Emissions from Ships

TLDR

Ship air emissions have been under‑evaluated, prompting the IMO to initiate the first framework to curb NOx and SOx from propulsion systems. The authors updated global ship emission inventories using a new estimation approach. Ships contribute over 14 % of global nitrogen and 16 % of sulfur emissions from fuel combustion, underscoring significant policy implications.

Abstract

Air emissions from ships have not been adequately evaluated for their scientific or policy importance. Current international policy initiatives by the International Maritime Organization (IMO) to reduce emissions from ship propulsion systems (NOand SO, primarily) mark the first efforts to define a framework to address this issue. Corbett and Fischbeck estimate ship emissions on a global scale, updating current emission inventories. Global annual nitrogen and sulfur emissions from ships are estimated to be 10.12 Tg (1012 grams) and 8.48 Tg, respectively, showing that ship emissions represent more than 14 percent of nitrogen emissions from global fuel combustion sources and more than 16 percent of sulfur emissions from world petroleum use. The policy implications of ship emissions are discussed.