Marine carbon dioxide removal (mCDR) in the Indian seas: current understanding, regional opportunities, and future directions

As the global community confronts the escalating threat of climate change driven by anthropogenic greenhouse gas emissions, carbon dioxide removal (CDR) has emerged as an essential strategy to complement emissions reductions, achieve net-zero goals, and plays an important role in removing legacy carbon emissions. Marine Carbon Dioxide Removal (mCDR), which influences the ocean’s natural carbon uptake processes, is gaining increasing attention for its vast sequestration potential. Despite the ocean absorbing a significant quantum of anthropogenic CO2 emissions, rising emissions are outpacing its natural buffering capacity. This paper synthesizes current understanding of mCDR approaches, including biological (e.g., seaweed cultivation, ocean fertilization), chemical (e.g., ocean alkalinity enhancement), and physical (e.g., artificial upwelling and downwelling) techniques, and evaluates their applicability to the Indian Seas, a region characterized by unique monsoon-driven dynamics, stratified biogeochemistry, and large CO2 outgassing. Drawing upon observational programs, model simulations, and ecosystem-specific assessments, this study highlights opportunities for regionally adapted mCDR deployments, such as macroalgal farming, mangrove restoration, and pilot-scale alkalinity enhancement in semi-enclosed coastal systems. It also discusses technical, ecological, and governance challenges, including monitoring uncertainties, regulatory gaps, and community engagement needs. Strategic recommendations are offered to integrate mCDR into India’s climate policy, blue economy goals, and international climate commitments. The current study highlights the development of inclusive, empirically supported maritime climate solutions for the Indian Seas while maintaining social justice, environmental integrity, and scientific openness in the development and deployment of mCDR.