CO₂ emissions in a global container shipping network and policy implications

This paper studies emissions in the global network of CMA-CGM, the world's third-largest carrier, in an effort to shed light on the environmental impacts of container shipping. We propose a bottom-up framework to quantify emissions inventories using operational data on shipping routes, deployed ships, ports of call and arrival/departure schedules. Emissions inventories are analysed at the worldwide level, as well as at individual ports, transport corridors and regions. Our findings provide insights into containership emissions, and implications for the industry and its policymakers who strive to mitigate the negative externalities of shipping activities. The company's weekly operations of 200 routes consume 392,313 tonnes of fuel and release 1,226,166 tonnes of CO2. The emissions mainly concentrate on a few strategic passages, regions and ports along the East-West corridor. Hub-and-spoke patterns influence the skewed distribution of in-port emissions. Most of such emissions take place in a small number of key hubs, which attract substantial vessel calls. Traffic concentration highlights the importance of green policies at strategic hubs, to attain the global environmental targets, and to reduce emissions in-port areas. In addition, collaboration between key hub ports and top carriers is necessary to facilitate cleaner transportation. This research also reveals the effects of operational efficiency, mega vessels and slow steaming on cutting carbon emissions.