Emission Controlled Areas (ECAs) (North Sea, Baltic Sea, English Channel and alongside North America) already exist for some years.
Also this year IMO decided the global sulphur cap should be reduced to 0,5%. That means refineries should produce more low sulphur fuels. Or, shipowners could install exhaust gas cleaning systems, so-called scrubbers, removing more than 90% of sulphur particles out of exhaust gas, which allows them to meet the stricter requirements when burning high sulphur fuels (so-called residual fuels).
This new piece of legislation will also boost the use of alternative fuels, such as LNG, methanol etc. These more environment friendly fuels face high investment cost and a better trained crew, but can reduce operational costs in the long run. Moreover, cleaner fuels seriously contribute to a better air quality in some regions and, as such, contribute to saving lives of people dying each year because of bad air quality.
Better fuels also mean less acidification and other associated environmental problems. But, burning better fuels also means less on board sludge generation.