It’s not worse than the original problem. SO2 emissions from shipping are a huge problem for human health, and are very damaging to aquatic and coastal ecosystems.

The potential heating effect from reducing atmospheric aerosols was predictable and was a foreseen consequence of this regulation that was considered at the time.

But it’s important to remember that this is a “one time bump” to global heating, not cumulative like GHG emissions. In the overall context of global heating it’s pretty insignificant in the longer term.