Prospective Life Cycle Assessment of Container Shipping

Abstract

International shipping has lower direct CO2 emissions per unit of mass transported than any other transportation mode. However, the sector s absolute direct emissions in 2012 totalled 815 million tonnes CO2-equivalents, accounting for 2.1% of all greenhouse gas emissions, and with a continuation of currents trends, are expected to increase between 50 and 250% by 2050. Containerships contribute about one fourth of these emissions, more than any other ship type. (Smith et al., 2014)

Life cycle assessments model a product or service from raw material extraction through to waste handling, capturing both direct and indirect environmental impacts occurring throughout their lifetime. Here, a bottom-up life cycle analysis of the global containership fleet is performed, as well as predictions for the composition and attributes of the containership fleet from 2016 until 2050. Thus emerges a more complete picture of the environmental footprint of the containership fleet, and the outcomes of different scenario developments can be examined.

The results show that the propulsion of the ship is the most important contributor to impacts where fuel combustion plays a central role: Ship propulsion accounts for about 80% of the climate change impact of the containership fleet. However, in other impact categories, e.g. toxicity potential, other stages of the vessel s life cycle, such as ship construction and the fuel value chain, plays a greater role. Looking at the development of the global warming potential of the fleet towards 2050 reveals that with the assumed improvements in ship emission efficiency and higher proportion of very large ships, above 8500 TEU, the emissions from the fleet do not exceed the 2016-level in any of the five business-as-usual scenarios.