Current studies primarily focus on blue carbon sinks and storage, and some researches have explored the socioeconomics and govern ance of blue carbon, such as management and strategies to minimize losses, and the assessment of blue carbon wealth through carbon social cost. However, the status of the sustainable development level of blue carbon is still unknown. Moreover, the relations among blue carbon ecosystems, driving forces for climate change mitigation, and socioeconomic interventions for development capacity on a global scale remain unclear. Such information is urgently required for promoting the global conservation and restoration of blue carbon ecosystems and the sustainable development of coastal zones.

Here we analyze the long-term blue carbon sustainable development level of global coastal countries and adopt a global cooperation model to collectively cope with global climate change challenges and enhance the synergies between blue carbon and society.

We have established a blue carbon development index (BCDI) that integrates three subsystems (driving force, resource endowment, and development capacity  to assess the long-term sustainable development level of blue carbon in 136 coastal countries and explore interrelationships between subsystems. Furthermore, a cooperation model was adopted to investigate the feasibility of global cooperation to increase carbon sequestration and the economic benefits of blue carbon.

The results showed an upward trend in BCDI scores with variations in regional performance over the past two decades, and we found a positive correlation between development capacity and blue carbon resource endowment. Based on the scenario simulations of global cooperation, we

found that coastal countries could improve the global average BCDI score, add 2.96 Mt of annual carbon sequestration, and generate $136.34 million in 2030 under Global Deep Cooperation scenario compared with the Business-As Usual scenario.

The results provide a sketch of the spatial and temporal sustainable development of blue carbon and a strategy to achieve ecological and economic benefits through cooperation, guiding future policy-making and international cooperation.