A Systematic Review of Carbon Sink Pathways and Deployment Strategies

Amid the global dual transformation toward deep decarbonization and net-zero emissions, carbon sequestration pathways have become indispensable pillars of climate governance. Natural sinks and engineered carbon removal approaches exhibit high heterogeneity in sequestration mechanisms, temporal effectiveness, environmental externalities and societal acceptance. Yet, current research lacks an integrated understanding of cross-pathway synergies, spatial deployment logics and dynamic scheduling strategies, calling for a more systemic and adaptive framework. This review provides a comprehensive synthesis of the carbon storage structure and regulatory drivers of terrestrial (forests, wetlands) and marine sinks, assessing their spatial potential and ecological coupling. It also critically evaluates the technological readiness, sequestration stability and deployment thresholds of engineered options such as BECCS, DAC, enhanced weathering and ocean alkalinization. Key divergences between natural and artificial pathways are highlighted in terms of carbon removal capacity, energy intensity, deployment timing and governance risk. We identify persistent bottlenecks, including the absence of synergistic deployment models, resource and institutional constraints at the regional scale, unquantified system feedbacks and limitations in monitoring, reporting and verification (MRV) mechanisms. These issues inhibit the scale-up and long-term stability of carbon sink systems. To address these challenges, we propose a Pathway-Region-Temporal (P-R-T) scheduling model that integrates technological characteristics, spatial suitability and sequencing dynamics into a unified optimization framework. We further advance a “Carbon Flow-Storage-Feedback Loop” architecture to guide the adaptive evolution of carbon sink systems under uncertainty, enabling coordinated deployment, real-time optimization and policy responsiveness. We argue for a strategic shift from fragmented pathway management toward systemic carbon sink engineering, integrating multi-path coordination, dynamic feedback recognition, scalable infrastructure and robust MRV systems. Such an approach lays the scientific foundation for achieving high-resilience, low-risk net-zero trajectories in global carbon governance.