Overview of the International Maritime Organisation’s regulations and guidelines concerning ship emissions. IMO regulations and guidelines address emissions from ship smokestacks (emission to air; IMO, 2008a) and from scrubber systems (emission to water; IMO, 2008b). Green indicates subject to IMO regulations; yellow, included in IMO guidelines; red, unregulated. DOI: https://doi.org/10.1525/elementa.167.f1