Spatiotemporal ship carbon emission exploitation and low-carbon shipping pathway evaluation

Against the background of the global low-carbon transition in the transportation sector, greenhouse gas (GHG) emissions from the maritime industry pose a significant challenge to achieving the sector's decarbonization goals. Accurately quantifying and characterizing these emissions is a fundamental prerequisite for formulating effective emission reduction strategies. This study integrates multi-source maritime data and employs a power-based method and a combined spatial allocation model to construct a high-resolution spatiotemporal inventory of ship carbon footprints across complete operational cycles. Notably, the inventory accounts for non-calling vessels that anchor but ultimately depart without berthing. Furthermore, this study constructs multiple emission reduction scenarios from the dual dimensions of operational optimization and energy technology upgrades to comprehensively evaluate the decarbonization potential and emission reduction effectiveness of various strategies. The results indicate that significant disparities in emission profiles between the two studied ports stem from differences in arriving vessel types and operational modes. Emissions from non-calling vessels reached 46,843 tons, accounting for nearly 9% of total emissions in the study area, making their management an indispensable component of carbon governance within the port district. Scenario evaluations demonstrate that the Virtual Arrival policy effectively reduces anchorage emissions from tramp ships, but achieving systemic deep decarbonization fundamentally relies on comprehensive energy substitution. These findings provide a practical scientific basis for advancing green shipping.