In January, the International Maritime Organisation (IMO) lowered the sulphur emissions limit from a ship’s engine from 3.5% to 0.5%, falling to 0.1% in four emission control zones.
Sulphur is emitted from the heavy fuel oil burned by most ships and the IMO’s website quotes a study estimating that, without the reduction, another 570,000 premature deaths would result by 2025.
Cruise lines have the choice of using more expensive low-sulphur fuel or to “scrub” normal fuel emissions, capturing the harmful residue, which most opt for. The residue can then be stored and pumped away, but many ships discharge the water into the sea, including when docked in port.
