Balancing Climate Mitigation and Adaptation: A Dynamic Economic Assessment of Blue Carbon in the Venice Lagoon

Climate adaptation measures are often perceived as an implicit concession to the limitations of mitigation efforts. Yet, adaptation and mitigation interact in ways that can either reinforce or undermine each other. In this study, we investigate the trade-offs between climate change adaptation and mitigation by assessing the impact of flood protection measures on blue carbon sequestration in the Venice Lagoon. Using a system dynamics framework, we integrate management and hydrodynamic processes and economic valuation within a simplified yet comprehensive model to evaluate how the operation of the MoSE flood barrier influences salt marsh carbon storage under different management and climate scenarios. Our findings reveal that, while MoSE effectively reduces immediate flood risk, its increasingly frequent closures could significantly diminish salt marsh carbon storage capacity — by over 40% within 2100 under a pessimistic sea level rise scenario (RCP 8.5) — thus reducing the economic value of blue carbon stocks by approximately €120 million compared to more flexible management scenarios. These insights support the case for adaptive MoSE operational strategies capable of reconciling immediate flood protection with long-term economic and environmental sustainability.