碳中和目标下中国海洋渔业碳汇能力与潜力评估

通过海洋渔业固碳增汇是实现“碳中和”的重要路径,其中的关键在于科学、精准、系统测算海洋渔业碳汇能力。本文剔除经典“可移出碳汇”模型中部分不具有碳汇功能的碳,把贝藻通过释放POC和DOC形成的碳汇纳入测算模型,基于2006—2020年中国9个沿海省份贝藻养殖产量面板数据,评估中国海洋渔业碳汇能力,并基于LMDI分解方法解构中国海洋渔业碳汇能力提升的贡献因素,预测不同情景下2030年中国海洋渔业的碳汇潜力。研究发现：①2020年中国海洋渔业碳汇能力达302.63万t/年,区域差异显著;②包含不具有碳汇功能的碳会高估海洋渔业贝类碳汇24.24%,而不考虑贝藻通过释放POC和DOC形成的碳汇会低估海洋渔业碳汇50.70%;③在当前注重规模效应的发展模式下,到2030年海洋渔业碳汇能力为335.51万t/年~399.92万t/年,碳汇增长潜力有限。基于此,应推动中国海洋渔业碳汇的增长模式向技术驱动的高质量发展转变,不断提高中国沿海省份海洋渔业碳汇能力,持续为实现“碳中和”目标作出贡献。

Assessment of carbon sink capacity and potential of marine fisheries in China under the carbon neutrality target

Increasing carbon sequestration and sink through marine fisheries is an important way to achieve “carbon neutrality”, in which the key lies in the scientific, accurate, and systematic calculation of the carbon sink capacity of marine fisheries. In this study, some carbon without carbon sink function in the classical “removable carbon sink” model was removed, and the carbon sink formed by shellfish and algae by releasing particulate organic carbon (POC) and dissolved organic carbon (DOC) was included. Using the panel data of production of shellfish and algae in nine coastal provinces of China’s mainland from 2006 to 2020, the carbon sink capacity of China’s marine fisheries was evaluated, and the contributing factors to the improvement of China’s marine fishery carbon sink capacity were deconstructed based on the Logarithmic Mean Divisia Index (LMDI) decomposition method. Then we predicted the potential of China’s marine fishery carbon sequestration by 2030 under different scenarios. The results show that: (1) The carbon sink capacity of China’s marine fisheries will reach 3.03 million tons in 2020, with significant regional differences; (2) Including carbon without carbon sink function will overestimate the carbon sink of marine shellfish fishery by 24.24%, while ignoring the carbon sink formed by shellfish and algae by releasing POC and DOC will underestimate the carbon sink of marine fishery by 50.70%; (3) Under the current development model that relies on scale effect, the carbon sink capacity of marine fisheries will reach 3.36~4.00 million t by 2030, and the growth potential of carbon sink is very limited. Based on this, China should promote its marine fishery carbon sequestration growth to a technology-driven and high-quality development model to continuously improve the coastal provinces’marine fishery carbon sequestration capacity and contribute to the realization of the target of carbon neutrality.