As nature-based solutions gain traction in climate mitigation, marine carbon dioxide removal through blue carbon ecosystems—such as seagrass meadows, mangroves, salt marshes, and seaweed cultivation—has emerged as a promising pathway. However, these extensive and climate-relevant ecosystems remain insufficiently understood due to the biogeochemical and physical complexity of their air-sea exchange processes, posing significant challenges to developing robust verification frameworks. Among the many knowledge gaps—including biomass quantification, nutrient cycling, sediment burial, and mixed-layer interactions—the air-sea exchange of greenhouse gases (GHGs) stands out as the most challenging and critical for verifying the net removal of GHGs from the atmosphere. This session will focus on the pivotal role of this complex air-sea gas exchange in assessing the net GHG budgets of blue carbon habitats and outline steps toward scientifically robust standards that promote transparency, prevent greenwashing, and build trust in marine climate solutions. We invite contributions from field studies, remote sensing, biogeochemical analyses, and modeling that evaluate the roles of macroalgae, seagrass meadows, and other blue carbon systems in climate mitigation and ecosystem functioning. Ultimately, this session aims to support the integration of blue carbon into global climate models and strengthen the scientific basis for marine carbon dioxide removal.

• Air-Sea Interactions -
• Climate and Ocean Change -
• Ocean Biology and Biogeochemistry -