Assessing the carbon neutrality capacity of wetland and non-wetland ecosystems in a typical coastal region

To achieve carbon neutrality in 2060, increasing carbon sequestration and reducing carbon emissions are necessary to mitigate climate change. In this study, we developed a framework for assessing the carbon neutrality of wetland and non-wetland ecosystems, by clarifying the wetland, non-wetland carbon sinks as well as carbon emissions, and selected the Yellow River Delta High-efficient Eco-economic Zone (YRDHEZ) in China as a case study. The results indicated that the total ecosystem carbon sinks fluctuated between 18.0 and 23.5 MtCO₂ yr⁻¹, with a decrease of 15.3% during the study period. The carbon sinks decreased from 9.1 to 5.2 MtCO₂ yr⁻¹ in wetland ecosystems and from 15.1 to 11.2 MtCO₂ yr⁻¹ for non-wetland ecosystems. The total anthropogenic carbon emissions showed a trend of initial increase, followed by a decrease, peaking at 111.0 MtCO₂ yr⁻¹ in 2015. The carbon neutrality capacity decreased from 31.7% to 6.8% for wetland ecosystems, from 44.8% to 17.3% for non-wetland ecosystems, which did not reach carbon neutrality. Comprehensive policies are proposed by forming a wetland carbon offset restoration system, optimizing low-carbon patterns, developing carbon emission trading. These results revealed a significant imbalance between carbon sinks and anthropogenic carbon emissions, highlighting the urgent need for carbon neutrality and environmental sustainability.