coastal wetlands - such as mangroves, salt marshes and seagrass meadows - protect our shores, too. These unique areas also draw in carbon as they grow, and store it in their leaves, stems and the rich soils held by their roots. This ‘blue carbon’ can remain in the soil for thousands of years. In fact, coastal wetlands store five times more carbon per hectare than rainforests, helping mitigate climate change.

The ocean is one of the largest carbon reservoirs on Earth, holding about 50 times more carbon than the atmosphere. But the ocean and marine ecosystems are being impacted by climate change in five major ways: ocean warming; ocean acidification; ocean deoxygenation; sea level rise; and heat stress. Coastal seas face the broadest array of human pressures and uses, as the rate of pollution and land-use change is greatest near the coast. Through agriculture, aquaculture, settlements, port development and tourism, the ability of coastal ecosystems to accumulate carbon is diminished, potentially leading to the release of CO2 from coastal sediments. 

Promoting a sea change

UNDP’s work on ocean action focuses primarily on how we can promote a blue economy transformation and work to conserve and sustainably use the oceans, seas and marine resources. Our projects and programmes bring a diverse suite of actors together to jointly protect ecosystems and ensure the sustainable use of water and ocean resources to build equitable, inclusive, and sustainable societies. 

Protect and restore key ‘blue carbon’ ecosystems: The protection and enhancement of marine ecosystems is a key nature-based contribution to climate mitigation efforts. There are currently 187 countries with some form of marine protection. Reviews of effectively managed Marine Protected Areas (MPAs) have shown that they can increase biodiversity, as well as the size and abundance of species. But these benefits are only realized when MPAs have high levels of protection, are ecologically coherent, are distant from human activities, and have long tenures. Such MPAs can also provide co-benefits, such as  food provision and protection of carbon stores.  

Ocean finance: A term used for financial mechanisms that invest in different sectors of the blue economy, ocean finance can play a critical role in helping achieve a sustainable ocean economy. This requires a financial regime that acknowledges the real costs of biodiversity loss, as well as risks to the climate and oceans. Ocean finance can include everything from private capital markets to central banks, we well as incentives for sustainable ocean finance. Innovation in this domain requires the development of new financial instruments (such as blue bonds), finance and insurance concepts for coastal zone resilience and blue infrastructure, and integrated nature-based solutions.