Global assessment shows blue carbon wealth dominated by ocean processes and unevenly distributed across countries

[Geoengineering News]

https://www.nature.com/articles/s44458-026-00117-8

Authors: Nathalie Hilmi, Loua Aurel De Vince Vehi, Marina Treskova, Cécile Sabourault & Lisa Levin 

21 July 2026

Abstract

Marine ecosystems remove carbon dioxide from the atmosphere and regulate climate, yet their contribution remains weakly represented in national wealth accounts. Here we develop a global valuation framework for blue carbon wealth that combines spatial data on coastal ecosystems, including mangroves, seagrasses and salt marshes, with country-level estimates of open-ocean biological carbon transport. We value annual removal flows using country-level social cost of carbon estimates. Coastal ecosystems remove about 111 million tonnes of carbon per year, corresponding to 228.6 billion United States dollars annually. Including open-ocean processes increases total annual removal to about 1.13 billion tonnes of carbon, valued at 2.32 trillion United States dollars. Open-ocean processes dominate annual removal value, while coastal ecosystems provide longer-term storage and local co-benefits. Blue carbon wealth is unevenly distributed across countries and weakly aligned with national emissions, highlighting overlooked marine natural assets in coastal and island economies.

Source: Communications Sustainability