Ships fitted with exhaust scrubbers are like people who have turned to vaping rather than smoking cigarettes: they both make more smoke than before but – we are led to believe – it’s “nice” smoke

ChasB46, indeed, rather than emitting sulphur into the air, the results from the scrubbing process are now dumped into the sea. Sometimes the maritime sector behaves in a very cynical way.

Scrubbers (Exhaust Gas Cleaning Systems) are designed to remove/reduce Sulphur Oxides and Nitrogen Oxides and not carbon. Quote from The Air Pollution & Climate Secretariat "All we do when we fit exhaust gas systems, especially open-loop scrubbers, is move pollutants somewhere else". Open scrubber systems are now being banned in many countries as they excessively pollute the seas.

I did read that the exhaust smoke from a vessel fitted with a scrubber emits more carbon into the air.

I think the scrubber is meant to prevent the escape of yellow smoke, in the picture it seems not to work properly.

That is because of the scrubber.
Cheers,
Roy

Quite a smoker for a newbie !