Low Sulfur

The fuel that cargo ships use to comes from what are literally the dregs of the oil refining process. The asphalt-colored substance is so thick that it must be mixed with heating oil so that its viscosity is low enough to be pumped. In the syrup-like fuel, there is a large amount of sulfur -- up to 4.5 percent.

When burnt, much of this sulfur in the form of sulfuric dioxide is emitted from ships' smokestacks. It then dissolves in the water, creating sulfuric acid. This in turn strongly increases the water's acidity levels.

The sulfuric dioxide creates little condensation particles in the atmosphere, thus building more clouds. The product of that process is acid rain.

Currently the Baltic sea has suffered very much from this acidity, this due to the fact of the fact that it acts more as a like than as an ocean with very little water movement.  To prevent further damage to the ecosystem ship navigating on the Baltic sea muss burn fuel that has a maximum of 1.5% Sulfur. Though most ships aren’t just moving within the Baltic sea they had to either add a second tank dedicated to the Baltic sea while using the main tank while in the non restricted areas. A second tank meant more investments it was therefore chosen to use a higher costing fuel with lower sulfur.

The difference in fuel price is currently 23.30€ more per ton, this seems like a small amount, but a container sheep can carry close to 12’000tons, which actually ends up making a big difference.