Accounting and monitoring challenges for blue carbon enhancement in national climate policy targets and international carbon markets

“Blue carbon” refers to carbon sequestration in marine ecosystems. While carbonuptake in coastal vegetated areas has been well-studied, emerging techniques toenhance carbon uptake in open ocean environments pose new challenges in termsof accounting and monitoring, reporting, and verification (MRV). Establishing baselinesfor carbon sequestration is particularly difficult, as the natural ocean sink is influencedby human activities and increased atmospheric CO2. Furthermore, the durability ofbiogenic oceanic carbon sinks is uncertain, particularly in the face of climate changeimpacts. Legal complexities arise due to the transboundary nature of open oceanecosystems, making it difficult to attribute carbon credits to specific nations. CurrentMRV methodologies and accounting frameworks do not sufficiently address openocean blue carbon enhancement. Without robust frameworks and internationallyaccepted standards, integrating these approaches into national climate policy andcarbon markets could lead to overestimating mitigation outcomes. We conclude thatgovernance to incentivize and regulate blue carbon activities should address bothclimate and environmental impacts and benefits and develop financing modelswhich do not rely on carbon crediting mechanisms.