A call for internationally coordinated scientific research for marine Carbon Dioxide Removal (mCDR) activities

Various mCDR activities have been proposed to reduce the atmospheric CO₂ concentration to curtail global warming and mitigate surface ocean acidification, such as coastal blue carbon, sinking crop residue, sinking macroalgae, sediment trapping, ocean fertilization, and ocean alkalinity enhancement, in recent decades. More than one hundred coastal states can technically carry out one or more such CDR activities. The efficacy and environmental impacts of significant scale of mCDR activities are not understood fully due to the absence of field scientific experiments. mCDR activities aim to modify the global atmospheric greenhouse gas composition, and the global ocean environment changes subsequently because the ocean and atmosphere are coupled. The international community, therefore, has waited for a globally transparent regulatory mechanism, such as the 2013 amendments to the London Protocol, to be universally accepted. Introducing substances or energy into the marine environment is much less costly than the efforts to assess the efficacy and environmental impact arising from such an introduction, commonly known as monitoring, reporting, and verification (MRV). Developing economies may introduce the material or energy needed, and the developed economies may transfer the required MRV technologies as a part of joint scientific research, which aligns with the Common But Differentiated Responsibilities (CBDR) formalized in the UNFCCC. Authors call for internationally coordinated scientific research for marine Carbon Dioxide Removal (mCDR) activities to meet the goals of the 2015 Paris Agreement. A more robust international governance regime will emerge by learning scientific facts through international joint scientific research.