The mostly used fuel for ocean ships (so called "Bunker") is a heavy heating oil which is gained as residue from crude oil distillation. Crude oil contains sulfur which after combustion in the ship’s motor produces emissions. Sulfur oxides (SOx) are damaging to human health, causing respiratory ailments and lung diseases. In the atmosphere SOx can lead to acid rain, can damage plants, forests and water and contributes to acidification of the ocean. It must therefore be attempted to reduce these SOx emissions of ships and thereby improve air quality and better protect the environment.

Concretely this means: from January 1, 2020 the limits for sulfur in crude oil which will be used on board the ships that travel outside of the identified emission control areas will be reduced to 0,50 % m/m (mass per mass). Either the ships as from 2020 will be tanked with low sulfur fuel or they will be furnished themselves with an exhaust gas cleaner, so-called «Scrubbers» on the ship.

This Scrubber comes in three forms: "Closed Loop Filter" (exhaust gases are cleaned and the pollutants are gathered in a tank which is emptied in the harbor for corresponding additional handling), "Open Loop Filter" (exhaust gases are cleaned and the cleaning water together with the pollutants contained therein are discharged into the sea) and "Hybrid Filter“ (that can be adjusted either for operation in an open or closed loop).

Seen as a whole, the most environmentally friendly form is the Closed Loop because such systems do not emit either in the atmosphere nor in the water provided the waste is treated after collection in the harbors. The Open Loop Filter indeed fulfills the requirements of the sulfur guidelines and reduces the emissions from shipping in the atmosphere, its use leads however to heavy metals, sulfur, etc. which land in the sea together with the cleaning water. China, Hong Kong and Singapore have already set forth that no ships with Open Loop Filter systems on board will be allowed in their harbors. It can be assumed from this that other Southeast Asian countries and Japan will likewise follow.

Whether it is equipping ships with filters or the use of low sulfur fuel: in both cases the operating costs for environmental protection will increase significantly. Therefore it has already been clearly signaled by the shipping companies that the introduction of surcharges at the latest from the time of tanking with low sulfur fuel (meaning: already 60 to 90 days before the key date of January 1, 2020) are unavoidable in order to cushion the impact of the additional costs arising which will make the entire transport by sea more expensive as from 2020. Several shipping companies have announced increasing their surcharges already before the key date of January 1, 2020 because they already have higher operational costs in 2019 due to the adjustments.

Due to the re-equipping of ships, first of all the short-term overall capacity on the world seas will be decreased because the installing of Scrubbers will take approx. 60 days per ship. In addition and in the long run the loading capacities of ships after the re-equipping will be smaller than before the adjustments because both the Scrubber and the Low Sulfur Tanks require more space on the ships.

Many experts assume the following consequences from the IMO2020 regulation: Increased use of slow steaming will lead to the increase of the range of ships. In order to be able to preserve the transit times at key harbors and therefore remain competitive, the shipping companies could be forced to leave out individual harbors from their fixed routes.

Additional information can be found directly at IMO.