Recent global regulations have significantly reduced sulfur emissions from ships, helping to improve air quality in coastal regions – confirmed by a new international study led by researchers at the National Centre for Atmospheric Science in the United Kingdom.
The research, published in Environmental Science: Atmospheres, used aircraft and ground-based instruments to measure sulfur dioxide and nitrogen oxides emitted by ships in the North-East Atlantic and European coastal waters between 2019 and 2023.
The team found that the average sulfur content in ship fuel dropped nearly tenfold in open ocean areas following the International Maritime Organization’s 2020 regulation, which capped sulfur content in marine fuel at 0.5%.
Before the change, many ships exceeded the previous 3.5% limit. After 2020, only a small number of ships were found to breach the new standard.
In European Sulfur Emission Control Areas (SECAs), such as the English Channel and the Port of Tyne, sulfur levels were even lower – well below the stricter 0.1% limit. Interestingly, ports outside these zones, like Valencia in Spain, also showed low sulfur levels, likely due to EU rules requiring cleaner fuel when ships are docked for extended periods.
This is the first study to use aircraft-based measurements and predictions from the Ship Traffic Emission Assessment Model (STEAM3) to assess ship emissions outside of sulfur control zones since the 2020 regulation came into effect. The findings support the widely held view that ships now emit around seven times less sulfur than before the rule change – an important step toward cleaner air and healthier coastal environments.
(Photo from NCAS)