The Xiamen Symposium on Marine Environmental Sciences (XMAS 2025)

The high-resolution ship emission inventory plays a critical role across multiple disciplines, including atmospheric and marine science, as well as environmental management. In this study, we present a global high spatiotemporal resolution ship emission inventory, developed using the Shipping Emission Inventory Model (SEIMv2.2) at a resolution of 0.1° × 0.1° for 2013, 2016–2021. Leveraging 30 billion Automatic Identification System (AIS) signals, SEIMv2.2 integrates real-time vessel positions, speeds, and technical parameters to model ship emissions for key species such as CO2, NOx, SO2, PM2.5, CO, HC, N2O, and CH4. Regarding the major air pollutants and greenhouse gases, global ships emitted 847.2 million tons of CO2, 2.3 million tons of SO2, 16.1 million tons of NOx, 791.2 kilotons of CO, 737.3 kilotons of HC, 415.5 kilotons of primary PM2.5, 61.6 kilotons of BC, 210.3 kilotons of CH4, 45.1 kilotons of N2O in 2021, accounting for 3.2% of SO2, 14.2% of NOx, and 2.3% of CO2 emissions from all global anthropogenic sources, based on the Community Emissions Data System (CEDS). According to the inventory results, the composition of vessel types contributing to global ship emissions remained relatively stable. Temporally, global ship emissions exhibited minimal daily fluctuations. Spatially, high-resolution emission datasets revealed varying patterns of ship emission contributions by different types of vessels among maritime regions.
Our study also reveals the short-term fluctuation characteristics of global ship emissions during the COVID-19 pandemic 2020, particularly focusing on their spatiotemporal evolution and the inherent disparities. Overall, ships emitted NOx, CO, HC, CO2, and N2O declined by 7.4%-13.8%, while SO2, PM2.5, and BC declined by 40.9%-81.9% in 2020 compared with 2019. Container ships, chemical tankers, and Ro-Ro vessels were the primary contributors to the emission reductions, with container ships alone responsible for 39.4% of the decrease. The ship's CO2 emissions variations revealed the decline-rebound patterns in response to the pandemic. Further analysis of CO2 emission in Exclusive Economic Zones (EEZs) showed high temporal consistency between vessel emissions, sailing speeds, and international trade volumes across continents. The results highlight the correlation between global ship emissions and trade, as well as the operational status of ships, and their rigidity.
Our dataset, freely accessible online (https://zenodo.org/records/11069531), provides a solid data foundation for fine-scale scientific research and shipping emission mitigation.

ship emissions, atmospheric pollution, maritime pollution, spatiotemporal analysis, COVID-19, IMO 2020