Establishing sustainability assessment framework for global blue carbon ecosystems
Mangroves, seagrass beds, and salt marshes, called Blue Carbon Ecosystems, which have become nature-based solutions to climate change due to their high carbon capture and burial efficiency. However, the long-term spatiotemporal sustainability of blue carbon has not been widely and comprehensively assessed.
Assistant Prof. Zhenci Xu from the Department of Geography at the University of Hong Kong, in collaboration with the research group of Prof. Guanqiong Ye from the Ocean College of Zhejiang University, as well as researchers from the Second Institute of Oceanography of the Ministry of Natural Resources and the Zhejiang Institute of Hydraulics & Estuary, conducted long-term and detailed research to address the above issues. They constructed the Blue Carbon Development Index (BCDI) to assess the sustainability levels and dynamic changes of blue carbon in 136 coastal countries over a period of 24 years. A global blue carbon cooperation model was proposed to explore the feasibility of global blue carbon cooperation and the benefits under different scenarios. The research results were recently published in the international academic journal Nature Communications.
The results show that the BCDI index increased from 20.26 in 1996 to 32.55 in 2019, a growth of 60.69%. Over a 24-year period, many countries have made significant progress in their BCDI scores. Most countries in the Americas, Asia, and Europe have seen significant improvements in their BCDI scores, while African countries have seen a slight increase. Europe, North America, and Oceania have higher BCDI scores than other regions. The global cooperation scenario simulation found that, compared to the 'business-as-usual' scenario, under the global deep cooperation scenario, coastal countries' blue carbon ecosystems can increase their annual carbon sequestration by 2.96 million tons in 2030, generating economic benefits of $136.34 million.
As the issue of climate change becomes increasingly severe, we must recognize the importance of international cooperation in blue carbon governance. This assessment not only clarifies the evolutionary trend of global blue carbon sustainable development levels but also proposes key models for global cooperative governance. It is hoped that this will draw attention to its importance and provide policy and management decision-making references for local sustainable blue carbon development.