No. They do emit a lot of sulfur oxides. Not as much as power generation but still a lot. Sometimes this gets simplified to container ships are 'one of the' big

No. They do emit a lot of sulfur oxides. Not as much as power generation but still a lot. Sometimes this gets simplified to container ships are 'one of the' biggest polluters. Which is pretty misleading since 'one of the' is such a weak phrase, doubly so when simplifying it down to a specific type of pollution.