Carbon footprints: Uncovering spatiotemporal dynamics of global container ship emissions during 2015–2021

Abstract

The proposed “peak carbon” and “carbon neutral” targets have catapulted the reduction of carbon dioxide (CO2) emissions in the shipping industry into a global focal point. Given their pivotal role in global trade, the worldwide movements of container ships provide insights for decision-making in maritime shipping CO2 emission mitigation. This paper employs Automatic Identification System (AIS) trajectory data from 2015 to 2021 to estimate the global carbon emissions of container shipping through a bottom-up methodology, allocating emissions on a 1° × 1° grid. Additionally, it delves into the evolving trends in CO2 emissions from 2015 to 2021, conducts spatial autocorrelation analysis, identifies hot spots, examines the spatio-temporal distribution patterns of global container ship CO2 emissions, and analyzes the emission characteristics of major ocean shipping routes. The findings reveal a temporal pattern in global emissions from container shipping, characterized by an initial decrease followed by a rebound, notably declining from 217 million tons in 2016 to 148 million tons in 2020, and subsequently rising to 168 million tons in 2021. The spatial distribution of CO2 exhibits pronounced heterogeneity, marked by notable spatial dependence and aggregation tendencies. The spatial distribution of annual emissions from container shipping demonstrates a similar pattern, with peak emission clusters predominantly concentrated along the coastline and major ocean shipping routes. This study provides a comprehensive understanding of carbon emissions from container shipping with high spatial and temporal resolution, facilitating a detailed analysis of emission patterns and influencing factors. Furthermore, the outcomes offer a scientific foundation and decision-making support for environmentally sustainable practices in the global maritime shipping.