[antubbs]

Newer ships aren't necessarily much better. Mærsk's E class container ships still burn bunker fuel. The Triple E Class made improvements in efficiency and emissions, but are still burning bunker fuel at about 50% of the emissions per container than the previous class.

[Tharkun]

From what I understand, these ships are huge and cover very large distances. This requires a lot of fuel. Bunker is the cheapest fuel for this use-case (it, -- sort of literally -- being a bottom of the barrel sort of thing).

Not sure what the global impact would be of banning bunker, or (trying to) refine it. Economic or environmental.

[antubbs]

With the disclaimer that I have no idea what I'm doing and there are probably many flaws in this reasoning:

A metric ton of bunker is about $300 (http://shipandbunker.com/prices)

The same volume of diesel would be about 315 gallons and would be about (https://www.extension.iastate.edu/agdm/wholefarm/html/c6-87.... / http://www.indexmundi.com/commodities/?commodity=diesel), so about $500.

The energy density of the diesel is about 13% higher than the bunker (https://people.hofstra.edu/geotrans/eng/ch8en/conc8en/energy...).

Assuming identical efficiency (no clue on this point), you would end up paying about 50% more for the same amount of "energy." We would also be dramatically increasing the worldwide demand for diesel and we'd still have the leftover residual product from refining that was previously used to fuel these ships.

50%+ margin increase on containerized shipping seems pretty significant.