This research provides a novel analysis that connects 2011 in-use shipping fleet characteristics, first-ever satellite data on ship movement, and technical literature on ship efficiency technology to analyze the long-term prospects for increasing shipping efficiency. The analysis provides a synthesis of several new data sources to assess how, why, and how widely ship efficiency and CO 2 emissions vary across the current fleet. A primary objective of this report is to explore the long-term implications of a recent 2013 analysis that provides a snapshot of global ship movement and ship efficiency in 2011. The recent study by University College London sheds light on the variation of real-world CO 2 emissions and energy efficiency from international shipping. That study was the first to analyze detailed, satellite-based ship-level operation; technical efficiency attributes; and operational in-use efficiency characteristics for the global shipping fleet.