Sequestration of carbon dioxide from the atmosphere in coastal ecosystems: Quantification, analysis, and planning

Many countries have come to a consensus that they need to reduce carbon dioxide (CO2) emissions and promote low-carbon development. Mangrove forests, seagrass beds, and coral reefs are important coastal ecosystems that can effectively sequester CO2 from the atmosphere. In this study, the Carbon Emission Pinch Analysis (CEPA) approach was applied to develop a method of comparing strategies for maximising CO2 sequestration while minimising the economic cost. The proposed method replaces the emission factors and carbon emissions in CEPA with the economic cost and carbon sequestration amount to better suit the objectives of this study. The proposed method was applied to a case study on the coastal areas of Hainan Island in China. Four scenarios were considered concerning to the planting area, carbon sink, and economic cost. Scenarios 1 (increase the carbon sink by 10 %), Scenario 2 (increase the carbon sink by 10 % while limiting the planting area to 30 km2), and Scenario 3 (increase the carbon sink by 11 %) were all considered feasible at an economic cost of <10 million EUR. However, Scenario 4 (increase the carbon sink by 12 %) exceeded the specified limit (10 million EUR in adjustment costs) by 2.55 million EUR. The study shows that Scenario 3 is optimal because it achieves the target of increasing carbon sinks by 11 % (increasing the annual carbon sequestration by 78.7423 million kg) within the constraints of planting area and economic costs. The study also shows that coral reefs are ideal for carbon sequestration. © 2024 Institution of Chemical Engineers